INTERNATIONAL JOURNAL OF RESEARCH AND SCIENTIFIC INNOVATION (IJRSI)  
ISSN No. 2321-2705 | DOI: 10.51244/IJRSI |Volume XII Issue IV April 2025  
Antibacterial Efficacy of Bagras (Eucalyptus Deglupta Blume) and  
Makopa (Syzygium Samarangense [Blume] Merr. & L.M. Perry)  
Leaf Ethanolic Extract Against Pseudomonas Aeruginosa  
Ampong, Wency Mae E1, Antolijao, Kisses Angeli Y2, Badua, Irish Chelsea Jean M3, Bagnol, Febby  
Jane L4, Castilla, Jeremy M5, Lobusta, Deuz George V6, Lumantas, Alvin Paolo F7, Matutino, Mary  
Allyson C8, Sonza, Kyle Yasmin Beatriz J9, Villarmia, Rhyza Myles A10, Bacan, Cleford Jay D.,  
Ellaga11, Mark Jobert C.12  
Cor Jesu College, Inc. Senior High School Digos City  
DOI: https://doi.org/10.51244/IJRSI.2025.12040061  
Received: 22 March 2025; Accepted: 03 April 2025; Published: 09 May 2025  
ABSTRACT  
The fluctuating spread of antibiotic-resistant Pseudomonas aeruginosa has rendered the development of  
alternative treatments against the global threat a necessity. Accordingly, this study aimed to assess the  
antibacterial efficacy of ethanolic extracts of bagras (Eucalyptus deglupta Blume) and makopa (Syzygium  
samarangense [Blume] Merr. & L.M. Perry) leaves against P. aeruginosa. This study utilized a true  
experimental posttest-only design using the surface application method to evaluate the antibacterial efficacy of  
the ethanolic leaf extracts against the bacteria. After 24 hours of incubation at 37°C, the zone of inhibition  
(ZOI) was measured and analyzed to determine antibacterial activity. Findings show that bagras extract  
exhibited strong antibacterial activity, with 21–31mm ZOI. In contrast, makopa extract was ineffective, with  
no ZOI observed; however, its combination with bagras showed enhanced efficacy, ranging from 25–34mm  
ZOI, suggesting a synergistic effect. Compared to Tobramycin, a commercial antibiotic, both bagras alone and  
in combination with makopa demonstrated significant differences in antibacterial activity, highlighting their  
potential as natural antibacterial agents. These findings serve as valuable reference for the Department of  
Health and the Department of Science and Technology in constructing strategies to combat the spread of P.  
aeruginosa. Likewise, it also provides insights into the antibacterial potential of bagras and makopa, providing  
a framework for pharmacologists and medical professionals in developing potent herbal treatments against  
multidrug-resistant bacteria. Additionally, it encourages further research into the phytochemical properties and  
synergistic effects of these plants, contributing to advancements in medicinal chemistry, pharmacology, and  
global health.  
Keywords: Antibiotic resistance, Pseudomonas aeruginosa, Bagras, Makopa, Antibacterial, Quantitative  
Research  
INTRODUCTION  
Cleanliness is essential for maintaining good health by minimizing exposure to harmful germs and reducing  
the risk of diseases. However, bacteria are everywhere, occurring in both beneficial and harmful forms, in  
different parts of the body, in the soil, and in moist environments. For instance, individuals with skin injuries  
like cuts and burns may come into contact with contaminated water or soil through activities like swimming  
and gardening. This exposure can introduce bacteria that may lead to respiratory, urinary tract, skin, and  
bloodstream infections, which can be challenging to treat due to antibiotic resistance. Additionally, the natural  
antibacterial properties of plants remain underutilized due to limited research into their potential, and questions  
about their efficacy and safety compared to manufactured antibiotics.  
Globally, gram-negative bacterium like Pseudomonas aeruginosa poses a major threat in healthcare settings  
and is a common cause of infections. In the study of Thomsen et al. (2023), P. aeruginosa was found in  
approximately 24% of ICU-acquired infections worldwide, specifically reaching 48.7% in Brazil. In South  
Page 680  
www.rsisinternational.org  
INTERNATIONAL JOURNAL OF RESEARCH AND SCIENTIFIC INNOVATION (IJRSI)  
ISSN No. 2321-2705 | DOI: 10.51244/IJRSI |Volume XII Issue IV April 2025  
Africa, patients with cystic fibrosis (CF) are highly susceptible to infections by multidrug-resistant isolates of  
P. aeruginosa, with 60-80% of CF adults showing chronic infection by this pathogen (Parkins et al., 2018;  
Hamiwe et al., 2024). As well as patients with community-acquired pneumonia (CAP) in Croatia, the rate of P.  
aeruginosa CAP in patients with prior infection caused by P. aeruginosa and at least one chronic lung disease  
was 67%. As mentioned by Garousi et al. (2023), in African and Western countries, the prevalence rates of P.  
aeruginosa in diabetic foot ulcer infections were reported at 16.3% and 11.1% respectively. This indicates how  
widespread this pathogen is globally and how it continues to be a healthcare burden.  
Additionally, the prevalence of antibiotic-resistant P. aeruginosa increases morbidity, limiting treatment  
options. The Pan American Health Organization/World Health Organization (PAHO/WHO) received a report  
concerning surgical site infections caused by antibiotic-resistant P. aeruginosa after invasive procedures were  
performed in Tijuana, Mexico (WHO, 2019). In a review, P. aeruginosa isolates from the Middle East and  
North Africa region, especially Saudi Arabia, Egypt, Libya, Syria, and Lebanon showed high-level resistance  
to different antibiotics, particularly in critical care units (Momenah et al., 2023). In Spain, approximately 30%  
of all P. aeruginosa strains from infections acquired in Spanish ICUs are resistant to carbapenems,  
ceftazidime, and quinolones. The increasing spread of highly resistant bacteria underscores the urgent need for  
improved treatments and more potent therapeutic solutions.  
In Southeast Asia, healthcare-acquired infections (HAI) caused by P. aeruginosa are significant health  
concerns affecting vulnerable populations. Notably, HAI caused by P. aeruginosa in Southeast Asia is high, at  
approximately 22%, which is at the higher end of the worldwide scale, with Indonesia having the highest  
prevalence rate of HAI at 30.4% in the region. This HAI can be attributed to P. aeruginosa, which made up  
13.8% of hospital-acquired pneumonia in Thailand.  
This rise of P. aeruginosa infections has also exhibited antibacterial and antimicrobial resistance, making  
various treatments in the region ineffective. In Indonesia alone, a total of 1554 P. aeruginosa isolates present  
resistance to multiple antibiotics, including colistin, an antibiotic used for HAI, was found to be 100%  
ineffective against the bacteria. Furthermore, P. aeruginosa isolates exhibited broad-spectrum resistance  
(87.8% multidrug resistance) in a public acute care hospital in Singapore, remaining only susceptible to  
polymyxin B (95.0%) and amikacin (55.0%). This information urges a need to address the complications and  
issues caused by P. aeruginosa.  
Given these concerns, the global burden of P. aeruginosa infections poses a rising challenge because of  
antibiotic resistance driving the development of a wide range of strategies to address it. Fiel and Roesch (2022)  
mentioned in their study that aminoglycosides like tobramycin exhibit effectiveness against the Gram-negative  
bacteria, including P. aeruginosa. A study by Reynolds and Kollef (2021) also demonstrated that patients who  
received 300mg of tobramycin twice daily for 28 days eradicated P. aeruginosa in more than 70% of patients  
while improving lung function. To add, aminoglycosides, including amikacin, gentamicin, and tobramycin are  
usually used to treat urinary tract infections caused by P. Aeruginosa.  
Additionally, the presence of multiple beneficial phytochemicals in medicinal herbs like bagras aid in the  
successful process of inhibiting various bacteria. From the study of Kareem et al. (2020), three varying  
concentrations of bagras ethanolic extracts against another gram-negative bacterium, E. coli, resulted in 18  
mm, 20.5 mm, and 22.5 mm of zone of inhibitions (ZOIs). This finding aligns with the study by Abiodun et al.  
(2024), which highlighted the strong antibacterial effects of eucalyptus essential oil on several respiratory  
pathogens, including E. cloacae with a mean ZOI of 23.0 mm, K. pneumoniae with 22.7 mm, and S. aureus  
with 16.0 mm, at a concentration of 100mg/mL. On the other hand, makopa showed weak to no signs of the  
zone of inhibitions against bacteria similar to the mentioned studies above. The makopa leaves ethanol extract  
presented weak inhibitory activity against Gram-negative bacteria such as E. coli showing 7 mm ± 0.99 mm  
and 9 mm ± 0.89 mm diameters of ZOIs respectively (Khandaker et al., 2015). This indicates that the bagras  
leaves have a greater potential of being an antibacterial agent against pathogens compared to makopa leaves.  
The Philippines has also been subjected to the spread of P. aeruginosa, contributing to the growing cases of  
diseases related to the said bacteria. In post-percutaneous nephrolithotripsy, it is highlighted that P. aeruginosa  
is the most common bacteria in kidney stones in the Philippines, noting its high resistance to standard  
Page 681  
www.rsisinternational.org  
INTERNATIONAL JOURNAL OF RESEARCH AND SCIENTIFIC INNOVATION (IJRSI)  
ISSN No. 2321-2705 | DOI: 10.51244/IJRSI |Volume XII Issue IV April 2025  
antibiotics. DomA rise of carbapenem-resistant P. aeruginosa in three tertiary hospitals in Metro Manila. To  
be precise, Chilam et al. (2021) explained that this continual spread of multidrug-resistant P. aeruginosa,  
complicates effective infection control and treatment in the country. To address these issues, traditional  
medical treatments for P. aeruginosa in the country include piperacillin-tazobactam. However, with the influx  
of varying, multidrug-resistant strains of P. aeruginosa in 2023, the efficacy of these treatments has been  
significantly compromised (Antimicrobial Resistance Surveillance Reference Laboratory [AMRSRL], 2023).  
Looking at the issue in a local lens, the spread of P. aeruginosa is not a minor matter, as the bacterium was  
detected in various sources. In Davao City, carbapenemase-producing P. aeruginosa has been recorded in the  
city’s coastal wetlands and in a tertiary-level private hospital, with samples coming from patients’ endotracheal  
aspirates and wounds, signifying a concerning surge of carbapenem-resistant P. aeruginosa within the city, and  
the potential for its spread to neighboring areas. With this rising threat of P. aeruginosa, researchers have  
explored the antibacterial activity of widely available plants in Mindanao as means to combat the bacterium.  
As a case in point, extracts from roots of Tabernaemontana pandacaqui Poir (pandakaki-puti) as well as  
essential oils from P. guajava (bayabas) leaves and L. domesticum (lanzones) pericarp displayed ZOIs of up to  
14.8mm, 12.7mm, and 12.9mm against P. aeruginosa, respectively (Sicalan et al., 2023). While these findings  
suggest that P. aeruginosa can be addressed using readily available natural resources in the locality, their  
efficacy falls short in the face of both the bacterium’s proliferation and multidrug resistance.  
Accordingly, the rising concern of antibiotic resistance of such bacteria has spurred an exploration into the  
antibacterial potential of the bagras as a source of novel therapeutic agents. Several studies highlight the  
efficacy of bagras extracts against various bacterial pathogens. For instance, Hapid et al. (2024) demonstrated  
that ethanolic leaf extracts of bagras effectively inhibited the growth of S. aureus with inhibition zones of  
15.67 mm and 19.32 mm at 25% and 100% concentrations, respectively. The practical applicability of these  
findings is further supported by Winarti et al. (2024), who developed a mouthwash nanoemulsion combining  
eucalyptol from bagras with peppermint oil and found significant antibacterial activity against both E. coli and  
S. aureus. These results suggest bagras has significant antibacterial properties worth further study.  
On the other hand, makopa has also been gaining significant attention for its potential health benefits. The  
presence of various bioactive compounds in makopa leaves including flavonoids, phenolic compounds,  
alkaloids, and saponins supports its medical and therapeutic potential. These bioactive compounds are  
important due to their diverse biological activities, including antibacterial, antioxidant, and anti-inflammatory  
(Tarigan et al., 2022; Jayakumari et al., 2023). However, the ethanolic extract of makopa leaves has  
demonstrated little to no susceptibility against few bacteria. As such, from the study of Khandaker et al.  
(2015), the makopa leaf ethanol extract showed weak inhibitory activity against E. coli showing 7 mm ± 0.99  
mm and 9 mm ± 0.89 mm diameters of ZOIs respectively. The study of Sulthana et al. (2023) showed similar  
outcomes as well, P. aeruginosa showed resistance against the makopa ethanolic extract with 8 mm and 9 mm  
diameters of ZOIs.  
To sum up, a highly drug-resistant Gram-negative bacterium like P. aeruginosa, notorious for causing  
infections in the lungs, urinary tract, and other body parts, should urgently be addressed as this bacterium is  
particularly harmful to vulnerable populations, including immunocompromised individuals and the elderly.  
The spread of this bacterium is a global health issue encapsulated in the third Sustainable Development Goal,  
focusing on good health and well-being, rendering a heightened need for new treatments against it. Due to its  
complexity, however, there is a shortage of further investigation regarding possible alternatives, specifically  
the plants bagras and makopa, for controlling the spread of P. aeruginosa compared to the currently available  
treatments, such as aminoglycosides and beta-lactam antibiotics. Hence, this study aimed to delve deeper into  
the antibacterial efficacy of the ethanolic extract of bagras (Eucalyptus deglupta Blume) and makopa  
(Syzygium samarangense [Blume] Merr. & L.M. Perry) leaves against P. aeruginosa.  
Theoretical Framework  
This research is anchored on Robert Koch and Louis Pasteur’s Germ Theory of Disease (1861). Robert Koch's  
postulates are essential criteria in proving that specific microorganisms cause specific diseases. This indicates  
that specific microorganisms become invariably present in diseased individuals and absent in healthy ones,  
Page 682  
www.rsisinternational.org  
INTERNATIONAL JOURNAL OF RESEARCH AND SCIENTIFIC INNOVATION (IJRSI)  
ISSN No. 2321-2705 | DOI: 10.51244/IJRSI |Volume XII Issue IV April 2025  
capable of being isolated and reproduced experimentally (Segre, 2013). This concept was seminal in  
underpinning Louis Pasteur’s germ theory of disease, which has since been elaborated to explain how P.  
aeruginosa— a bacterial pathogen utilized in this study, causing pneumonia, UTI, and various other  
infections— brings about disease (Liddell & Hartsock, 2023).  
This study is also anchored on the theory of non-random selection of medicinal plants, proposed by Daniel  
Moerman in 1979. The theory propounds that the selection and usage of plants for traditional medicinal  
methods are hinged on their curative properties and effectiveness. Those characteristics are said to be  
empirical, which means that over time, taxonomic groups that share similar medicinal qualities are bound to be  
prominently utilized. In Bagras (Eucalyptus deglupta Blume) and Makopa (Syzygium samarangense [Blume]  
Merr. & L.M. Perry) leaves, high amounts of monoterpene hydrocarbons are observed, which are known to  
synthesize antibacterial activity, thus supporting the use of the herbs against P. aeruginosa in this study (Insuan  
et al., 2021).  
In summary, this study is anchored on two theories that accurately substantiate the use of bagras and makopa  
leaves as well as the utilization of P. aeruginosa. By isolating the bacterium and testing its response to ethanol  
extracts, the researchers aim to demonstrate a direct antibacterial effect, thus supporting the germ theory of  
disease. Assessing the antibacterial properties of bagras and makopa against P. aeruginosa gives grounds for  
utilizing the said herb in the study, supporting Moerman’s theory of non-random selection of medicinal plants.  
Statement of the Problem  
The main purpose of the study was to determine the efficacy of different ethanolic extract concentrations of  
bagras (Eucalyptus deglupta Blume) and makopa (Syzygium samarangense [Blume] Merr. & L.M. Perry)  
against P. aeruginosa. Specifically, it aimed to assess whether there was a significant difference in inhibiting  
bacterial growth when using different concentrations of the extract compared to the positive control group.  
1. What is the level of the antibacterial efficacy of the different concentrations of bagras leaf ethanolic  
extract against Pseudomonas aeruginosa in terms of:  
1.1 40 mg/mL concentration of bagras leaf ethanolic extract;  
1.2 60 mg/mL concentration of bagras leaf ethanolic extract; and  
1.3 80 mg/mL concentration bagras leaf ethanolic extract?  
2. What is the level of the antibacterial efficacy of the different concentrations of makopa leaf ethanolic  
extract against Pseudomonas aeruginosa in terms of:  
2.1 40 mg/mL concentration of makopa leaf ethanolic extract;  
2.2 60 mg/mL concentration of makopa leaf ethanolic extract; and  
2.3 80 mg/mL concentration of makopa leaf ethanolic extract?  
3. What is the level of the antibacterial efficacy of the different concentrations of bagras and makopa leaf  
ethanolic extract against Pseudomonas aeruginosa in terms of:  
3.1 40 mg/mL concentration of the combination of bagras and makopa leaf ethanolic extract;  
3.2 60 mg/mL concentration of the combination of bagras and makopa leaf ethanolic extract; and  
3.3 80 mg/mL concentration of the combination of bagras and makopa leaf ethanolic extract?  
4. What is the level of the antibacterial efficacy of the commercial antibiotic, Tobramycin, against  
Pseudomonas aeruginosa?  
Page 683  
www.rsisinternational.org  
INTERNATIONAL JOURNAL OF RESEARCH AND SCIENTIFIC INNOVATION (IJRSI)  
ISSN No. 2321-2705 | DOI: 10.51244/IJRSI |Volume XII Issue IV April 2025  
5. Is there a significant difference in inhibiting the growth of P. aeruginosa using the different  
concentrations of the ethanolic extract of bagras (Eucalyptus deglupta Blume) and makopa (Syzygium  
samarangense [Blume] Merr. & L.M. Perry) leaves compared to the control treatment Tobramycin?  
Hypothesis  
To objectively answer the problem listed in the preceding section, the given null hypotheses was formulated:  
Ho: There is no significant difference in the effectiveness between bagras (Eucalyptus deglupta Blume) and  
makopa (Syzygium samarangense [Blume] Merr. & L.M. Perry) leaf ethanolic extract on the inhibition of  
Pseudomonas aeruginosa.  
Ho1: There is no significant difference in the effectiveness between bagras (Eucalyptus deglupta Blume) and  
makopa (Syzygium samarangense [Blume] Merr. & L.M. Perry) leaf ethanolic extracts and control treatment  
on the inhibition of Pseudomonas aeruginosa.  
Significance of the Study  
This study explored the efficacy of bagras (Eucalyptus deglupta Blume) and makopa (Syzygium samarangense  
[Blume] Merr. & L.M. Perry) leaves ethanolic extract inhibiting the growth of P. aeruginosa. Therefore, the  
researchers conducted this study, which could be beneficial to the following:  
Department of Health Officials. This study can give new insights to the Department of Health about the  
antibacterial efficacy of bagras and makopa leaves as a potential inhibitor against different infections. The  
Department of Health can use the data and results gathered to investigate bagras and makopa leaves and their  
efficacy in inhibiting the spread of P. aeruginosa further, which could improve public health initiatives of  
healthcare professionals to respiratory diseases.  
Department of Science and Technology Officials. The findings of this study can give insights to the  
Department of Science and Technology by exploring the antibacterial properties of the bagras and makopa  
leaves as inhibitors of P. aeruginosa infection that could help in advancing research involving bacterias.  
Moreover, this could further support research and innovations in the field of bacteriology.  
Pharmacologists. The results gathered from this study can provide insights into the pharmaceutical industry  
by exploring the antibacterial properties of the bagras and makopa leaves as inhibitors of P. aeruginosa  
infection that could also serve as a basis for developing innovative plant-based medicines alternatives.  
Furthermore, this could be helpful to the pharmaceutical industry to further improve alternative treatments  
against drug-resistant pathogens.  
Medical Professionals. The findings of this study can assist medical professionals to contribute to the  
development of natural alternative treatment for infections caused by P. aeruginosa in partnership with the  
pharmaceutical industry. Additionally, this study could provide knowledge about bacterial resistance resulting  
in improved treatment formulations and encouraging further studies into natural plant-based treatments.  
Future Researchers. This study can provide comprehensive knowledge to future researchers that could aid  
new possibilities to the antibacterial properties of bagras and makopa leaves and their efficacy in inhibiting the  
growth of highly drug-resistant pathogens like P. aeruginosa. The findings of this study can serve as a helpful  
reference for future developments.  
Scope and Limitations  
This study focused on investigating the antibacterial properties of ethanolic extracts from bagras (Eucalyptus  
deglupta Blume) and makopa (Syzygium samarangense [Blume] Merr. & L.M. Perry) leaves against P.  
aeruginosa. The fresh bagras and makopa leaves were sourced locally within Davao del Sur. The research was  
conducted during the first and second semesters of the academic year 2024-2025 in laboratories within Davao  
Page 684  
www.rsisinternational.org  
INTERNATIONAL JOURNAL OF RESEARCH AND SCIENTIFIC INNOVATION (IJRSI)  
ISSN No. 2321-2705 | DOI: 10.51244/IJRSI |Volume XII Issue IV April 2025  
del Sur. The antibacterial activity was determined by culturing P. aeruginosa on Mueller-Hinton agar plates  
and incubating at 37 °C. After 24 hours, the zone of inhibition was measured in millimeters.  
However, this study had certain limitations. Primarily, this study was limited to the ethanolic extracts of bagras  
and makopa leaves and their antibacterial activity solely against P. aeruginosa. Other extraction methods and  
solvents were not explored. Furthermore, the focus of the study was on P. aeruginosa, meaning that other  
bacterial species were excluded from the analysis. In terms of methodology, the use of laboratory equipment  
and materials was also a limitation, as the study specifically focused on using Mueller-Hinton agar plates.  
Moreover, the geographic scope was limited to Davao del Sur for sourcing plant materials, potentially  
affecting the generalizability of the findings to bagras and makopa leaves from other regions.  
Definition of Terms  
To have a clearer understanding of this study, the following terminologies were conceptually and  
operationally defined:  
Antibacterial. It refers to the ability of a substance to destroy or suppress the growth of bacteria and their  
ability to reproduce. In this study, it is the ability of the ethanolic extract of bagras and makopa leaves to  
inhibit the growth of P. aeruginosa that was assessed according to the zone of inhibitions.  
Bagras (Eucalyptus deglupta Blume). It is famous for its multicolored trunk, also known as Mindanao gum. It  
thrives in the biodiverse rainforests of the Philippines, Indonesia, and Papua New Guinea which can grow to  
more than 1,800 meters and is the only eucalyptus species in the Northern Hemisphere. In this study, the  
antibacterial efficacy of its leaf ethanolic extract against P. aeruginosa was evaluated using the disk diffusion  
method.  
Ethanolic extract. It is a preparation obtained by using ethanol as a solvent to dissolve and separate soluble  
compounds from a source material, typically plant matter. In this study, this refers to the type of solution which  
the bagras and makopa leaves were made from to determine its antibacterial efficacy against P. aeruginosa.  
Makopa (Syzygium samarangense [Blume] Merr. & L.M. Perry). It is also known as the wax apple, a  
tropical tree native to Southeast Asia including the Philippines, it bears a bell-shaped fruit in various colors  
with crisp, apple-like flesh. In this study, this refers to the antibacterial properties of the ethanolic extract of its  
leaves will be evaluated using the disk diffusion method.  
Pseudomonas aeruginosa. It is a Gram-negative, rod-shaped, opportunistic bacteria notable for its antibiotic  
resistance and role as a frequent cause of hospital-acquired infections. In this study, this is the pathogenic  
bacteria that was utilized in the experiment and examined using the dosc diffusion method.  
Surface Application Method. It is when the surface application method in antibacterial testing involves  
directly applying a measured amount of a substance onto the surface of an inoculated agar plate, allowing it to  
diffuse and inhibit bacterial growth, which is then assessed by measuring zones of inhibition. In this study, the  
extract of Bagras, Makopa, and their combination was directly applied to the inoculated agar plate in a 30 μL.  
This was done to assess their potential antibacterial activity.  
Zone of Inhibition. It is an area of media where the microorganisms are unable to reproduce, due to the  
presence of a drug that prevents their ability to grow. In this study, this refers to an area on the MH agar plates  
where the P. aeruginosa cannot grow, because of the presence of antibacterial agents such as bagras and  
makopa leaf ethanolic extract  
METHODS  
This chapter provides the subject of the study, sampling methodologies, sources of data, procedures for data  
collection, measurement techniques, methods of analysis and interpretation, and ethical considerations.  
Page 685  
www.rsisinternational.org  
INTERNATIONAL JOURNAL OF RESEARCH AND SCIENTIFIC INNOVATION (IJRSI)  
ISSN No. 2321-2705 | DOI: 10.51244/IJRSI |Volume XII Issue IV April 2025  
Research Design  
In this study, a true experimental quantitative research design was utilized, specifically posttest-only. A true  
experimental quantitative design was essential as this study’s main objective was to assess the antibacterial  
efficacy of bagras and makopa leaf ethanolic extract by quantifying the means of the zone of inhibition of each  
extract against Pseudomonas aeruginosa. By manipulating the three (3) independent variables and observing  
the effects on the dependent variable, the researchers were able to draw conclusions about how changes in one  
factor influence another (Bhat, 2018).  
Moreover, this study specifically utilized a posttest-only research design. The researchers applied the bagras  
and makopa leaf ethanolic extracts to the P. aeruginosa strains and then measured the independent variables’  
effect on the dependent variable without conducting any pretests. In this particular research design, subjects  
received specific interventions or treatments, and only after the intervention were their results assessed (Birt et  
al., 2022). This design allowed researchers to evaluate changes in bacterial growth following exposure to the  
plant extract without requiring a baseline measurement.  
Subject of the Study  
This study used Gram-negative bacteria, known as P. aeruginosa, as the subject. For this study, a total of 30 P.  
aeruginosa cultures were required, with three experimental groups and one positive control group. Each  
experimental group consisted of nine bacteria cultures, with three cultures for each concentration of the leaf  
ethanolic extract of bagras, makopa, and a combination of both. Meanwhile, the positive control group  
consisted of three bacteria cultures. The experiment was replicated thrice to ensure the validity and  
significance of the result. Furthermore, the study was carried out in a microbiology laboratory in Digos City,  
Davao del Sur.  
Sampling Technique  
In this study, the researchers utilized the complete random sampling technique to select subjects in the  
experiment. Complete random sampling involves selecting bacterial samples in a way that ensures complete  
randomness to avoid any systematic bias in the sampling process (Ma & Tu, 2022). This method enabled each  
strain to have an equal chance of being chosen, thus guaranteeing an unbiased and accurate representation of  
the subset of bacteria used for study analysis.  
According to Horton (2024), this technique allowed the researchers to statistically measure a subset of subjects  
selected from a larger population to approximate a response from the entire group. This approach contributed  
to the preservation of strong internal validity by lowering the risk of research biases through randomization.  
Hence, the application of this method greatly improved the validity and reliability of the study’s outcome,  
ensuring that it chose an accurate representative subset of P. aeruginosa.  
Measures  
This quantitative study adopted the disk diffusion method introduced by Gomes et al. (2021). In this method,  
the plates undergo a 24-hour incubation period at 37 °C, and the diameter of the zone of inhibition (ZOI)  
surrounding each extract was measured with a ruler to assess the antibacterial activity of the plates. The  
evaluation was conducted by an experienced medical laboratory technologist with over two years of expertise  
in bacterial infection studies, who specifically examined the efficacy of the ethanolic extract of bagras and  
makopa leaves in inhibiting P. aeruginosa growth. This research established the antibacterial activity of the  
leaf extract by monitoring the duration of bacterial growth inhibition. Additionally, the ZOI was taken to  
determine the degree of the antibacterial activity of the extract through the criteria of Hudzicki (2016), wherein  
an inhibition zone size less than 14 mm indicates resistance, while those 15 to 16 mm reflects moderate  
activity, and a zone of 17 mm above signifies high sensitivity to the extract.  
The primary objective of this evaluation was to assess the efficacy of bagras and makopa leaf extracts in  
inhibiting the growth of P. aeruginosa, focusing on their antibacterial properties and inhibition zones. The  
Page 686  
www.rsisinternational.org  
INTERNATIONAL JOURNAL OF RESEARCH AND SCIENTIFIC INNOVATION (IJRSI)  
ISSN No. 2321-2705 | DOI: 10.51244/IJRSI |Volume XII Issue IV April 2025  
technologist’s assessment was focused on evaluating parameters based on a standardized scale to determine the  
effectiveness of the leaf extracts in inhibiting the growth of P. aeruginosa. Post-assessment, the compiled  
evaluations were organized using an interpretation table and subjected to systematic analysis. This analytical  
approach aimed to evaluate the extracts’ potential influence on bacterial growth inhibition, highlighting its  
relevance for future applications against P. aeruginosa.  
Table 1. Pseudomonas aeruginosa’s Growth Inhibition Interpretation  
Mean Score Interval  
Descriptive Equivalent  
Interpretation  
The antibacterial activity showed an excellent image of  
the zone of inhibition.  
≥17 mm  
Susceptible  
15.00 mm - 16.00 mm  
Moderate  
Resistant  
The antibacterial activity showed a fair  
image of the zone of inhibition.  
≤14 mm  
The antibacterial activity showed poor  
image of the zone of inhibition.  
Data Gathering Procedure  
In the process of gathering data for this study, the researchers followed specific procedures to acquire  
information.  
Extraction of Bagras (Eucalyptus deglupta Blume)  
The following procedures were adapted from the studyof Hapid et al. (2024):  
1. The researchers obtained bagras tree leaves from the City Environment and Natural Resources  
Office (CENRO) Digos City and gathered and washed sufficient quantities of leaves, ensuring they  
were free from dirt and contaminants.  
2. The leaves were dried using an air fryer and oven while maintaining a controlled temperature and  
crushed using a blender to create a coarse powder.  
3. The researchers used an electronic weighing scale for each leaf powder to ensure equal  
measurements.  
4. After doing so, the leaf powders for the 40 mg/mL, 60 mg/mL, and 80 mg/mL concentrations were  
placed in separate glass jars, and then each was mixed with 50 mL of 95% ethanol.  
5. The sealed jar was left to macerate at room temperature for approximately 120 hours with gentle  
shaking from time to time, after which the mixture was filtered with filter paper to separate the  
liquid extract from the solid residue.  
6. To evaporate the ethanol, some of the extracts were soaked in a water bath while some were soaked  
in a large beaker placed on a hot plate with a magnetic stirrer for an hour at 40°C.  
7. The ethanol extract was stored in a glass jar at 4°C to protect it from light and degradation.  
8. All materials utilized in the extraction process were sterilized to prevent bacterial contamination.  
Extraction of Makopa (Syzygium samarangense [Blume] Merr. & L. M. Perry)  
The following procedures have been adapted from the research of Idris et al. (2023).  
1. The researchers collected makopa tree leaves directly from a nearby backyard. The branches were  
separated since only the leaves were utilized in the study.  
2. The leaves were thoroughly washed using clean running water to remove any dirt or impurities,  
then it was dried in an oven and air fryer at a controlled temperature, and crushed into a coarse  
powder using a blender.  
3. The researchers used an electronic weighing scale for each leaf powder to ensure equal  
measurements.  
Page 687  
www.rsisinternational.org  
INTERNATIONAL JOURNAL OF RESEARCH AND SCIENTIFIC INNOVATION (IJRSI)  
ISSN No. 2321-2705 | DOI: 10.51244/IJRSI |Volume XII Issue IV April 2025  
4. Each weighed leaf powders for the 40 mg/mL, 60 mg/mL, and 80 mg/mL were placed in separate  
glass jars, and was mixed with 50 mL of 95% ethanol.  
5. The sealed jar was left to macerate at room temperature for approximately 120 hours with gentle  
shaking from time to time, after which the mixture was filtered with filter paper to separate the  
liquid extract from the solid residue.  
6. To evaporate the ethanol, some of the extracts were soaked in a water bath while some were soaked  
in a large beaker placed on a hot plate with a magnetic stirrer for an hour at 40°C.  
7. The ethanol extract was stored in a sealed glass jar at 4°C until further analysis.  
8. All materials utilized in the extraction process were sterilized to prevent bacterial contamination.  
Extraction of Bagras (Eucalyptus deglupta Blume) and Makopa (Syzygium samarangense [Blume] Merr. &  
L.M. Perry)  
The following procedures were adapted from the studyof Hapid et al. (2024) and Idris et al. (2023).  
1. The researchers obtained the bagras tree leaves from the City Environment and Natural Resources  
Office (CENRO) Digos City, while the makopa tree leaves were acquired from a nearby backyard.  
2. The leaves were separated from the branches, then the researchers washed them thoroughly to  
ensure they are free from dirt and contaminants.  
3. The leaves were then dried using an air fryer and an oven at a controlled temperature, and was  
crushed into a coarse powder using a blender.  
4. The researchers used an electronic weighing scale for each leaf powder to ensure equal  
measurements.  
5. Each of the leaf powders for the 40 mg/mL, 60 mg/mL, and 80 mg/mL were then placed separately  
into sanitary glass jars and were mixed with 50 mL of 95% ethanol.  
6. The sealed jar was left to macerate at room temperature for approximately 120 hours with gentle  
shaking from time to time, after which the mixture was filtered with a filter paper to separate the  
liquid extract from the solid residue.  
7. To evaporate the ethanol, some of the extracts were soaked in a water bath while some were soaked  
in a large beaker placed on a hot plate with a magnetic stirrer for an hour at 40°C.  
8. The ethanol extract was stored in a sealed glass jar at 4°C until further analysis.  
9. All materials utilized in the extraction process were sterilized to prevent bacterial contamination.  
Preparation of Pseudomonas aeruginosa and Culture Media  
The following procedures were adapted from the studyof Kareem et al. (2020)  
1. Before actuating the inoculation for the bacterial cultures, the researchers wore complete Personal  
protective equipment (PPE) which includes a laboratory gown, gloves, and face mask to maintain  
and ensure proper handling and safety.  
2. Then, the P. aeruginosa bacteria cultures were obtained from a laboratory in a local hospital, which  
they had acquired from the Department of Health (DOH).  
3. 30 MH agar plates were prepared and used as a medium for storage and culture for the bacteria set-  
up.  
4. A culture tube containing a normal saline solution was prepared and inoculated with cultures of P.  
aeruginosa.  
5. Each MH agar plate was evenly streaked on its surface using a sterile swab that had been dipped  
into the inoculum.  
Evaluation of Antibacterial Activity by Surface Application Method  
The following procedures were adapted from the studies of Lyons et al. (2020)  
1. The Mueller-Hinton agar plates that had been streaked with P. aeruginosa were then inoculated  
with the prepared extracts.  
Page 688  
www.rsisinternational.org  
INTERNATIONAL JOURNAL OF RESEARCH AND SCIENTIFIC INNOVATION (IJRSI)  
ISSN No. 2321-2705 | DOI: 10.51244/IJRSI |Volume XII Issue IV April 2025  
2. Each trial extract was precisely measured at 30 μL using a sterile electronic micropipette, which  
was then used to apply the extract to the respective MH agar plates.  
3. For the antibiotic tobramycin, exactly 40 μL (equivalent to one drop) was applied to the MH agar  
plates.  
4. The inoculated Mueller-Hinton agar plates were left at 37°C for 24 hours to allow the extracts to  
diffuse and interact with the bacteria. After this incubation period, the plates were assessed for  
antibacterial activity by measuring the zone of inhibition around each extract using a ruler.  
Analysis and Interpretation  
To analyze the data of this experimental study, the researchers will measure the means, as well as utilize both  
the Analysis of Variance (ANOVA) and Tukey Honestly Significant Difference (HSD) test method to further  
investigate the distinction between three independent variables based on one dependent variable.  
1. The mean serves as an indicator of the average value calculated from a set of given results from  
each concentration, measured in millimeters. Statistical analyses often rely on comparing means to  
determine if there are significant differences between groups (Saha, 2024).  
2. Analysis of Variance (ANOVA) is a statistical method used to compare the means of three or more  
groups to determine if there are any statistically significant differences among them (Hassan, 2024).  
A one-way ANOVA was utilized to determine the significant difference between the antibacterial  
properties of the ethanolic extract of bagras, makopa, and a combination of both plant extracts  
against P. aeruginosa.  
3. Tukey Honestly Significant Difference (HSD) Test is a statistical tool that was used to assess if the  
relationship between sets of data is statistically significant and to identify specific differences  
between group means. This means that it evaluates whether there’s a strong chance that the  
numerical change in one variable is causally related to an observed change in another variable  
(Beck, 2022). After the demonstration of the ANOVA, the HSD Test was then established to  
statistically verify which among the concentrations is most and least effective against P. aeruginosa.  
Ethical Considerations  
This study upheld firm ethical standards to ensure responsible and conscientious research practices. Such  
considerations were implemented to uphold the study’s integrity, ensure the proper management of biological  
materials, and comply with scientific, environmental, and institutional standards.  
Biosafety and risk management. is vital in ensuring the safety of the researchers, as well as other individuals  
involved in this study. In particular, strict adherence to laboratory regulations in both institutional and hospital  
facilities helps minimize exposure to harmful agents. As stressed by the National Institutes of Health (2021),  
this also entails appropriate handling and storage of extracts, substances, laboratory apparatus, as well as the  
disposal of utilized agar plates and expendable personal protective equipment, thereby maintaining a safe and  
controlled research environment.  
Environmental responsibility and sustainability. are fundamental considerations in this study, ensuring that  
the research practices do not harm any ecosystems associated with the study. In particular, the researchers  
ensured that the extraction of bagras and makopa leaves and the bacterial culturing of P. aeruginosa do not  
negatively affect or contribute to the degradation of the environment (Dapar et al., 2020).  
Integrity and transparency. are significant qualities of a study that ensures all research processes are  
conducted at utmost honesty and without alteration or misrepresentation. Throughout the stages of this  
research endeavor, from assessing the antibacterial efficacy of bagras and makopa leaf ethanolic extracts  
against P. aeruginosa to evaluating the findings of said experiments, the researchers put morality and respect  
as their footing in taking part in the data collection, analysis, and reporting (Zhaksylyk et al., 2023)  
Page 689  
www.rsisinternational.org  
INTERNATIONAL JOURNAL OF RESEARCH AND SCIENTIFIC INNOVATION (IJRSI)  
ISSN No. 2321-2705 | DOI: 10.51244/IJRSI |Volume XII Issue IV April 2025  
RESULTS AND DISCUSSION  
This chapter deals with the presentation, analysis, and interpretation of data. The first part describes the levels  
of antibacterial activity of the different concentrations of bagras (Eucalyptus deglupta Blume) leaf ethanolic  
extract, makopa (Syzygium samarangense [Blume] Merr. & L.M. Perry) leaf ethanolic extract, combined  
bagras and makopa leaf ethanolic extract, and the control group, tobramycin. The second part describes the  
significance of the differences in the effectiveness among the different concentrations in inhibiting the growth  
of P. aeruginosa, including comparisons with the control treatment and the Post Hoc Comparison using the  
Tukey HSD test and a one-way ANOVA.  
Antibacterial Efficacy of the Different Concentrations of Bagras Leaf Ethanolic Extract on the  
Pseudomonas aeruginosa  
The study determined the effectiveness of the bagras leaf ethanolic extract on the growth inhibition of P.  
aeruginosa with three different treatments: Treatment 1 - 40 mg/mL concentration of bagras leaf ethanolic  
extract; Treatment 2 - 60 mg/mL concentration of bagras leaf ethanolic extract; and Treatment 3 - 80 mg/mL  
concentration of bagras leaf ethanolic extract. The researchers determined its antibacterial efficacy by  
measuring the zone of inhibition per treatment in each replication. Hence, the researchers obtained the  
following results.  
Table 1. Antibacterial Efficacy of the Different Concentrations of Bagras Leaf Ethanolic Extract on the  
Pseudomonas aeruginosa  
Treatments  
Zone of Inhibition (in mm)  
Mean  
SD  
Description  
R1  
30  
30  
26  
R2  
29  
28  
31  
R3  
21  
29  
27  
T1  
T2  
T3  
26.67  
29.00  
28.00  
4.93  
1.00  
2.65  
Susceptible  
Susceptible  
Susceptible  
Table 1 exhibits the level of antibacterial activity of bagras leaf ethanolic extract on P. aeruginosa. Previous  
studies have greatly highlighted the plant’s potential for medicinal treatments due to its phytochemical  
properties, one of which is 1,8-cineole (eucalyptol), which bagras contains 81% percent of (Dihingial et al.,  
2020). That being said, it has been recognized as one of the contributing factors to bagras' antibacterial  
activity, which has been effectively demonstrated in these results.  
In this study, all treatments (T1, T2, and T3) were classified as susceptible, indicating that the ethanolic extract  
of bagras leaves effectively inhibited the growth of the bacteria. These findings support the study of Kareem et  
al. (2020), which also involved the utilization of bagras against E. coli, a gram-negative bacterium, resulting in  
a range of 18 mm, 20.5 mm, and 22.5 mm zones of inhibition. The findings are also akin to that of Hapid et al.  
(2024), wherein bagras leaves were used against E. coli, which led to inhibition zones of 15.67 mm, 17.10 mm,  
18.17 mm, and 19.32 mm, respectively. This efficacy also strengthens the findings of Winarti et al. (2024),  
wherein a mouthwash nanoemulsion combining eucalyptol from bagras and peppermint oil exhibited  
significant antibacterial activity, with inhibition zones of 13.1 mm against E. coli and 17.4 mm against S.  
aureus.  
Contrastingly, the findings of this study contradict those of Kambira et al. (2020), who stated that the  
phytochemical properties found in various species of the Eucalyptus genus, including bagras, are not linked to  
its antibacterial activity, and that Gram-negative bacteria show low susceptibility to such genus. Nevertheless,  
the satisfactory zones of inhibition shown by each treatment underscores bagras' efficacy as an antibacterial  
agent, and how potent it can be as a medication.  
Page 690  
www.rsisinternational.org  
INTERNATIONAL JOURNAL OF RESEARCH AND SCIENTIFIC INNOVATION (IJRSI)  
ISSN No. 2321-2705 | DOI: 10.51244/IJRSI |Volume XII Issue IV April 2025  
Antibacterial Efficacy of the Different Concentrations of Makopa Leaf Ethanolic Extract on the  
Pseudomonas aeruginosa  
The study assessed the effectiveness of the ethanolic extract of makopa leaves in inhibiting the growth of P.  
aeruginosa using three different concentrations: Treatment 4 - 40 mg/mL of makopa leaf ethanolic extract;  
Treatment 5 - 60 mg/mL of makopa leaf ethanolic extract; and Treatment 6 - 80 mg/mL of makopa leaf  
ethanolic extract. The researchers determined its antibacterial efficacy by measuring the zone of inhibition per  
treatment in each replication. Based on this, the researchers obtained the following results.  
Table 2. Antibacterial Efficacy of the Different Concentrations of Makopa Leaf Ethanolic Extract on the  
Pseudomonas aeruginosa  
Treatments  
Zone of Inhibition (in mm)  
Mean  
SD  
Description  
R1  
R2  
R3  
T4  
T5  
T6  
0
0
0
0.00  
0.00  
0.00  
0.00  
0.00  
0.00  
Resistant  
Resistant  
Resistant  
0
0
0
0
0
0
Table 2 presents the antibacterial activity of various concentrations of makopa leaf ethanolic extract against P.  
aeruginosa. Previous studies have greatly highlighted the plant’s potential for medicinal treatments due to its  
phytochemical properties, one of which are flavonoids and tannins, which contribute to their antibacterial  
effects (Choironi & Fareza, 2018). However, the results of this study indicate that none of the tested  
concentrations exhibited inhibitory effects on P. aeruginosa, suggesting that the extract lacks antibacterial  
efficacy.  
The antibacterial activity of makopa leaf ethanolic extract against P. aeruginosa was not observed in this study.  
Similarly, this finding aligns with the study of Khandaker et al. (2015), which states that makopa ethanolic  
extract exhibited weak to no inhibitory activity against Gram-negative bacteria, including E. coli, E. cloacae,  
K. pneumoniae, and S. aureus. Also, the study of Sulthana et al. (2024) found makopa leaf ethanolic extract  
ineffective as Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans exhibited resistance to  
the said leaf extract.  
In contrast, the findings of this study differ from those of Tarigan et al. (2022), who reported that the ethanolic  
extract of makopa leaves exhibited notable antibacterial activity, particularly against Bacillus cereus and  
Salmonella enterica, attributing this effect to the presence of phenolic compounds and tannins in the extract.  
Similarly, the findings of Yahaya et al. (2023) and Jayakumari et al. (2023) further support the antibacterial  
potential of ethanolic extracts from makopa leaves, demonstrating significant activity against various  
pathogenic bacteria, including E. coli and K. pneumoniae. These varying findings emphasize the need for  
further research to determine the factors influencing the antibacterial activity of makopa leaf ethanolic extract,  
such as differences in extraction methods, plant maturity, and bacterial susceptibility.  
Antibacterial Efficacy of the Different Concentrations of Bagras and Makopa Leaf Ethanolic Extract on  
the Pseudomonas aeruginosa  
The study investigated the effectiveness of the combination of bagras and makopa leaves ethanolic extract on  
the growth inhibition of P. aeruginosa with three different treatments: Treatment 7 - 40 mg/mL concentration  
of bagras and makopa leaves ethanolic extract; Treatment 8 - 60 mg/mL concentration of bagras and makopa  
leaves ethanolic extract; and Treatment 9 - 80 mg/mL concentration of bagras and makopa leaves ethanolic  
extract. The researchers determined its antibacterial efficacy by measuring the zone of inhibition per treatment  
in each replication. Hence, the researchers obtained the following results.  
Page 691  
www.rsisinternational.org  
INTERNATIONAL JOURNAL OF RESEARCH AND SCIENTIFIC INNOVATION (IJRSI)  
ISSN No. 2321-2705 | DOI: 10.51244/IJRSI |Volume XII Issue IV April 2025  
Table 3. Antibacterial Efficacy of the Different Concentrations of Bagras and Makopa Leaf Ethanolic Extract  
on the Pseudomonas aeruginosa  
Treatments  
Zone of Inhibition (in mm)  
Mean  
SD  
Description  
R1  
R2  
R3  
T7  
T8  
T9  
28  
34  
25  
29.00  
26.00  
31.33  
4.58  
1.73  
1.15  
Susceptible  
Susceptible  
Susceptible  
25  
32  
28  
30  
25  
32  
These findings align with the study of Dihingial et al. (2020) and Kareem et al. (2021), which highlights that  
bagras contains up to 81% eucalyptol (1,8-cineole), a compound known to disrupt bacterial cell membranes,  
and its antibacterial efficacy in inhibiting Gram-negative bacteria like E. coli. To add, makopa is also highly  
valued for its diverse bioactive compounds, which contributes to its effectiveness in inhibiting the growth of  
pathogens (Jayakumari et al., 2023; Yahaya et al., 2023). However, conflicting results exist, as Khandaker et  
al. (2015) and Sulthana et al. (2023) reported weak or inconsistent antibacterial activity against P. aeruginosa  
and E. coli, suggesting that makopa’s efficacy may depend on the solvent used for extraction.  
Hence, these results prove Daniel Moerman’s Theory of Non-Random Selection of Medicinal Plants (1979),  
which suggests that traditional plant use is based on curative properties, with similar taxonomic groups widely  
utilized. Bagras and makopa, both from the Myrtaceae family, exemplify this by potentially enhancing  
medicinal effects when combined, supporting the idea that related plants are selected to maximize healing  
benefits. Overall, the synergistic effect of these compounds increases the antibacterial efficacy of the combined  
leaf ethanolic extract of bagras and makopa in inhibiting the growth of P. aeruginosa.  
Antibacterial Efficacy of the Control Group on the Pseudomonas aeruginosa  
The study included the antibacterial property of the commercial treatment for P. aeruginosa using  
Tobramycin. The researchers determined the antibacterial by measuring the zone of inhibition of Tobramycin  
in each replication. Hence, the researchers finally attained the following results.  
Table 4. Antibacterial Efficacy of the Control Group on the Pseudomonas aeruginosa  
Treatments  
Zone of Inhibition (in mm)  
Mean  
SD  
Description  
R1  
R2  
R3  
Tobramycin  
52  
56  
56  
54.67  
2.31  
Susceptible  
Table 1 presents the antibacterial property of the tobramycin as the control group against P. aeruginosa. This  
finding aligns with the study of Fiel and Roesch (2022), which states effectiveness of tobramycin in treating  
infections caused by Gram-negative bacteria, including P. aeruginosa. Both studies showed that tobramycin is  
often used to manage chronic infections like cystic fibrosis, due to its strong antibacterial efficacy. In contrast,  
the study of Atassi et al. (2023), stated that P. aeruginosa exhibits resistance to multiple antibiotics, including  
aminoglycosides like tobramycin, due to the presence of at least one tobramycin-active gene. It was also  
reported lower susceptibility rates to tobramycin, ranging from 86% to 88%, showing the difficulty in  
effectively treating infections caused by P. aeruginosa. To conclude, although the result showed tobramycin  
effective in inhibiting the growth of P. aeruginosa, studies have also reported lower susceptibility rates leading  
to difficulty in treating infections caused by P. aeruginosa.  
Page 692  
www.rsisinternational.org  
INTERNATIONAL JOURNAL OF RESEARCH AND SCIENTIFIC INNOVATION (IJRSI)  
ISSN No. 2321-2705 | DOI: 10.51244/IJRSI |Volume XII Issue IV April 2025  
Significant Difference in the Effectiveness of Different Concentrations of Bagras and Makopa Leaf  
Ethanolic Extract on the Inhibition of Pseudomonas aeruginosa  
Table 3 shows the results of one-way analysis of variance to determine the significance of the difference in the  
effectiveness of different concentrations of bagras and makopa leaf ethanolic extract on the inhibition of P.  
aeruginosa growth. It can be observed that the F value is 95.033 with 8 and 18 degrees of freedom. The p-  
value is 0.000 which is less than 0.05. This further means that the null hypothesis should be rejected, indicating  
that at least one among the nine treatments significantly differ from the other in terms of its effectiveness in the  
inhibition of P. aeruginosa growth.  
Table 5. Significant Difference in the Effectiveness of Different Concentrations of Bagras and Makopa Leaf  
Ethanolic Extract on the Inhibition of Pseudomonas aeruginosa  
Sum of Squares  
4871.333  
df  
Mean Square  
608.917  
F
p
Decision  
Reject 퐻0  
(Significant)  
Between Groups  
Within Groups  
Total  
8
95.033  
0.000  
115.333  
18  
26  
6.407  
4986.667  
To determine which among the nine concentrations significantly differ from the other, post hoc analysis was  
conducted particularly the pair-wise comparisons of sample means via the Tukey HSD test. The Tukey's  
honestly significant difference test (Tukey's HSD) is used to test differences among sample means for  
significance. The Tukey's HSD test is one of several tests designed for this purpose and fully controls this  
Type I error rate (Nanda et al., 2021).  
Meanwhile, Table 4 presents the results of the post hoc comparisons conducted using the Tukey HSD test. This  
analysis was performed to identify which of the nine treatments showed significant differences in  
effectiveness. The results reveal that significant differences were found between Treatments 1, 2, 3, 7, 8, and 9  
compared to Treatments 4, 5, and 6, as shown by the p-values less than 0.05. Additionally, positive mean  
differences between these treatments indicate that the former treatments are significantly more effective than  
the latter. This suggests that Treatments 4, 5, and 6 were not effective in inhibiting the growth of P.  
aeruginosa.  
Table 6. Post Hoc Comparisons using the Tukey HSD Test  
Mean Difference  
-2.333  
p
Decision  
Interpretation  
Not Significant  
Not Significant  
Significant  
Between T1 and T2  
Between T1 and T3  
Between T1 and T4  
Between T1 and T5  
Between T1 and T6  
Between T1 and T7  
Between T1 and T8  
Between T1 and T9  
0.962  
0.999  
0.000  
0.000  
0.000  
0.962  
1.000  
0.413  
Fail to Reject 퐻0  
Fail to Reject 퐻0  
-1.333  
Reject 퐻0  
26.667  
Reject 퐻0  
26.667  
Significant  
Reject 퐻0  
26.667  
Significant  
Fail to Reject 퐻0  
Fail to Reject 퐻0  
Fail to Reject 퐻0  
-2.333  
Not Significant  
Not Significant  
Not Significant  
0.667  
-4.667  
Page 693  
www.rsisinternational.org  
INTERNATIONAL JOURNAL OF RESEARCH AND SCIENTIFIC INNOVATION (IJRSI)  
ISSN No. 2321-2705 | DOI: 10.51244/IJRSI |Volume XII Issue IV April 2025  
Fail to Reject 퐻0  
Reject 퐻0  
Between T2 and T3  
Between T2 and T4  
Between T2 and T5  
Between T2 and T6  
Between T2 and T7  
Between T2 and T8  
Between T2 and T9  
Between T3 and T4  
Between T3 and T5  
Between T3 and T6  
Between T3 and T7  
Between T3 and T8  
Between T3 and T9  
Between T4 and T5  
Between T4 and T6  
Between T4 and T7  
Between T4 and T8  
Between T4 and T9  
Between T5 and T6  
Between T5 and T7  
Between T5 and T8  
Between T5 and T9  
Between T6 and T7  
Between T6 and T8  
Between T6 and T9  
Between T7 and T8  
Between T7 and T9  
Between T8 and T9  
1.000  
1.000  
0.000  
0.000  
0.000  
1.000  
0.863  
0.962  
0.000  
0.000  
0.000  
1.000  
0.984  
0.787  
1.000  
1.000  
0.000  
0.000  
0.000  
1.000  
0.000  
0.000  
0.000  
0.000  
0.000  
0.000  
0.863  
0.962  
0.260  
Not Significant  
Significant  
29.000  
29.000  
29.000  
0.000  
Reject 퐻0  
Significant  
Reject 퐻0  
Significant  
Fail to Reject 퐻0  
Fail to Reject 퐻0  
Fail to Reject 퐻0  
Reject 퐻0  
Not Significant  
Not Significant  
Not Significant  
Significant  
3.000  
-2.333  
28.000  
28.000  
28.000  
-1.000  
2.000  
Reject 퐻0  
Significant  
Reject 퐻0  
Significant  
Fail to Reject 퐻0  
Fail to Reject 퐻0  
Fail to Reject 퐻0  
Fail to Reject 퐻0  
Fail to Reject 퐻0  
Reject 퐻0  
Not Significant  
Not Significant  
Not Significant  
Not Significant  
Not Significant  
Significant  
-3.333  
0.000  
0.000  
-29.000  
-26.000  
-31.333  
0.000  
Reject 퐻0  
Significant  
Reject 퐻0  
Significant  
Fail to Reject 퐻0  
Reject 퐻0  
Not Significant  
Significant  
-29.000  
-26.000  
-31.333  
-29.000  
-26.000  
-31.333  
3.000  
Reject 퐻0  
Significant  
Reject 퐻0  
Significant  
Reject 퐻0  
Significant  
Reject 퐻0  
Significant  
Reject 퐻0  
Significant  
Fail to Reject 퐻0  
Fail to Reject 퐻0  
Fail to Reject 퐻0  
Not Significant  
Not Significant  
Not Significant  
-2.333  
-5.333  
Based on the test and the mean of each treatment, T1, T2, T3, T7, T8, and T9 are considered to be significantly  
more effective in inhibiting the growth of P. aeruginosa. This means that out of the various leaf ethanolic  
Page 694  
www.rsisinternational.org  
INTERNATIONAL JOURNAL OF RESEARCH AND SCIENTIFIC INNOVATION (IJRSI)  
ISSN No. 2321-2705 | DOI: 10.51244/IJRSI |Volume XII Issue IV April 2025  
extracts tested, the different concentrations of the leaf ethanolic extract with the presence of bagras showed  
more efficacy compared to the leaf ethanolic extract consisting of just makopa. These findings align with the  
study of Dihingial et al. (2020) with regards to bagras, he stated in the review that eucalyptus species, and E.  
deglupta Blume in particular, has an 81% 1,8-cineole (eucalyptol) content, making it effectively antibacterial  
due to its ability to disrupt cell membranes and alter their permeability. Additionally, Galan et al. (2020), also  
highlighted the potential pharmacological benefits of eucalyptol, which exhibits antibacterial properties  
beneficial for respiratory health. Aforementioned studies suggest that bagras showed effectiveness in inhibiting  
the growth of P. aeruginosa because of its antibacterial content compared to the other plant used.  
On the other hand, T7, T8, and T9 the combination of ethanolic extract of both the bagras and makopa leaves  
also showed effectiveness in inhibiting the growth of P. aeruginosa. Phytochemicals such as flavonoids and  
phenolic compounds are known to be present in both bagras and makopa, this shows the synergistic  
antibacterial effects when combining plants. The following studies from Tarigan et al. (2021) showed that  
silver nanoparticles (AgNPs) synthesized from the bagras extract provide valuable insights into their  
phytochemical properties and health benefits. It shows that various phytochemicals, including flavonoids and  
phenolic compounds, are crucial for the biosynthesis and stabilization of AgNPs, which boosts their  
antibacterial effectiveness against Gram-positive and Gram-negative bacteria. Also, the study of Issah Yahay  
et al. (2023) stated that makopa leaves contain compounds, including flavonoids, phenolic compounds,  
alkaloids, and saponins, which enhances medical and therapeutic potential as an antibacterial agent. These  
findings highlights the potential of enhanced antibacterial efficacy in terms of combining plants that share the  
same bioactive compounds.  
Significant Difference in the Effectiveness Between Bagras and Makopa Treatment and Control  
Treatment on the Inhibition of Pseudomonas aeruginosa  
Table 3 presents the results of a one-way ANOVA to assess the significance of differences in the effectiveness  
of various concentrations of bagras and makopa leaf ethanolic extracts on inhibiting P. aeruginosa. The F  
value is 13.24, with 4 and 10 degrees of freedom. The p-value is 0.000, which is less than 0.05. This indicates  
that the null hypothesis should be rejected, meaning that at least one of the six treatments (T1, T2, T3, T7, T8,  
T9) or the control group treatment differs significantly from the others in terms of its effectiveness in inhibiting  
P. aeruginosa.  
Table 7. Significant Difference in the Effectiveness of Different Concentrations of Bagras and Makopa Leaf  
Extract Extract on the Inhibition of Pseudomonas aeruginosa  
Sum of Squares  
1837.810  
df  
Mean Square F  
p
Decision  
Between Groups  
Within Groups  
Total  
6
306.302  
9.000  
34.034  
0.000  
Reject 퐻0  
(Significant)  
126.000  
14  
20  
1963.810  
Post hoc comparisons using the Tukey HSD test reveal a significant difference in the effectiveness between  
Treatments 1, 2, 3, 7, 8, 9, and the control group, as indicated by the p-values less than 0.05. The results also  
show negative mean differences between these treatments, suggesting that the control group is significantly  
more effective in inhibiting the growth of P. aeruginosa compared to the bagras and makopa leaf ethanolic  
extract treatments.  
Table 8. Post Hoc Comparison on T1, T2, T3, T7, T8, T9, and Control using the Tukey HSD Test  
Mean Difference  
p
Decision  
Interpretation  
Reject 퐻0  
Between T1 and Control  
Page 695  
-28.000  
0.000  
Significant  
www.rsisinternational.org  
INTERNATIONAL JOURNAL OF RESEARCH AND SCIENTIFIC INNOVATION (IJRSI)  
ISSN No. 2321-2705 | DOI: 10.51244/IJRSI |Volume XII Issue IV April 2025  
Reject 퐻0  
Reject 퐻0  
Reject 퐻0  
Reject 퐻0  
Reject 퐻0  
Between T2 and Control  
Between T3 and Control  
Between T7 and Control  
Between T8 and Control  
Between T9 and Control  
-25.667  
-26.667  
-25.667  
-28.667  
-23.333  
0.000  
0.000  
0.000  
0.000  
0.000  
Significant  
Significant  
Significant  
Significant  
Significant  
Overall, the Tukey HSD post-hoc test illuminated statistically significant differences between the various  
treatments (T1, T2, T3, T7, T8, and T9) and the control group in their effectiveness in inhibiting the growth of  
P. aeruginosa. As indicated by the data, the results showed that all treatments had a significant impact, as the  
null hypothesis was rejected in every comparison. This means that each treatment had a distinct effect  
compared to the baseline established by the control group. Although the control treatment, tobramycin, had  
greater effectiveness in inhibiting the growth of P. aeruginosa, the plant extracts also demonstrated  
considerable inhibitory effects. These results support the study of Kaur et al. (2018) in which the crude extract  
of bagras leaves is rich in phytochemicals, including phenolics and flavonoids.  
Furthermore, the antibacterial potential of phytochemicals derived from the bagras plant is evident in the  
substantial zones of inhibition observed after treatment. These results align with previous studies of Hapid et  
al. (2024), and Galan et al. (2020), which identified the presence of chemical components, including α-  
phellandrene, α-pinene, and p-cymene. Additionally, Issah Yahay et al. (2023) highlighted the significance of  
the makopa plant, noting that its leaves contain various bioactive compounds, including flavonoids, phenolic  
compounds, alkaloids, and saponins, which support its medical and therapeutic potential as an antibacterial  
agent. The synergistic combination of bagras and makopa demonstrated a noticeably greater zone of inhibition  
compared to when each plant extract was used on its own. This suggests that their combined bioactive  
compounds enhanced antibacterial effectiveness.  
SUMMARY  
This study aimed to evaluate the antibacterial efficacy of bagras (Eucalyptus deglupta Blume) and makopa  
(Syzygium samarangense [Blume] Merr. & L.M. Perry) leaf ethanolic extract at varying concentrations in  
inhibiting the growth of P. aeruginosa. The findings revealed that the bagras leaf ethanolic extract  
demonstrated strong antibacterial activity across all concentrations, with zones of inhibition ranging from  
21mm to 31mm. On the other hand, makopa leaf extract was completely ineffective alone, as no zones of  
inhibition were observed at any concentration.  
Notably, the combination of bagras and makopa extracts produced better antibacterial results than the bagras  
leaf ethanolic extract alone. Results showed large zones of inhibition (ranging from 25 mm to 34 mm),  
indicating possible synergistic effects between the two extracts. Compared to the commercial antibiotic  
Tobramycin, the bagras leaf ethanolic extract and the combination of both makopa and bagras showed  
significant differences in antibacterial efficacy, highlighting its potential as a natural antibacterial agent. The  
ineffectiveness of the makopa leaf ethanolic extract also emphasizes the value of exploring extract  
combinations.  
CONCLUSION  
Acknowledging the need for effective alternatives to conventional antibiotics in inhibiting the growth of P.  
aeruginosa, this research explored the potential of ethanolic extracts from bagras and makopa leaves as  
antibacterial agents. The study aimed to assess the antibacterial properties of these plant extracts and their  
effectiveness in inhibiting bacterial growth. The findings of this study yielded the following conclusions:  
1. The ethanolic extract of bagras leaves exhibited high antibacterial activity against P. aeruginosa at all  
tested concentrations, indicating strong susceptibility. This suggests its potential as an alternative  
Page 696  
www.rsisinternational.org  
INTERNATIONAL JOURNAL OF RESEARCH AND SCIENTIFIC INNOVATION (IJRSI)  
ISSN No. 2321-2705 | DOI: 10.51244/IJRSI |Volume XII Issue IV April 2025  
treatment to antibiotics for combating P. aeruginosa infections.  
2. The ethanolic extract of makopa leaves exhibited no antibacterial activity against P. aeruginosa at any  
tested concentration, as evidenced by the absence of inhibition zones. This indicates that the extract  
lacks antibacterial efficacy, regardless of concentration. These findings indicate that makopa leaves  
may not contain bioactive compounds effective against P. aeruginosa, emphasizing the need for  
further research to investigate other plant extracts or alternative extraction methods that could enhance  
antibacterial properties.  
3. The combined bagras and makopa leaf ethanolic extracts exhibited improved antibacterial efficacy  
against P. aeruginosa, even though makopa extract alone showed no inhibitory effect. The interaction  
between the compounds in both extracts resulted in greater antibacterial activity compared to the  
bagras leaf ethanolic extract alone. While makopa extract may not have direct antibacterial properties,  
it may contain compounds that enhance the effectiveness of bagras extract. These findings indicate  
that plant extracts with limited individual antibacterial activity may still contribute to improving the  
antibacterial efficacy of other plants when combined.  
4. The commercial antibiotic tobramycin exhibited strong antibacterial activity against Pseudomonas  
aeruginosa, as indicated by significant zones of inhibition. This confirms its effectiveness in inhibiting  
P. aeruginosa growth, supporting its role as a widely used antibiotic.  
5. The different concentrations of the ethanolic extract of bagras and makopa as compared to the control  
treatment (T10) showed negative mean differences in inhibiting the growth of P. aeruginosa. This  
result implies that the control treatment exhibited significant effectiveness in inhibiting the growth of  
P. eruginosa compared to the bagras and makopa leaf ethanolic extract.  
REFERENCES  
1. Abiodun, A. K., Nike, A. R., Olanike, K. M., Olakunle, O. F., & Mojisola, A. Z. (2024). Antibacterial  
efficacy of eucalyptus essential oil against respiratory infection pathogens and characterization of its  
bioactive  
compounds.  
Journal  
of  
Pharmaceutical  
Research,  
23(1),  
61–67.  
https://doi.org/10.18579/jopcr/v23.1.8  
2. Antimicrobial Resistance Surveillance Reference Laboratory. (2023). Antimicrobial resistance  
surveillance program 2023 annual report. https://arsp.com.ph/download/1947/?tmstv=1729530223  
3. Atassi, G., Medernach, R., Scheetz, M., Nozick, S., Rhodes, N. J., Murphy-Belcaster, M., Murphy, K.  
R., Alisoltani, A., Ozer, E. A., & Hauser, A. R. (2023). Genomics of aminoglycoside resistance in  
Pseudomonas aeruginosa bloodstream infections at a United States academic hospital. Microbiology  
Spectrum, 11(3). https://doi.org/10.1128/spectrum.05087-22  
4. Beck, K. (2022, March 24). What is the Tukey HSD test? Sciencing. https://tinyurl.com/scienceing-  
tukey-hd-test  
5. Bhat, A. (2018). Experimental Research: What it is + Types of designs. QuestionPro.  
https://www.questionpro.com/blog/experimental-research/  
6. Birt, J., Krosel, A., Eads, A., Sherman, C., Murray, J., Herrity, J., Gafner, J., & Garcia, R. (2022). 7  
types of experiments and what they measure. Indeed. https://www.indeed.com/career-advice/career-  
development/types-of-experiments  
7. Chilam, J., Argimón, S., Limas, M. T., Masim, M. L., Gayeta, J. M., Lagrada, M. L., ... & Carlos, C. C.  
(2021). Genomic surveillance of Pseudomonas aeruginosa in the Philippines, 2013–2014. Western  
Pacific  
surveillance  
and  
response  
journal:  
WPSAR,  
12(2),  
4.  
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8421739/  
8. Dapar, M. L. G., Alejandro, G. J. D., Meve, U., & Liede-Schumann, S. (2020). Ethnomedicinal  
importance and conservation status of medicinal trees among indigenous communities in Esperanza,  
Agusan del Sur, Philippines. Journal of Complementary Medicine Research, 11(1), 59-71.  
https://www.jocmr.com/uploads/paper/c04644019993d34034499e9b54e915eb.pdf  
9. Dihingial, D., Verma, R., Sharma, G. K., & Chandrul, K. K. (2020). A review: extraction of oil and  
chemical investigation of different species of Eucalyptus tree in India. International Research Journal of  
Engineering and Technology, 7(7). https://www.irjet.net/archives/V7/i7/IRJET-V7I716.pdf  
Page 697  
www.rsisinternational.org  
INTERNATIONAL JOURNAL OF RESEARCH AND SCIENTIFIC INNOVATION (IJRSI)  
ISSN No. 2321-2705 | DOI: 10.51244/IJRSI |Volume XII Issue IV April 2025  
10. Fiel, S. B., & Roesch, E. A. (2022). The use of tobramycin for Pseudomonas aeruginosa: a review.  
Expert  
Review  
of  
Respiratory  
Medicine,  
16(5),  
503–509.  
https://doi.org/10.1080/17476348.2022.2057951  
11. Garousi, M., MonazamiTabar, S., Mirazi, H., Farrokhi, Z., Khaledi, A., & Shaker Moghaddam, A.  
(2023). Epidemiology of Pseudomonas aeruginosa in diabetic foot infections: a global systematic review  
and meta-analysis. Germs, 13(4), 362. https://doi.org/10.18683/germs.2023.1406  
12. Gomes, J., Barbosa, J., & Teixeira, P. (2021). The inhibitory concentration of natural food preservatives  
may be biased by the determination methods. Foods, 10(5), 1009. https://www.mdpi.com/2304-  
8158/10/5/1009/pdf  
13. Hamiwe, T., White, D. A., Kwenda, S., Ismail, A., Klugman, S., Bruwaene, L. V., Goga, A., Kock, M.  
M., Smith, A. M., & Ehlers, M. M. (2024). Detection of the epidemic Pseudomonas aeruginosa AUST‐  
03 (ST242) strain in people with cystic fibrosis in South Africa. Pediatric Pulmonology, 59(12), 3340–  
3348. https://doi.org/10.1002/ppul.27202  
14. Hapid, A., Ariyanti A., Erniwati E., Adrianta, K. A., Yuniarti K., Suena, N. M. D. S., & Zulkaidhah Z.  
(2024). Antioxidant and anti-bacterial activity of medicinal plant Leda (Eucalyptus deglupta Blume)  
extract.  
International Journal of Design  
& Nature  
and  
Ecodynamics,  
19(2),  
505–512.  
https://doi.org/10.18280/ijdne.190216  
15. Hassan, M. (2024). ANOVA (Analysis of variance) - Formulas, types, and examples. Research Method.  
https://researchmethod.net/anova/  
16. Horton, M. (2024). Simple random sampling: Definition, advantages, and disadvantages. Investopedia.  
https://tinyurl.com/npmpcucp  
17. Hudzicki, J. (2016). Kirby-Bauer disk diffusion susceptibility test protocol. American Society for  
Microbiology. https://tinyurl.com/disk-diffusion-method  
18. Idris, N. S., Khandaker, M. M., Rashid, Z. M., Majrashi, A., Alenazi, M. M., Nor, Z. M., Mohd Adnan,  
A. F., & Mat, N. (2023). Polyphenolic compounds and biological activities of leaves and fruits of  
Syzygium samarangense cv. “Giant Green” at three different maturities. Horticulturae, 9(3), 326.  
https://doi.org/10.3390/horticulturae9030326  
19. Insuan, O., Thongchuai, B., Chaiwongsa, R., Khamchun, S., & Insuan, W. (2021). Antioxidant and anti-  
inflammatory properties of essential oils from three Eucalyptus species. Chiang Mai University Journal  
of Natural Sciences, 20(4). http://dx.doi.org/10.12982/CMUJNS.2021.091  
20. Issah Yahaya, Gyasi, S., & Atibe Hamadu. (2023). Phytochemical screening of bioactive compounds  
and antimicrobial activity of different extracts of Syzygium samarangense leaves. SSRN Electronic  
Journal. https://doi.org/10.2139/ssrn.4632512  
21. Jayakumari, L., Sivaraj, C., & Manimaran, A. (2023). Methanol leaf extract of Syzygium samarangense:  
Antioxidant, antibacterial activities and GC-MS analysis. Research Journal of Pharmacy and  
Technology. https://doi.org/10.52711/0974-360X.2023.00354  
22. Kambira, P. F. A., Liliana, M., Arfenda, L. B., & Marcella, S. (2020). Aktivitas antibakteri dan antivirus  
dari  
minyak  
kayu  
putih:  
Sistematik  
review.  
JFIOnline|  
Print  
ISSN,  
12(2),  
145-154.  
https://tinyurl.com/bda8pjk7  
23. Kareem, M. H., Khalaf, J. M., Hasan, M. S., Saleh, E. N., & D Salih, N. O. (2020). Effects of  
Eucalyptus Alcoholic Extracts on Pathogenic E. coli, Invitro Study. International Journal of  
Pharmaceutical Research, 12(1),1033-1034. https://tinyurl.com/4hry7td3  
24. Khandaker, M. M., Alebidi, A. I., Hossain, A. S., Mat, N., & Boyce, A. N. (2015). Physiological and  
biochemical properties of three cultivars of wax apple (Syzygium samarangense (Blume) Merrill & L.  
M.  
Perry)  
fruits.  
Journal  
of  
Sustainability  
Science  
and  
Management,  
10(1),  
66–75.  
https://tinyurl.com/yexry26h  
25. National Institutes of Health. (2025). Laboratory Safety Guidelines. University of the Philippines  
Manila. https://nih.upm.edu.ph/research/laboratory-safety-guidelines  
26. Le, H. H., Nguyen, A. V., Vu, L. H., Nguyen, V. T. H., Pham, H. Q., Le, H. V., Nguyen, S. T., Le, H.  
T., Dinh, H. V., Le. N. V., Le, T. D., Le, M. N., Nguyen, V. H., Hoang, K. T., & Le, H. H. L. (2024).  
Antimicrobial resistance patterns of common gram-negative microorganisms isolated from patients with  
lower respiratory tract infections in a teaching hospital in Vietnam. Japanese Journal of Infectious  
Diseases, 77(3). https://doi.org/10.7883/yoken.JJID.2023.260  
Page 698  
www.rsisinternational.org  
INTERNATIONAL JOURNAL OF RESEARCH AND SCIENTIFIC INNOVATION (IJRSI)  
ISSN No. 2321-2705 | DOI: 10.51244/IJRSI |Volume XII Issue IV April 2025  
27. Li, Y., Roberts, J. A., Walker, M. M., Aslan, A. T., Harris, P. N. A., & Sime, F. B. (2024). The global  
epidemiology of ventilator-associated pneumonia caused by multi-drug-resistant Pseudomonas  
aeruginosa: A systematic review and meta-analysis. International Journal of Infectious Diseases, 139,  
78–85. https://doi.org/10.1016/j.ijid.2023.11.023  
28. Lyons, V. T., Dick, J. F., & Weinstein, A. R. (2020). Dartmouth Geisel School of Medicine. Academic  
Medicine, 95(9S), S305–S308. https://doi.org/10.1097/ACM.0000000000003388  
29. Liddell,  
https://study.com/learn/lesson/louis-pasteurs-germ-theory-of-disease-overview-effects.html  
30. Ma, K., & Tu, Q. (2022). Random sampling associated with microbial profiling leads to overestimated  
stochasticity inference in community assembly. Frontiers in Microbiology, 13.  
https://doi.org/10.3389/fmicb.2022.1011269  
31. Moerman, D. E. (1979). Symbols and selectivity: A statistical analysis of native american medical  
ethnobotany. Journal of Ethnopharmacology, 1(2), 111–119. https://doi.org/10.1016/0378-  
8741(79)90002-3  
C.,  
&
Hartsock,  
A.  
(2023).  
Germ  
theory  
of  
disease.  
Study.Com.  
32. Nanda, A., Mohapatra, B. B., Mahapatra, A. P. K., Mahapatra, A. P. K., & Mahapatra, A. P. K. (2021).  
Multiple comparison test by Tukey’s honestly significant difference (HSD): Do the confident level  
control type I error. International Journal of Statistics and Applied Mathematics, 6(1), 59–65.  
https://doi.org/10.22271/maths.2021.v6.i1a.636  
33. Saha,  
S.  
(2024).  
What  
is  
Experimental  
Research:  
Definition,  
types  
&
examples.  
https://www.entropik.io/blogs/experimental-research  
34. Sulthana, D. S. G., Sapna, B., & Gowdara, P. (2024). Evaluation of antibacterial efficacy of wax apple  
(Syzygium samarangense) fruit extracts against Poryphyromonas gingivalis, Fusobacterium nucleatum,  
and Aggregatibacter actnimycetemcomitans — an In vitro study. Journal of Indian Association of Public  
Health Dentistry, 22(2), 124-130. https://doi.org/10.4103/jiaphd.jiaphd_229_23  
35. Tarigan, C., Pramastya, H., Insanu, M., & Fidrianny, I. (2021). Syzygium Samarangense: Review of  
phytochemical compounds and pharmacological activities. Bio interface Research in Applied  
Chemistry, 12(2), 2084–2107. https://doi.org/10.33263/briac122.20842107  
36. Thomsen, J., Menezes, G. A., Abdulrazzaq, N. M., UAE AMR Surveillance Consortium, Moubareck, C.  
A., Senok, A., & Everett, D. B. (2023). Evolving trends among Pseudomonas aeruginosa: a 12-year  
retrospective study from the United Arab Emirates. Frontiers in Public Health, 11, 1243973.  
https://doi.org/10.3389/fpubh.2023.1243973  
37. Winarti, C., Hamaisa, A., Lesmayati, S., Misgiyarta, M., & Gusmaini, G. (2024). Emulsifier ratio and  
shock treatment effect on the characteristics of eucalyptus–peppermint oil-based mouthwash  
nanoemulsion.  
Journal  
of  
Applied  
Pharmaceutical  
Science.  
https://japsonline.com/admin/php/uploads/4390_pdf.pd  
38. World Health Organization. (2019). Carbapenem-resistant Pseudomonas aeruginosa infection–Mexico–  
Infection à Pseudomonas aeruginosa résistant au carbapénème–Mexique. Weekly Epidemiological  
Record= Relevé épidémiologique hebdomadaire, 94(17), 210-212.  
39. Zhaksylyk, A., Zimba, O., Yessirkepov, M., & Kocyigit, B. F. (2023). Research Integrity: Where We  
Are  
and  
Where  
We  
Are  
Heading.  
Journal  
of  
Korean  
Medical  
Science,  
38(47).  
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10695751/  
Page 699  
www.rsisinternational.org