Background: The World Health Organization's 2014 report on global surveillance of antimicrobial resistance shows that antimicrobial resistance is no longer an anticipated phenomenon. It is now happening and more so rampant.1 Misuse and overuse antimicrobial agents have caused the advent of the said resistance. This stressing issue has led to drastic changes in the practice of Medicine.2 Methicillin-resistant Staphylococcus aureus (MRSA) has been recognized as the most significant representative of nosocomial pathogens.3 Infections caused by this pathogen have posed notable mortality and morbidity. Alongside the health care-associated MRSA (HA-MRSA) the emergence of community-acquired MRSA (CA-MRSA) brought about vital alterations in the epidemiology of S. aureus infections.4 Since its appearance in 1960 and subsequent identification in 1961, MRSA strains have steadily spread among shared facilities and has since become widespread threat in hospitals, intensive care units, and nursing homes. The National Nosocomial Infection Surveillance System has since reported the growing emergence with MRSA strains accounting for more than 60% of S. aureus isolates found in US hospitals ICUs. Retrospective reports also showed growing emergence of community-acquired MRSA infections which posed an added threat having no established risk factors and infecting a wide range of risk groups varying from children under 2 years old to adults aged more than 65 years. Several recent reports has since showed an alarming emergence of the strain in the hospital setting and its increasing prevalence with global outbreaks having been reported in USA, Saudi Arabia, and New Zealand.5 Worldwide studies have since demonstrated varying in the incidence of MRSA with USA, Japan, and Southern European countries showing a high prevalence of between 20% and 60%. While in Germany, there is an extensive rise in the incidence of nosocomial MRSA infections rising from 2% to approximately 23% in the past 10 years.6 Furthermore, WHO fact sheets stated that people infected with MRSA are approximately 64% more likely to die than people with non-resistant S. aureus infection.7 Asian countries have shown to have very high rates (>50%) of MRSA, which is the most important cause of hospital acquired infections. The study of ANSORP on S. aureus infections in Asia revealed that MRSA accounted for 25.5% of community-associated (CA) infections and 64.7% of health care-associated (HA) infections. In recent years, there has been evidence of emerging community-associated MRSA (CA-MRSA) infections worldwide, and this has added another serious concern to the epidemiology of S. aureus infections. The ANSORP study showed that the proportion of MRSA in CA S. aureus infections varied by country: Taiwan (34.8%); the Philippines, Vietnam (30.1%) and Korea (15.6% ).8 Very few studies have addressed the epidemiology of MRSA infection in the community in Asian countries despite the widespread emergence of MRSA in hospitals in many Asian countries.4 In the Philippines, 22 hospital bacteriology laboratories located in 14 regions provided resistance data for 50,859 bacterial isolates. For 2015, a total of 3,900 Staphylococcus aureus isolates were reported. These were commonly isolated from cutaneous/wound, blood and respiratory specimens. In 2015, the most common isolate from cutaneous or wound specimens was S. aureus.9 The body tasked to monitor the MRSA status in the country is the Research Institute of Tropical Medicine (RITM), and according to its latest data, the number of people who have contracted MRSA infections in the hospital setting is 60.3% in 2014 and rose to 62.4% in 2015.10 According to RITM's Antimicrobial Resistance Surveillance Program, 85% of MRSA isolates were "presumptively community associated."10 Significance: With first-line drugs no longer effective, there have been extended hospitalizations and more expensive therapies applied, which pose an immediate economic liability. Thus, the proponents seek to aid in the development of new treatments by establishing antibacterial activity of Mangifera indica, an endemic constituent of the country's flora, against methicillin-resistant Staphylococcus aureus. This will entail a probable advent of an inexpensive treatment that would benefit patients especially those who are marginalized. Moreover, the study will benefit the Department of Health in their pursuit of alternative and complementary medicine if results are proven to be significant. Limitations: 1. The mango leaves in the study does not represent the total mango strains present in the country. 2. The study does not aim to compare M. indica antibacterial activity with standard MRSA treatment rather, only establishes the presence of activity. 3. No phytochemical analysis was done to identify the active components of the crude extract as well as levels of such. Research Question: Does crude leaf extract of Mangifera indica (Carabao mango) possess antibacterial activity against Methicillin-resistant Staphylococcus aureus, using agar well diffusion assay and broth micro dilution assay with vancomycin as positive control and sterile water as negative control? General Objective: To determine whether Mangifera indica crude leaf extract possess antibacterial activity against Methicillin-resistant Staphylococcus aureus activity, using agar well diffusion and broth micro dilution assay with vancomycin as positive control and sterile water as negative control. Specific Objectives: 1. To determine the antibacterial activity of M. indica crude leaf extract reconstituted at varying concentrations (150, 200, 250 mg/mL ) against MRSA using agar well diffusion assay with vancomycin as positive and sterile water as negative control. 2. To determine which among the predetermined concentrations of M. indica crude leaf extract ( 50, 75, 100, 125, 150, 200, 250 mg/mL ) will exhibit the minimum inhibitory concentration (MIC) against MRSA through broth micro dilution assay.