Prevalence of methicillin resistant Staphylococcus aureus in patient specimens referred to National Reference Laboratory, Ethiopian Public Health Institute

Abstract

Introduction: Staphylococcus aureus is the leading cause of increased morbidity and mortality both in hospital and community settings and produces a wide spectrum of diseases, ranging from minor skin infections to fatal necrotizing pneumonia.

Objective: To determine the prevalence and antibiotic pattern of methicillin resistant Staphylococcus aureus and methicillin sensitive Staphylococcus aureus among referred specimens.
Materials and Methods: Cross sectional study design of modified Kirby Bauer disk diffusion and minimum inhibitory concentration was conducted at Ethiopian Public Health Institute National Referral bacteriology Laboratory. All types of specimens those collected from 2008 to 2014 period were included in the study, and 238 Staphylococci isolates were identified and subject to E-test to determine their MRSA status.
Results: A total of 2,768 Staphylococcus isolates were identified from a range of clinical specimens and S. aureus accounted for 75.9% (2102) from all Staphylococcus species and 50.5% from the 4,159 identified bacterial pathogens. The prevalence of Methicillin resistance Staphylococcus aureus was 44.5% (106/238) and that of Methicillin sensitive Staphylococcus aureus was 55.5 % (132/238). From the total methicillin resistant Staphylococcus aureus isolates (n=106), 49 of them showed highest level of resistance with concentration of cefoxitin 24 and above mg/ml. The highest proportion of methicillin resistant Staphylococcus aureus was found in age group 19+ years (75.5%) followed by age group 6-18(18.9%).
Conclusion and Recommendation
Among all bacterial pathogens, Staphylococcus aureus accounted for 50.5% which indicated that the pathogen was the leading cause of clinical infection among the various bacterial agents. The highest prevalence of methicillin resistant Staphylococcus aureus and multidrug resistant strains of Staphylococcus aureus were isolated from clinical specimens which was found to be alarming. Therefore, strengthening and expanding the existing antimicrobial resistance surveillance system is recommended for effective infection prevention and control operations at health facilities.