Prevalence and Antibiotic Susceptibility Pattern of Staphylococcus Aureus Strains From Inpatients and Outpatients in Jimma University Specialized Hospital, Jimma, Southwest Ethiopia

Background: Staphylococcus aureus (S. aureus) is one of the most serious gram-positive bacteria causing several nosocomial and community acquired infections. Both global, national and local previous studies showed that it is also among the primary bacterial species showing a very high prevalence, rate of drug resistance and multidrug resistance pattern. Because of its intrinsic ability to develop resistance to many antimicrobial agents, we are in the era where only few drugs can be confidentially mentioned for the treatment of S. aureus infections.

Objective: To determine the prevalence and antibiotic susceptibility pattern of S. aureus isolated from patients in Jimma University Specialized Hospital, February 12 to April13, 2008.

Method: A cross sectional study was conducted on prevalence and antibiotic susceptibility pattern of S. aureus among patients (inpatients and outpatients) of Jimma University Specialized Hospital, from February 12 to April13, 2008. A total of 323 wound swab and nasal swab specimens were collected by using systematic sampling technique. Collected specimens were inoculated on mannitol salt agar (HIMEDIA) and incubated at 37^oC for 18 to 24 hours. Gram-staining and specific biochemical tests were used to identify the study organism (9). Sensitivity of the isolates to thirteen commonly used antibiotics was determined by modified Kirby-Bauer antibiotic sensitivity testing method (43).

Result: The overall prevalence of S. aureus was found to be 25.08% (81/323); 20.25% and 26.64% for outpatient and inpatient isolates, respectively. The isolates were found to be highly resistant to the antibiotics penicillin and cephalothin (98.77%; each), ampicillin (90.12%), cloxacillin (83.95%), methicillin (81.48%), oxacillin (79.01%) and chloramphenicol (79.01%). A resistance of 50.62% was obtained for amoxicillin/clavulanic acid and erythromycin.

Conclusion: The S. aureus isolates in the study showed high resistance and multidrug resistance pattern to several of the tested antibiotics; and thus further large scale studies should be conducted in the hospital.