Background: The current anti-staphylococcal therapy is increasingly compromised by the emergence and spread of resistant strains. The presence of multi-drug resistant bacteria is a great threat and because of the increasing members of resistant strains with time, updated information on prevalence and sensitivity of local major pathogens is of paramount importance.
Objectives: To determine the prevalence of S. aureus infections among outpatients and inpatients and the drug resistance patterns of the isolates to the commonly used antimicrobials.
Materials and methods: The study is a laboratory based retrospective analysis of different bacteriological specimens which were processed for culture and antimicrobial susceptibility testing in the bacteriology laboratory of the University of Gondar Teaching hospital from September 2001 to August 2005.
Results: Of the 616 isolates of S. aureus from different clinical specimens, the highest rate of isolation was from pus cultures (38.5%) followed by urine (32.5%). The isolates showed high level of drug resistance against tetracycline (68.3%), penicillin (54.9%), ampicillin (49.7%), trimethoprim-sulfamethoxazole (48.2%), and chloramphenicol (44.2%) but a moderate degree of resistance to erythromycin (21.6%) and gentamicin (19.6%). Resistance to ciprofloxacin was found only in 6.8% of the isolates. The isolates also showed increased resistance to the antibiotics tested with passage of time (from 2001 through 2005) and higher resistance was observed among ward isolates compared to the outpatients.
Conclusion: Our results demonstrate the existence of multidrug resistant strains of S. aureus in Gondar indicating a strong need to ease selective antibiotic pressure to limit spread of drug resistance in the region. A continuous surveillance of antimicrobial susceptibility patterns and strong antibiotic policies are needed in order to minimize the emergence and spread of resistant pathogenic bacteria.