Prevalence and antimicrobial susceptibility of methicillin resistant Staphylococcus aureus isolated from clinical specimens in Harare, Zimbabwe

Abstract

Objective:  The study was carried out to determine the prevalence and antimicrobial susceptibility of Methicillin Resistant Staphylococcus aureus (MRSA) in Harare, Zimbabwe.

Design:  This was a cross-sectional study on the prevalence of MRSA and antimicrobial susceptibility of the MRSA isolates. S. aureus isolates were collected from clinical laboratories in Harare and were tested for MRSA. The MRSA isolates were tested for their susceptibility to antimicrobial drugs.

Setting:  This was a laboratory-based study.

Subjects: Three hundred and eighty one clinical isolates of Staphylococcus aureus were included in the study.

Main Outcome Measures:  The prevalence of MRSA was 11.8% and they were all susceptible to vancomycin and teicoplanin. There was a high resistance rate of 73.3% to erythromycin and clindamycin inducible resistance was detected in 46.7% of the MRSA isolates.

Results:  Methicillin Resistant Staphylococcus aureus was detected in 45 (11.8%) of the 381 S. aureus isolates which were tested. High MRSA prevalence rates of over 10% were observed in isolates from blood cultures and urethral, pus, eye and nasal swabs. All the MRSA isolates were susceptible to vancomycin and teicoplanin and 82.2% were susceptible to mupirocin.  About 50% of the isolates were susceptible to doxycycline, gentamicin and rifampicin. Most of the isolates (75.6%) were susceptible to clindamycin but 73.3% were resistant to erythromycin. Clindamycin inducible resistance was detected in 42.2% of the MRSA isolates.

Conclusion: There was a low prevalence of MRSA amongst the S. aureus isolates which were all susceptible to vancomycin and teicoplanin but showed a high resistance to some drugs commonly used in Zimbabwe.