Isolation and screening of methicillin-resistant Staphylococcus aureus from healthcare workers in Libyan hospitals

Mohamed O. Ahmed
Department of Microbiology and Parasitology, Faculty of Veterinary Medicine, Al Fateh University P.O. Box 13662, Tripoli, Libya

Abstract:

Background: To investigate and report the prevalence and antimicrobial susceptibility of methicillin resistant Staphylococcus aureus (MRSA) among healthcare workers (HCWs) from four hospitals in Tripoli, Libya.

Methods: A total of 569 HCWs were screened for MRSA with specimens collected from anterior nares. Identification of MRSA was based on growth on selective media and biochemical tests and further confirmation by PCR. Susceptibility to antimicrobial agents was tested by the disc diffusion susceptibility test and agar dilution methods (MICs); D-tests were also performed.

Results: Isolates from 109 of the 569 HCWs screened were confirmed as MRSA by PCR; the majority (98/109) were from a general hospital. Antimicrobial resistance was as follows: erythromycin (81/109; 74%), clindamycin (33/109; 20%), mupirocin (5/109; 4.5%), ciprofloxacin (84/109; 77%), trimethoprim-sulfamethoxazole (55/109; 50%), quinuprisin-dalfopristin (21/109; 19.2%), and vancomycin (13/109; 12% of which none were confirmed resistant by MICs. Eighteen isolates exhibited macrolide-lincosamide-streptogramin B (MLSB) resistance (18/109): six were MLSBi and 12 were MLSBc.

Conclusion: This is the largest Libyan study to date to examine the incidence and antimicrobial susceptibility of MRSA among HCWs. The results provide evidence that Libyan HCWs could serve as MRSA carriers and play a role in the dissemination of MRSA with associated risk to the public and other HCWs..

Keywords: Methicillin resistant Staphylococcus aureus (MRSA), health care workers (HCWs), MRSA carriers, inducible clindamycin resistance (MLSBi)