Antimicrobial Susceptibility Profiles of Methicillin-Resistant Staphylococcus aureus isolates from the University Teaching Hospital, Lusaka, Zambia (original) (raw)

Staphylococcus aureus is implicated in nosocomial infections worldwide and is associated with a variety of infections such as endocarditis, food poisoning, toxic shock syndrome, septicaemia, skin and soft tissue infections, and bone infections. The emergence and spread of multi-drug resistant strains of S. aureus, particularly methicillin- resistant strains, is worrisome as they are resistant to many antibiotics. However, there is sparse information on the burden of methicillin-resistant Staphylococcus aureus in Zambia. Knowledge of antimicrobial susceptibility patterns of bacterial pathogens is crucial for optimal treatment of patients. It is also important for monitoring the spread of resistant organisms in hospitals and communities. The objective of this study was to identify and determine the antimicrobial susceptibility patterns of methicillin-resistant Staphylococcus aureus at the University Teaching Hospital in Lusaka, Zambia. A total of 95 stored isolates of suspected methicillin-resistant Staphylococcus aureus from pus and blood specimens collected from June 2009 to December 2012 at the University Teaching Hospital were analysed. Conventional microbiological methods and Clinical Laboratory Standards Institute criteria were used to identify and determine the antimicrobial susceptibility of isolates. Of the 95 S. aureus isolates, 43% were identified as methicillin-resistant Staphylococcus aureus strains. These methicillin- resistant Staphylococcus aureus strains were resistant to trimethoprim/sulfamethoxazole (100%), ciprofloxacin (95%), penicillin (95%), erythromycin (79%), tetracycline (76%) and gentamicin (67%). Multi-drug resistance to a combination of, four, five, six and seven antibiotics was observed in 17.5%, 27.5%, 35%, and 17.5% of the methicillin resistant Staphylococcus aureus isolates, respectively. The prevalence of multi-drug resistant methicillin resistant Staphylococcus aureus at the University Teaching Hospital was found to be high. Regular surveillance for multi-drug infections is recommended for infection control and to guide treatment. Key Words: MRSA, Staphylococcusaureus, Multi-drug resistance, Antimicrobial susceptibility