Antimicrobial Susceptibility of Staphylococcus aureus Isolated from Recreational and Natural Water Bodies in Lusaka, Zambia

Abstract

Introduction: Staphylococcus aureus is a potentially harmful human pathogen associated with both nosocomial and community-acquired infections with increasingly antibiotic resistance. Although microbial contamination of marine waters is predicted to be responsible for millions of gastrointestinal, and acute respiratory infections, and several skin infections, there is little information regarding the microbial contamination of water bodies in many Sub-Saharan countries. Therefore, this study aimed at determining the antimicrobial susceptibility of S. aureus isolated from recreational waters and natural water bodies in Lusaka, Zambia. Methods: This was a cross-sectional study with a total of 90 water samples collected from recreational and natural water bodies. To isolate S. aureus, standard microbiological methods were used while the Kirby-Bauer disk diffusion method was used for susceptibility testing. Methicillin-resistant Staphylococcus aureus was detected by use of cefoxitin. Results: The overall results showed that there was 36.7% bacterial contamination in the waters tested. From the 90 samples collected, a total of 33 bacteria were isolated, of which 12 (36.4%) were Coagulase Negative Staphylococcus, 9 (27.2%) were S. aureus and 12 (36.4%) were non-staphylococcus species. All the isolates showed 100% resistance to penicillin G and ampicillin. The S. aureus isolates were most susceptible to chloramphenicol (88.9%), cefoxitin (88.9%), ciprofloxacin (100%), amikacin (88.9%) and gentamicin (88.9%). Only 11.1% of isolates showed phenotypic resistance to methicillin after testing against cefoxitin. Conclusion: The results from this study signify that recreational and natural water bodies in Lusaka, Zambia, may be possible reservoirs of antibiotic-resistant S. aureus, which may possibly be transmitted to humans when using the same waters.