Diversity of SCCmec Elements in Methicillin-Resistant Staphylococcus Aureus (MRSA) Recovered from a Healthy Student Population in Kenya
Abstract Background: Methicillin-resistant S. aureus continues to be a concern for public health systems, particularly due to infections emerging in non-hospital settings. Resistance to methicillin is presently classified as a serious phenomenon because the majority of methicillin-resistant strains are also multi-drug resistant. The genetic determinant of resistance to methicillin and other β-lactam antibiotics is the mec-A gene, which lies in the SCCmec resistance island. In Kenya, studies done previously have shown the existence of SCCmec types in clinical isolates, but similar information on isolates recovered from healthy populations is scanty.Methods: A cross-sectional study was conducted on healthy university students residing within the university residence halls to determine the carriage of MRSA. MRSA was detected using Cefoxitin (30µg), and mec-A gene and Sccmec elements were detected using conventional PCR methods. A total of 237 students were recruited, and 657 swabs were collected using standards methods for recovering S. aureus.Results: A total of 231 S. aureus isolates were recovered, out of which 26 (11.3%) were MRSA. Out of the 26 MRSA strains, 17 carried the mecA gene in their gene cassettes. SCCmecV was the most prevalent (61.5%), followed by SCCmecII (53.9%) among the MRSA strains. SCCmecIVa, SCCmecIVb, SCCmecIVc and SCCmecIVd were absent in all the isolates. SCCmecV was found to be highly prevalent (64.7%) followed by SCCmecII, 8 (47.1%) among the mecA-positive MRSA strains. On the other hand, small proportions of mecA-negative isolates harbored SCCmecI (0.9%), SCCmecII (3.3%), SCCmec III (0.5%) and SCCmecV (2.3%).Conclusion: This study revealed that the strains recovered from the student population were highly diverse in terms of the SCCmec elements they carried in their gene cassettes.