Absence of themecA Gene in Methicillin ResistantStaphylococcus aureusIsolated from Different Clinical Specimens in Shendi City, Sudan

Abstract

Absolute dependence onmecA gene as the defining standard in determining the resistance ofS. aureusto methicillin became the subject of distrust by many researchers. The present study aimed to determine the frequency ofmecA gene in methicillin resistantS. aureus(MRSA) isolates using polymerase chain reaction and to correlate its presence to conventional method. In this regard, two hundredS. aureusisolates were collected from patients with different diseases attending different hospitals in Shandi City, Sudan. Phenotypic Kirby-Bauer method confirmed the existence of methicillin resistantS. aureusin 61.5% of the subjected isolates with MICs ranging from 4 μg/mL to 256 μg/mL when usingE-test. However, when amplifying a 310 bp fragment of themecA gene by PCR, twelve out of the 123 MRSA isolates (9.8%) weremecA negative, whereas all the 77 methicillin sensitiveS. aureus(MSSA) weremecA negative. In conclusion, this study drew attention to the credibility of themecA gene and its usefulness in the detection of all MRSA strains without referring to the traditional methods. Hence, it is highly recommended to consider alternative mechanisms forβ-lactam resistance that may compete withmecA gene in the emergence of MRSA phenomenon in the community.