Prevalence of MecC Gene Among Methicillin Resistant Staphylococcus aureus isolated from Patients in Ain-Shams University Hospital

Methicillin-Resistant Staphylococcus aureus (MRSA) is an important cause of healthcare associated infections globally. New mecA homologue (mecC), was first reported in the UK and Denmark. The mecC mediated MRSA is resistant only to B-lactams antibiotics and is sensitive to other antibiotics. Detecting the prevalence of mecC MRSA provides more options in treatment of MRSA infections. The aim of this study was to prevalence of mecC gene in clinical isolates of MRSA in Ain-Shams university hospitals & to correlate Minimal Inhibitory concentration (MIC) of Oxacillin with the mecC gene expression in MRSA isolates. Fifty MRSA isolates were collected from different intensive care units (ICUs) of Ain-Shams university hospital from April-December 2018. Methicillin resistance was detected by Cefoxitin disc, and antimicrobial susceptibility testing was done for all isolates and its results were interpreted according to Clinical & Laboratory Standards Institute (CLSI) guidelines 2018. Minimal Inhibitory Concentration of Oxacillin was detected using Oxacillin E-test and the results were interpreted according to the manufacturer's instructions, then Polymerase Chain Reaction was done to detect mecA and mecC genes among MRSA isolates. Fifty isolates were identified as MRSA by Cefoxitin disc out of 163 samples. Twelve isolates were sensitive to Oxacillin while 38 isolates were resistant to Oxacillin. All isolates were positive to mecA gene while only 3 isolates were positive to both mecA and mecC genes. MecC is a new emerging gene responsible for methicillin resistance in staphylococci and was detected in 6 % of the isolates in this study.