The emerging threat of multidrug-resistant mecA gene-positive coagulase-negative Staphylococci.

Background and objectives: Coagulase-negative staphylococci (CoNS), previously classified as normal bacterial flora, have recently been associated with serious infectious diseases. The clinical isolation rate of these bacteria has increased in parallel with a rising prevalence of antibiotic resistance. Therefore, this study aims to determine the prevalence and species diversity of CoNS and their antibiotic susceptibility patterns.

Materials and methods: Two hundred samples were collected from patients attending outpatient clinics. Bacterial genus, species, and antimicrobial susceptibility patterns were confirmed by the Vitek2 system. The mecA gene was then detected in all isolated bacteria using a polymerase chain reaction.

Results: The most frequently isolated bacterium was Staphylococcus haemolyticus accounting for 37.83% of the isolates and was identified in different specimens. The antibiotic susceptibility profile illustrated the highest resistance against cefoxitin, followed by erythromycin, tetracycline, gentamicin, levofloxacin, clindamycin, and tobramycin. The mecA gene was detected in 95.49%, and all isolates demonstrated resistance to one or more classes of antibiotics. The highest degree of multiple resistance involved six classes of antibiotics.

Conclusion: Methicillin resistance in coagulase-negative staphylococci is alarmingly high. Periodic surveillance of multidrug-resistant CoNS is essential to monitor changes in their antimicrobial susceptibility and to prevent their transition from opportunistic pathogens to regular pathogens.