Identification of Hemolysin encoding Genes and their Association with Antimicrobial Resistance Pattern among Clinical Isolates of Coagulase-Negative Staphylococci
Abstract Objection : Coagulase-negative staphylococci (CoNS) are considered opportunistic pathogens which capable of producing several toxins, enzymes and also resistance genes. The current study aimed to determine the occurrence of different hemolysins and patterns of antibiotic resistance among CoNS species. Results : The highest frequency of antibiotic resistance was observed against cefoxitin in 49 isolates (53.8%), and the lowest resistance was against novobiocin in 5 isolates (5.5%). None of the isolates were resistant to vancomycin. The prevalence of hla, hla_yidD, hld, and hlb genes were determined as 87.9%, 62.6%, 56%, and 47.3%, respectively. The hla/yidD and hld genes were detected in 69.4% of S. epidermidis and the hla gene in 94.6% of S. haemolyticus ; hlb gene was detected in 53.1% of the S. epidermidis isolates. mecA gene was identified in 50 (55%) of the CoNS isolates. In conclusion, the results of statistical analysis showed that the hld gene had a significant association with resistance to levofloxacin and erythromycin and the hlb with clindamycin resistance. The results of this study showed that there is a significant relationship between hemolysin encoding genes and antibiotic resistance patterns; therefore, detection of virulence factors associated with antibiotic resistance has become a significant issue of concern.