ERIC-PCR fingerprint profiling and genetic diversity of coagulase negative Staphylococcus in Malaysia

ABSTRACT

@#Aims: The coagulase-negative staphylococci (CoNS) are a group of Staphylococcus that is gaining clinical significance as major agents of nosocomial infections, especially amongst neonates and immuno-compromised patients. The identification of CoNS remains problematic, and there has been little information on their molecular genotyping. The overall aim of this study was to evaluate Enterobacterial Repetitive Intergenic Consensus-Polymerase Chain Reaction (ERIC-PCR) as a rapid and cost-effective tool for the genotyping of CoNS isolates from within a hospital setting. Methodology and results: A total of 200 isolates of CoNS were collected from Hospital Tuanku Ampuan Rahimah, Klang, Malaysia and identified via sodA gene sequence analysis. Genetic diversity among the isolates was evaluated using the ERIC-PCR. The most frequently isolated species was S. epidermidis (37%) followed by S. haemolyticus (30%), S. hominis (18%) and S. capitis (8.5%). ERIC-PCR was found to be efficient for the differentiation of S. hominis isolates with a discriminatory index (DI) of 0.949 and satisfactory for S. epidermidis isolates at DI of 0.808. Poor discriminatory power was observed in S. haemolyticus (0.377) and S. capitis (0.111). The majority of the S. haemolyticus and S. capitis isolates were found to be genetically homogenous which imply that the source of these infections are due to hospital-derived contaminants. In contrast, the S. epidermidis and S. hominis strains displayed high genetic diversity suggesting the presence of different endemic strains and inflow of exogenous strains brought in by nonlocal residents. Conclusion, significance and impact of study ERIC-PCR is a useful tool to differentiate and track selected species of CoNS.