ABSTRACT
@#Introduction: S. haemolyticus is known to be commensals residing on human skin. However, their ability to develop as pathogens among the healthy community has becoming increasingly vital. Methods: In this study, a total of 49 non-duplicated samples of S. haemolyticus was isolated from the skin of healthy adults and confirmed via sodA gene sequencing method. Cefoxitin (30μg) disc diffusion test was performed to determine methicillin resistance among the S. haemolyticus isolates. The isolates were then subjected to mecA amplification and Staphylococcus Cassette Chromosome (SCCmec) typing of I, II, III, IV and V. Results: Interestingly, 59.2% of the S. haemolyticus commensal isolates were found to be methicillin-resistant (MRSH) while the remaining 40.8% was methicillin-sensitive (MSSH). Amplification of mecA gene showed that 43 isolates (87.8%) were positive while only six isolates were negative for the gene. A majority of the positive mecA isolates (90.7%) were discovered to harbour SCCmec Type II while the remaining 44.2% were Type V followed by 23.3% of Type I and 18.6% of Type IV. Only one of the isolates was found to be SCCmec Type III while another isolate, T187 was non-typeable. Conclusion: The data indicates the acquisition of SCCmec typing circulated among the commensal strains which could be a potential route of pathogenicity among the isolates.
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.