Virulence gene typing of Methicillin-susceptible Staphylococcus aureus (MSSA)isolates in Universiti Kebangsaan Malaysia Medical Centre (UKMMC)

We determined the presence of four virulence genes: (cna, seh, PVL, TSST-1) using multiplex PCR in 880 isolates of methicillin-susceptible Staphylococcus aureus (MSSA) collected from the Universiti Kebangsaan Malaysia Medical Centre (UKMMC) in 2009. We found that 51.59% (454/880) of the strains had cna; 21.82% (192/880) possessed seh; 10.23% (90/880) had PVL and 6.82% (60/880) haboured TSST-1. Although methicillin-susceptible, MSSA carries important virulence genes which could affect patient’s clinical course

Species identification of Coagulase Negative Staphylococci (CoNS) isolates in Universiti Kebangsaan Malaysia Medical Centre (UKMMC)

Coagulase negative Staphylococcus (CoNS) are common colonizers of the human skin but has become increasingly recognized as agents of clinically significant infections. At the Universiti Kebangsaan Malaysia Medical Centre (UKMMC), the prevalence of CoNS among staphylococcus genus in 2009 was 47.1%. The aim of this study was to identify Staphylococcus epidermidis, S. saprophyticus and S. xylosus from the CoNS and MRCoNS (methicillin resistant CoNS) collected in 2009 using a multiplex PCR approach with primers specific for each species. Our results showed that S. epidermidis is the most common species among both MRCoNS and CoNS isolates in UKMMC. Among 1142 CoNS strains, 68.4% were S. epidermidis, 1.3% were S. saprophyticus while 30.3% were non-typeable (other species). A total of 659 CoNS strains have been identified as methicillin resistant (MRCoNS); where 68.1% were S. epidermidis,1.5% was S. saprophyticus and 30.3% were from other CoNS species. S. xylosus was not identified among the isolates

Clonal Diversity of Methicillin-resistant Staphylococcus aureus in UKM Medical Centre: characterisation by Multilocus Sequence Typing of different SCCmec type representatives

Multilocus sequence typing (MLST) has been used to characterise methicillin-resistant Staphylococcus aureus (MRSA) isolates into sequence types (STs) and together with SCCmec typing, form the clonal nomenclature for MRSA. MLST was conducted as per the standard protocol on ten out of 236 isolates collected previously from January to December 2009 representing four different SCCmec types. Relationship analysis was performed with eBURST via the MLST website. Four unlinked ‘singleton’ STs were detected: ST30, ST239, ST772 and ST1178. Together with SCCmec typing, five MRSA clones were identified: ST30-IV, ST239-II, ST239-III, ST772-V and ST1178-IV. Clones ST239-III and ST30-IV are already established in Malaysian hospitals and in the local community, respectively. ST772-V is an emerging clone reported previously to have a propensity to displace pre-existing predominant clones. A clone involving the predominant ST in Malaysia (ST239) with SCCmec type II is the first of its kind to be identified. MRSA clones in our centre are very diverse and clone surveillance with large sample sizes should be undertaken as collaborative efforts between local institutions to maximise detection coverage