First report on the molecular epidemiology of Malaysian Staphylococcus epidermidis isolated from a University Teaching Hospital

Abstract

BackgroundStaphylococcus epidermidis is a pathogen associated with nosocomial infections whose medical importance has increased due to progressively invasive medical procedures. In this study, we characterized the molecular epidemiology of S. epidermidis strains circulating in our university hospital situated in Kuala Lumpur, Malaysia.FindingsA total of 798 S. epidermidis were isolated from our university hospital, where 56.3% of the isolates were found to be cefoxitin (methicillin) resistant and also positive for the mecA gene. Staphylococcus Cassette Chromosome mec (SCCmec) typing revealed that 39.6% of the methicillin-resistant S. epidermidis (MRSE) were SCCmec-untypeable, with 54.6% harboring the cassette chromosome recombinase C (ccrC) gene. A total of 67 isolates from the neonatal intensive care unit (NICU) was selected for pulsed-field gel electrophoresis (PFGE) typing, where 13 pulsotypes were identified at a cut-off value of 80% similarity. No significant association was found between the PFGE pulsotypes, SCCmec types and antibiotic susceptibilities. Polymerase chain reaction (PCR) assays to detect biofilm-associated genes in the ica operon and also 4 staphylococcal toxin genes (cna, seh, PVL genes and tst-1) revealed that only 8.0% isolates had the complete operon, while cna was the most prevalent toxin gene detected amongst the isolates (35.8%).ConclusionTo our knowledge, this is the first report on the molecular epidemiology of Malaysian S. epidermidis. We found the strains to be low in virulence potential; nevertheless further studies have to be conducted to determine if this phenomenon translates into a better clinical outcome for patients.

Biofilm production by clinical isolates of Staphylococcus epidermidis and its relationship with genotypic profile, presence of virulence-related genes and antibiotic resistance

“…Such as was observed in our results, a large genetic variability in PFGE analysis of healthcare associated S. epidermidis has been reported in many studies (Nunes et al, 2005;Cherifi et al, 2013;Sani et al, 2014). In spite of the diversity observed in the PFGE analysis, multilocus sequence typing (MLST) studies of these isolates showed that the prevalent PFGE types generally belonged to few sequence types (ST) of clonal complex 2 (CC2); among them, ST2 and ST23 in Brazil (Iorio et al, 2012), ST2 and ST54 in Belgium (Cherifi et al, 2014) and ST2 in China (Li et al, 2009;Du et al, 2014).…”

Antibiotic resistance properties of Staphylococcus epidermidis isolated from hospitals in Selangor

“…These findings questions on the eligibility of these antibiotics to be used in the treatment of S. epidermidis infections. Pattern of resistance of S. epidermidis against cefoxitin, erythromycin and gentamicin were generally similar to a study conducted in a teaching hospital in Malaysia in 2014 [54]. This resistance frequencies is also in agreement with reports that this bacterium are commonly resistant to group of antibiotics like penicillins, macrolides and aminoglycosides [2,12,15] None of the clinical S. epidermidis isolates were found to be resistant against linezolid.…”

Diversity of staphylococcal cassette chromosome mec (SCCmec) types among methicillin-resistant coagulase-negative staphylococci (MR-CoNS)

“…49,50 In regards to the distribution of SCCmec types, similar outcome was found between this study and Garza-Gonzalez et al, 51 whereby the most detected SCCmec type was IVa. Mert et al, 52 had reported that generally, majority of MR-CoNS isolated from blood harboured SCCmec type IV (n=65, 24.9%) while Sani et al, 53 found that type IV as the most common (42%) in clinical samples. In contrast, type III was observed as the most commonly distributed in Brazil in which more than 50% were isolated from blood cultures from 1990 to 2009.…”