ABSTRACT
Methicillin-resistant Staphylococcus aureus (MRSA) is an important pathogen causing nosocomial and other types of infections worldwide. In a one-year survey of patients in two tertiary hospitals, namely, Maharaj Nakhon Si Thammarat and VachiraPhuket Hospitals, southern Thailand, 64 MRSA strains (prevalence of 8.1%) were obtained mainly from the elderly (> 45 years of age). PCR-based assay revealed high prevalence of virulence genes, femB (30%) and spa (34%), and of SCCmec type II from VachiraPhuket (36%) and Maharaj Nakhon Si Thammarat (38%) Hospitals. The majority of MRSA strains were resistant to clindamycin (98%), erythromycin (95%), gentamicin (84%), and tetracycline (80%), while still sensitive to chloramphenicol, cotrimoxazole, fusidic acid, and vancomycin. These data are important for effective treatment of MRSA-infected patients and for implementing control strategies to prevent spread of MRSA within hospitals.
Subject(s)
Cross Infection/epidemiology , Cross Infection/microbiology , Methicillin-Resistant Staphylococcus aureus , Staphylococcal Infections/epidemiology , Staphylococcal Infections/microbiology , Aged , Aged, 80 and over , Anti-Bacterial Agents/therapeutic use , Cross Infection/drug therapy , Female , Genes, Bacterial , Humans , Male , Methicillin-Resistant Staphylococcus aureus/drug effects , Methicillin-Resistant Staphylococcus aureus/genetics , Methicillin-Resistant Staphylococcus aureus/pathogenicity , Middle Aged , Staphylococcal Infections/drug therapy , Tertiary Care Centers , Thailand , Virulence/geneticsABSTRACT
Due to the existence of sporadic cases caused by methicillin-resistant Staphylococcus aureus (MRSA) in Songklanagarind Hospital, Songkhla, southern Thailand where a canteen is located in close vicinity, this study investigated the presence of MRSA, including mecA-carrying S. aureus (MCSA), contamination in 105 ready-to-eat (RTE) food samples sold in this canteen. Coagulase-negative MRSA (MR-CoN) and coagulase-negative MCSA (MCSA-CoN) contaminations were observed in various RTE foods with unriped-papaya salad having significantly highest incidence of MCSA-CoN contamination (p < 0.05). The majority of MCSA-CoN isolates were resistant to clindamycin and fusidic acid. Two MCSA-CoN strains PSU172 and PSU180 were subsequently shown to be MR-CoN. Staphy- lococcal enterotoxins (SEs)-carrying MCSA-CoN strain PSU109 was isolated from seasoned rice. The SE-carrying MCSA-CoN strain PSU109, MR-CoN strain PSU172 and MCSA-CoN strain PSU173 were able to survive in the acidic unriped-papaya salad sauce (pH 4.0-4.5) for up to 6 hours. Typing by pulsed-field gel electrophoresis revealed 80% genetic relatedness among MCSA-CoN strains from RTE food and clinical strains. This study suggests the plausibility of RTE foods sold in a hospital canteen as vehicles of hospital-acquired MR-CoN and of MCSA-CoN.
