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Vancomycin resistant enterococci (VRE) isolates from humans (23 isolates) and poultry (20 isolates) were characterized by antibiotic susceptibility, vancomycin resistance transferability, pulsed-field gel electrophoresis (PFGE), and structural analysis of Tn 1546-like elements. VRE isolates from humans and poultry showed different resistance patterns, transferability, and transfer rate. In addition to these phenotypic differences between humans and poultry VRE, PFGE and the structure of Tn 1546-like elements were also distinct. Most poultry isolates (16/20) were identical to the prototype vanA transposon, Tn 1546, while most human isolates (21/23) had multiple integrations of insertion sequence. The transmission of VRE and vancomycin resistance determinant between humans and poultry could not be demonstrated in this study. [ABSTRACT FROM AUTHOR]

Abstract: Enterococci for which the minimum inhibitory concentration (MIC) of vancomycin was ≥8 mg/l were isolated from meat, feces, and raw milk samples collected in Korea from March to November 2003. Among the 243 vancomycin-resistant enterococci (VRE) that were identified the vanA vancomycin resistance gene was carried by 51 Enterococcus faecium and one Enterococcus sp., vanC1 was carried by 151 Enterococcus gallinarum, vanC2 was carried by 39 Enterococcus casseliflavus, and one Enterococcus sp. carried no van genes. Of the isolated enterococci carrying vanA, 4% were found to be highly resistant to gentamicin and 11% were resistant to ampicillin. Further genotyping of the E. faecium isolates carrying vanA using pulsed-field gel electrophoresis (PFGE) revealed extensive heterogeneity. The vancomycin resistance transferability test revealed that only two of the 52 enterococci carrying the vanA gene were able to transfer vancomycin resistance to other enterococci. The VRE were recovered from various animal sources with a particularly high prevalence of E. faecium carrying the vanA gene being found in poultry meat. [Copyright &y& Elsevier]

Abstract: Methicillin resistant Staphylococcus aureus (MRSA) is one of the most important pathogens in human and veterinary hospitals. The isolation of MRSA from animals and foodstuffs has been reported with an increased incidence. However, methicillin (oxacillin) is not used in animal husbandry or in animal hospitals in Korea. In this study, three pre-MRSA and one silent mecA-carrying methicillin susceptible S. aureus (smMSSA) were isolated from retail chicken meat, and three MRSA were isolated from hospitalized dogs in Korea. The three pre-MRSA isolates were determined to have a staphylococcal cassette chromosome mec (SCCmec) type III, and the smMSSA isolate was not classified. The animal hospital isolates were found to contain SCCmec type II. Seven and 15 S. aureus isolated from hospitalized humans and bovine milk, respectively, were also examined in this study in order to determine the epidemiological origins of MRSA. Multilocus sequencing typing (MLST) revealed that the chicken meat and bovine milk isolates were closely related to the animal hospital isolates. The SCCmec characteristics and MLST analyses indicated the possibility of the human to animal transmission of MRSA. These results highlight the importance of identifying MRSA carriers as well as intercepting MRSA transmission because MRSA is becoming increasingly widespread without any plausible relationship with the use of methicillin (oxacillin). [Copyright &y& Elsevier]