Quinupristin/dalfopristin-resistant enterococci of the satA (vatD) and satG (vatE) genotypes from different ecological origins in Germany

The semisynthetic streptogramin combination quinupristin/dalfopristin (Syne rcid(R)) is a promising alternative for treatment of infections due to mult iply resistant Gram-positive bacteria including vancomycin-resistant Entero coccus faecium. Resistance is mediated by acetyltransferases SatA (VatD) or SatG (VatE), Recent papers have indicated a possible link between the use of the streptogramin virginiamycin S/M as a feed additive in commercial ani mal husbandry and a selection of guinupristin/dalfopristin-resistant E, fae cium (QDRE), We screened manure samples from two different turkey farms and from six different pig farms (using virginiamycin), samples from a sewage water treatment plant, 24 broiler carcasses, 10 pork samples, and 200 stool samples of nonhospitalized humans for QI)RE. Our strain culture collection of hospital E, faecium isolates from the last 2 years was also reviewed fo r QDRE, All manure and sewage samples were positive for QDRE, as well as 11 from broiler carcasses (46%), 1 from pork (10%), and 28 from human stool s pecimens (14%), Thirty-six hospital isolates of E, faecium exhibited resist ance to quinupristin/dalfopristin. In 141 QDRE of different origin satA (va tD) and satG (vatE) genes were detected (seven isolates from humans with an unknown resistance mechanism). Streptogramin resistance determinants were tansferable in filtermating experiments for 5 of 10 satA (vatD) and 9 of 22 satG (vatE) isolates. Different EcoRI patterns of satG (vatE) plasmids and corresponding hybridizations of the satG (vatE) gene indicated nonhomologo us resistance plasmids in isolates of different origin. The results of this study indicate a common gene pool for streptogramin resistance in E. faeci um of different ecological origin. A selection of QDRE using the streptogra min virginiamycin S/M as a feed additive and a spread of the resistance via the food chain to humans is probable.