Occurrence of glycopeptide-resistant enterococci in transplant medicine internal wards in 2001-2005

The appearance of vancomycin-resistant enterococci (VRE) has caused serious therapeutic problems. In Poland, the frequency of VRE isolation is lower than in the United States or some other European countries. The aim of our work was to analyze the occurrence and characterization of VRE isolated from patients of 2 transplant medicine wards. These wards contained liver or kidney transplant patients. This study examined 5 years, including 235 to 313 enterococcal isolates per year. In 2001-2002, none of the isolated enterococci was confirmed as VRE, which appeared in 2003 (11 strains) and continued on a similar level (from 4% to 6%) in the next 2 years. Among all isolated enterococci, Enterococcus faecalis predominated. In 2003 and 2004, the numbers of E. faecium and E. faecalis among isolated VRE strains were similar, but in 2005, we observed significant predominance of E. faecium. Among VRE strains examined by polymerase chain reaction for the presence of vanA, vanB, vanD, vanE, and vanG ligases, only vanA was found in all cases. The examined strains represented several patterns of resistance to other antibiotics.