Highly variable vancomycin-resistant enterococci in the north-eastern part of the Czech Republic.

Vancomycin-resistant enterococci (VRE) are nosocomial pathogens of increasing medical importance. This study involved 121 VRE selectively obtained from a representative set of 1464 samples collected from various sources in the north-eastern part of the Czech Republic. In total, 119 VRE belonged to Enterococcus faecium and two to Enterococcus faecalis. All isolates of E. faecium were resistant to at least three antibiotic classes. The resistance genes vanA, erm(B), tet(M), tet(L), aac(3)-IIIa and aac(6')-aph(2'') were detected. We assigned the E. faecium to sequence types ST5, ST18, ST38, ST64, ST92, ST273, ST549 and ST640. In E. faecium isolates, we identified the presence of replicases rep20p LG 1 , rep2p RE 25 , rep17p RUM , rep21p VEF 1/2 and rep14p RI 1 , as well as relaxases relp EF 1 , relp LG 1 , relp CIZ 2 , relp RE 25 and relp RUM . The presence of the toxin-antitoxin system axe-txe was detected mainly among isolates of hospital origin. The A and D types of transposon Tn1546 were those occurring most frequently. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first extensive study of vancomycin-resistant enterococci of diverse origin in a single well-defined area of the Czech Republic. The isolates were investigated for their antibiotic resistance, epidemiological characteristics and plasmid characteristics. Based on the results obtained, we can make assumptions as to the ways that vancomycin resistance is disseminated throughout the environment including humans and animals.