VANA GENES IN VANCOMYCIN-RESISTANT CLINICAL ISOLATES OF OERSKOVIA-TURBATA AND ARCANOBACTERIUM-(CORYNEBACTERIUM)-HAEMOLYTICUM

We report the cloning and sequencing of vanA genes present in the high -level vancomycin- and teicoplanin-resistant clinical isolates Oerskov ia turbata 892 and Arcanobacterium (Corynebacterium) haemolyticum 872. The presence of vanA was detected by Southern blotting and PCR and co nfirmed by DNA sequencing. vanA-like sequences were encoded on plasmid s of 15 and 20 kb respectively. The A. haemolyticum 872 DNA sequence w as identical to the published vanA sequence of vancomycin-resistant En terococcus faecium BM4147, but the O. turbata 892 sequence showed thre e coding changes. Induction experiments indicated that vancomycin resi stance in A. haemolyticum 872 and O. turbata 892 was constitutive. SDS -PAGE analysis of membrane proteins showed the presence of a c. 39 kD protein in both clinical isolates whose expression was unaltered in th e presence of vancomycin, while a similar protein in E. faecium BM4147 was inducible. Since A. haemolyticum and O. turbata are naturally sus ceptible to vancomycin, the high-level constitutive resistance seen in these isolates appears to be mediated by vanA. This is the first repo rt confirming the presence of vanA in genera other than Enterococcus.