Intestinal colonization by vanA- or vanB2-containing enterococcal isolates of healthy animals in Spain

Fecal samples of healthy animals (66 pigs, 22 pets) recovered during 1998 in La Rioja, Spain, were analyzed for vancomycin-resistant enterococci colonization. Vancomycin resistance mechanisms were analyzed by PCR and sequencing. vanA-containing enterococci were detected in 3 of 66 samples (4.5%) and 5 of 22 samples (22.7%) of the pig and pet samples, respectively. Seven unrelated pulsed-field gel electrophoresis (PFGE) patterns were detected among the 8 vanA isolates (7 Enterococcus faecium, 1 E. faecalis). The tet(M) gene was present in all eight vanA enterococcal isolates, while the erm(B) and aac(6')-Ie-aph(2")-Ia genes were detected in 6 and 3 isolates, respectively. Colonization by vanC-1-containing enterococci (E. gallinarum) was demonstrated in 3% and 4.5% of the pig and pet samples. The aac(6')-Ie-aph(2")-Ia, ant(6)-Ia, aph(3')-IIIa, erm(B) and tet(M) genes were identified in one of the E. gallinarum isolates from a pig fecal sample. One vanB2-containing E. hirae strain was detected in the fecal sample of a healthy pig. In this isolate, the vanB2 gene cluster was integrated into the Tn5382-like element, as demonstrated by specific PCRs and sequencing. The tet(M) and erm(B) genes were also detected in this isolate. This is the first report in which a vanB2-containing enterococci is detected in animals and in E. hirae.