Characterization of vanA-containing Enterococcus faecium isolates carrying Tn5397-like and Tn916/Tn1545-like transposons in wild boars (Sus Scrofa).

The presence of vanA-containing Enterococcus faecium isolates was demonstrated in two of 67 fecal samples (3%) of healthy wild boars recovered in Portugal. One isolate per sample was studied further (E. faecium PG5V and PG48V). The mechanisms of resistance for other antibiotics were analyzed in these two vancomycin-resistant isolates, as well as the presence of genes related with virulence factors. The tet(M), tet(L), and erm(B) genes, associated with tetracycline or erythromycin resistance, were identified in both isolates, and the presence of aph(3′)-IIIa gene (associated with kanamycin resistance) was detected in one of them. E. faecium PG48V exhibited an ampicillin minimum inhibitory concentration (MIC) of 64 μg/ml and showed eight amino acid substitutions in the carboxy-terminal end of the PBP5 protein (461Q → K, 470H → Q, 485M → A, 496N → K, 499A → T, 525E → D, 586V → L, and 629E → V) with respect to the reference sequence (GenBank accession number X84860). The purK-6 allele was identified in isolat...