Detection of vanA and vanB2-containing enterococci from food samples in Spain, including Enterococcus faecium strains of CC17 and the new singleton ST425.
Two-hundred-twenty-nine food samples of animal origin were tested to know the prevalence of vancomycin-resistant enterococci (VRE) after a decade of avoparcin ban as animal growth promoter in Spain. VRE with acquired mechanism of resistance were detected in 9 of these 229 samples (3.9%, obtained from chicken, veal and rabbit), and one VRE per food sample was further characterized. The vanA gene was identified in seven isolates (2 E. faecium, 3 E. durans, and 2 E. hirae), and the vanB2 gene in the remaining 2 isolates (identified as E. faecium). The two vanB2 isolates showed a phenotype of multiresistance that included, in addition to vancomycin, also ampicillin, erythromycin, tetracycline, streptomycin, kanamycin, ciprofloxacin, chloramphenicol and trimethoprim-sulfamethoxazole and contained, among others, erm(B), tet(M), ant(6), and aph(3')-III genes. Most of vanA enterococci showed erythromycin and tetracycline resistance and contained the erm(B) and tet(M) genes. One vanA- and both vanB2-positive E. faecium isolates were classified by MLST analysis into the CC17 clonal complex (ST17 and ST78), and one additional vanA isolate was included in a new sequence type named ST425 (singleton). Co-transference by conjugation of erm(B) and vanA genes was demonstrated in one vanA-positive E. faecium isolate. The inclusion of vanB2 cluster into Tn5382 structure was demonstrated in the two vanB2 isolates, as well as the linkage pbp5-Tn5382, and beta-haemolysis and gelatinase production was identified in one of them. Food sample of animal origin could be a vehicle of transference of VRE of vanA and vanB2 type that could be transferred to humans.
López
María
M
Departamento de Agricultura y Alimentación, Universidad de La Rioja, Logroño, Spain.
Sáenz
Yolanda
Y
Rojo-Bezares
Beatriz
B
Martínez
Santiago
S
del Campo
Rosa
R
Ruiz-Larrea
Fernanda
F
Zarazaga
Myriam
M
Torres
Carmen
C
D000818:Animals; D000900:Anti-Bacterial Agents; D002417:Cattle; D002645:Chickens; D003227:Conjugation, Genetic; D024881:Drug Resistance, Bacterial / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial; D004335:Drug and Narcotic Control; D016984:Enterococcus faecium / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D005516:Food Microbiology; D018093:Gelatinases; D005798:Genes, Bacterial; D014644:Genetic Variation; D006020:Glycopeptides; D006801:Humans; D011817:Rabbits; D013030:Spain; D020713:Vancomycin Resistance / Q000235:genetics*; D014774:Virulence / Q000235:genetics
D000900:Anti-Bacterial Agents; D006020:Glycopeptides; D018093:Gelatinases; C016249:avoparcin