title: Antimicrobial resistance and the mechanisms implicated in faecal enterococci from healthy humans, poultry and pets in Portugal.
abstract: Antimicrobial resistance and the mechanisms implicated were studied in 440 enterococci (227 Enterococcus faecium, 177 Enterococcus faecalis, 32 Enterococcus hirae and 4 Enterococcus durans) recovered from 220 faecal samples of healthy humans, poultry and pets in Portugal. Higher levels of resistance were detected for ampicillin, tetracycline, erythromycin and chloramphenicol in poultry isolates (10.5%, 97%, 87.5% and 16%, respectively) compared with human isolates (0%, 26%, 31.5% and 5%, respectively); intermediate levels of resistance for these antibiotics were found in pet isolates. Thirty-three per cent of the E. faecium isolates of poultry origin showed quinupristin/dalfopristin resistance. High-level resistance to gentamicin or streptomycin was detected in 1-7% of isolates in our series of enterococci. The aac(6')-aph(2''), aph(3')-IIIa, erm(B) and tet(M) genes were demonstrated in most of the gentamicin-, kanamycin-, erythromycin- and tetracycline-resistant isolates, respectively. The vat(E) gene was found in 39% of the quinupristin/dalfopristin-resistant E. faecium isolates of poultry origin.
authors.affiliation: Universidade de Trás-os-Montes e Alto Douro, Departamento de Ciências Veterinárias, Vila Real, Portugal.
authors.forename: Patrícia
authors.initials: P
authors.lastname: Poeta
authors.forename: Daniela
authors.initials: D
authors.lastname: Costa
authors.forename: Jorge
authors.initials: J
authors.lastname: Rodrigues
authors.forename: Carmen
authors.initials: C
authors.lastname: Torres
mesh_terms: D000818:Animals; D000829:Animals, Domestic / Q000382:microbiology*; D002415:Cats; D004285:Dogs; D024881:Drug Resistance, Bacterial / Q000235:genetics; D016983:Enterococcus / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification*; D013293:Enterococcus faecalis / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification; D016984:Enterococcus faecium / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification; D005243:Feces / Q000382:microbiology; D005798:Genes, Bacterial; D006801:Humans; D008826:Microbial Sensitivity Tests; D011174:Portugal; D011200:Poultry / Q000382:microbiology*