title: Antibiotic resistance, virulence determinants and production of biogenic amines among enterococci from ovine, feline, canine, porcine and human milk.
abstract: BACKGROUND
  Recent studies have shown that mammalian milk represents a continuous supply of commensal bacteria, including enterococci. The objectives of this study were to evaluate the presence of enterococci in milk of different species and to screen them for several genetic and phenotypic traits of clinical significance among enterococci.
  
  
  RESULTS
  Samples were obtained from, at least, nine porcine, canine, ovine, feline and human healthy hosts. Enterococci could be isolated, at a concentration of 1.00 × 10(2) -1.16 × 10(3) CFU/ml, from all the porcine samples and, also from 85, 50, 25 and 25% of the human, canine, feline and ovine ones, respectively. They were identified as Enterococcus faecalis, Enterococcus faecium, Enterococcus hirae, Enterococcus casseliflavus and Enterococcus durans. Among the 120 initial enterococcal isolates, 36 were selected on the basis of their different PFGE profiles and further characterized. MLST analysis revealed a wide diversity of STs among the E. faecalis and E. faecium strains, including some frequently associated to hospital infections and novel STs. All the E. faecalis strains possessed some of the potential virulence determinants (cad, ccf, cob, cpd, efaA(fs), agg2, gelE, cylA, esp(fs)) assayed while the E. faecium ones only harboured the efaA(fm) gene. All the tested strains were susceptible to tigecycline, linezolid and vancomycin, and produced tyramine. Their susceptibility to the rest of the antimicrobials and their ability to produce other biogenic amines varied depending on the strain. Enterococci strains isolated from porcine samples showed the widest spectrum of antibiotic resistance.
  
  
  CONCLUSIONS
  Enterococci isolated from milk of different mammals showed a great genetic diversity. The wide distribution of virulence genes and/or antibiotic resistance among the E. faecalis and E. faecium isolates indicates that they can constitute a reservoir of such traits and a risk to animal and human health.
authors: Esther
authors: E
authors: Jiménez
authors: Victor
authors: V
authors: Ladero
authors: Irene
authors: I
authors: Chico
authors: Antonio
authors: A
authors: Maldonado-Barragán
authors: María
authors: M
authors: López
authors: Virginia
authors: V
authors: Martín
authors: Leonides
authors: L
authors: Fernández
authors: María
authors: M
authors: Fernández
authors: Miguel A
authors: MA
authors: Álvarez
authors: Carmen
authors: C
authors: Torres
authors: Departamento de Nutrición, Bromatología y Tecnología de los Alimentos, Universidad Complutense de Madrid, Ciudad Universitaria, Avda, Puerta de Hierro, Madrid s/n, 28040, Spain. jmrodrig@vet.ucm.es.
authors: Juan M
authors: JM
authors: Rodríguez
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001679:Biogenic Amines / Q000378:metabolism*; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D016983:Enterococcus / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D005260:Female; D014644:Genetic Variation; D006801:Humans; D008826:Microbial Sensitivity Tests; D008892:Milk / Q000382:microbiology*; D008895:Milk, Human / Q000382:microbiology*; D058885:Multilocus Sequence Typing; D016133:Polymerase Chain Reaction; D037521:Virulence Factors / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D001679:Biogenic Amines; D037521:Virulence Factors