title: Vancomycin-resistant enterococci from Portuguese wastewater treatment plants.
abstract: The objective of this study was to evaluate the incidence of vancomycin resistant enterococci in sludge and sewage of urban and poultry-slaughterhouse wastewater treatment plants. A total of 17 vancomycin resistant enterococci (eight vanA -containing Enterococcus faecium and nine vanC1/vanC2 -containing Enterococcus gallinarum/casseliflavus) were found among 499 isolates of sewage and sludge samples of 14 urban and nine poultry-slaughterhouse wastewater treatment plants. These seventeen VRE isolates showed resistance to kanamycin (n = 8), tetracycline (n = 7), erythromycin (n = 7), ciprofloxacin (n = 7), ampicillin (n = 7), streptomycin (n = 6), and gentamicin (n = 2). The tetM gene, related with tetracycline resistance, was found in six of eight van A-containing isolates, in all seven vanC-1 isolates and in one of two vanC-2 isolates. The ermB gene in seven erythromycin-resistant isolates; and the aac6 '-aph2 ″ gene in the two high-level-gentamicin-resistant isolates. Moreover, two vanA -containing E. faecium isolates harbored the hyl virulence gene, and three isolates the entA bacteriocin gene. The purK-1 allele was detected in our urban vanA -containing E. faecium isolate, and we found as well the purK-6 allele in one poultry-slaughterhouse vanA -containing E. faecium isolate. This study suggests that the wastewater treatment plants might be an important source of dissemination of antibiotic-resistant enterococci in Portugal.
authors.affiliation: Centre of Studies of Animal and Veterinary Sciences, Vila Real, Portugal.
authors.forename: Carlos
authors.initials: C
authors.lastname: Araújo
authors.forename: Carmen
authors.initials: C
authors.lastname: Torres
authors.forename: Nuno
authors.initials: N
authors.lastname: Silva
authors.forename: Catarina
authors.initials: C
authors.lastname: Carneiro
authors.forename: Alexandre
authors.initials: A
authors.lastname: Gonçalves
authors.forename: Hajer
authors.initials: H
authors.lastname: Radhouani
authors.forename: Susana
authors.initials: S
authors.lastname: Correia
authors.forename: Paulo Martins
authors.initials: PM
authors.lastname: da Costa
authors.forename: Rui
authors.initials: R
authors.lastname: Paccheco
authors.forename: Myriam
authors.initials: M
authors.lastname: Zarazaga
authors.forename: Fernanda
authors.initials: F
authors.lastname: Ruiz-Larrea
authors.forename: Patrícia
authors.initials: P
authors.lastname: Poeta
authors.forename: Gilberto
authors.initials: G
authors.lastname: Igrejas
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D016983:Enterococcus / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification*; D005798:Genes, Bacterial; D006801:Humans; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction; D011174:Portugal; D012722:Sewage / Q000382:microbiology*; D014640:Vancomycin / Q000494:pharmacology*; D020713:Vancomycin Resistance; D018508:Water Purification
chemical_list: D000900:Anti-Bacterial Agents; D012722:Sewage; D014640:Vancomycin