title: Polymorphisms of the pbp5 gene and correlation with ampicillin resistance in Enterococcus faecium isolates of animal origin.
abstract: The C-terminal region of the pbp5 gene was sequenced in 11 ampicillin-resistant and 5 ampicillin-susceptible Enterococcus faecium isolates of animal origin, and compared with a pbp5 reference sequence (GenBank accession no. X84860). Eight different pbp5 alleles (designated A-H) were detected when amino acid changes in the region 461-629 were considered. Three of these alleles (A-C) were detected in ampicillin-susceptible isolates (MIC range 1-8 microg ml-1), and included the changes 470H-->Q, 471V-->I, 487Q-->L, 581I-->V, 595E-->A or 622E-->D. The remaining five alleles (D-H) were found in ampicillin-resistant isolates (MIC range 32-256 microg ml-1); three of these alleles (F-H) presented a serine insertion at position 466', in addition to other important amino acid changes (485M-->A, 496N-->K, 499A-->T, 525E-->D, 586V-->L or 629E-->V). The other two alleles presented the amino acid changes 496N-->K and 629E-->V (allele D), and 470H-->Q (allele F). A correlation between deduced amino acid changes in PBP5 and ampicillin MICs was detected in animal E. faecium isolates.
authors.affiliation: Centro de Estudos de Ciências Animais e Veterinárias, Vila Real, Portugal.|Área de Bioquímica y Biología Molecular, Universidad de La Rioja, Logroño, Spain.|Departamento de Ciências Veterinárias, Universidade de Trás-os-Montes e Alto Douro, Vila Real, Portugal.
authors.forename: Patricia
authors.initials: P
authors.lastname: Poeta
authors.affiliation: Área de Bioquímica y Biología Molecular, Universidad de La Rioja, Logroño, Spain.|Departamento de Ciências Veterinárias, Universidade de Trás-os-Montes e Alto Douro, Vila Real, Portugal.
authors.forename: Daniela
authors.initials: D
authors.lastname: Costa
authors.affiliation: Departamento de Genética e Biotecnologia, Universidade de Trás-os-Montes e Alto Douro, Vila Real, Portugal.
authors.forename: Gilberto
authors.initials: G
authors.lastname: Igrejas
authors.affiliation: Área de Bioquímica y Biología Molecular, Universidad de La Rioja, Logroño, Spain.
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Sáenz
authors.affiliation: Área de Bioquímica y Biología Molecular, Universidad de La Rioja, Logroño, Spain.
authors.forename: Myriam
authors.initials: M
authors.lastname: Zarazaga
authors.affiliation: Centro de Estudos de Ciências Animais e Veterinárias, Vila Real, Portugal.|Departamento de Ciências Veterinárias, Universidade de Trás-os-Montes e Alto Douro, Vila Real, Portugal.
authors.forename: Jorge
authors.initials: J
authors.lastname: Rodrigues
authors.affiliation: Área de Bioquímica y Biología Molecular, Universidad de La Rioja, Logroño, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Torres
mesh_terms: D000483:Alleles; D019943:Amino Acid Substitution / Q000235:genetics; D000667:Ampicillin / Q000494:pharmacology; D000668:Ampicillin Resistance; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004285:Dogs / Q000382:microbiology*; D016984:Enterococcus faecium / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D005243:Feces / Q000382:microbiology*; D008969:Molecular Sequence Data; D009154:Mutation; D046915:Penicillin-Binding Proteins / Q000235:genetics*; D011110:Polymorphism, Genetic; D011200:Poultry / Q000382:microbiology*; D011995:Recombination, Genetic; D017422:Sequence Analysis, DNA
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D046915:Penicillin-Binding Proteins; D000667:Ampicillin