title: Streptococcus gallolyticus subsp. gallolyticus from human and animal origins: genetic diversity, antimicrobial susceptibility, and characterization of a vancomycin-resistant calf isolate carrying a vanA-Tn1546-like element.
abstract: The aim of this work was to characterize the antibiotic susceptibility and genetic diversity of 41 Streptococcus gallolyticus subsp. gallolyticus isolates: 18 isolates obtained from animals and 23 human clinical isolates. Antibiotic susceptibility was determined by the semiautomatic Wider system and genetic diversity by pulsed-field gel electrophoresis (PFGE) with SmaI. Animal isolates grouped separately in the PFGE analysis, but no statistical differences in antimicrobial resistance were found between the two groups. The LMG 17956 sequence type 28 (ST28) strain recovered from the feces of a calf exhibited high levels of resistance to vancomycin and teicoplanin (MIC, ≥256 mg/liter). Its glycopeptide resistance mechanism was characterized by Southern blot hybridization and a primer-walking strategy, and finally its genome, determined by whole-genome sequencing, was compared with four closely related S. gallolyticus subsp. gallolyticus genomes. Hybridization experiments demonstrated that a Tn1546-like element was integrated into the bacterial chromosome. In agreement with this finding, whole-genome sequencing confirmed a partial deletion of the vanY-vanZ region and partial duplication of the vanH gene. The comparative genomic analyses revealed that the LMG 17956 ST28 strain had acquired an unusually high number of transposable elements and had experienced extensive chromosomal rearrangements, as well as gene gain and loss events. In conclusion, S. gallolyticus subsp. gallolyticus isolates from animals seem to belong to lineages separate from those infecting humans. In addition, we report a glycopeptide-resistant isolate from a calf carrying a Tn1546-like element integrated into its chromosome.
authors.affiliation: Servicio de Microbiología, Hospital Universitario Ramón y Cajal, and IRYCIS, Madrid, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Romero-Hernández
authors.affiliation: Servicio de Microbiología, Hospital Universitario Ramón y Cajal, and IRYCIS, Madrid, Spain CIBER en Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain.
authors.forename: Ana P
authors.initials: AP
authors.lastname: Tedim
authors.affiliation: Departament de Genètica i Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain.
authors.forename: José Francisco
authors.initials: JF
authors.lastname: Sánchez-Herrero
authors.affiliation: Departament de Genètica i Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Librado
authors.affiliation: Departament de Genètica i Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain.
authors.forename: Julio
authors.initials: J
authors.lastname: Rozas
authors.affiliation: UCAGT, IRYCIS, Madrid, Spain.
authors.forename: Gloria
authors.initials: G
authors.lastname: Muñoz
authors.affiliation: Servicio de Microbiología, Hospital Universitario Ramón y Cajal, and IRYCIS, Madrid, Spain CIBER en Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Baquero
authors.affiliation: Servicio de Microbiología, Hospital Universitario Ramón y Cajal, and IRYCIS, Madrid, Spain Red Española de Investigación en Patología Infecciosa (REIPI), Seville, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: Cantón
authors.affiliation: Servicio de Microbiología, Hospital Universitario Ramón y Cajal, and IRYCIS, Madrid, Spain Red Española de Investigación en Patología Infecciosa (REIPI), Seville, Spain rosacampo@yahoo.com.
authors.forename: Rosa
authors.initials: R
authors.lastname: Del Campo
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics*; D019729:Carbon-Oxygen Ligases / Q000235:genetics*; D002417:Cattle; D002418:Cattle Diseases / Q000382:microbiology*; D002876:Chromosomes, Bacterial / Q000235:genetics; D003227:Conjugation, Genetic; D005243:Feces / Q000382:microbiology; D014644:Genetic Variation; D016680:Genome, Bacterial / Q000235:genetics; D006801:Humans; D008826:Microbial Sensitivity Tests; D010957:Plasmids / Q000235:genetics; D013290:Streptococcal Infections / Q000382:microbiology* / Q000662:veterinary*; D013291:Streptococcus / Q000187:drug effects* / Q000235:genetics*; D017334:Teicoplanin / Q000494:pharmacology; D020713:Vancomycin Resistance / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C071437:VanA ligase, Bacteria; D017334:Teicoplanin; D019729:Carbon-Oxygen Ligases