title: Antimicrobial resistance determinants among anaerobic bacteria isolated from footrot.
abstract: Antibiotic resistance has been evaluated among 36 Gram negative and anaerobic bacilli (10 Bacteroides, 11 Prevotella, 7 Porphyromonas and 8 Fusobacterium strains) isolated from clinical cases of caprine and ovine footrot (necrotic pododermatitis). The initial analysis on this bacterial consortium evaluates the relationships existing among antimicrobial resistance determinants, phenotype expression and mobilization potential. The Bacteroides strains were generally resistant to penicillins, first-generation cephalosporins, tetracycline and erythromycin, and expressed low level of β-lactamase activity. The main determinants found among the Bacteroides strains were cepA and tetQ genes, conferring resistance to β-lactams and tetracycline, respectively. A general susceptibility to β-lactams was shown for most Prevotella, Porphyromonas and Fusobacterium strains, where none of the β-lactamase genes described in Bacteroides was detected. Resistance to tetracycline and/or erythromycin was found among the three bacterial groups. Although tetQ genes were detected for several Prevotella and Porphyromonas strains, a unique ermF positive was revealed among Prevotella strains. The expression of resistance markers was not related with the polymorphism of their coding sequences. However, the finding of sequence signatures for conjugative transposons in the vicinities of tetQ and ermF suggests a mobilization potential that might have contributed to the spread of antimicrobial resistance genes.
authors.affiliation: Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de Extremadura, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Lorenzo
authors.forename: Nuria
authors.initials: N
authors.lastname: García
authors.forename: Juan Alfonso
authors.initials: JA
authors.lastname: Ayala
authors.forename: Santiago
authors.initials: S
authors.lastname: Vadillo
authors.forename: Segundo
authors.initials: S
authors.lastname: Píriz
authors.forename: Alberto
authors.initials: A
authors.lastname: Quesada
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D005535:Foot Rot / Q000188:drug therapy / Q000382:microbiology*; D005798:Genes, Bacterial; D006041:Goats / Q000382:microbiology; D006089:Gram-Negative Anaerobic Bacteria / Q000187:drug effects* / Q000235:genetics; D017422:Sequence Analysis, DNA; D012756:Sheep / Q000382:microbiology; D001618:beta-Lactamases / Q000235:genetics; D047090:beta-Lactams / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D047090:beta-Lactams; D001618:beta-Lactamases