title: Prevalence of quinolone resistance determinants in non-typhoidal Salmonella isolates from human origin in Extremadura, Spain.
abstract: Resistance to the quinolones nalidixic acid (NAL) and ciprofloxacin (CIP) and the occurrence of quinolone resistance determinants have been investigated in 300 non-typhoidal Salmonella from human origin, isolated in the years between 2004 and 2008, in 6 hospitals within Extremadura (Spain). Salmonella Enteritidis was the major serotype found among quinolone-resistant isolates, most of which were clustered by clonal analysis to a single clone, which presented D87 or S83 substitutions in GyrA. Eleven isolates presented the non-classical quinolone resistance phenotype (resistance to CIP and susceptibility to NAL), lacking mutations in the quinolone resistance determinant region of topoisomerase genes. Among them, one Salmonella Typhimurium isolate carried a qnrS1 gene in a low-molecular-weight plasmid, pQnrS1-HLR25, identical to plasmids previously found in the UK, Taiwan, and USA. The occurrence of this genetic element could represent a risk for the horizontal transmission of quinolone resistance among Enterobacteriaceae in the Iberian Peninsula.
authors.affiliation: Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de Extremadura, Cáceres, Spain; Grupo de Investigação em Recursos Marinhos (GIRM), Instituto Politécnico de Leiria (IPL), Peniche, Portugal. Electronic address: mcampos@ipleiria.pt.
authors.forename: Maria Jorge
authors.initials: MJ
authors.lastname: Campos
authors.affiliation: Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de Extremadura, Cáceres, Spain.
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Palomo
authors.affiliation: Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de Extremadura, Cáceres, Spain.
authors.forename: Lorena
authors.initials: L
authors.lastname: Hormeño
authors.affiliation: Servicio de Bacteriología, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Spain.
authors.forename: Silvia
authors.initials: S
authors.lastname: Herrera-León
authors.affiliation: Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense, Madrid, Spain.
authors.forename: Lucas
authors.initials: L
authors.lastname: Domínguez
authors.affiliation: Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de Extremadura, Cáceres, Spain.
authors.forename: Santiago
authors.initials: S
authors.lastname: Vadillo
authors.affiliation: Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de Extremadura, Cáceres, Spain.
authors.forename: Segundo
authors.initials: S
authors.lastname: Píriz
authors.affiliation: Departamento de Bioquímica, Facultad de Veterinaria, Universidad de Extremadura, Cáceres, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Quesada
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D002648:Child; D015331:Cohort Studies; D004269:DNA, Bacterial / Q000235:genetics; D024881:Drug Resistance, Bacterial; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D015995:Prevalence; D015363:Quinolones / Q000494:pharmacology*; D012480:Salmonella Infections / Q000453:epidemiology / Q000382:microbiology*; D012477:Salmonella enteritidis / Q000187:drug effects* / Q000235:genetics*; D013030:Spain / Q000453:epidemiology
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D015363:Quinolones
keywords: Antimicrobial resistance; Ciprofloxacin; Mobilisable plasmid; Nalidixic acid; PMQR; Quinolone resistance; Salmonella enterica; gyrA; gyrB; parC; parE; qnrS