title: Trend of plasmid-mediated quinolone resistance genes at the Children's Hospital in Tunisia.
abstract: The prevalence of plasmid-mediated quinolone resistance genes [qnr, aac(6')-Ib-cr and qepA] was sought among Enterobacteriaceae strains obtained from the Children's Hospital of Tunis (Tunisia). Non-duplicate isolates (n = 278) with resistance to extended-spectrum cephalosporins and collected in 2003, 2007, 2008 and 2009 were screened for qnr genes. Forty (14.4 %) isolates were qnr positive and were screened for the presence of the aac(6')-Ib-cr and qepA genes. qnrB was detected in 21 Klebsiella pneumoniae, 11 Escherichia coli and 6 Enterobacter cloacae isolates. Sequence analysis of the qnrB amplicons revealed variants including 24 qnrB1, 11 qnrB2 and 3 qnrB6. qnrS (qnrS1 allele) was detected only in K. pneumoniae isolates, either alone (two isolates) or with the qnrB gene (one isolate). The qnrA, qnrC and qnrD genes were not found in any of the 278 isolates. No qnr-positive isolates carried the qepA gene. Pyrosequencing results showed that aac(6')-Ib-cr, a variant of the aac(6')-Ib gene, was present in 31 qnr-positive isolates (21 K. pneumoniae isolates, seven Escherichia coli isolates and three Enterobacter cloacae isolates). aac(6')-Ib was also found either alone (two isolates) or in association with aac(6')-Ib-cr (one isolate). Of the 40 qnr-positive isolates, 92.5, 82.5, 57.5, 85 and 82.5 % were non-susceptible to nalidixic acid, ciprofloxacin, levofloxacin, ofloxacin and norfloxacin, respectively, and all were extended-spectrum β-lactamase producers. Random amplified polymorphic DNA-PCR typing of these isolates showed 16, 8 and 5 different genotypes in K. pneumoniae, Escherichia coli and Enterobacter cloacae isolates, respectively. Our study highlights the high prevalence of qnr in association with aac(6')-Ib-cr among Enterobacteriaceae isolates, even from children, who are patients not overtreated with quinolones.
authors.affiliation: EA3964, Université Paris Diderot, Paris, France.|Unité de Recherche UR12ES01, Faculté de Médecine de Tunis, Université de Tunis El Manar; Laboratoire de Microbiologie, Hôpital d'Enfants Béchir Hamza, Bab Saadoun 1068, Tunis, Tunisia.
authors.forename: Nour El-Houda
authors.initials: NE
authors.lastname: Jlili
authors.affiliation: Département des Sciences Biologiques, Faculté des Sciences de Tunis, Université Tunis El Manar, 2092, Tunis, Tunisia.|Unité de Recherche UR12ES01, Faculté de Médecine de Tunis, Université de Tunis El Manar; Laboratoire de Microbiologie, Hôpital d'Enfants Béchir Hamza, Bab Saadoun 1068, Tunis, Tunisia.
authors.forename: Samia
authors.initials: S
authors.lastname: Réjiba
authors.affiliation: Unité de Recherche UR12ES01, Faculté de Médecine de Tunis, Université de Tunis El Manar; Laboratoire de Microbiologie, Hôpital d'Enfants Béchir Hamza, Bab Saadoun 1068, Tunis, Tunisia.
authors.forename: Hanen
authors.initials: H
authors.lastname: Smaoui
authors.affiliation: Laboratoire de Bactériologie-Virologie-Hygiène, Hôpital Robert Debré, CHU Reims, F-51092 Reims, France.|EA3964, Université Paris Diderot, Paris, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Guillard
authors.affiliation: EA3964, Université Paris Diderot, Paris, France.
authors.forename: Françoise
authors.initials: F
authors.lastname: Chau
authors.affiliation: Unité de Recherche UR12ES01, Faculté de Médecine de Tunis, Université de Tunis El Manar; Laboratoire de Microbiologie, Hôpital d'Enfants Béchir Hamza, Bab Saadoun 1068, Tunis, Tunisia.
authors.forename: Amel
authors.initials: A
authors.lastname: Kechrid
authors.affiliation: Laboratoire de Bactériologie, APHP, Hôpital Lariboisière, Paris, France.|EA3964, Université Paris Diderot, Paris, France.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Cambau
mesh_terms: D000293:Adolescent; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002648:Child; D002675:Child, Preschool; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D024881:Drug Resistance, Bacterial; D016972:Enterobacter cloacae; D004755:Enterobacteriaceae / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D004756:Enterobacteriaceae Infections / Q000453:epidemiology* / Q000382:microbiology; D004926:Escherichia coli; D005260:Female; D005798:Genes, Bacterial; D014644:Genetic Variation; D006776:Hospitals, Pediatric; D006801:Humans; D007223:Infant; D007711:Klebsiella pneumoniae; D008297:Male; D010957:Plasmids / Q000032:analysis*; D015995:Prevalence; D015363:Quinolones / Q000494:pharmacology*; D017422:Sequence Analysis, DNA; D014416:Tunisia / Q000453:epidemiology
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D015363:Quinolones