title: Occurrence of bla CTX-M-1, qnrB1 and virulence genes in avian ESBL-producing Escherichia coli isolates from Tunisia.
abstract: Avian ESBL-producing Escherichia coli isolates have been increasingly reported worldwide. Animal to human dissemination, via food chain or direct contact, of these resistant bacteria has been reported. In Tunisia, little is known about avian ESBL- producing E. coli and further studies are needed. Seventeen ESBL-producing Escherichia coli isolates from poultry feces from two farms (Farm 1 and farm 2) in the North of Tunisia have been used in this study. Eleven of these isolates (from farm 1) have the same resistance profile to nalidixic acid, sulfonamides, streptomycin, tetracycline, and norfloxacine (intermediately resistant). Out of the six isolates recovered from farm 2, only one was co-resistant to tetracycline. All isolates, except one, harbored bla CTX-M-1 gene, and one strain co-harbored the bla TEM-1 gene. The genes tetA and tetB were carried, respectively, by 11 and 1 amongst the 12 tetracycline-resistant isolates. Sulfonamides resistance was encoded by sul1, sul2, and sul3 genes in 3, 17, and 5 isolates, respectively. The qnrB1 was detected in nine strains, one of which co-harbored qnrS1 gene. The search for the class 1 and 2 integrons by PCR showed that in farm 1, class 1 and 2 integrons were found in one and ten isolates, respectively. In farm 2, class 1 integron was found in only one isolate, class 2 was not detected. Only one gene cassette arrangement was demonstrated in the variable regions (VR) of the 10 int2-positive isolates: dfrA1- sat2-aadA1. The size of the VR of the class 1 integron was approximately 250 bp in one int1-positive isolate, whereas in the second isolate, no amplification was observed. All isolates of farm 1 belong to the phylogroup A (sub-group A0). However, different types of phylogroups in farm 2 were detected. Each of the phylogroups A1, B22, B23 was detected in one strain, while the D2 phylogroup was found in 3 isolates. The virulence genes iutA, fimH, and traT were detected in 3, 7, and 3 isolates, respectively. Two types of gene combination were detected: iutA+fimH+traT in 3 isolates and iutA+fimH in one isolate. The isolates recovered in farm 1 showed the same profile of PFGE macro-restriction, while isolates of farm 2 presented unrelated PFGE patterns. We conclude that these avian ESBL-producing E. coli isolates show homo- and heterogenic genetic background and that plasmids harboring ESBL genes could be involved in the dissemination of this resistance phenotype.
authors.affiliation: Laboratory of Bacteriological Research, Institut de la Recherche Vétérinaire de Tunis, Université de Tunis El Manar Tunis, Tunisia ; LR99ES09 Laboratoire de Résistance aux Antimicrobiens, Faculté de Médecine de Tunis, Université de Tunis El Manar Tunis, Tunisia.
authors.forename: Hajer
authors.initials: H
authors.lastname: Kilani
authors.affiliation: Laboratory of Bacteriological Research, Institut de la Recherche Vétérinaire de Tunis, Université de Tunis El Manar Tunis, Tunisia ; LR99ES09 Laboratoire de Résistance aux Antimicrobiens, Faculté de Médecine de Tunis, Université de Tunis El Manar Tunis, Tunisia.
authors.forename: Mohamed Salah
authors.initials: MS
authors.lastname: Abbassi
authors.affiliation: LR99ES09 Laboratoire de Résistance aux Antimicrobiens, Faculté de Médecine de Tunis, Université de Tunis El Manar Tunis, Tunisia ; Hôpital Charles Nicolle, Service de Microbiologie Tunis, Tunisia.
authors.forename: Sana
authors.initials: S
authors.lastname: Ferjani
authors.affiliation: Laboratory of Bacteriological Research, Institut de la Recherche Vétérinaire de Tunis, Université de Tunis El Manar Tunis, Tunisia ; Regional Animal Health Center for North Africa (RAHC-NA) Tunis, Tunisia.
authors.forename: Riadh
authors.initials: R
authors.lastname: Mansouri
authors.affiliation: Laboratory of Bacteriological Research, Institut de la Recherche Vétérinaire de Tunis, Université de Tunis El Manar Tunis, Tunisia.
authors.forename: Senda
authors.initials: S
authors.lastname: Sghaier
authors.affiliation: Laboratory of Bacteriological Research, Institut de la Recherche Vétérinaire de Tunis, Université de Tunis El Manar Tunis, Tunisia.
authors.forename: Rakia
authors.initials: R
authors.lastname: Ben Salem
authors.affiliation: Laboratory of Bacteriological Research, Institut de la Recherche Vétérinaire de Tunis, Université de Tunis El Manar Tunis, Tunisia.
authors.forename: Imen
authors.initials: I
authors.lastname: Jaouani
authors.affiliation: Laboratory of Bacteriological Research, Institut de la Recherche Vétérinaire de Tunis, Université de Tunis El Manar Tunis, Tunisia.
authors.forename: Gtari
authors.initials: G
authors.lastname: Douja
authors.affiliation: Laboratory of Bacteriological Research, Institut de la Recherche Vétérinaire de Tunis, Université de Tunis El Manar Tunis, Tunisia.
authors.forename: Sana
authors.initials: S
authors.lastname: Brahim
authors.affiliation: École Nationale de Médecine Vétérinaire de Sidi Thabet Sidi Thabet, Tunisia.
authors.forename: Salah
authors.initials: S
authors.lastname: Hammami
authors.affiliation: Laboratory of Bacteriological Research, Institut de la Recherche Vétérinaire de Tunis, Université de Tunis El Manar Tunis, Tunisia.
authors.forename: Noureddine
authors.initials: N
authors.lastname: Ben Chehida
authors.affiliation: LR99ES09 Laboratoire de Résistance aux Antimicrobiens, Faculté de Médecine de Tunis, Université de Tunis El Manar Tunis, Tunisia ; Hôpital Charles Nicolle, Service de Microbiologie Tunis, Tunisia.
authors.forename: Ilhem Boutiba-Ben
authors.initials: IB
authors.lastname: Boubaker
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000235:genetics; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D029968:Escherichia coli Proteins / Q000235:genetics*; D005243:Feces / Q000382:microbiology; D005838:Genotype; D032023:Integrons; D008826:Microbial Sensitivity Tests; D058889:Molecular Typing; D010957:Plasmids / Q000032:analysis; D016133:Polymerase Chain Reaction; D011200:Poultry / Q000382:microbiology*; D014416:Tunisia; D037521:Virulence Factors / Q000235:genetics*; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; C485384:Qnr protein, E coli; D037521:Virulence Factors; C055184:beta-lactamase TEM-3; D001618:beta-Lactamases
keywords: Escherichia coli; blaCTX-M-1; clonality; integrons; poultry; qnrB1