title: High prevalence of extended-spectrum and plasmidic AmpC beta-lactamase-producing Escherichia coli from poultry in Tunisia.
abstract: This study was conducted to detect extended spectrum beta-lactamases (ESBLs) and plasmidic AmpC beta-lactamase (pAmpC-BL)-producing Escherichia coli isolates in industrial poultry samples were collected from healthy chickens of the three farms. Samples were inoculated onto desoxycholate-lactose-agar plates supplemented with cefotaxime (2mg/L). E. coli was identified by biochemical and molecular methods and antibiotic susceptibility testing by the disk diffusion method. Genes encoding ESBLs and pAmpC-BL were detected by PCR and sequencing. Phylogenetic groups were determined by triplex PCR. The molecular typing of strains was done by pulsed field gel electrophoresis (PFGE) and Multilocus Sequence Typing (MLST) in those isolates showing different PFGE patterns. Cefotaxime-resistant E. coli isolates were recovered in 48 of 137 fecal samples (35%), and one isolate/sample was further studied. The following beta-lactamase genes were detected: blaCTX-M-1 (29 isolates, isolated in all three farms), blaCTX-M-15 (5 isolates, confined in farm II), blaCTX-M-14 and blaCMY-2 (one isolate and 13 isolates, respectively, in farm III). The 48 cefotaxime-resistant isolates were distributed into phylogroups: B1 (n=21), A (n=15) and D (n=12). PFGE analysis revealed 19 unrelated patterns: 15 different profiles among ESBL-positive strains and 4 among the CMY-2-positive isolates. The following sequence types-associated phylogroups were detected: a) CTX-M-1-positive strains: lineages ST542-B1, ST212-B1, ST58-B1, ST155-B1 and ST349-D; b) CTX-M-15-positive strain: lineage ST405-D; c) CTX-M-14-positive strain: lineage ST1056-B1; d) CMY-2-positive strains: lineages ST117-D, ST2197-A, and ST155-B1. Healthy chickens constitute an important reservoir of ESBL- and pAmpC-BL-producing E. coli isolates that potentially could be transmitted to humans via the food chain or by direct contact.
authors.affiliation: University of Tunis El Manar, Faculty of Medicine of Tunis-Research Laboratory «Antimicrobial resistance», Tunis, Tunisia.
authors.forename: Elaa
authors.initials: E
authors.lastname: Maamar
authors.affiliation: University of Tunis El Manar, Faculty of Medicine of Tunis-Research Laboratory «Antimicrobial resistance», Tunis, Tunisia; University of Gafsa, Faculty of Sciences of Gafsa, Tunisia.
authors.forename: Samia
authors.initials: S
authors.lastname: Hammami
authors.affiliation: Universidad de La Rioja, Area de Bioquímica y Biología Molecular, Logroño, Spain.
authors.forename: Carla Andrea
authors.initials: CA
authors.lastname: Alonso
authors.affiliation: University of Tunis El Manar, Faculty of Medicine of Tunis-Research Laboratory «Antimicrobial resistance», Tunis, Tunisia.
authors.forename: Nouha
authors.initials: N
authors.lastname: Dakhli
authors.affiliation: University of Tunis El Manar, Faculty of Medicine of Tunis-Research Laboratory «Antimicrobial resistance», Tunis, Tunisia; University of Tunis El Manar, Institute of Veterinary Research of Tunisia-Laboratory of bacteriological research, Tunis, Tunisia.
authors.forename: Mohamed Salah
authors.initials: MS
authors.lastname: Abbassi
authors.affiliation: University of Tunis El Manar, Faculty of Medicine of Tunis-Research Laboratory «Antimicrobial resistance», Tunis, Tunisia.
authors.forename: Sana
authors.initials: S
authors.lastname: Ferjani
authors.affiliation: University of Tunis El Manar, Faculty of Medicine of Tunis-Research Laboratory «Antimicrobial resistance», Tunis, Tunisia.
authors.forename: Zaineb
authors.initials: Z
authors.lastname: Hamzaoui
authors.affiliation: University of Tunis El Manar, Faculty of Medicine of Tunis-Research Laboratory «Antimicrobial resistance», Tunis, Tunisia; Charles Nicolle Hospital, Laboratory of Microbiology, Tunis, Tunisia.
authors.forename: Mabrouka
authors.initials: M
authors.lastname: Saidani
authors.affiliation: Universidad de La Rioja, Area de Bioquímica y Biología Molecular, Logroño, Spain. Electronic address: carmen.torres@unirioja.es.
authors.forename: Carmen
authors.initials: C
authors.lastname: Torres
authors.affiliation: University of Tunis El Manar, Faculty of Medicine of Tunis-Research Laboratory «Antimicrobial resistance», Tunis, Tunisia; Charles Nicolle Hospital, Laboratory of Microbiology, Tunis, Tunisia.
authors.forename: Ilhem
authors.initials: I
authors.lastname: Boutiba-Ben Boubaker
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism*; D002645:Chickens / Q000382:microbiology*; D004197:Disease Reservoirs; D004926:Escherichia coli / Q000145:classification / Q000302:isolation & purification* / Q000378:metabolism / Q000502:physiology; D005516:Food Microbiology; D058885:Multilocus Sequence Typing; D010802:Phylogeny; D015995:Prevalence; D014416:Tunisia; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; C048795:AmpC beta-lactamases; D001618:beta-Lactamases
keywords: CMY-2; CTX-M-1; Fecal carriage; Plasmids