title: Prevalence and diversity of integrons and associated resistance genes in Escherichia coli isolates from poultry meat in Tunisia.
abstract: Fifty-five Escherichia coli isolates were acquired from chicken and turkey meat obtained from two slaughterhouses in Tunis. Eighty-nine percent, 80%, 78%, 67%, 45%, 27%, 7%, 4%, and 2% of these isolates showed resistance to tetracycline, trimethoprim/sulfamethoxazole, streptomycin, nalidixic acid, ampicillin, chloramphenicol, ciprofloxacin, colistine, and gentamicin, respectively. No resistance was detected to cefotaxime, ceftazidime, or amikacin. bla(TEM) gene was found in 22 of 25 ampicillin-resistant isolates, and 1 isolate harbored bla(OXA-1) gene. Tetracycline resistance was predominately mediated by the tetA gene. The sul1, sul2, and sul3 genes, alone or combined, were detected in 46 of 48 sulfonamide-resistant isolates, and sul1 and sul3 were included in class 1 integrons in some cases. Sixty percent of isolates harbored integrons (class 1, 30 isolates; class 2, 5 isolates). Class 2 integrons contained in all cases the dfrA1-sat1-aadA1-orfX gene cassette arrangement. Nine gene cassette arrangements have been detected among class 1 integrons, containing different alleles of dfrA (five alleles) and aadA (2 alleles) genes, which encode trimethoprim and streptomycin resistance, respectively. An uncommon gene cassette array (sat-psp-aadA2-cmlA1-aadA1-qacH-IS440-sul3) has been identified in three class 1 integron-positive isolates, and one additional isolate had this same structure with the insertion of IS26 inside the aadA1 gene (included in GenBank with accession no. FJ160769). The 55 studied isolates belong to the four phylogenic groups of E. coli, and phylogroups A and D were the most prevalent ones. At least one virulence-associated gene (fimA, papC, or aer) was detected in 44 of the 55 (80%) studied isolates. E. coli isolates of poultry origin could be a reservoir of antimicrobial-resistance genes and of integrons, and its evolution should be tracked in the future.
authors: Institute of Veterinary Research of Tunisia, Tunis, Tunisia.
authors: Leila
authors: L
authors: Soufi
authors: Mohamed Salah
authors: MS
authors: Abbassi
authors: Yolanda
authors: Y
authors: Sáenz
authors: Laura
authors: L
authors: Vinué
authors: Sergio
authors: S
authors: Somalo
authors: Myriam
authors: M
authors: Zarazaga
authors: Asad
authors: A
authors: Abbas
authors: Rafika
authors: R
authors: Dbaya
authors: Latifa
authors: L
authors: Khanfir
authors: Assia
authors: A
authors: Ben Hassen
authors: Salah
authors: S
authors: Hammami
authors: Carmen
authors: C
authors: Torres
mesh_terms: D000483:Alleles; D000818:Animals; D002645:Chickens; D003227:Conjugation, Genetic; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D019450:Genes, MDR; D005838:Genotype; D032023:Integrons / Q000235:genetics*; D008460:Meat / Q000382:microbiology* / Q000706:statistics & numerical data; D008826:Microbial Sensitivity Tests; D016254:Mutagenesis, Insertional / Q000706:statistics & numerical data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D014416:Tunisia; D014422:Turkeys; D014774:Virulence / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics
chemical_list: D037521:Virulence Factors