title: Phenotypic and genotypic characterization of Salmonella enterica recovered from poultry meat in Tunisia and identification of new genetic traits.
abstract: Thirty-seven Salmonella enterica isolates obtained from poultry meat in Tunisia were included in this study for characterization of antibiotic resistance mechanisms. High percentages of resistance were detected to ampicillin, sulfonamides, tetracycline, nalidixic acid, and streptomycin (32.4%-89.2%), and lower percentages to amoxicillin-clavulanic acid, kanamycin, amikacin, trimethoprim-sulfamethoxazol, and chloramphenicol (2.7%-18.9%). All strains showed susceptibility to ceftazidime, cefotaxime, gentamicin, and ciprofloxacin. Class 1 integrons were detected in 30% of Salmonella isolates, and four different gene cassette arrangements were detected, including genes implicated in resistance to aminoglycosides (aadA1 and aadA2) and trimethoprim (dfrA1). Four different Pc variants (PcW, PcH1, PcH1(TTN-10), PcW(TGN-10)) with inactive P2 have been found among these isolates. Integron-positive isolates were ascribed to eight different serotypes. A Salmonella Schwarzengrund isolate harbored a new class 1 integron containing the qacH-dfrA1b-aadA1b-catB2 gene cassette arrangement, with the very unusual PcH1(TTN-10) promoter, which has been registered in GenBank (accession no. HQ874651). Different plasmid replicon types were demonstrated among integron-positive isolates: IncI1 (8 isolates), IncN (8), IncP (2), IncFIB (2), and IncFII (2). Ten different pulsed-field gel electrophoresis profiles were detected among the 11 integron-positive isolates and 8 different sequence types were identified by multilocus sequence typing, one of them (registered as ST867) was new, detected in 3 Salmonella Zanzibar isolates. A high diversity of clones is observed among poultry Salmonella isolates and a high proportion of them show a multiresistant phenotype with very diverse mobile genetic structures that could be implicated in bacterial dissemination in different environments.
authors.affiliation: Institute of Veterinary Research of Tunisia, Tunis, Tunisia.
authors.forename: Leila
authors.initials: L
authors.lastname: Soufi
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Sáenz
authors.forename: María
authors.initials: M
authors.lastname: de Toro
authors.forename: Mohamed Salah
authors.initials: MS
authors.lastname: Abbassi
authors.forename: Beatriz
authors.initials: B
authors.lastname: Rojo-Bezares
authors.forename: Laura
authors.initials: L
authors.lastname: Vinué
authors.forename: Ons
authors.initials: O
authors.lastname: Bouchami
authors.forename: Arabella
authors.initials: A
authors.lastname: Touati
authors.forename: Assia
authors.initials: A
authors.lastname: Ben Hassen
authors.forename: Salah
authors.initials: S
authors.lastname: Hammami
authors.forename: Carmen
authors.initials: C
authors.lastname: Torres
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins; D002645:Chickens; D024881:Drug Resistance, Bacterial; D015964:Gene Expression Regulation, Bacterial; D005838:Genotype; D032023:Integrons / Q000235:genetics / Q000502:physiology; D008460:Meat / Q000382:microbiology*; D011401:Promoter Regions, Genetic; D012481:Salmonella Infections, Animal / Q000453:epidemiology / Q000382:microbiology*; D019779:Salmonella enterica / Q000235:genetics* / Q000302:isolation & purification*; D012703:Serotyping; D014416:Tunisia / Q000453:epidemiology
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins