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, PcH1TTN-10, PcWTGN-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 in...