| Autor: |
Oueslati W; Laboratory of Management of Animal Production's Health and Quality, National School of Veterinary Medicine of Sidi Thabet, University Manouba, La Manouba 2010, Tunisia.; Department of Animal Production, National Agronomic Institute, University Carthage, Carthage 1054, Tunisia., Rjeibi MR; Laboratory of Parasitology, National School of Veterinary Medicine of Sidi Thabet, University Manouba, La Manouba 2010, Tunisia.; Laboratory of Parasitology, Veterinary Research Institute, University de Tunis El Manar, Tunis 1068, Tunisia., Benyedem H; Laboratory of Parasitology, National School of Veterinary Medicine of Sidi Thabet, University Manouba, La Manouba 2010, Tunisia., Mamlouk A; Laboratory of Microbiology, National School of Veterinary Medicine of Sidi Thabet, University Manouba, La Manouba 2010, Tunisia., Souissi F; Laboratory of Management of Animal Production's Health and Quality, National School of Veterinary Medicine of Sidi Thabet, University Manouba, La Manouba 2010, Tunisia., Selmi R; Laboratory of Microbiology, National School of Veterinary Medicine of Sidi Thabet, University Manouba, La Manouba 2010, Tunisia., Ettriqui A; Laboratory of Management of Animal Production's Health and Quality, National School of Veterinary Medicine of Sidi Thabet, University Manouba, La Manouba 2010, Tunisia. |
| Abstrakt: |
This study was conducted in northeastern Tunisia to estimate both the prevalence and the risk factors of Salmonella in broiler flocks as well as to characterize the isolated multidrug-resistant (MDR) Salmonella strains. In the present study, a total number of 124 farms were sampled; Salmonella isolates were identified by the alternative technique VIDAS Easy Salmonella . The susceptibility of Salmonella isolates was assessed against 21 antimicrobials using the disk diffusion method on Mueller-Hinton agar using antimicrobial discs. Some antimicrobial resistance genes were identified using PCR. The prevalence rate of Salmonella infection, in the sampled farms, was estimated at 19.9% (64/322). Moreover, a total number of 13 different serotypes were identified. High rate of resistance was identified against nalidixic acid (82.85%), amoxicillin (81.25%), streptomycin (75%), and ciprofloxacin (75%). Alarming level of resistance to ertapenem (12.5%) was noticed. A total of 87.5% (56/64) of isolated strains were recognized as MDR. Three MDR strains were extended-spectrum β-lactamases (ESBL)-producers and three MDR strains were cephalosporinase-producers. The bla CTX -M gene was amplified in all the three ESBL strains. The qnrB gene was not amplified in fluoroquinolones-resistant strains. The tetA and tetB genes were amplified in 5% (2/40) and 2.5% (1/40) of tetracycline-resistant strains, respectively. The dfrA1 gene was amplified in five of the 20 trimethoprim-resistant strains. The mcr-1, mcr-2, mcr-3, mcr-4, and mcr-5 genes were not amplified in any of the phenotypically colistin-resistant strains. In terms of integrase genes int1 and int2, only gene class 2 was amplified in 11% (7/64) of analyzed strains. Risk factors, such as the poor level of cleaning and disinfection, the lack of antimicrobial treatment at the start of the breeding, and a crawl space duration lower than 15 days, were associated with high Salmonella infection in birds. These data should be considered when preparing salmonellosis control programs in Tunisian broiler flocks. |
