title: Prevalence, virulence and antibiotic susceptibility of Salmonella spp. strains, isolated from beef in Greater Tunis (Tunisia).
abstract: The aim of this work was to investigate the presence of Salmonella spp. in 300 beef meat samples collected from cattle carcasses of different categories (young bulls, culled heifers and culled cows). The detection of Salmonella spp. was performed by the alternative VIDAS Easy Salmonella technique and confirmed by PCR using Salmonella specific primers. Salmonella serotypes were determined by slide agglutination tests. The resistance to 12 antibiotics was determined by the diffusion method on Mueller-Hinton agar antibiotic discs. The overall contamination rate of beef by Salmonella spp. was 5.7% (17/300). This rate varied from naught (0/100) in bulls' meat to 14% (14/100) in culled cows' meat (p<0.001). The prevalence of Salmonella spp. was higher in summer and in cattle with digestive disorders: chronic gastroenteritis (6/17), traumatic peritonitis (3/17) and intestinal obstruction (2/17) (p<0.0001). Of the 17 Salmonella isolates, 6 serotypes were identified, namely Salmonella Montevideo (8/17), Salmonella Anatum (3/17), Salmonella Minnesota (2/17), Salmonella Amsterdam (2/17), Salmonella Kentucky (1/17) and Salmonella Brandenburg (1/17) (p<0.05). Unlike other serotypes, S. Montevideo was present during the whole year except winter. Almost all of the strains (16/17) were resistant to at least one of the 12 tested antibiotics. Multidrug-resistance concerned 14/17 of the strains, including Amoxicillin (13/17), Tetracycline (12/17), Streptomycin (10/17) and Nalidixic acid (6/17). All the strains were sensitive to the association (Amoxicillin+Clavulanic acid), Cefoxitin and Ceftazidime. In addition, our study showed that all Salmonella strains (17) were positive for invasion gene invA and negative for the virulence gene spvC. Only one isolate (S. Kentucky) harbored the h-li virulence gene.
authors.affiliation: Laboratory of Food Microbiology, University Manouba, National School of Veterinary Medicine of Sidi Thabet, 2020 Sidi Thabet, Tunisia. Electronic address: drwalid04@yahoo.fr.
authors.forename: Walid
authors.initials: W
authors.lastname: Oueslati
authors.affiliation: Laboratory of Parasitology, University Manouba, National School of Veterinary Medicine of Sidi Thabet, 2020 Sidi Thabet, Tunisia.
authors.forename: Mohamed Ridha
authors.initials: MR
authors.lastname: Rjeibi
authors.affiliation: Laboratory of Parasitology, University Manouba, National School of Veterinary Medicine of Sidi Thabet, 2020 Sidi Thabet, Tunisia.
authors.forename: Moez
authors.initials: M
authors.lastname: Mhadhbi
authors.affiliation: Department of National Defense, 1008 Tunis, Tunisia.
authors.forename: Mounir
authors.initials: M
authors.lastname: Jbeli
authors.affiliation: Laboratory of Food Microbiology, University Manouba, National School of Veterinary Medicine of Sidi Thabet, 2020 Sidi Thabet, Tunisia.
authors.forename: Samia
authors.initials: S
authors.lastname: Zrelli
authors.affiliation: Laboratory of Food Microbiology, University Manouba, National School of Veterinary Medicine of Sidi Thabet, 2020 Sidi Thabet, Tunisia.
authors.forename: Abdelfettah
authors.initials: A
authors.lastname: Ettriqui
mesh_terms: D000658:Amoxicillin / Q000494:pharmacology; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D019757:Carbon-Oxygen Lyases / Q000235:genetics / Q000378:metabolism; D002417:Cattle; D002440:Cefoxitin / Q000494:pharmacology; D002442:Ceftazidime / Q000494:pharmacology; D019818:Clavulanic Acid / Q000494:pharmacology; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D005260:Female; D005506:Food Contamination; D005516:Food Microbiology; D008297:Male; D009268:Nalidixic Acid / Q000494:pharmacology; D000069466:Red Meat / Q000382:microbiology*; D012475:Salmonella / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification*; D012703:Serotyping; D013752:Tetracycline / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C075518:invA protein, Bacteria; D019818:Clavulanic Acid; D009268:Nalidixic Acid; D002440:Cefoxitin; D000658:Amoxicillin; D002442:Ceftazidime; D019757:Carbon-Oxygen Lyases; C527194:phosphothreonine lyase, Salmonella enterica; D013752:Tetracycline
keywords: Amoxicillin (PubChem CID: 33613); Antibiotic resistance; Beef; Cefoxitin (PubChem CID: 441199); Ceftazidime (PubChem CID: 5481173); Clavulanic acid (PubChem CID: 5280980); Nalidixic acid (PubChem CID: 4421); Salmonella; Serotype; Streptomycin (PubChem CID: 19649); Tetracycline (PubChem CID: 54675776); Tunisia; h-li; invA; spvC