Department of Microbiology and Immunology, Institute of Biosciences, São Paulo State University, Botucatu, SP, Brazil.
Adolfo Lutz Institute Bacteriology Division, São Paulo, SP, Brazil.
Food Res Int. 2020 Mar;129:108835. doi: 10.1016/j.foodres.2019.108835. Epub 2019 Nov 29.
Salmonella spp. is responsible for severe foodborne disease, and is one of the main agents involved in foodborne outbreaks worldwide. Contamination occurs mainly as a result of poultry and egg consumption since they can carry some serotypes pathogenic to humans. The aim of the study was to evaluate the persistence and pathogenic potential of Salmonella spp. (n = 40) isolated from poultry slaughterhouse mats, using adhesion and invasion assays, antimicrobial susceptibility by disc diffusion, and biofilm production as phenotypic tests and genotypic analyses. Polystyrene mats presented 3.2 times greater chance of isolating Salmonella than canvas mats. Besides, we observed resistance to tetracycline (17.5%), ampicillin (10%), cefotaxime (7.5%), trimethoprim-sulfamethoxazole (5%), and chloramphenicol (2.5%). All strains possessed the invA, sipB, sipD, ssaR, sifA, sitC, iroN, tolC, flgK, fljB, and flgL genes. The genes sopB and sipA were both present in 92.5% of the isolates, while sopD and spvB were observed in 90% and 32.5% of strains, respectively. All strains adhered to and invaded HeLa cells. Regarding biofilm production, 31 (77.5%) strains were able to produce biofilm on polystyrene microplates. Using PFGE, we detected the persistence of clones in the environment for up to 18 fromthe 20 weeks. The ability of these strains to produce a biofilm and thus persist in the environment and disperse through contact surfaces in the processing plant favors the contamination of food, aggravated by the pathogenic potential of these isolates demonstrated by their adhesion capacity, invasion and resistance to various antibiotic agents.
肠炎沙门氏菌是引起严重食源性疾病的病原体之一，也是全球食源性疾病爆发的主要病原体之一。污染主要是由于食用家禽和鸡蛋引起的，因为它们可能携带一些对人类致病的血清型。本研究旨在评估从家禽屠宰场垫料中分离的肠炎沙门氏菌（n=40）的持续存在和致病潜力，使用粘附和侵袭试验、药敏纸片扩散法测定抗菌药物敏感性、生物膜生成作为表型试验和基因分析。聚苯乙烯垫料比帆布垫料分离出肠炎沙门氏菌的几率高 3.2 倍。此外，我们观察到对四环素（17.5%）、氨苄西林（10%）、头孢噻肟（7.5%）、复方新诺明（5%）和氯霉素（2.5%）的耐药性。所有菌株均携带 invA、sipB、sipD、ssaR、sifA、sitC、iroN、tolC、flgK、fljB 和 flgL 基因。sopB 和 sipA 基因在 92.5%的分离株中均存在，而 sopD 和 spvB 基因分别在 90%和 32.5%的菌株中存在。所有菌株均能粘附并侵袭 HeLa 细胞。关于生物膜生成，31（77.5%）株能够在聚苯乙烯微量板上生成生物膜。使用 PFGE，我们检测到在环境中 20 周内可检测到 18 周的克隆持续存在。这些菌株在环境中产生生物膜并因此持续存在并通过加工厂接触表面传播的能力，加上这些分离株通过粘附能力、侵袭能力和对各种抗生素药物的耐药性表现出的致病潜力，有利于食品污染。
