Salam Fathima, Lekshmi Manjusha, Prabhakar Parmanand, Kumar Sanath H, Nayak Binaya Bhusan
Quality Control Laboratory, ICAR-Central Institute of Fisheries Education, Mumbai, Maharashtra, India.
Fish Processing Technology, College of Fisheries, Bihar Animal Sciences University, Patna, Bihar, India.
Vet World. 2023 Mar;16(3):431-438. doi: 10.14202/vetworld.2023.431-438. Epub 2023 Mar 15.
All serotypes of are considered potentially pathogenic. However, the non-typhoidal (NTS) serotypes vary considerably in terms of pathogenicity and the severity of infections. Although diverse serotypes of NTS have been reported from tropical seafood, their sources, physiological characteristics, and virulence potentials are not well understood. This study aimed to compare the physiological characteristics of selected serovars of from seafood and investigate possible variations in the distribution of known genes within the pathogenicity islands.
A series of biochemical tests, including carbohydrate fermentation and amino acid decarboxylation tests were performed to physiologically compare the isolates. The genetic characterization with respect to putative virulence genes was done by screening for genes associated with pathogenicity island (SPI) I-V, as well as the toxin- and prophage-associated genes by polymerase chain reaction.
Irrespective of serotypes, all the isolates uniformly harbored the five SPIs screened in this study. However, some virulence genes, such as the , , and were not detected in all isolates. The biochemical profiles of serotypes were highly conserved except for variations in inositol fermentation and citrate utilization. All the isolates of this study were weak biofilm formers on polystyrene surfaces.
The pathogenicity profiles of environmental NTS isolates observed in this study suggest that they possess the virulence machinery necessary to cause human infections and therefore, urgent measures to contain contamination of seafood are required to ensure the safety of consumers.
所有血清型的[具体细菌名称未给出]都被认为具有潜在致病性。然而，非伤寒型[具体细菌名称未给出]（NTS）血清型在致病性和感染严重程度方面差异很大。尽管已从热带海鲜中报道了多种NTS血清型，但其来源、生理特征和毒力潜力尚未得到充分了解。本研究旨在比较从海鲜中分离出的选定血清型[具体细菌名称未给出]的生理特征，并调查致病岛中已知基因分布的可能差异。
进行了一系列生化试验，包括碳水化合物发酵和氨基酸脱羧试验，以对分离株进行生理比较。通过聚合酶链反应筛选与[具体细菌名称未给出]致病岛（SPI）I - V相关的基因以及毒素和原噬菌体相关基因，对假定的毒力基因进行遗传特征分析。
无论血清型如何，所有分离株均一致含有本研究中筛选的5个SPI。然而，并非所有分离株都检测到某些毒力基因，如[具体基因名称未给出]、[具体基因名称未给出]和[具体基因名称未给出]。除肌醇发酵和柠檬酸盐利用存在差异外，[具体细菌名称未给出]血清型的生化特征高度保守。本研究中的所有分离株在聚苯乙烯表面形成生物膜的能力较弱。
本研究中观察到的环境NTS分离株的致病特征表明，它们拥有引起人类感染所需的毒力机制，因此，需要采取紧急措施控制海鲜中的[具体细菌名称未给出]污染，以确保消费者安全。
