Physiological characteristics and virulence gene composition of selected serovars of seafood-borne Salmonella enterica

Vet World Vol.16 March-2023 Article-2

Research Article

Veterinary World, 16(3): 431-438

https://doi.org/10.14202/vetworld.2023.431-438

Fathima Salam¹, Manjusha Lekshmi¹, Parmanand Prabhakar², Sanath H. Kumar¹, and Binaya Bhusan Nayak¹

1. Quality Control Laboratory, ICAR-Central Institute of Fisheries Education, Mumbai, Maharashtra, India.
2. Fish Processing Technology, College of Fisheries, Bihar Animal Sciences University, Patna, Bihar, India.

Background and Aim: All serotypes of Salmonella enterica are considered potentially pathogenic. However, the non-typhoidal Salmonella (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 Salmonella from seafood and investigate possible variations in the distribution of known genes within the pathogenicity islands.

Materials and Methods: 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 Salmonella pathogenicity island (SPI) I– V, as well as the toxin- and prophage-associated genes by polymerase chain reaction.

Results: Irrespective of serotypes, all the isolates uniformly harbored the five SPIs screened in this study. However, some virulence genes, such as the avrA, sodC, and gogB were not detected in all Salmonella isolates. The biochemical profiles of Salmonella 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.

Conclusion: 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 Salmonella contamination of seafood are required to ensure the safety of consumers. Keywords: biofilm, invasion, non-typhoidal Salmonella, Salmonella pathogenicity islands, seafood, virulence.

Keywords: biofilm, invasion, non-typhoidal Salmonella, Salmonella pathogenicity islands, seafood, virulence.

How to cite this article: Salam F, Lekshmi M, Prabhakar P, Kumar SH, and Nayak BB (2023) Physiological characteristics and virulence gene composition of selected serovars of seafood-borne Salmonella enterica, Veterinary World, 16(3):431-438.

Received: 28-12-2022 Accepted: 29-01-2023 Published online: 15-03-2023

Corresponding author: Manjusha Lekshmi E-mail: manjusha@cife.edu.in

DOI: 10.14202/vetworld.2023.431-438

Copyright: Salam, et al. This article is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.