Advanced Journal of Microbiology Research

Advanced Journal of Microbiology Research ISSN 2736-1756 Vol. 19 (5), pp. 001-010, May, 2025. www.internationalscholarsjournals.org/ © International Scholars Journals

Full Length Research Paper

Survival Strategies of Vibrio parahaemolyticus and Vibrio alginolyticus in Seawater: Impact of Long-Term Starvation on Virulence and Cellular Characteristics

Fethi Ben Abdallah1,2*, Ali Ellafi1, Rihab Lagha1, Héla Kallel2 and Amina Bakhrouf1

1Laboratoire d’Analyse, Traitement et Valorisation des Polluants de l’Environnement et des Produits, Faculté de
Pharmacie Rue Avicenne, Monastir 5000, Tunisie.
2Unité de Fermentation et de Développement de Vaccins Virologiques, Institut Pasteur de Tunis, 13 Place Pasteur, 1002, Tunisie.

Accepted 1 March, 2025

In this study, we incubated Vibrio parahaemolyticus and Vibrio alginolyticus (marine food-borne pathogens bacteria) in seawater for 8 months to study their morphologic, proteomic and genetic responses to starvation. The atomic force micrographs of stressed strains showed a reduction of the cells size and an evolution to two coccoid-shape forms whose length is less than 0.4 m and between 0.5 and 1 m. Extracellular protein patterns and gelatinase profiles of stressed bacteria were also altered. Indeed, these modifications were manifested by the appearance and/or disappearance of bands as well as in the level of expression of certain proteins. In addition, we also searched for the presence of eight Vibrio cholerae virulence genes: toxR, toxS, toxRS, ctxA, zot, ace, toxT, and Virulence Pathogenicity Island (VPI) in the genome of investigated strains. The expression level of VPI gene studied by reverse transcriptase polymerase chain reaction was decreased, whereas the mRNA quantities of toxR, toxS, and ace in starved Vibrio remained stable.

Key words: Vibrio, seawater, alterations, morphology, proteins secreted, virulence gene expression, RT-PCR.