Molecular characterization and phylogenetic analysis of highly pathogenic Vibrio alginolyticus strains isolated during mortality outbreaks in cultured Ruditapes decussatus juvenile

Mechri, Badreddine; Monastiri, Abir; Medhioub, Amel; Medhioub, Mohamed Néjib; Aouni, Mahjoub

doi:10.1016/j.micpath.2017.09.020

Cited by 21 publications

(12 citation statements)

References 55 publications

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“…Instead of using the Vibrio pathogens reported in other literature (Mechri et al, 2017; Rameshkumar et al, 2017; Lv et al, 2019) as hosts for lytic phage isolation, our study started with the isolation of Vibrio strains from the diseased shrimp within the shrimp-farmed pond. Furthermore, the pathogenicity of the five Vibrio sp.…”

Section: Discussionmentioning

confidence: 99%

Isolation and Characterization of Specific Phages to Prepare a Cocktail Preventing Vibrio sp. Va-F3 Infections in Shrimp (Litopenaeus vannamei)

et al. 2019

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Vibrio is one of the most detrimental agents of shrimp premature death syndrome. Phage therapy for prevention and treatment of Vibrio infections has attracted increasing attentions due to the emergence of antibiotic-resistant bacterial variants. Here, we describe a workflow of preparing a phage cocktail against Vibrio infections for practical applications. Twenty Vibrio strains were isolated from the gut of diseased shrimp and aquaculture wastewater, and five of them were identified as pathogens causing shrimp vibriosis. Twenty-two lytic phages were then isolated using the above five pathogens as hosts, and five of them showed broad host ranges and high lytic capability against the Vibrio strains. Whole genomic sequencing and phylogenetic analysis of the five phages indicated that they are novel and belong to the Siphoviridae family. The phage cocktail consisting of these five phages showed higher efficiency in inhibiting the growth of pathogenic Vibrio sp. Va-F3 than any single phage in vitro. We then evaluated the performance of the phage cocktail in protecting shrimp against Vibrio sp. Va-F3 infections in situ. The results showed that shrimp survival rates could reach 91.4 and 91.6% in 7 days, for the cocktail-treated and the antibiotic-treated groups, respectively. By contrast, the shrimp survival rate of the group without any treatment was only 20.0%. Overall, this study describes a general workflow of how to prepare a phage cocktail and apply it in controlling bacterial infections in the shrimp aquaculture. Knowledge gained from this study will not only help fight against the shrimp vibriosis in practical but also facilitate the design of phage cocktails with a satisfying performance in controlling other animal diseases in aquaculture.

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Section: Discussionmentioning

confidence: 99%

Isolation and Characterization of Specific Phages to Prepare a Cocktail Preventing Vibrio sp. Va-F3 Infections in Shrimp (Litopenaeus vannamei)

et al. 2019

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“…Vibrio alginolyticus , a mildly halophilic Gram‐negative bacillus, is considered a critical opportunistic pathogen in mariculture (Cai, Cheng, Pang, Jian, & Wu, ; Chen, Cai, & Jian, ; Liu et al., ; Nishiki, Minami, Murakami, Hoai, & Fujiwara, ). V. alginolyticus is responsible for many epidemics of maricultured animals, such as coral reefs (Xie et al., ), shellfish (Mechri, Monastiri, Medhioub, Medhioub, & Aouni, ), fish (Cai, Cheng, Pang, Lu, & Jian, ; Zhao et al., ) and crustaceans (Gomez‐Gil et al., ; Jayaprakash, Pai, Philip, & Singh, ), which result in heavy economic losses V. alginolyticus also infects humans in warm periods, potentially causing otitis and wound infections (Campanelli, Sanchez‐Politta, & Saurat, ).…”

Section: Introductionmentioning

confidence: 99%

The role of rpoS in the regulation of Vibrio alginolyticus virulence and the response to diverse stresses

Huang

Guo

et al. 2019

Journal of Fish Diseases

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Vibrio alginolyticus is a leading aquatic pathogen, causing huge losses to aquaculture. rpoS has been proven to play a variety of important roles in stress response and virulence in several bacteria. In our previous study, upon treatment with Cu2+, Pb2+, Hg2+ and low pH, the expression levels of rpoS were downregulated as assessed by RNA‐seq, while impaired adhesion ability was observed, indicating that rpoS might play roles in the regulation of adhesion. In the present study, the RNAi technology was used to knockdown rpoS in V. alginolyticus. In comparison with wild‐type V. alginolyticus, RNAi‐treated bacteria showed significantly impaired abilities of adhesion, growth, haemolytic, biofilm production, movement and virulence. Meanwhile, alterations of temperature, salinity, pH and starvation starkly affected rpoS expression. The present data suggested that rpoS is a critical regulator of virulence in V. alginolyticus; in addition, rpoS regulates bacterial adhesion in response to temperature, pH and nutrient content changes. These are helpful to explore its pathogenic mechanism and provide reference for disease control.

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“…Most molluscs microbiota is involved in antibacterial activity, biofilm formation, protease and siderophore production (Desriac et al ., 2014; Hernández‐Robles et al ., 2016; Leite et al ., 2017). Although siderophore synthesis is poorly studied in mollusc microbiota, previous works suggest that its production should play an important role in Vibrio diseases affecting bivalve molluscs (Gómez‐León et al ., 2005; Mechri et al ., 2017). However, this hypothesis is based on the high frequency of siderophore producing strains found in the microbiota of these animals and not on functional studies.…”

Section: Resultsmentioning

confidence: 99%

The marine bivalve molluscs pathogen Vibrio neptunius produces the siderophore amphibactin, which is widespread in molluscs microbiota

Galvis

Ageitos

Martínez-Matamoros

et al. 2020

Environmental Microbiology

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Amphiphilic siderophores, including amphibactins, are the most abundant siderophores in oceans. Genes putatively encoding the amphibactin system were proposed in some bacteria and homologues of these genes are particularly abundant in multiple bacterial lineages inhabitant of low-iron seawater. However, since no defective mutant strains in any of these genes were studied to date, their role in amphibactin synthesis or uptake was not demonstrated. In this work, an in silico analysis of the genome of the mollusc pathogen Vibrio neptunius leads us to identify a gene cluster (denoted absABDEF) that is predicted to encode an amphibactin-like siderophore and several mutant strains unable to synthesize or use siderophores were constructed. The results showed that genes absABDEF are required for amphibactin synthesis. A comparative chemical analysis of V. neptunius wild type and biosynthesis mutants allowed us to identify a mixture of nine amphibactin forms produced by this bacterium. In addition, the gene abtA is predicted to encode the ferri-amphibactin outer membrane transporter. The prevalence of the amphibactin system in bivalve hemolymph microbiota was also studied. We found that the amphibactin system is widespread in hemolymph microbiota including both commensal and pathogenic bacterial species. Thus, its contribution to bacterial fitness must be more related to environmental persistence than to pathogenicity.

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Molecular characterization and phylogenetic analysis of highly pathogenic Vibrio alginolyticus strains isolated during mortality outbreaks in cultured Ruditapes decussatus juvenile

Cited by 21 publications

References 55 publications

Isolation and Characterization of Specific Phages to Prepare a Cocktail Preventing Vibrio sp. Va-F3 Infections in Shrimp (Litopenaeus vannamei)

Isolation and Characterization of Specific Phages to Prepare a Cocktail Preventing Vibrio sp. Va-F3 Infections in Shrimp (Litopenaeus vannamei)

The role of rpoS in the regulation of Vibrio alginolyticus virulence and the response to diverse stresses

The marine bivalve molluscs pathogen Vibrio neptunius produces the siderophore amphibactin, which is widespread in molluscs microbiota

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