Genotypic diversity, antimicrobial resistance and screening of Vibrio cholerae molecular virulence markers in Vibrio alginolyticus strains recovered from a Tunisian Ruditapes decussatus hatchery.
In this study, a total of 54 Vibrio alginolyticus strains were analyzed. The isolates were recovered from different compartments of the Ruditapes decussatus hatchery in the National Institute of Marine Sciences and Technologies, Monastir, Tunisia. All isolates were biochemically identified (API 20E and API ZYM strips), characterized by amplification of the Hsp-40 gene polymerase chain reaction (PCR) and analyzed by enterobacterial repetitive intergenic consensus (ERIC)-based genotyping to evaluate genetic relationship between the isolated strains. We also looked for the presence of ten V cholera virulence genes (toxRS, toxR, toxT toxS, tcpP, tcpA, ace, vpi, zot and ctxA) in the genomes of Vibrio isolates. The antibiotics susceptibility, exoenzymes production and in vitro cytotoxic activitiy against HeLa cell line were also carried out for all tested bacteria. Most of V alginolyticus isolates showed significant antimicrobial resistance rates to at least ten antibacterial agents. For most isolates, the minimum inhibitory concentration (MIC) data showed that tetracydclin and streptomycin were the most effective antibiotics. Construction of the phylogenetic dendogram showed that studied isolates were in general genetically heterogeneous; however some Vibrio strains were present in different structures of the R. decussatus hatchery. The V cholerae virulence genes investigation showed a wild distribution of toxS (49/54), toxaR (45/54) and toxT (22/54) genes among V alginolyticus strains isolated from the R. decussatus rearing system. Cytotoxic effects of several Vibrio extracellular products (28154) were also observed on HeLa cells.
Laboratoire des Maladies Transmissibles et Substances Biologiquement Actives, Université de Monastir, Faculté de Pharmacie, rue Avicenne 5000 Monastir, Tunisie mechri_bader@yahoo.fr
Badreddine
B
Mechri
Laboratoire d'Aquaculture-Institut National des Sciences et Technologies de la Mer, Route de Khniss 5000 Monastir-B.P. 59, Tunisie.
Amel
A
Medhioub
Laboratoire d'Aquaculture-Institut National des Sciences et Technologies de la Mer, Route de Khniss 5000 Monastir-B.P. 59, Tunisie.
Mohamed Nejib
MN
Medhioub
Laboratoire des Maladies Transmissibles et Substances Biologiquement Actives, Université de Monastir, Faculté de Pharmacie, rue Avicenne 5000 Monastir, Tunisie
Mahjoub
M
Aouni
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D049872:Bivalvia / Q000254:growth & development / Q000382:microbiology*; D024881:Drug Resistance, Bacterial; D022761:Gene Transfer, Horizontal; D005819:Genetic Markers; D014644:Genetic Variation; D005838:Genotype; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D012758:Shellfish / Q000382:microbiology*; D014416:Tunisia; D044149:Vibrio alginolyticus / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D014734:Vibrio cholerae / Q000235:genetics*; D037521:Virulence Factors / Q000235:genetics
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D005819:Genetic Markers; D037521:Virulence Factors