title: Molecular variations in Vibrio alginolyticus and V. harveyi in shrimp-farming systems upon stress.
abstract: A study was performed to investigate the genomic variations in the shrimp farm isolates of Vibrio alginolyticus and V. harveyi when the isolates were subjected to environmental stress. Samples of shrimps, water and sediment were collected from Southern Indian coastal shrimp farms. Vibrio isolates were biochemically identified and confirmed using 16S rDNA and gyrB gene specific PCR. The bacterial strains were genotyped by PCR fingerprinting using GTG(5) and IS (Insertion Sequence) primers. Seven strains each of V. alginolyticus and V. harveyi were subjected to 10 passages through trypticase soya broth (TSB), which contained different NaCl concentrations (3, 6 and 8%) and trypticase soya agar (TSA). V. alginolyticus was also passaged through TSB with a 12% NaCl concentration. PCR fingerprinting, which was performed on the strains that were passaged through different salt concentrations, confirmed that V. alginolyticus and V. harveyi could affect the genomic variations, depending on the environmental conditions of the culture. The study highlights the complex genotypic variations that occur in Vibrio strains of tropical aquatic environment because of varied environmental conditions, which result in genetic divergence and/or probable convergence. Such genetic divergence and/or convergence can lead to the organismal adaptive variation, which results in their ability to cause a productive infection in aquatic organisms or generation of new strains.
authors.affiliation: Department of Fish Pathology and Health Management, Tamilnadu Fisheries University, Tuticorin, India.
authors.forename: Anix Vivek
authors.initials: AV
authors.lastname: Santhyia
authors.affiliation: Department of Fish Pathology and Health Management, Tamilnadu Fisheries University, Tuticorin, India.
authors.forename: Rosalind George
authors.initials: RG
authors.lastname: Mulloorpeedikayil
authors.affiliation: Department of Fish Pathology and Health Management, Tamilnadu Fisheries University, Tuticorin, India.
authors.forename: Riji John
authors.initials: RJ
authors.lastname: Kollanoor
authors.affiliation: Department of Fish Pathology and Health Management, Tamilnadu Fisheries University, Tuticorin, India.
authors.forename: Prince M J
authors.initials: PM
authors.lastname: Jeyaseelan
mesh_terms: D000818:Animals; D017756:Aquaculture; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D017753:Ecosystem; D033561:Penaeidae / Q000254:growth & development / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D014733:Vibrio / Q000235:genetics* / Q000302:isolation & purification; D044149:Vibrio alginolyticus / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D017931:DNA Primers; D004269:DNA, Bacterial