Title | Shrimp pathogenicity, hemolysis, and the presence of hemolysin and TTSS genes in Vibrio harveyi isolated from Thailand. |
Publication Type | Journal Article |
Year of Publication | 2009 |
Authors | Rattanama P, Srinitiwarawong K, Thompson JR, Pomwised R, Supamattaya K, Vuddhakul V |
Journal | Dis Aquat Organ |
Volume | 86 |
Issue | 2 |
Pagination | 113-22 |
Date Published | 2009 Sep 23 |
ISSN | 0177-5103 |
Keywords | Animals, Bacterial Proteins, Fish Diseases, Fishes, Hemolysis, Lethal Dose 50, Penaeidae, Phylogeny, Random Amplified Polymorphic DNA Technique, Survival Analysis, Thailand, Vibrio, Virulence |
Abstract | The virulence factors of Vibrio harveyi, the causative agent of luminous vibriosis, are not completely understood. We investigated the correlations between shrimp mortality, hemolysis, the presence of a hemolysin gene (vhh), and a gene involved in the type III secretion system (the Vibrio calcium response gene vcrD). V harveyi HY01 was isolated from a shrimp that died from vibriosis, and 36 other V. harveyi isolates were obtained from fish and shellfish in Hat Yai city, Thailand. An ocean isolate of V. harveyi BAA-1116 was also included. Thirteen isolates including V harveyi HYO1 caused shrimp death 12 h after injection. Most V harveyi isolates in this group (designated as Group A) caused hemolysis on prawn blood agar. None of the shrimp died after injection with V harveyi BAA-1116. Molecular analysis of all V harveyi isolates revealed the presence of vcrD in both pathogenic and non-pathogenic strains. Although vhh was detected in all V harveyi isolates, some isolates did not cause hemolysis, indicating that vhh gene expression might be regulated. Analysis of the V harveyi HYO1 genome revealed a V cholerae like-hemolysin gene, hlyA (designated as hhl). Specific primers designed for hhl detected this gene in 3 additional V harveyi isolates but the presence of this gene was not correlated with pathogenicity. Random amplified polymorphic DNA (RAPD) analysis revealed a high degree of genetic diversity in all V harveyi isolates, and there were no correlations among the hhl-positive isolates or the pathogenic strains. |
DOI | 10.3354/dao02119 |
Alternate Journal | Dis. Aquat. Org. |
PubMed ID | 19902840 |