Classification of isolates of Vibrio harveyi virulent to Penaeus monodon larvae by protein profile analysis and M13 DNA fingerprinting

Abstract

A total of 17 Vibrio harveyi isolates were examined for virulence to Penaeus monodon larvae and classified by total soluble protein profiles generated by sodium-dodecyl-sulphate polyacrylamide-gel electrophoresis (SDS-PAGE) under reducing conditions. Two isolates out of 17 proved to be virulent. Most isolates fell within 2 protein groups. Group I was characterised by a 42 kDa protein and contained 8 isolates including both virulent isolates. Group I1 was characterised by a 40 kDa polypeptide and contained 7 isolates. A further 2 isolates could not be assigned to either group. Isolates were further characterised by M13 DNA fingerprinting. V. harveyi isolates were compared to V. parahaemolyticus isolates and found to be substantially more diverse in genotype. This suggested high genetic diversity within V harveyj. The separation of isolates into Groups I and I1 by SDS-PAGE was shown to be genetically based, however the 2 virulent isolates classified within Group I did not demonstrate a high genetic association. Based on the present results, it is suggested that virulent isolates within V. harveyi are rare and that virulence may be explained by genetic transfer of virulence factors.

PCR detection of hemolysin (vhh) gene in Vibrio harveyi

“…Recently, Vibrio harveyi has appeared to be a primary pathogen infecting hatchery-reared fish and shellfish species over a wide geographical area (Pass et al, 1987;Pizzutto and Hirst, 1995;Vandenberghe et al, 1998;Zhang and Austin, 2000). Mortalities in hatchery-reared penaeid shrimps caused by Vibrio harveyi infection has resulted in severe economic losses in producing countries in Asia (Karunasagar et al, 1994;Lavilla-Pitogo et al, 1990;Liu et al, 1996).…”

Virulence Changes to Harveyi Clade Bacteria Infected with Bacteriophage from Vibrio owensii

“…The virulence of V. harveyi to P. monodon larvae has been studied by several authors [7,20,23]. Doses of 10 2 of V. owensii 47666-1 have shown to cause 100 % mortality after 48 h of incubation [7].…”

“…The mixed protein samples were then diluted with equal volume of SDS reducing buffer, mixed, boiled at 100°C for 5 min and used immediately in SDS-PAGE. One-dimensional poly-acrylamide gels of 7.5 cm length, using 0.75 mm spacers, with a 12 % separating gel and 4 % stacking gel were used and run by the method of [20] and [14]. A Bio-Rad Mini PROTEAN 3 Electrophoresis Cells (Bio Rad Laboratories, Regents Park, NSW, Australia) was used to electrophorese the gels with 19 SDS running buffer (pH 8.3).…”

“…It was suggested that virulent isolates within V. harveyi are rare and that virulence is likely to be due to a mobile genetic element such as plasmids or bacteriophages [20]. Virulence factors encoded on bacteriophages may confer a wide range of traits to their hosts including toxin production and immunity to superinfection [18].…”

Vibriosis in Farm Reared White Shrimp, Litopenaeus Vannamei in Andhra Pradesh-Natural Occurrence and Artificial Challenge

“…In this regard, bacterial diseases due to Vibrio species are often associated with low survival rates in hatchery or grow out conditions (Denis Saulnier et al, 2000). Larval mortalities associated with the presence of V. harveyi have been reported in P. monodon and P. vannamei in Indonesia (Sunaryanto and Mariam, 1986), Thailand (Jiravanichpaisal et al, 1994), India (Karunasagar et al, 1994), Philippines , Australia (Pizzutto and Hirst, 1995), Taiwan (Song and Lee, 1993;Liu et al, 1996) and Ecuador (Robertson et al, 1998). Disease outbreaks attributed to other Vibrio species such as V. alginolyticus, V. damsela, V. parahaemolyticus, V. vulnificus and V. penaeicida have been observed in nursery or grow out ponds of P. vannamei, P. monodon, P. japonicus and P. stylirostris in Ecuador (Lightner, 1992) Malaysia (Anderson et al, 1988) Taiwan (Song et al, 1993Lee et al, 1996), Philippines (AlapideTendencia and Dureza, 1997), Japan (de la Pena et al, 1993) and New Caledonia (Costa et al, 1998).…”