title: Prevalence and molecular characteristics of Vibrio spp. isolated from preharvest shrimp of the North Western Province of Sri Lanka.
abstract: This study investigated the prevalence and molecular characteristics of Vibrio spp. in farmed shrimp (Penaeus monodon) in Sri Lanka. A total of 170 shrimp samples (100 g of whole shrimp each) taken from individual ponds from 54 farms were collected 1 week prior to harvest  from the North Western Province of Sri Lanka. Overall, 98.1% of the farms and 95.1% of the ponds were positive for Vibrio spp. in shrimp; at the pond level, V. parahaemolyticus (91.2%) was most common, followed by V. alginolyticus (18.8%), V. cholerae non-O1/non-O139  (4.1%), and V. vulnificus (2.4%). Multiple Vibrio spp. were detected in 20.6% of the ponds. None of the V. parahaemolyticus isolates (n = 419) were positive for the virulence-associated tdh (thermostable direct hemolysin) and trh (TDH-related hemolysin)  genes. V. cholerae was confirmed by the presence of ompW, and all isolates (n = 8) were negative for the cholera toxin (ctxA) gene. V. cholerae isolates were serogrouped by PCR and identified as V. cholerae non-O1/non-O139. All four V. vulnificus  strains, isolated from different ponds of two geographical regions, showed pathogenic potential; they belonged to vcgC sequence type, type B 16S rRNA genotype and contained a pilF polymorphism associated with human pathogenicity. The results of this study revealed the ubiquitous  nature of vibrios in farmed shrimp. To minimize the potential risk of Vibrio infections due to handling or consumption of raw or undercooked seafood products, good manufacturing practices as well as proper handling and processing should be addressed.
authors.affiliation: Government Veterinary Office, Walikanda 51070, Polonnaruwa, Sri Lanka.
authors.forename: Madura Sanjeevani Gonsal
authors.initials: MS
authors.lastname: Koralage
authors.forename: Thomas
authors.initials: T
authors.lastname: Alter
authors.forename: Duangporn
authors.initials: D
authors.lastname: Pichpol
authors.forename: Eckhard
authors.initials: E
authors.lastname: Strauch
authors.forename: Karl-Hans
authors.initials: KH
authors.lastname: Zessin
authors.forename: Stephan
authors.initials: S
authors.lastname: Huehn
mesh_terms: D000818:Animals; D015373:Bacterial Typing Techniques; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D004269:DNA, Bacterial / Q000032:analysis; D005398:Fisheries; D005506:Food Contamination / Q000032:analysis*; D005511:Food Handling / Q000379:methods*; D006801:Humans; D033561:Penaeidae / Q000382:microbiology*; D011110:Polymorphism, Genetic; D015995:Prevalence; D018570:Risk Assessment; D012758:Shellfish / Q000382:microbiology*; D013045:Species Specificity; D013188:Sri Lanka / Q000453:epidemiology; D014733:Vibrio / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D014774:Virulence
chemical_list: D004269:DNA, Bacterial