Virulence properties and pathogenicity of Flavobacterium columnare in hybrid red tilapia (Oreochromis sp.)

Authors

Le Dinh Hai
Putita Chockmangmeepisan
Rungnapa Sakulworakan
Ha Thanh Dong
Pattanapon Kayansamruaj
Tiladit Rung-ruangkijkrai
Napadon Pirarat
Channarong Rodkhum

Abstract

Flavobacterium columnare is the causative organism of columnaris disease in freshwater fish, which may exhibit differences in pathogenicity. The virulence properties and the pathogenicity of F. columnare in juvenile hybrid red tilapia were investigated using a collection of F. columnare isolates recovered from diseased fish. Ten isolates were selected to perform immersion challenge assay in juvenile tilapia. The pathogenicity was highly diverse. Subsequently, three bacterial isolates exhibited different pathogenicity levels, consisting of high, moderate and low virulence (100%, 80% and 0% mortality respectively) and were subjected to virulence properties evaluation e.g. the median lethal dose (LD50), bacterial adhesion, capsular production and biofilm formation. Interestingly, the adhesion ability to the gill surface, biofilm formation and the production of capsular polysaccharide are significantly associated with the highly pathogenic traits of F. columnare. These findings suggest that efficient columnaris disease control in farmed fish should target these pivotal virulence properties.

DOI

10.56808/2985-1130.3081

First Page

103

Last Page

108

Recommended Citation

Hai, Le Dinh; Chockmangmeepisan, Putita; Sakulworakan, Rungnapa; Dong, Ha Thanh; Kayansamruaj, Pattanapon; Rung-ruangkijkrai, Tiladit; Pirarat, Napadon; and Rodkhum, Channarong (2020) "Virulence properties and pathogenicity of Flavobacterium columnare in hybrid red tilapia (Oreochromis sp.)," The Thai Journal of Veterinary Medicine: Vol. 50: Iss. 1, Article 13.
DOI: https://doi.org/10.56808/2985-1130.3081
Available at: https://digital.car.chula.ac.th/tjvm/vol50/iss1/13