Investigation into the Virulence of Psuedomonas fluorescens associated with the diseased fresh water Cirrhina mrigala

Abstract

In India, fish bacteriology has a slow progress when compared to developed countries. The bacterial diseases reported so far are dropsy or hemorrhagic septicemia, fin rot, ulcer disease, columnaris disease, eye disease of Catla, skin disease of Catfish, stereptococcal infection etc Among the Indian Major Carps are Labeo calbasu, Cyprinus carpio, Cirrhinus mrigala, Catla catla and Labeo rohita. Cyprinus carpio and Cirrhinus mrigala are the second fast growing and are widely consumed throughout India.

Cirrhinus mrigala is susceptible to bacterial diseases in natural as well as cultured system and is infected with Pseudomonas fluorescens. The survey revealed the occurrence in the region of Marathwada in most of the waterbodies surveyed. Two most virulent isolate among the isolated strains were tested for their ability t cause symptoms and subsequent death in the experimental fishes. The preliminary tests indicated that ulcers were associated with Pseudomonas fluorescens PF-02 and PF-14 isolates. The LD50 values were estimated as 0. 971 X 105, and 0.901 X 105 for isolates PF-02 and PF-14, respectively.