Phenotyping, Genotyping and Whole Cell Protein Profiling of Edwardsiella tarda Isolated from Cultured and Natural Habitat Freshwater Fish

A total of 18 isolates of Edwardsiella tarda was successfully isolated from African Catfish (Clarias gariepinus), Red Hybrid Tilapia (Tilapia sp.), Asian Swamp Eel (Monopterus albus) and Snakeskin Gouramy (Trichogaster pectoralis). The percentage similarity of phenotypic, genotypic and proteotypic characteristics of the present isolates was ranged from 80.8 to 100%, 27.9 to 89.4% and 46.3 to 100%, respectively. 3 dendrograms were generated using NTSYSpc version 2.1 software based on phenotypic, genotypic and proteotypic characteristics of the present isolates. Numerical analysis of 59 unit characters of biochemical and physiological of the present isolates was failed to discriminate them as well as RAPD fingerprinting using 3 types of primers namely, (GTG) , M13 Universal and M13 Wild Type Phage. However, it was interesting to note 5 that whole cell protein profiling of present isolates by using one dimensional SDS PAGE was able to discriminate the isolates. Generally, the isolates obtained from cultured African Catfish and Red Hybrid Tilapia were included into one group whereas isolates that isolated from wild caught Asian Swamp Eel and Snakeskin Gouramy were shared in one similar group. Key word: Edwardsiella tarda Phenotypic Genotypic Proteotypic Freshwater fish INTRODUCTION The losses attributed to E. tarda infectious in cultured eel Edwarsiella tarda is well known as a causative agent corresponds to quart of the total losses. Due to that, of edwardsiellosis that can devastate both freshwater and edwardsiellosis has been known as a disease of primary marine fish culture. At present, the information on importance and posed a big problem in eel culture. phenotypic, genotypic and proteotypic characteristics of Although infectivity of E. tarda is not very high but E. tarda from both environmental and clinical, are lacking. the bacterium is thought to survive in eel ponds This may lead our fish farmer misidentified the actual throughtout the rearing period and causes disease when pathogen which attacking their culture fish and misuse the physiological condition of the fish or the quality of the appropriate treatment against edwardsiellosis the water deteriorates. It is difficult to eliminate the outbreak. Subsequently, fish farmer was suffered the loss pathogen from the environment, as there is a variety of due to this fish disease. [1] reported that infected catfish natural reservoirs including worms, retiles and birds. with edwardsiellosis can cause noxious odours whenever Passive transmission by water, equipment, tools and food the fish enter processing plant. Thus the processing may occur. No vertical transmission of the disease is plants had to stop production for disinfection and suspected. E. tarda posseses pilus on the cell surface and deodorization. This may result heavy financial losses due it is likely these are the means by which the bacterium to only the presence of small infected fishes. However, initially attaches to its host and establishes infection. catastrophic losses of catfish culture due to this disease Thus, this study was conducted to reveal phenotypic, have not been recorded. According to [2], E. tarda is genotypic and proteotypic characteristics of E. tarda distributed worldwide and edwardsiellosis is a problem isolated from freshwater fishes. Therefore, the information principally in Africa, America and Asia and is an is useful for bacterial fish disease diagnosis purpose important disease of cultured eels in Japan and Taiwan. especially for our fish farmer. in Japan for the year 1984 are about 815 million yen, which