Casualties arising from Plesiomonas shigelloides in rainbow trout, in Sabzevar

Objective: Regarding to increase in the number of population, consequently the need for producing more energy has increased. Most of this need must be provided by animal proteins specially fish white meat. The fish breeding centers has been developed but the knowledge of breeders has not grown up proportionate to them. This bacteria is gram negative and of vibrionacea family that the first time was reported in rainbow trout in Portugal in 1986. Some casualties were reported in the fish (80-100 grams) in a cold water fish breeding center in Baghan Village in Sabzevar. Method & Materials: Symptoms, such as increasing secretion of mucus in body, anorexia and the darkness of body were observed. Some of the alive fish were autopsied had intense bleeding on their liver, splenomegaly and one third of the ending part of their intestine tissues were observed that they were still bleeding. Some of ill fish were caught and after anaesthetic they were autopsied sterilized. Their kidney and liver tissues were cultured in macconkey and blood agar.After 24 hours, round colonies were formed. After purifying and differential culture and different biochemical exams, colonies were recognized. Anti-biogram test was carried out, as well. Results & Conclusion: Plesiomonas shigelloides was identified in affected fish. In anti-biogram test bacteria was sensitive to chloramphenicol, enero floxasin and resistant to many antibiotics (tetracycline, oxytetracycline, ampicillin, penicillin, gentamicin). It was advised to the breeder to increase the dose of giving oxygen temporary and decrease the 30% of food dose. After 10 days casualties were completely stopped by using chloramphenicol in their diets.

Keywords:

Plesiomonas shigelloides , rainbow trout , anti-biogram test , chloramphenicol