Abstract

Streptococcosis is one of the serious diseases in cultured salmonids, specially rainbow trout, Oncorhynchus mykiss. Streptococcus iniae is one of the important pathogens for fish which is also dangerous for human. The aim of this study is to investigate the streptococcosis caused by S. iniae in rainbow trouts farms. For this purpose, we evaluate fishes that showed clinical signs similar to streptococcosis from 10 farms in west of Iran on the subject of S. iniae existence. At first, the specific culture for streptococcus was done and, then, polymerase chain reaction (PCR) for detection of S. iniae was used. Out of 50 evaluated specimens, 13 were suspected to S. iniae after biochemical tests. PCR uses specific primers for S. iniae and 6 samples were revealed positive. The results of this study showed the high existence of S. iniae in this region. PCR is an effective technique for the rapid and specific detection of S. iniae in fish tissues.

Key words: Streptococcus iniae, polymerase chain reaction (PCR), Chaharmahal –va- Bakhtyari Province, Iran.