Isolation and Molecular Characterization of Streptococcus iniae from African Catfish (Clarias gariepinus) from Selected Markets in Federal Capital Territory, Abuja, Nigeria

Fish plays an important role in the human diet. Streptococcus iniae is an opportunistic zoonotic pathogen and causes serious infections in humans, often through transmission of Streptococcus iniae-contaminated fish. The risk of zoonotic transmission to humans highlights the need to evaluate Streptococcus iniae from African catfish (Clarias gariepinus) in the Federal Capital Territory, Abuja. To achieve these goals, four hundred (400) samples of Clarias gariepinus organs namely liver, kidney, intestine, gills, heart and skin were purchased from selected markets (Wuse, Garki, Kado fish market, Gwagwalada, Zuba, Kubwa and Duste Allah). Detection of Streptococcus iniae was carried out using standard method on tryptic soy agar. Isolates were further identified using conventional biochemical tests: Gram’s staining, catalase, oxidase, hemolytic zone on 5% sheep blood agar, hydrolysis of starch and fermentation of mannitol, ribose, xlylose, sorbitol, glucose, inulin, lactose, arginine, arabinose, inositol, raffinose, rhamnose. Forty-three 43 (10.8%) suspected isolates of Streptococci were subjected to species specific polymerase chain reaction for amplification at 377 bp and all of the isolates turned out negative. It is therefore suggested that more investigative studies become necessary to determine the presence of this pathogen in different fish species in Nigeria.