Temperature and ph influence on bacterial pathogens infecting farmed Nile tilapia in aquaculture systems in Bungoma county, Kenya

Abstract

Aquaculture production, therefore, has been expanding in recent years through Governement support via financial and input subsidies in small scale farmers. However, fish farming just like other productive sectors face challenges which include fish diseases that constitute the largest cause of economic loss in aquaculture. The fish bacterial infections are caused by Aeromonas, Edwardsiella, Flavobacterium, Francisella, Photobacterium, Piscirickettsia, Pseudomonas, Tenacibaculum, Vibrio, Yersinia, Lactococcus, Renibacterium, Streptococcus, Nocardia, Staphylococcus, Vagococcus and Weissella species. This study focused on characterizing pathogenic bacteria present in aquaculture systems in Bungoma County. The sampled fish were transferred to a microbiology laboratory in Nairobi where they were subjected to bacterial analysis including microscopy, culture methods and biochemical tests. The study showed that temperature and pH were outside the recommended levels of fish culture production. Further, pathogenic bacteria recovered were Vibrio vulnificus, Vibrio parahaemolyticus, Aeromonas hydrophila, and Pseudomonas aeruginosa from Nile tilapia. Vibrio vulnificus and Vibrio parahaemolyticus were isolated from gills and were found to be significantly different (P