Microbial assessment of selected earthen fish ponds in western Kenya

Abstract

Water-borne infections are among the most recent emerging and re-emerging infectious diseases throughout the world. WHO estimates that 80% of all illnesses in the world are caused by water-borne disease pathogens that thrive due to inadequate sanitation and polluted water. This study determined the presence of enteric microbes in medium earthen fish farm ponds and waters in the region. Fifty-seven Oreochromis niloticus L. and 36 water samples were collected over three months from 12 ponds within Maseno and Luanda Division. Sixty-six enteric microbes were found – Vibrio hollisae (18.2%), Proteus vulgaris (12.1%), Yersinia spp. (7.6%), Salmonella typhi (7.6), Aeromonas hydrophilia (7.6%), Edwardsiella tarda (6.1%), and Escherichia coli (6.1%) were the most isolated Enterobacteriaceae from water. Fifty enteric microbes were collected from fish intestines; Citrobacter freundi (62%) and Proteus spp. were the most common. Thirty-nine bacteria were isolated from the macerated fish flesh with Citrobacter spp., Proteus spp. and Pseudomonas being the most common. Water temperature, salinity dissolved oxygen and pH were within the expected range. Earthen fish ponds harbor enteric microbes that could be pathogenic to humans, although they had low faecal bacterial indicators signifying minimal contamination from human waste.