Helminthiasis and Gram Negative Enteric Bacteria in Freshwater Fish from Selected Lakes of Haramaya District, Ethiopia

Abstract

Microbiological and helminthiasis examination of fish from Tinike and Adelle Lakes were conducted at Haramaya District, Ethiopia. The types of fish available in the lakes were also assessed. Adelle Lake has only Clarias gariepinus while the Tinike Lake has only Oreochromis niloticus fish species. Ten fish of each species, 20 in total, were collected from the lakes and post-mortem examined for the presence of adult helminthiasis in the body parts. Twelve samples from different body parts of each fish, 240 samples in total, and 11 samples of lakes water were aseptically collected and examined for gram-negative enteric bacteria. No adult parasites were observed in fish from Adelle Lake. However, 15% and 20% of the fish from Tinike Lake had cestodes in their intestine, and nematodes in their heart respectively. Of 251 total samples from fish and the lake water, 178 (70.9%) were positive for pathogenic microbial. Except for muscle tissue to which only 5% are positive, 50% and above samples were found positive for some Gram’s-negative bacteria. From total of fish and water sample, 43%, 36.3%, 15.1%, 12.8%, and 1.2% are positive for Proteus, E. coli, Salmonella, Yersinia and Klebsiella respectively in the descending order. Two bacterial genera, Proteus and E. coli (13.6%), Proteus and Yersinia (2%), Proteus and Salmonella (4%), E. coli and Yersinia (2%), E. coli and Salmonella (1.2%), and E .coli and Klebsiella (0.4%) while triplet of genera Proteus, E. coli and Yersinia (6%), Proteus, E. coli and Salmonella (0.8%), and Proteus, E. coli and salmonella (0.4%) were observed. Salmonella spp. was not detected from fish from Lake Adelle compared to the 30% in fish from Lake Tinike (P<0.0001). Proper cooking of fish could destroy those spoilage and public health risk. Observing similar levels of gram-negative enteric bacteria in the fish and water suggesting contaminated water as a source for the fish contamination.