Potential Bacterial Zoonotic Pathogens Isolated from a Major Abattoir and its Receiving Surface Water in Abeokuta, Nigeria

The rapid pace and scale of urbanization in Nigeria has led to large volumes of domestic, agricultural and industrial wastes, which pose threats to the environment and public health. Currently, in Nigeria, there seems to be neither sufficient measures nor facilities to treat such wastes to ensure environmental safety or recovery of usable energy and material. This study was conducted to determine the microbial status of the Lafenwa abattoir effluent and its receiving nearby surface water. The various waste disposal methods at the abattoir were also assessed. The Total viable and Coliform counts (TBC and TCC) using surface plating techniques were performed. The mean TBC and TCC for waste water during and after slaughtering were 5.2x10^7, 4.9x1067 and 4.26x10^7, 3.06x10^7 cfu/ml respectively. Meanwhile, the receiving surface water during and after slaughtering had mean TBC and TCC of 4.15x10^7, 3.83x10^7, and 3.89x10^7, 2.87x10^7 cfu/ml respectively. Waste disposal at the abattoir was by open dumping of solid wastes while effluent was discharged into a nearby Ogun River, which is also used by butchers for meat processing. Bacterial organisms isolated from abattoir effluent included Enterobacter aerogenes, Hafnia alvei, Erwinia mallotivora, Edwardsiella ictaluri, Enterobacter amnigenus and Escherichia coli O157strains. Meanwhile, Proteus miriabilis, Staphylococcus spp, Pseudomonas aeruginosa, Enterobacter intermedius, Yersinia aleksiciae, Serratia odorifera, Enterobacter cloacae, Enterobacter aerogens and Eschericia coli O157 were isolated from the surface water. The high microbial load and the isolation of pathogenic organisms of public health importance especially Escherichia coli O157 strains further demonstrates the need for adequate waste disposal and treatment. Also, the current methods of waste disposal at the abattoir greatly reduces the quality of the surrounding environment and portends a risk to public health and food safety.