Microbiological Assessment and Public Health Risk Potential of Fresh Cow Dung from Selected Locations in Gwagwalada, Abuja, Nigeria

Abstract

Fresh cow dung is widely used as an organic fertilizer because of its high nutrient content and beneficial effects on soil fertility. However, it may also harbour microorganisms of environmental and public health importance. This study investigated the Microbiological Assessment and Public Health Risk Potential of Fresh Cow Dung collected from four locations (Old Kutunku Abattoir, University of Abuja environment, Gwako and Giri) in Gwagwalada, Abuja, Nigeria. Fresh cow dung samples were collected aseptically and analysed using standard microbiological techniques. Serially diluted samples were cultured on Nutrient Agar, MacConkey Agar and Potato Dextrose Agar using the spread plate technique, with the 10⁻³ dilution used for plating. Bacterial isolates were identified based on cultural characteristics, Gram staining and biochemical tests, while fungal isolates were identified using colony morphology and lactophenol cotton blue microscopy. Total viable bacterial counts on Nutrient Agar ranged from 3.50 × 10⁴ to 6.10 × 10⁵ CFU/mL, while total enteric bacterial counts on MacConkey Agar ranged from 4.50 × 10⁴ to 7.00 × 10⁵ CFU/mL. The lowest counts were recorded at Giri, with 3.50 × 10⁴ CFU/mL on Nutrient Agar and 4.50 × 10⁴ CFU/mL on MacConkey Agar, whereas the highest counts were recorded at the University of Abuja environment, with 6.10 × 10⁵ and 7.00 × 10⁵ CFU/mL, respectively. Six bacterial taxa (Staphylococcus aureus, Streptococcus sp., Bacillus sp., Escherichia coli, Proteus mirabilis and Salmonella spp.) and three fungal taxa (Aspergillus sp, Mucor sp. and Rhizopus sp.) were identified. Although bacterial counts varied among locations, the differences were not statistically significant (p > 0.05). The findings demonstrate that fresh cow dung contains diverse microorganisms, including organisms of public health significance. Proper handling and treatment before agricultural application are recommended to minimize environmental contamination and potential health risks.