Pathogenic Bacterial Flora of Raw Chicken Eggs Sold in Jos, Plateau State, Nigeria

Abstract

Eggs are an important component of the diets of increasing numbers of Nigerians and are used in a number of foods such as salad dressings and home-made creams. Jos, Plateau State, Nigeria is an important source of eggs consumed in Nigeria. However, most eggs in Jos are produced by subsistence poultry farmers with poor regard for hygienic practices. To determine the bacterial load and hence sanitary health quality of eggs sold and consumed, 100 eggs were randomly sampled from egg vendors in twenty locations of Jos North, Jos South and Jos East municipalities. Dilutions of egg shell washes and egg contents were cultured on Nutrient, and subcultured on McConkey agar and Xylose Lysine Desoxycholate (XLD) agar. All egg surfaces (shells) sampled had CFUs ranging between 1.0 x 106 - 1.1 x 108/mL in Jos East, 4.3 x 105 – 6.0 x 107/mL in Jos South and 3.4 x 105 – 1.1 x 108/mL in Jos North respectively. While ANOVA and t-test showed no statistically significant differences (p>0.05) in bacterial counts from within sample locations, Chi Square (χ2) showed association (p<0.05) between bacterial counts and sample locations; Mean counts 1.06 x 109, 1.32 x 108 and 5.11 x 107 per mL respectively in Jos North, Jos East and Jos South. Eggs with bacteria isolated from their contents constituted 8(8.0%), while bacteria isolated included E. coli 65 (65%), Shigella 25 (25%) and Salmonella spp. 4(4%). E. coli was the only bacterium isolated from within 8 (8%) the eggs. While no other bacteria were found in eggs contents, the pathogenic bacteria present on the eggs indicated that eggs could be potential sources of outbreaks of food-borne diseases. Regulations and awareness on sanitary quality of eggs are advocated to help safeguard the health of the egg consuming public from egg-borne food infections.