Abstract: Eggs, a staple food consumed globally, are at risk of contamination, posing a severe threat to their safety and quality. The bacterial load on the eggshell surface is crucial in predicting bacterial penetration and egg interior contamination. Exposure to nesting material and faecal matter can introduce egg-borne pathogens, some of which can lead to food-borne illnesses. The global scale of epidemics caused by egg-borne pathogens underscores the criticality of egg safety.
A comprehensive study was conducted in Punjab, Pakistan, to assess the potential risk of contamination. A total of 360 eggs from various breeds of hens were tested and categorized as unclean, soiled and clean. The bacteria Salmonella, Proteus and Staphylococcus were isolated from the eggs. The highest percentage of isolates were found in unclean eggs: Salmonella (26.7%), Proteus (24.5%) and Staphylococcus (33%). In soiled eggs, the highest percentage of isolates were Salmonella (22.6%), Proteus (17.6%) and Staphylococcus (10.9%). In cleaned eggs, Proteus showed the highest prevalence (15.5%), followed by Salmonella (10.3%) and Staphylococcus (9.4%).
The antibiotic susceptibility test (AST) results showed that all bacterial isolates were sensitive to the drugs Ofloxacin (5 µg/ml) and Cefotaxime (30 µg/ml). However, Staphylococcus and Proteus also showed sensitivity to Trimethoprim + Sulphamethoxazole (2.25/23.75 µg/ml).
The study aimed not only to raise awareness about the importance of egg safety and identify the most common pathogens found on eggshells but also to develop effective strategies to reduce the risk of contamination of eggs and egg products. Once implemented, these strategies will ensure the safety and quality of this essential food source, offering a promising solution to the current challenges.