Public healthazards of some bacterial pathogens associated with consumption of eggs and studying the best cooking method for their vdestruction

الملخص EN

A tota of 450 commercial eggs (Balady 20 farm hens and ducks) representing 150 eggs for each were collected randomly from Assiut city markets, different groceries, supermarkets and farmer's houses.

Every 5 eggs represent one sample.

Shell surfaces, shell surfaces mixed with shell membranes aad egg contents were examined for the isolation of some pathogens of public health importance including Staph, aureus, E.

coli, Salmonella spp..

Listeria spp., Aeromonas spp., Yersinia enterocolitica and Erysipelothrix spp.

An experimental part was applied to evaluate the best method used for cooking of eggs at different temperatures for different times to determine the safety of eggs for consumption.

The obtained results of isolation revealed that Staph, aureus recorded the highest percentage of contamination among all the isolated pathogens specially from shell surfaces of all types of eggs.

Commercial Balady hen eggs were the best type and advised to be consumed.

Staph, aureus recovered from 23.3, 13.3 and 10 % of shell surfaces, shell mixed with shell membranes and egg contents, respectively while, E.

coli, s.

paratyphi, s.

enteritidis, Y.

enterocolitica and Erysipelothrix organisms were failed to he detected in the examined Balady hen egg samples.

Commercial farm hen eggs came seconda to Balady hen eggs.

Staph, aureus isolated from both shell surfaces and egg contents with percentages of 23.3 % and 13.3 % from the shell mixed with shell membranes, s.

enteritidis recorded high rate of isolation from egg parts 16, 10 and coli, some of Aeromonas spp.

and Y.

enterocolitica could be isolated from some egg parts examined, s.

paratyphi, s.

gallinarium, Listeria spp.

and Erysipelothrix spp.

failed to be detected from farm hen egg samples examined.

Highest rate of contamination was observed in commercial duck eggs.

Staph, aureus was recoverd from shell surfaces, shell mixed with shell membranes and egg contents in 36.7, 30 and 33.3 %, respectively.

E.

coli also recorded in high percentages of infection shell and shell mixed with shell membranes (13.3 and 10 %, respectively).

Moreover, varying rcentages of contamination by Salmonella, Listeria and Aeromonas spp.

were recorded in different parts of duck egg samples examined, in addition to Y.

enterocolitica which could be isolated from shell, shell mixed with shell membranes and egg contents in 10, 3.3 and 6.7 %, respectively.

On the other hand, Erysipelothrix S.

failed to be detected in all examined duck egg samples.

Concerning the experimental part, results showed that cooking of eggs by Omelet method at l63°c for 25 minutes is the best since none of the test organisms used could be detected.

Secondary, was the open method where s.

enteritidis destroyed after 1 minute, and complete destruction of Staph, aureus and E.

coli after 12 minutes.

Boiling procedure for 7 and 12 minutes were adequate to destroy aureus and S.

enteritidis, respectively, while, E.

coli still be alive.

The economic and public health importance of some pathogens that affect the human health through consumption of eggs were discussed.

Likewise, suggestive measures for improving the quality of produced eggs and the suitable procedure to cook eggs are given.