Bacteriological and molecular characterization of some pathogens from fast foods

الملخص EN

This study was conducted to evaluate the bacteriological status of some fast food and the public health significance of some isolated pathogenic bacteria from their bacteriological and molecular point of view.

Sixty random samples of chicken nuggets, beef shawerma and sausage sandwiches (20 samples for each) were collected from different fast food restaurants in Dakahlia Governorate and examined for their bacteriological status.

The obtaind results indicated that the mean values of APC count, coliform and Staph.

aureus counts of chicken nuggets, beef shawerma and sausage were 9.1x103±1.2x103 1.3x104±3.5x103 and 1.2x104±2.2x103; < 10, 1.1x103±1.2x102 and 8.5x103±1.1x103, 5.6x103±1.2x103, 8.7x103±1.2x103 and 6.3x103±3.1x103 respectively.

The bacteriological examination of these products showed the presence of one Salmonella isolate (S.

Typhimurium) with a percentage of (5%) and two E.

coli isolates with a percentage of (10%) in 20 meat shawerma samples, meanwhile nuggets and sausage were negative for both Salmonella and E.coli isolation.

Eight coagulase positive Staphylococcus aureus were isolated with a percentage of (10%, 15% and 15%) from chicken nuggets, beef shawerma and sausage, respectively.

PCR was applied to evaluate the presence of some virulence genes in the isolated Salmonella, E.

coli and Staphylococcus aureus.

The isolated S.

Typhimurium harbored invA and stn genes.

The isolated E.coli showed absence of shiga toxin genes (stx1 and stx2).

The examined coagulase positive Staphylococcus aureus showed the presence of different enterotoxin genes (sea, seb, sec, sed and see).

The puplic health significance and the possible sourcs of contamination of isolated organisms as well as some recommendations to improve the quality were discussed.