Molecular characterizations of some hazard bacteria isolated from table eggs

الملخص EN

The objective of this study was to determine bacteriological status, incidence and molecular characterization of E.coli, salmonellae and staph.

aureus in both baladi and farm table eggs.

A total of 50 random chicken eggs contents samples (25 for each baladi and farm eggs) were collected from different supermarkets in Kafr-Elsheikh Governorate.

Aerobic plate count showed mean values of 2.48x104± 0.39x104 for baladi eggs and 6.15x103± 1.41x103 for farm eggs, coliform count showed mean value of 9.53x102± 2.16x102 for baladi eggs and 4.99x102± 0.72x102 for farm eggs and staphylococcal count showed mean value of 2.05x103± 0.91x102 for baladi eggs and 5.00x102± 0.30x102 for farm eggs.

Incidence of E.

coli isolated from the examined samples of baladi and farm eggs contents (25 for each) were 4 isolates (16%) and 2 isolates (8 %), respectively.

Serotypes of isolated E.

coli were O1: H7 (1 isolate from farm eggs), O2: H6(1 isolate from baladi eggs), O44: H18 (1 isolate from baladi eggs), O78(2 isolate from baladi eggs and 1 isolate from farm eggs).

Incidence of salmonellae isolated from the examined samples of baladi and farm eggs contents (25 for each) were 5 isolates (20%) from baladi eggs (2 isolates for S.

enteritidis and 1 isolate for S.

typhimurium, S.

kentucky and S.

virchow) and 3 isolates (12%) from farm eggs (2 isolates for S.

enteritidis and 1 isolate for S.

kentucky).

Incidence of staph.aureus isolated from the examined samples of baladi and farm egg contents (25 for each) 2 isolates (8%) were isolated from each type.

Multiplex PCR for identification of tetracycline resistance genes (tetB, tetC and tetD) of E.

coli were (O78 and O1) Positive E.

coli strains for tetB gene, (O78 and O44) Positive e.

coli strains for both tetB and tetD genes, (O78) positive E.

coli strain for tetC gene, (O2) positive E.

coli strain for tetD gene.

Multiplex PCR for identification of B-lactamase resistance genes of Salmonella species were (S.

enteritidis) Positive strains for blaCMY gene, (S.

enteritidis and S.

kentucky) Positive strains for blaCTX gene, (S.

typhimurium) Positive strain for blaCTX and blaCMY genes, (S.

enteritidis) and (S.

virchow) Negative strains for both genes.

Multiplex PCR of enterotoxins genes (sea, seb, sec and sed) for characterization of s.

aureus, 1 isolate positive s.

aureus strain for sea and seb genes, 1 positive isolate s.

aureus strain for sec gene, 1 isolate positive s.

aureus strain for sea gene and 1 isolate negative s.

aureus strain for enterotoxins genes.

Farm eggs were bacteriologically better than baladi eggs.

We recommend that strict hygienic measures to safe guard eggs from being deteriorated should be adopted in the farms and during handling and processing of eggs and not consumed raw.