Prevalence of some antibiotic resistant strains of salmonellae in commercial table eggs in Port-Said City

الملخص EN

Multi-drug resistant Salmonella strains have emerged, presumably due to the extensive use of antimicrobial agents both in human and animals.

In veterinary practice, antibiotics are used in livestock production, disease prevention and as growthpromoting feed additives.

In the present study, the occurrence of Salmonella in local chicken eggs and their pattern of antibiotic resistance were determined.

One hundred and forty chicken egg samples - collected from different locations of Port-Said City - were analyzed and Salmonella spp.

detected in 3.6% of the samples.

Among all presumptive Salmonella isolates, the isolates were confirmed as Salmonella Typhimurium (40%), Salmonella agona (20%) and Salmonella derby (40%) on the basis of serotyping and biochemical analysis.

These isolates were subjected to susceptibility test against 9 antimicrobial disks.

All the isolates were sensitive (100%) to doxycycline hydrochloride, chloramphenicol and trimethoprim-sulphamethoxazole.

The highest percentage of resistance (100%) was found to erythromycin.

Resistance against, streptomycin (20%), and penicillin G.

(40%) was also found.

One isolate of the Salmonella Typhimurium serovars (50%) showed resistance for streptomycin, nalidixic acid, oxytetracycline and penicillin G., while the other Salmonella typhimurium isolate (50%) showed high susceptibility for the same 4 antimicrobial drugs.

Nearly similar results were shown for the isolated Salmonella derby, were one isolate (50%) showed high susceptibility for neomycin and oxytetracycline, while it was resistant to penicillin G.

The other Salmonella derby isolate (50%) showed intermediate susceptibility for neomycin and oxytetracycline, while it was highly sensitive for penicillin G.

Salmonella isolated from egg shell surfaces had more antimicrobial resistance than that of the egg contents.

The present study suggested that, poultry eggs are potential reservoir of antibiotic resistant Salmonellae.

The public health hazard of this microorganism, as well as recommended measures to improve quality status of table eggs were discussed.