الفهرس 
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Abstract
In the present study the prevalence of Arcobacterspp.was determined in 150 egg samples including balady hen’s eggs and farm hen’s eggs (75 samples each as every 5 eggs constitute one sample) and in 90 samples of egg-based products including mayonnaise, cream cake and crème caramel (30 each) that were collected from different localities in Assiut City, Egypt.
Arcobacterwas recovered from 18.7% of balady hens’ egg shells and could be isolated from egg content in a percentage of 13.3% usingArcobacter selective agar (ASA) supplemented with CAT supplement. The identified species were A.butzleriwhich could be isolated only from 5.33% of egg shellsamples and failed to be detected in egg contents, A. skirrowiiwith a percent of 8% from each of egg shell andegg contentsandA. cryaerophiluswhich could be isolated from5.33% of each egg shell andegg contents.
In case of farm hens’ eggs, Arcobacter spp. isolates represented 9.3 and 2.7% from egg shells and contents, respectively. The recovered isolates were A.butzleriwith a percentage of1.33%from egg shell samples and not detected in egg contents,A. cryaerophiluswas detected in both shell and contents in a ratio of 1.33% for each and A. skirrowiiwith percentages of 6.7 and 1.33% from egg shell andcontents, respectively.
Regarding to egg-based products, Arcobacter spp. were existed in in 5 (16.7%) of the examined mayonnaise samples. In addition, A. cryaerophilusand A. skirowii were isolated from the positive samples in incidences of 6.7 and 10%, respectively. While A. butzelri was not detected in the examinedsamples.
The incidence of Arcobacterin the examined cream cake samples was 6.7%.However, A. cryaerophilus wasthe only identified species from positive samples (6.7%).
Moreover, A. skirowiiwas the only identified species ofthe isolated Arcobacterstrains from the examined crème caramel samples with a ratio of 10%.
The identified A. butzleristrains were subjected to confirmation by using PCR and the results were compatible with the biochemical identification.
In the present study,PCR was carried out for screening of some putativevirulence genes in the isolated A. butzleristrains. The obtained data revealed that the detected genes were cadF and pldA in one strain andcadF only in another strain. The geneciaB gene could not be recovered from any tested strain, while, there were 3 isolates did not carry any of the studied virulence genes.
The effect of propolis and chitosan on survival of A.butzleri was evaluated by coating of egg shells with different concentrations of both (4 and 8% propolis; 2 and 4% chitosan) following the shells inoculation with the previously isolated and identified A.butzlericarrying cadF and pldAgenes to yield a concentration of 1×108 cfu/egg shell. The eggs stored in refrigerator at 5±1⁰C. A.butzleri counts were determined at 0, 2, 4, 7, 9, 11, 13 and 15 days. Propolis 8%, chitosan 2% and propolis 4% caused significant (P < 0.05) DROP in A. butzleri count and propolis 8% effect was the highest.
The results indicated high potential of propolis and chitosan as antibacterial and disinfectant agents, suggesting their potential applicationas egg decontamination and disinfection for safe prolonged storage shelf life.
The public health hazards and the recommended measures required to prevent contamination of eggs and its products by Arcobacterwere discussed.