الفهرس Only 14 pages are availabe for public view
 |  | from | 109 |  |  |
| | | from | 109 | | |
Abstract
Milk as well as milk products under the influence of their high nutritive value are considered excellent media for pathogenic as well as non pathogenic bacteria.
A total of 350 random samples of milk and some milk products including raw milk (150), soft cheeses (Damietta and Kareish cheese, 50 samples of each), yoghurt and ice-cream (50 samples of each) were collected from different localities in Assiut City. These samples were examined for the prevalence of P. shigelloides using 2 selective media: Plesiomonas agar (PL agar) and modified Rimler-Shotts medium.
The samples were examined bacteriologically for isolation and identification of P. shigelloides. The results revealed that 4 (2.7%), 1 (2%), 3 (6%), 3 (6%) and 2 (4%) of the examined raw milk, Damietta cheese, Kareish cheese, Yoghurt and Ice-cream samples were contaminated with P. shigelloides using PL agar, respectively.
However, the incidence of P. shigelloides on modified Rimler-Shotts medium was 2 (1.3%), 1 (2%), 2 (4%), 1 (2%) and 2 (4%) in the same samples, respectively.
from the previous results, the presence of P. shigelloides in the examined raw milk and milk products could be attributed to neglected sanitary control during handling, manufacture and distributions.
Comparison between Plesiomonas agar (PL agar) and modified Rimler-Shotts medium revealed the superiority of PL agar.
Growth and survival of P. shigelloides was evaluated in yoghurt which was laboratory prepared, inoculated with the previously isolated and identified P. shigelloides to yield a concentration of 3 x 109 cfu/g. P. shigelloides count and pH value were determined daily, where the count decreased to reach 7 x 103 cfu/g with decrease of pH to reach 3.6 by the end of the 7th day of storage.
It is evident from the results that the reduction in the viability of P. shigelloides may be due to unfavorable pH value of yoghurt and competition of the starter cultures.
The public health significance of the organism and the precautions, which should be taken to control this organism in the dairy industry as well as the recommended sanitary measures, were also discussed.