Studies on some food poisoning bacteria in raw milk sold in Sharkia Governorate

الملخص EN

One hundred raw farm bulk milk samples were collected from Sharkia Governorate.

A survey was conducted to determine the incidence of food poisoning bacteria in raw milk and experiments were carried to determine antibiotic sensitivity of Campylobacter jejuni & Yersinia enterocolitica and proteolytic & lipolytic activities of isolated Pseudomonas spp.

Out of the 100 raw farm bulk milk samples tested 1 (1 %), 1 (1 %) and 2 (2.0 %) were found to contain, Campylobacter jejuni against Karmali, Columbia and modified Preston agar, respectively.

Serotyping of Campylobacter jejuni isolated from the examined raw milk samples resulted in two strains were belonged to Campylobacter jejuni serotype 2 while only one was Campylobacter jejuni serotype 1.

Antibiotic sensitivity revealed that all the tested Campylobacter jejuni isolates were 100 % sensitive to Genitamycin and Chloramphenicol while none were sensitive to Cefoperazone and Ampicillin.

Yersinia enterocolitica and Yersinia krestensenii could be detected in 7 % and 4 % respectively when cultured on bile oxalate sorbose enrichment broth, while using Yersinia enrichment broth (YEB) 7.33 % and 4 % of milk samples were positive for Yersinia enterocolitica and Yersinia krestensenii respectively.

50 % of the examined samples were contaminated with Pseudomonas spp.

The high level of contamination was 0.5 × 108 ; the low level was 2.3 × 102 and the mean value was 1.8 × 104 ± 0.5 × 104.

Also, it is found that out of the examined 100 raw bulk milk samples 2 (2 %) were positive for E.

coli.