الفهرس 
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Abstract
A total of 400 samples including raw milk (100), soft cheeses (Damietta and Kareish cheeses), ice cream, butter and yoghurt (60 samples each) were collected from Assiut Governorate and analyzed for the presence of Listeria spp. using FDA-90 method. The Listeria spp. could be detected in 6(6%), 2(3.3%), 1(1.66%) and 3(5%) of the examined milk, Kareish cheese, ice cream and butter samples, respectively.
L. monocytogenes was isolated from 1% of the raw milk samples and 1.66% of both Kareish cheese and butter samples. The serotyping results of L. monocytogenes strains revealed that all the isolates were of serotype 1. L. innocua could be detected in 3% of milk samples and 1.66% from the examined samples of Kareish cheese, ice cream and butter samples L. welshimeri and L. seeligeri were isolated from 1% of raw milk samples while, L. grayi could be detected in 1.66% of butter samples only.
On the otherr hand, Listeria spp. failed detection in the examined Damietta cheese and yoghurt samples.
Comparison between Oxford and PALCAM agars for isolation of Listeria spp. revealed the superiority of Oxford agar, however, the use of one medium was not enough for isolation of listeria spp.