الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 16 |  |  |
| | | from | 16 | | |
Abstract
This study aimed to investigate the prevalence of Listeria monocytogenes in raw milk and white soft cheese and detect the antimicrobial resistance.L.monocytogenes has been recognized as a cause of disease in humans and animals and has been responsible for listeriosis outbreaks in past years associated with the consumption of milk and dairy products.This study included examination of 200 samples (50 of each market raw milk, individual farm milk and kariesh cheese plus 25 of each Damietta cheese and Talaga cheese). Samples were randomly collected from dairy farms, different shops and supermarkets in Mansoura city, Dakahlia, Egypt.Isolation of Listeria done on Oxford media and compared between direct and indirect (enrichment) methods followed by biochemical identification and for accurate isolation of L.monocytogenes PCR was done. Also antimicrobial susceptibility for L.monocytogenes was done.The prevalence of L.monocytogenes by direct method was 10%, 8%, 8% and 4% in raw market milk, kariesh cheese, Talaga cheese and Damietta cheese, respectively. While enrichment isolation of L.monocytogenes revealed that the prevalence of L.monocytogenes was 8% and 4% in raw market milk and Talaga cheese, respectively.L.ivanovii and L.seeligeri were also detected as 24% and 12% in raw market milk, 24% and 30% in individual farm milk, 16% and 32% in kariesh cheese, 48% and 36% in Talaga cheese and 24% and 36% in Damietta cheese by direct method. While by enrichment method L.ivanovii and L.seeligeri were 14% and 2% in raw market milk, 6% and 14% from individual farm milk, 12% and 12% from Talaga cheese and 12% and 16% in Damietta cheese, but kariesh cheese were free from L.ivanovii and L.seeligeri was 4%.Frequency distribution by direct method showed L.monocytogenes as 18.2%, 11.9%, 4.25% and 5% in raw market milk, kariesh cheese, Talaga cheese and Damietta cheese, respectively. While by enrichment method was 52% and 25% in raw market milk and Talaga cheese, respectively.L.ivanovii and L.seeligeri showed frequency distribution by direct method as 60.6% and 21.2% in raw market milk, 45.2% and 54.76% in farm milk, 35.7% and 52.4% in Kariesh cheese, 59.6% and 36% in Talaga cheese and 40% and 55% in Damietta cheese. While by enrichment method L.ivanovii and L.seeligeri showed 44% and 4% in raw market milk, 27.3% and 72.7% in farm milk, 0% and 100% in Kariesh cheese, 37.5% and 37.5% in Talaga cheese and 15.7% and 84.2% in Damietta cheese.Antimicrobial susceptibility of L.monocytogenes isolates showed that 100% of Listeria monocytogenes isolates were resistance against Oxytetracycline T followed by Penicillin P 96.5%, Neomycin N 93.1%, Nalidixic acid NA 89.7%, Kanamycin K 82.8%, Chloramphenicol C 75.9%, Erythromycin E72.4%, Amoxicillin AMX68.9% Streptomycin S 58.6%, Sulphamethoxazol SXT 55.2%, Ciprofloxacin CP 44.8%, Ampicillin AM 31%, Gentamycin GM 13.8% and Norfloxacin NOR 10.3%.