الفهرس 
REVIEW OF LITERATUREOnly 14 pages are availabe for public view
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Abstract
NTS is a zoonotic bacterium that can be transmitted from cattle to human through milk, dairy products and feces. The current study aimed to investigate NTS in milk, dairy products and feces of healthy and diseased cattle in New Valley and Assiut Governorates. Moreover, this study was carried out to determine the occurrence of NTS among healthy people, patients with diarrhea and human in contact with animals or dairy products. The study aimed also to examine the recovered isolates for its susceptibility against the main antibiotics used for treatment of NTS then detection of virulence genes (invA, stn, hilA and spvC) as well as β-lactamase resistance genes (blaCMY-1 and blaOXA-2) in MDR isolates.
A total of 800 samples (280 from New Valley and 520 from Assiut) including raw milk (80), Kareish cheese (80), Damietta cheese (80), yoghurt (80), ice cream (80), animal fecal swabs (160), human stool (170) and hand swabs (70) were collected from different localities in New valley and Assiut Governorates. Samples were bacteriologically examined and the recovered isolates were serotyped using ”O” and ”H” antisera.
Totally, 87 samples out of the examined 800 samples were NTS positive. In New Valley Governorate, occurrence of NTS was 8.57%, 3.33%, 0.00%, 20,00%, 17.14% and 5.71% of milk, Kareish cheese, Damietta cheese, yoghurt, fecal swabs and stool samples, respectively. The occurrence of NTS in Assiut was 15.56%, 18.00%, 12.50%, 4.44, 8.75%, 15.56%, 11.43% and 8.00% of milk, Kareish cheese, Damietta cheese, yoghurt, ice cream, fecal swabs, hand swabs and stool samples, respectively.
The recovered isolates (87) were serotyped into 13 different serotypes including S. typhymurium and S. enteritidis which were the predominant serotypes with an occurrence rate of 24.14% and 20.69%, respectively, followed by S. tsieve (12.64%), S. infantis (8.05%), S. larochelle (9.20%), S. virchow (5.75%), S. molade (8.05%), S. haifa (3.45%), S. shubra (1.15%), S. alfort (1.15%), S. essen (2.30%), S. apeyeme (1.15%) and S. heidelberg (2.30%).
The recovered NTS isolates showed 100% resistance to clindamycin, followed by streptomycin (98.85), nalidixic acid (90.80%), penicillin G (75.86%), norocillin (64.37%), tetracycline (52.87%), sulphamethoxazol (37.93%), kanamycin (28.74%), ampicillin (22.99%), doxycycline (19.54%), ciprofloxacin (14.94%), gentamicin (8.05%), cephalothin (5.75%) and amikacin (2.30%).
The occurrence of the invA gene was 100%, while 72.22%, 30.56%, and 94.44% of the examined strains were positive for stn, spvC, and hilA genes, respectively. blaOXA-2 was detected in 16.67% (6/ 36) of the tested isolates, while blaCMY-1 was detected in 30.56% (11of 36) of the tested isolates.
Phylogenesis, depending on the invA gene, was performed for two S. typhimurium isolates (one of animal origin and the other of human origin) which revealed a high degree of similarity between the two isolates and other strains in GeneBank.