الفهرس 
INTRODUCTION
Historical BackgroundOnly 14 pages are availabe for public view
 |  | from | 167 |  |  |
| | | from | 167 | | |
Abstract
Salmonella infection remains an important public health problem worldwide, particularly in developing countries.Moreover,Salmonella is the second leading cause of food borne illness in most developed countries. Non Typhoidal Salmonellosis (NTS) are considered one of the most widespread foodborne zoonoses worldwide.Animal salmonellosis has been established as the main source of outbreaks in humans.Human salmonellosis varies from self-limiting gastroenteritis to septicemia. Asymptomatic infections can also be seen.NTSare the most frequent bacterial etiologic agents of infantile diarrhea in Egypt.
The aim of this study was to elucidate the Salmonella occurrence among healthy, clinically infected cattle and buffaloes. Study the role of feedstuff and water troughs in transmission of Salmonella to animals. Determine the occurrence of Salmonella inmarket milk and some milk products. Study the role of dairy handlers as a possible source of Salmonella. Moreover, determine the occurrence of Salmonella in children with acute diarrhea. Finally, phylogenetic analysis of the gyrB gene of the obtained Salmonella strains.
A total of 1040 sampleswere collected randomly including fecal swabs of cattle and buffaloes (500), farm milk (300), feed stuff (60), water troughs (60), market milk (60), yoghurt (30) and kareish cheese (30). In addition 160 humanstoolsampleswere collected randomly from dairy handlers (60) and children with acute diarrhea (100). Fecal swabs and milk of cattle and buffaloes, feedstuff, water troughs and dairy handlers samples were collected from differentgovernmental and private farms in Assiut Governorate. Market milk, yoghurt and kareish cheese sampleswere collected from different street vendors, markets and milk shops in Assiut Governorate. The study also, included 100 stool samples were collected from children suffered from acute diarrheawhowere investigated in Children University Hospital during the period from May 2014 to February 2015.
Data obtained in this study revealed that 26(2.4%) strains recovered from the 1200 examined samples gave positive pattern of Salmonellaby using API 20E. However, when these strains were subjected to serological identification only 19 out of the 26 strains confirmed to be Salmonella. On the other hand by using PCR and sequencing of gyrB gene, only 8 out of the 19 strains were confirmed as Salmonella. It was concluded that molecular methods are more accurate in identification of Salmonella. The overall occurrence of Salmonella spp. was 8(0.7%) of the examined samples. Salmonella spp.were isolated with percentages of (0.6%), (0.33%), (5%) and (1%) from fecal swabs of animals, farm milk, dairy handlers and children stool samples, respectively.Theoccurrence of Salmonella species in cattle was (0.5%), includingfecal matter(0.4%) and milk samples(0.7%). S. Enteritidis was isolated from healthy cattle with a percentage of (0.8%) including 0.7% and 1% from fecal matter and milk, respectively. S. Enteritidis was isolated from both the milk and fecal matter of the same animal. On the other hand, Salmonella wasn’t isolated from both the feces and milk of the examined diarrheic cattle.The occurrence of Salmonella species in buffaloes was 0.5%, S. Typhimurium was recovered from feces with a percentage of 0.8% and Salmonella wasn’tisolated from the milk of diarrheic buffaloes. Salmonella wasn’t isolated from both the feces and milk of the examined healthy buffaloes. S. Typhimurium was isolated from diarrheic buffalo’s fecal matter with a percentage of 2 %. Salmonella was isolated from dairy handlers with a percentage of 5%. S. Typhimurium was isolated from 4% and 14.3% of the dairy handlers in Assiut university farm and Rifa ,respectively.S. Enteritidiswasisolated from 1(3.6%) of the examined dairy handlers inArab elaoamer.None of the examined animal feed stuff, water troughs, market milk, yoghurt and kareish cheese samples were contaminated with Salmonella.S.Typhimuriumwas isolated from children stool with a percentage of 1%. S.Typhimurium was isolated from a child in a rural area with a percentage of 1.2% and in the age group less than 7 monthswith a percentage of 3.3%. The child was fed on mixed diet including (breast milk, animal milk and yoghurt) with a percentage of 2.6%. Salmonella was isolated from a male child with a percentage of 1.7%.
Phylogenetic analysis of gyrB gene of the obtained S. Enteritidis strains divided S. Enteritidis in to two major cluster groups. The first group include S. Enteritidis1 and S. Enteritidis2. The second group include S. Enteritidis3 and two strains obtained from the gene bank. Although S. Enteritidis 1 and S. Enteritidis2 were isolated from the same animal, the genotype was slightly different.Phylogenetic analysis of gyrB gene of the obtained S. Typhimurium strains showed that the genotype of S. Typhimurium doesn’t correspond to the epidemiological origin of the Salmonella strains. S. Typhimurium was scattered independent of the origin. Phylogenetic analysis of gyrB gene of the obtained Salmonellastrains was unable to cluster members of the same serotype in one group.