The Pathogenicity And Drug Sensitivity Test Of Salmonella Typhimurium To Chickens

Salmonella typhimurium belongs to salmonella B group, a group of nonadaptive salmonella, which has extensive host. It is one of the highest separationrate bacteria in the world. It has important public health implications which can cause all sorts of poultry paratyphoid and human food poisoning. This study aims to explore the Pathogenesis and pharmacological inhibition effect of the Salmonella typhimurium, to compare the effect of Traditional Chinese medicine and western medicine and to screen out the best Chinese medicine for clinical research.Chickens was challenged with the strain of Salmonella typhimurium after it was separated, cultivated and identification. The clinical symptoms, pathological creations, and histopathological examination of the sick chicken were explored. The Antimicrobial susceptibility test was also carryed out to compare the effect of Traditional Chinese medicine and western medicine. We choose the most effective Traditional Chinese medicine to feed the chicken with the dose of three percent and six percent. vaginal swab samples were collected every tow days to count the number of the typhoid salmonella and intestinal bacteria to research the bacteriostatic effect of Traditional Chinese medicine.The Chickens which infected with Salmonella typhimurium showed loss of appetite,increased drinking, chronic diarrhea,dehydration and mental fatigue and other symptoms. Necropsies showed that vaccinated chickens had severe lesions whilst control chickens had mild lesions compatible with Salmonella typhimurium. The chickens which were vaccinated were emaciated, hepatomegalia and cystic swelling. There were duodenal hemorrhage and jejunal hemorrhage in the pathogenetic chickens. The mucous membrane of small intestine showed catarrhal esoenteritis and serous effusion. The conspicuous pathological changes were not found in the chickens'organs such as thoracic gland, bursa of Fabricius,abdominal salivary gland,stomachus glandularis, brain and air bladder. There were not conspicuous pathological changes in the articulus and articular cavity. The results of drug sensitivity tests showed that the high sensitivity drug were Amikacin and Neomycin,the medium was Tobramynic,the low were Cefoperazone,Ceftriaxone, Spectinomycin and Nitrofurantoin. The inhibitory effect of Scutellaria crushed samples of 25 micron particle size is the best. So we use it as a test drug.The total number of intestinal bacteria of the chickens which were fed with scutellaria is increase. Scutellaria can promote the growth of intestinal bacteria of chickens. With the medication time, the total number of intestinal bacteria showed a downward trend. The total number of chicken intestinal bacterial in test group is more than the control group. The total number of intestinal bacteria of the chickens which were fed with Traditional Chinese medicine of six percent was more than the total number of intestinal bacteria of the chickens which were fed with Traditional Chinese medicine of three percent. The results showed that scutellaria can go a long way towards to proliferation of intestinal bacteria. The number of the Intestinal Salmonella typhimurium increased from the 6th day and got to the peak at the 9th day. The number of group 3% dosage were obviously more than group 6% dosage and both of them were obviously more than the control group. On the contrary,The number of group 6% dosage were obviously more than group 3% dosage from the 19th to the 32th day. It showed that the scutellaria were in favor of the proliferation of Salmonella typhimurium. This may because that some normal flora were inhabited leading to the flora disequilibrium so that some of the bacterium had the opportunity to reproduce quickly and result to the increase of the total number of intestinal bacteria. In addition,the scutellaria affect the feed intake that lead to the weight loss of the chicken.In conclusion, salmonella typhimurium can cause significant clinical symptoms and intestinal tract hemorrhage on chickens. The extracts of scutellaria had a good effect on inhibiting salmonella typhimurium in vitro. However, the inhibition of scutellaria crushed samples in vivo was not obvious. There is still a lot of questions which need to be studied to utilize the extracts of scutellaria in the control of Salmonella typhimurium.