Pathogeny Characteristics Analysis And Prevention-treatment Research Of Bamboo Rat Colibacillosis

A bamboo rat farm bought48bamboo rats and37were contracted a disease, the incidence rate was over77percent;9rats were dead and the case fatality rate was24%. The main symptom of the injected bamboo rats was increased abdominal girth. Anatomical observation of infected bamboo rats we could find large amounts of fluid in Chest and abdomen, Mesenteric lymph node enlargement, the intestinal wall thinning and hemorrhagic spot in Intestinal mucosa. The pathological histology observation results showed that injected bamboo rats’intestinum tenue、intestinum crassum showed the worst pathological change, The lung, liver and speen had congestion, hemorrhage in different degrees, then the heart、uterus and ovary did not be obviously effected.and a little seriflux or protein leaching out. The main pathological change was exudative inflammation. Stomach and intestinal tract presented different levels of edema、haemorrhage、fell off of the mucosal epithelial cells, The main pathological change was Serous gastroenteritis.The experiment isolated a gram negative bacteria from the liver and intestinal tracks. We inferred the bacteria was E.coli through the cultural characteristics and biochemical characteristics. Using separate strains of broth cultures inoculated health bamboo rat to proceed the animal regression test, which made the healthy bamboo rats similar pathological changes, Thus we determined the escherichia coli caused the sent bamboo rats’disease. The experiment made clone and sequencing of16S rDNA isolated from the E.coli, and compare homology with some already tested sequences, found it with the highest homology of e.coli,and had97.2%-99.4%homology with E.colis isolated from different animals. Median lethal dose test based on Bliss was undertook on KM mice with the e.coli, the result showed the LD0was1.7×107CFU, LD100was4.3×108CFU, LD50was9.8597×107CFU. We held the drug sensitive test that based on Kirby-Bauer with the E.coli, and the result showed that it was sensitive to some antibiotics, such as ceftriaxone sodium、 kanamycin、amikacin、gentamicin、florfenicol、Ciprofloxacin、ofloxacin、cotrimoxazole etc.We chose kanamycin and florfenicol to treat the infectious bamboo rats and proventer the last ones, which got a effective result. Meanwhile, improvement on living condition, feedstuff’s component and sanitation had good impact on rats, the case rate decrease to4.76%, and the profit of baby rats of each couple increase about127.59RMB.