| Escherichia coli-induced diarrhea of piglet is a common clinical disease mainly caused,which seriously jeopardizes the health of piglets and is harmful to the development of swine industry.Currently,methods for treating Escherichia coli-induced diarrhea of piglet mainly depend on antibiotics.However,heavy problems about drug resistance and antibiotic-residue which due to abuse of antibiotics have appeared,therefore it is very important to develop a novel pharmaceutical preparation for diarrhea in piglets.Traditional Chinese medicine has a long history in China,with many advantages such as no drug resistance,small toxic and side effects,and natural ingredients.Recent years,the widely research and application prospects on probiotics have provided new ideas for developing novel-oral Chinese medicine preparations which combined probiotics with traditional Chinese medicine.Probiotics can ferment traditional Chinese medicine,which is more beneficial for a human body to absorb and enhance the curative effect.On the other hand,traditional Chinese medicine can provide nutrients for probiotics.Fermentation of traditional Chinese medicine with probiotics is being a hot research spot and it proves a novel idea,a novel way and a novel direction in Chinese medicine development.In order to explore the therapeutic effect of microbial fermentation herb-products on the prevention and treatment of Escherichia coli-induced Diarrhea,the growth and fermentation conditions of Lactobacillus reuteri ATCC55730 were optimized.Then13 single Chinese herbs and 8 compound Chinese medicines were used in this experiment.After determing the minimum inhibitory concentration(MIC)and antibacterial test in vitro,the dark plum was showed to have the most obvious inhibitory effect against ETEC.Finally,antibacterial test and animal experiments for fermentation products which co-fermenting dark plum with Lactobacillus reuteri ATCC55730 were conducted in vitro.For the subsequent animal experiment,the piglets model of diarrhea challenged with ETEC.Fifteen healthy piglets were randomly divided into three groups,each piglet was orally administrated with 5 mL of6×10~9CFU/mL E.coli every day until all of piglets appeared diarrhea.This was considered as a successful establishment of a piglet diarrhea model.The three groups were respectively orally administrated the 0.3 mL/kg of dark plum water extract,0.3mL/kg of the dark plum fermentation broth and PBS everyday for consecutives four days.After treatment with different drug,body weight,feed intake and other indicators were measured every two days.Colonization level of Escherichia coli in intestinal tract was detected on day 0,7 and 14 by collecting feces from piglets.Routine blood test,blood biochemistry,immune indexes and serum antioxidant capacity were measured on day 7 and 14.After 14 days,all piglets were sacrificed,the immune organs were collected to be weighed and the small intestine was taken for pathological section analysis.The results were as follows:(1)The optimum growth conditions of Lactobacillus reuteri ATCC55730 were as follows:2%bacteria of Lactobacillus reuteri were inoculated in 100mL MRS medium.The time,temperature,speed and time of inoculation were 42℃,180r/min,12 hours respectively.For determination of minimum inhibitory concentration of 13traditional Chinese medicines and 8 pairs of compound Chinese Medicine,the results showed that dark plum,dandelion,tokyo violet herb and coptidis decoction for detoxification had similar antimicrobial effects.The diameter of the inhibition zone was as followed:2.220±0.036cm,1.300±0.072cm,1.200±0.027cm,1.500±0.065cm.According to these data,dark plum had the most obvious antimicrobial effect.(2)Optimization of fermentation condition of dark plum and Lactobacillus reuteri ATCC55730,the optimal fermentation condition was as followed:100 mL culture liquid,initial value of pH modulation,2%bacteria inoculation,and the temperature,speed,time were 42℃,180r/min,12h respectively.Simulated fermentation experiment of Lactobacillus reuteri ATCC55730 and dark plum were carried out.The result of antimicrobial test showed that the inhibition zone was 2.520±0.023 cm.(3)The study on the therapy effect on Escherichia coli-induced diarrhea showed:compared to dark plum water extract group and E.coli group,the average daily gain of piglets in the dark plum fermentation liquid group was the highest and the difference was significant(P<0.05),there was no significant difference in feed weight ratio among the treatment groups.And IgG content in serum was also no significant difference among these four groups.There was a significant difference of IL-2 and IFN-γin serum among the four groups(P<0.05).The content of IL-2 and IFN-γin dark plum fermentation liquid group were the highest and the difference was significant(P<0.01).There was no significant difference of superoxide dismutase(SOD)content in serum in each group.The content of superoxide dismutase(SOD)in liver of each group was significantly different(P<0.01).The result for dark plum fermentation liquid group was significantly higher than other groups.The content of CD3~+CD4~+T and CD3~+CD8~+T in dark plum fermentation liquid group were the highest and the difference was significant(P<0.05).In group dark plum fermentation liquid group and dark plum water extract group,the level for intestinal pathological change was lower than E.coli group;the copy number of K88 gene in group dark plum fermentation liquid group was the lowest and its difference was significant(P<0.01).The fermenting broth of dark plum could significantly reduce the colonization level of Escherichia coli K88 strain in the intestinal tract of piglets.In the study,the results indicate that the best treatment for ETEC Escherichia coli is the dark plum fermentation with Lactobacillus reuteri ATCC55730.Co-fermentation of dark plum and Lactobacillus reuteri significantly improved inhibitory effect on E.coli.The growth performance of piglets were enhanced after oral administration with the co-fermentation solution,which not only improved imm-une response of body,but also provided protection against bacteria challenge.Our experiment build up a good theoretical basis for the prevention and cure of the Escherichia coli-induced diarrhea of piglet,and provides a novel way for the treatment disease. |
PDF Full Text Request