An Experimental Study Of Compound Probiotics With Lactobacillus Acidophilus, Lactobacillus Rhamnosus And Bacillus Subtilis In Animal Models Of Cow Endometritis

Cow endometritis is an inflammation occurring on the superficial endometrium of cow. It is a genital disease after calfing and one of important reasons causing infertility. The main treatments of cow endometritis are systemetic treatment and local anti-infective treatment aiming at the uterus. At present, due to long-term, overdose and unscientific usage, the therapeutic effects of many drugs are not satisfactory and result in dysbacteriosis and drug resistance. In particular, the issue of drug residues in the food chain has attracted wide world attention. Therefore, the dairy industry needs a safe, effective and environmentally drug without residues. The drug could treat cow endometritis and ensures the healthy development of dairy industry.In this study, Lactobacillus were isolated from vaginal secretions of healthy cows and identified by bacterial morphology, cultural characteristics, antibacterial activity in vitro, biochemical tests and PCR analysis. Whether the lactobacilli isolated from vaginal secretions of healthy dairy,Bacillus subtilis, Lactobacillus rhamnosus selected as the strains of probiotics can be used to develop the probiotics to prevent and treat cow endometritis were determined by researching their biological characteristics. Rabbits were used for establishing cow endometritis pathological model to research the effect of prevention and treatment of cows endometritis by filling compound probiotics in uterine.E.coli, Staphylococcus aureus, Streptococcus agalactiae, Bovine Streptococcus faecalis, Streptococcus faecalis, and Staphylococcus epidermidis were isolated from uterine secretions of cow suffering from endometritis. E.coli, Staphylococcus aureus, Streptococcus agalactiae, and Staphylococcus epidermidis are pathogenic by security test. 15 gram-positive, anaerobic, non-spore, acidogenic bacteria were isolated from cow vaginal secretions. A strain named LB-2 was screened by antibacterial activity in vitro and identified as Lactobacillus acidophilus. Lactobacillus acidophilus, Lactobacillus rhamnosus and Bacillus subtilis can inhibit the cow endometritis pathogenic bacteria Escherichia coli, Staphylococcus aureus and Streptococcus agalactiae and adhere to cow endometrial epithelial cells. However, antibacterial activity and adhesion of Bacillus subtilis are less than those of the other two bateria. The best culture conditions of Lactobacillus acidophilus include temperature 39℃, initial pH6.6, inoculum amount 3%, medium volume 300mL, static and anaerobic culture. The best culture conditions of Lactobacillus rhamnosus include temperature 39℃, initial pH6.4, inoculum amount 4%, medium volume 300mL, oscillation and anaerobic culture. The best culture conditions of Bacillus subtilis include temperature 37℃, initial pH7.0, inoculum amount 4% , medium volume 50mL, aerobic and oscillation culture. The heat-resistance of Bacillus subtilis is the best, and Lactobacillus acidophilus and Lactobacillus rhamnosus are not as good as that of Bacillus subtilis. The three strains are non-pathogenic and can be symbiotic in the same environment. The best harvest time of the three strains is 18～20 hours after culturing. Clinical changes and determination of the main organ index indicate that the probiotics are safe. The research on compound probiotics for preventing and treating cow endometritis using rabbit as a model shows that the compound probiotics can treat effectively experimental rabbit endometritis, cure rate 75%, improvement rate 100%, and plays a role in prevention of endometritis. At the same time, application of the compound probiotics can stimulate the immune system of rabbit, increase the IgG, IgA, and IgM levels significantly.To sum up, the compound probiotics prepared with Lactobacillus acidophilus, Lactobacillus rhamnosus and Bacillus subtilis can treat and prevent rabbit endometritis caused by common pathogens of cow endometritis. The compound probiotics could increase the antibody level of rabbit significantly. It can be applied to clinical research on preventing and treating cow endometritis.