Epidemiological Investigation Of Rhodococcus Equi And Its Infected Cases Diagnosis And Treatment From Five Equine Farms In Xinjiang

Rhodococcus equi(R.equi)is a Gram-positive facultative intracellular parasite which is distributed worldwide and is an important pathogen causing pneumonia and death in 1-6 month old foals,affecting development of the equine industry.Xinjiang,as the province with the largest number of horses in my country,has little study on R.equi.In order to understand the status of Rhodococcus equi infection in horses in Xinjiang,this study detected the infection/distribution of R.equi in horses and their soil environment in some equine farms in Xinjiang,and conducted drug susceptibility monitoring and virulenceity verification of the isolated strains.Moreover,diagnosis and treatment of infected cases,in order to provide reference for the prevention and treatment of R.equi in Xinjiang.(1)Five equine farms in Xinjiang were selected,247 equine anal/nasal swab samples and 172 equine farm soil samples were collected,and the differential culture and PCR identification of R.equi were carried out.The results showed that the isolation rate of R.equi was 22.0%,and the isolation rate of virulence R.equi was 1.7%.The sensitivity test results of 7 virulence R.equi isolates to 17 chemical drugs and 8 single Chinese herbal medicines showed that the isolates were sensitive to Norfloxacin,Clarithromycin,Polymyxin,Doxycycline,Gentamicin,Cotrimoxazole,Kanamycin,and Ampicillin were all sensitive;the resistance rate to streptomycin,erythromycin,spectinomycin,and rifampicin was 14.2%,and the resistance rate to chloramphenicol was 14.2%.The resistance rate of cefotaxime and cefotaxime was 28.6%,and the resistance rate to amoxicillin was 42.6%.The diameter of inhibition zone of Scutellaria baicalensis and Coptis chinensis reached 16.5 ± 1.6 mm and 11.3 ± 1.5 mm,respectively.(2)Three clinical isolates of virulence R.equi were intraperitoneally injected into mice,which could cause the lung,liver,and spleen,and carrying bacteria,and inflammatory reaction or injury occurred.The mortality rate was 5.6%(1/18)on the second day after infection,and the mortality rate was 50.0%(9/18)on the seventh day after infection.(3)Four cases foals had elevated body temperature,dyspnea,purulent nasal fluid,bronchial and lung auscultation wet rales,increased blood leukocytes,and virulence Rhodococcus equi infection detected.The initial diagnosis was Rhodococcus equi infection.After combined treatment with Rifampicin and Macrolide antibiotics,3 cases of foals were cured,but 1 case of foals was severe at the beginning of treatment,and was dead.Multiple cysts in the lung tissue were autopsied.The above results indicate that the infection rate of virulence R.equi in the investigated equine farms is relatively low,and the commonly used clinical antibiotics have a good therapeutic effect on Rhodococcus equi,but there are certain drug resistance,and Coptis and Scutellariae and other Chinese herbal medicines are expected to be used for the treatment of the disease,and the results of this study provide a reference for the screening,diagnosis and treatment of Rhodococcus equi infection.