Isolation And Identification And Study On Part Of The Biological Characters Of Vancomycin-Resistant Enterococcus Faecalis From Calve Diarrhea

There are many pathogenic factors causing calf diarrhea that comes very quickly.Calf diarrhea can retard growth and even bring death to the calves,therefore it is one of the most severe diseases threatening the breeding and growth of calves.It is a common case that the animals be more easily infected by dung enterococcus because of low immunity.But in recent years,with the appearance of vancoycin-resistant dung enterococcus faecali,its easy infection and special resistant mechanism have attracted worldwide attention.The veterinary clinical experiment finds as a kind of Leather LanYangShi aureus,dung enterococcus is a normal flora in the intestines of both animals and people.Commonly scattered in nature,dung enterococcus usually do not bring the onset of a disease,but it is a very important conditional pathogenic bacteria.In recent years,the reports on dung enterococcus' s bringing the illness and death of different animals are on the rise.Especially,the emergence of vancoycin-resistant dung enterococcus faecali makes it rather difficult to cure the animals infected by dung enterococcus.Therefore,taking dung enterococcus from intestines of normal calf and diarrheal calve as the object of study,we identify species with the methods of routine microbiological testing and 16 s r RNA molecular biology.We study the characteristics of its physiology and biochemistry,cultivation,molecule,drug-resistance and virulence genes of isolates.The result of study shows as follows:(1)Adopting routine microbiological method and molecular biological method,we separate 23 dung enterococcus from the cotton swab with shit of 48 normal and diarrheal calves.We separate one vancomycin-resistance dung enterococcus from cotton swab gained from anus of calves in a large cattle farm in Shi Hezi,Xin Jiang province.The characteristics of its physiology and biochemistry,cultivation conform to dung enterococcus' s.Through homological comparison of other existed dung enterococcus sequence in NCBI with the corresponding sequence,the result shows the similarity of the one gotten from the large cattle farm in Shi Hezi,Xin Jiang province and the ones,NBRC100480 and ATCC 19433,reaches as high as 100%.(2)According to the K-B which detects the resistant phenotypes of 9 kinds of antibiotics to this bacteria and which is recommended by CLSI,the result shows this bacteria is resistant to eight detected antibiotics(amoxicillin,ciprofloxacin,streptomycin,erythromycin,ammonia,vancomycin,tetracycline,penicilin),especially to vancomycin that is rarely used in veterinary clinical cases.And it is sensitive to macrodantin.(3)Among the PCR testing results of three vancoycin-resistant genes: vanA,vanB,vanC,we only find vanC gene.Through recycling,purifying and sequencing,the result of sequencing is totally similar to the one detected in NCBI.(4)The PCR testing result of five virulent factors(gather material Asa1,Asa373;collagen binding protein adhesion,Ace,hemolysin CylA;endocarditis antigen EfaA)shows that the isolate only carries Ace virulent genes,and the virulent genes only express in early infection of dung enterococcus,which indicates dung enterococcus,the isolate,maybe one of the causes of disease in early infection of calves.The research result reveals that there are cases of animals' being infected by vancoycin-resistant dung enterococcus faecali in this area.Although there is a low separation rate(only 4.3%),we should strengthen the monitoring work of vancoycin-resistant dung enterococcus faecali to prevent the spread of vancoycin-resistant dung enterococcus faecali to human being when eating.