| Objective: To study the existence of cattle STEC in cow dung,carcass,feed and drinking water in parts of Xinjiang,and to reveal the distribution of STEC in cattle farms and their epidemiological characteristics;Method: 1.From September 2015 to January 2017,cattle anus swabs,fecal samples,carcass swabs,feed and water samples were collected from 9 cattle farms,1 live animal trading market and 1 cattle slaughtering house respectively.After EC broth enrichment,conventional method combined with PCR(16S r RNA)technology was used to isolate and identify E.coli,and then the Stx1 and Stx2 genes were detected by PCR.2.The isolated bovine origin STEC strains were detected by PCR method for "the Big Six" serotype strains.3.The isolated bovine origin STEC strains were detected by PCR method for eae A and Hly genes,K-B test was used for sensitive detection of 17 kinds of veterinary clinical commonly used anti gram negative bacillus drugs;Results:1.A total of 9cattle farms,a live animal trading market and a slaughter house were surveyed.Of 1453 samples,266 were identified as STEC positive.The samples' STEC positive rates of Yili,Bole,Shihezi,Changji,Wujiaqu and Urumqi in Xinjiang were9.9%,19.9%,4%,26.2%,43% and 7.5% respectively;Samples of STEC positive rates in spring(March-May),summer(June-August),autumn(September-November)and winter(December-next year's February)were 27.3%(147/538),0.8%(2/247),13%(49/376)and 6.5%(19/292)respectively,spring is the highest.The positive rate of STEC of cattle anus swabs,carcass swabs,fecal samples,feed and water samples were 19.4%(190/978),8.3%(4/48),6.7%(16/239),1.1%(1/94)and6.4%(6/94)respectively and the anus swab samples was the highest.There are 468 STEC(32.2%,468/1453)strains were isolated from PCR positive samples,among them,132 were Stx1 positive,122 were Stx2 positive,and 214 were both Stx1 and Stx2 positive.2.The detection rates of the strains of O26,O45,O103,O111,O121,O145 and O157 of cattle strain STEC were 2.5%,0%,0%,1.0%,0%,1.0% and 0.75%.3.The carrying rate of the eae A gene in the 7 STEC strains isolated from diarrhea yaks was 14.3%(1/7),and the Hly gene carrier rate was 100%.7 strains of STEC isolated from diarrhea yaks had the highest resistance to madoxin and the resistance rate reached 100%,while cefotaxime,cefalotin,cefoperazone,cefazolin,ceftriaxone,ceftazidime,Cefuroxime,cefepime,cefotaxime,aztreonam,tobramycin,ampicillin,ofloxacin and streptomycin have the highest sensitivity,reaching 100%,followed by kanamycin up to 85.7%;Conclusion:In this study,STEC were isolated from different cattle farms,live animal trading market and cattle slaughter house in some areas of Xinjiang,suggesting that there is a potential threat of STEC in the region,We should strengthen the detection and control of bovine origin STEC,thus ensuring the quality of animal products and the safety of environmental.At present,in some parts of Xinjiang there is a more prevalent non-O157 serotype of the strain,but the detection rate is not high,so is the O157 serotype strain.It is speculated that it has strong potential pathogenicity to humans beacuse all 7 isolates were detected Hly genes.All7 isolates were resistant to antibiotics,but the overall level of drug resistance was not high. |
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