This study aims to understand the Escherichia coli drug resistance isolated from different parts of Tibet yak in order to provide scientific evidence for controling Escherichia coli.PCR analysis of drug resistance phenotype and drug resistance gene of aminoglycosides,florfenicol and sulfonamides were carried out in 200 strains of yak-derived Escherichia coli from 6 different places in Tibet.The results showed that the resistance rate of aminoglycoside to yak-derived Escherichia coli was 96％ of amikacin,94.59％ of streptomycin,19％ of neomycin,23％ of gentamicin,19％ of kanamycin.The detection rate of rmtB gene was 100％.The drug resistance rate of florfenicol was 25％ with 25％ detection rate of resistance geneflor.The resistance rate of sulfonamides was 32％ with 7％,7％ and 17％ detection rates of sul1,sul2 and sul3 respectively genes,Moreover,the result of drug resistance phenotype was consistent with that of drug resistance gene.Meanwhile,the expression of sull gene in different regions of Tibet were different in drug resistance of the bacilli,and those from the population-intensive and flow-sensitive Lhasa,Nyingchi and Xigaze were more resistant to drug resistance,while those from Ali,Shannan and Nagqu were relatively light.The above-mentioned drug-resistant phenotype and drug resistance genes were detected in different cities and regions of Tibet,and there were multiple drug-resistant phenomena.The results showed that there was resistance to Escherichia coli in Tibetan yak,which should be paid attention to,and suggested that the in Tibetan area the antibiotics should be rationally used to reduce the drug resistance.

Toxocara vitulorum has been rarely reported in yaks at high altitudes and remote areas of Sichuan Province of Tibetan Plateau of China. The current study was designed to investigate the prevalence, associated risk factors, and phylogenetic characteristics of T. vitulorum in yak calves on the Qinghai Tibetan plateau. Fecal samples were collected from 891 yak calves and were examined for the presence of T. vitulorum eggs by the McMaster technique. A multivariable logistic regression model was employed to explore variables potentially associated with exposure to T. vitulorum infection. T. vitulorum specimens were collected from the feces of yaks in Hongyuan of Sichuan Province, China. DNA was extracted from ascaris. After PCR amplification, the sequencing of ND1 gene was carried out and phylogenetic analyses was performed by MEGA 6.0 software. The results showed that 64 (20.1%; 95% CI 15.8–24.9%), 75 (17.2; 13.8–21.1), 29 (40.9; 29.3–53.2), and 5 (7.6; 2.5–16.8) yak calves were detected out to excrete T. vitulorum eggs in yak calve feces in Qinghai, Tibet, Sichuan, and Gansu, respectively. The present study revealed that high infection and mortality by T. vitulorum is wildly spread on the Qinghai Tibetan plateau, China by fecal examination. Geographical origin, ages, and fecal consistencies are the risk factors associated with T. vitulorum prevalence by logistic regression analysis. Molecular detection and phylogenetic analysis of ND1 gene of T. vitulorum indicated that T. vitulorum in the yak calves on the Qinghai Tibetan plateau are homologous to preveiously studies reported.
Altitude ; Animals ; Ascaris ; Cattle* ; China* ; DNA ; Eggs ; Feces ; Logistic Models ; Mortality ; Ovum ; Polymerase Chain Reaction ; Prevalence* ; Risk Factors* ; Tibet ; Toxocara*