| Diarrhea in lambs is a common disease in large-scale farms,and the causes of the disease are complex,in that diarrhea in lambs due to Escherichia coli is common.Improper prevention and treatment measures will cause a large number of lamb deaths,which is more serious to the sheep farms.At present,antibiotics are mainly used to prevent and treat diarrhea lambs in China,but with the abuse of a large number of antibiotics,the sensitivity of strains to various antibiotics is reduced,and the clinical drug resistance is serious.The prevalence of pathogens causing lamb diarrhea is different in different areas of large-scale sheep farms,and the antibiotic resistance is also different.Therefore,before the treatment of diarrhea lambs,the identification of pathogenic bacteria,the selection of sensitive drugs and the formulation of a reasonable treatment plan are of great significance to guide the veterinary clinical treatment of diarrhea lambs.Isolation and identification of E.coli: in this study,75 feces of diarrhea lambs from large-scale sheep farms in southern Xinjiang were collected,and 55 strains of Escherichia coli were isolated through isolation,culture,purification,biochemical detection and 16 S r RNA detection,with the isolation rate of73%.The similarity between the isolates and pathogenic strains MF919606.1(EHEC),MF919608.1(EPEC),MF919609.1(ETEC)and MK920164.1(EHEC)was more than.Ten of E.coli were randomly selected for irp2,eae,fim C,hly F,fyu A virulence gene testing,and it was found that 10 strains except irp2 virulence gene were detected in 10 strains,among which fim C,eae virulence gene is more common;strains vaccinated in mice can lead to the onset of mice.Mice pathogenicity test: screening test mice,the above 10 strains that also had virulence genes were picked out to conduct the E.coli pathogenicity test,and the results showed that mice developed diarrhea and died.Drug sensitivity test of 10 strains.The results showed that: cefazolin,cefuroxime,ceftazidime,minocycline,ofloxacin,tetracycline,ampicillin and sulfamethoxazole were highly sensitive;Diminkana,cefadine,peracicillin,B,cephalosporin moderate sensitivity;The drug resistance of penicillin,erythromycin,Cefradine and gentamicin was low.The formula composed of licorice and mugwort leaves has a bacteriostatic effect on 10 Escherichia coli. |
