Isolation, Identification And Drug Susceptibility Of Pathogenic Escherichia Coli Isolated From Calf

Escherichia coliwascommonly known as E. coli, which was a kind of bacteria normally inhabit in intestine of human and animal,underintestinal flora disturbance it can cause fever,blood poisoning, sepsis,pneumonia, enteritis, pericarditis, nephritis, and even shock, death. The relevant reports of calf pneumonia caused by E. coli wererare in domestic and abroad. In order todetermine the reason of calf pneumonia break in one farm in Urumqi toutunhe district of Xinjiang,We made a description of isolated bacteria on the basis of morphological features,physiologeical, biochemical characteristic, molecule biology, to animal infection assay, drug sensitivity test.The results showed that,8 strains separated are all gram-negative brevibacterium.withblunt ends. The morphological characteristics, culture characteristics, biochemical characteristics of isolated bacteria were same with E. coli.Specific gene fragment were amplified by PCR method of the 8 strains separated, all of them can amplified the positive stripes, the result of BLAST of 16 S rDNA are E. coli.After the mice was inoculated with a pure culture of isolates, Mice have all died within 24-48 h, it showed that the inoculant were separated, and with highly pathogenic.Drug sensitivity test of 15 kinds of veterinary drugs of 8 strains separated were taken by kirbybauer method, except azithromycin and ofloxacinallof the 8 strains resistance to the othersdrugs, these Confirm serious drug resistance of this pathogenic bacteria.The results confirmed that, Pathogens separated in this farm and caused Calf Pneumonia were pathogenic E. coli, with serious drug resistance and highly pathogenic. This Provides a theoretical basis for the prevention and treatment of calf pneumonia. Also provided basic data for further study of the disease.