Isolation and Identification of Four Strains of Salmonella and Drug Susceptibility Test

摘要

In order to isolate and identify the pathogenic bacteria causing dead chickens in a chicken farm in Qinhuangdao area, the liver, heart and other organs of dead chickens suspected of salmonella disease were collected aseptically, and streaked on SS agar medium and chromagar medium. Transparent colonies were observed on SS agar medium, and purple and transparent colonies on CAS medium. The isolate was conducted purification, staining microscopy, biochemical tests, and 16 S rRNA sequence analysis, and the results showed that four strains of the isolated bacte-ria were salmonella. The 16 S rRNA sequence analysis of four strains of salmonella showed that the isolates shared more than 99% homology. Drug susceptibility test was performed using paper method, and the results showed that most of the strains were resistant to tilmicosin, cefradine and sul-famethoxazole, but were sensitive to ceftriaxone.