The Investigation Of Drug Resistance On E. Coli Compound Antibacterial Agents Screen And Drug Efficacy Study

In this study, 812 isolation were collected, and 737 isolation of themwere identified as E.coil. Pathogenicity test was done, 111 Pathogenic bacteria were conformed from 126 E. coil. Antimicrobial resistance test was done by K-B method, and 15 kinds of antibiotics were selected for the test. Phenotype Results showed that drug resistance rate were as follows: drug resistance rate higher than 80% were TCY(96.2%),AMP(93.3%),DOX(88.6%),ENR(86.7%),AMC(84.8%),STR(80.0%),drug resistance rate between 60%-30% were :TIO (51.4%),OFL(47.6%),GEN(40.0%),NEO(37.1%); drug resistance rate below 30% were: FLR (24.8%) SPT (21%),APR (17.1%),POL (14.3%).On the basis of drug resistance test, union drug susceptibility test was done, and drug A was selected as main drug, other 6 drugs were selected as adjuvant drug. The best proportion of done by orthogonal experiment. The result showed that drug A has no antagonistic phenomenon with the other 6 drugs. we also found that drug A has strong synergism (add) effect with drug C. Drug A and drug C were show the best efficacy when combined with another adjunct drug, and the best proportion of them is 2:1:2. The MIC value of compound preparation to test organism was four-sixteen times lower than single used drug A or drug C.The efficacy of the compound preparation was test by clinical experiment , the result indicated that: when medium-dose of compound preparation (18 mg/kg) was used, the cure rate was 91.7%, significantly higher than the low dose group, drug C control group, the control group of anti-bacterial and infection control group's cure rate(0.01< P<0.05). The pigs' mortality rate was reduced from normal mortality rate (about 30%) to 8.3%, significantly lower than infection control group's.