The Detection Of Resistance Analysis And Plasmid-mediated ESBLs Gene In Pathogenic Escherichia Coli Isolated From Swines

Escherichia coli are one of the members of the human and animal intestinal normal flora, but some of E.coli is a zoonotic pathogen. The outbreak and epidemic of E.coli disease will bring huge economic losses. There are some common pig epidemic diseases which are caused by pathogenic E.coli including the ED etc. The morbidities and mortalities of these diseases are high in the breed industry of pigs. Antimicrobial drugs are widely and nonstandardly used in the breed industry of pigs frequently, for which it can effectively treat pig diseases caused by E.coli. It leads that drug resistance of bacteria, especially for multiple drug resistance of bacteria is growing day by day. Nowadays the study of resistance in pathogenic bacteria has become the focus of scientific research.The drug resistance of Pathogenic Escherichia coli isolated from Swines to β-lactams drugs has a trend of increasing for the recent years. Therefore this trial will do some studies for two aspects, which is the test of drug resistance of Pathogenic Escherichia coli from Swines which is from Jiangxi province and the prevalence of plasmid-mediated β-lactam resistance genes, these will help us learn more about the development of drug resistance and the mechanism of spread further, and then provide some basis for using drugs intelligently. These tests detected 67 pathogenic E.coli which is isolated from large-scale pig farms and recorded the data of the drug resistance that is developed to the 14 kinds of commonly used antibiotics according to the disk diffusion method recommended by CLSI(2007). The analysis compared the resistance rates and multiple drug resistance which is developed by the pathogenic E.coli to various antimicrobial drugs. The results of the tests: 67 pathogenic E.coli isolated from Swines are expressed as multi-drug resistance. The resistance rates are above 83%, which is developed by multi-drug-resistant strains to ceftriaxone, gentamicin, trimethoprim-sulfamethoxazole, amikacin and streptomycin. The resistance rates are above 50% which is developed to chloramphenicol, florfenicol and amoxicillin / clavulanate. The resistance rates are relatively sensitive which is developed to ceftiofur, enrofloxacin, ciprofloxacin, fosfomycin, doxycycline, and polymyxin B, among them the resistance rates of fosfomycin, doxycycline, and polymyxin B are 2.98%, 0 and 0. The tests use the micro-dilution method to study the minimum inhibitory concentration MIC of 67 pathogenic E.coli isolated from Swines at the same time. The result of proceeded by trace dilution method is consistent with the result proceeded by disk diffusion method. It confirms the phenotype of drug resistance and the resistance rates of 67 pathogenic E. coli isolated from Swines further.The serotypes of 67 pathogenic Escherichia coli strains were indentified in this test. The results showed that 4 strains weren’t confirmed, and others were identified accounting for 94.03% in resistant strains. It contained 19 kinds of serotype, and O4 and O9 were the mainly popular serotype in Jiangxi province.67 pathogenic Escherichia coli strains were inspected in this test. Through the results of PCR, CTX-M, TEM and OXA genes were found, but SHV gene was not detected in the 67 pathogenic Escherichia coli strains. The results show that CTX-M, TEM and OXA were the main popular ESBLs resistance genes in Jiangxi province.The tests obtain 30 joint-Sub-strains successfully, and the successful rate of the joining experiment is 44.78%. The result of drug sensitive tests shows that the tested strains which are separated show the phenomenon of multidrug resistance in the different levels. Joint-Sub-strains also show the phenomenon of multidrug resistance comparing to their parent strains, and it has stronger ability to obtain exogenous resistant genes. Through the results of PCR, it can be observed zygomycete also carry resistance genes, which showed resistance genes can be spread by joint plasmid.The tests analysis the changes of the expression of drug resistance after resistance genes spread in the level of jointing plasmid. Resistance genes can change the drug resistance of strains during the spreading in the level of jointing plasmid. So improving the study and monitoring of jointing plasmid spreading happened in Pathogenic Escherichia coli from Swines is an effective mean which can control the enhancement of drug resistance of Escherichia coli.