Studies On The Relationship Between Class Ⅰ Integron And Multidrug Resistance Of E.coli

Escherichia coli (E.Coli) is one of the most common pathogens in the medicine and veterinary surgeon clinically, which endanger the poultry industry and humans. Antimicrobial agents play a very important role in controlling diseases caused by Escherichia coli. Along with the widely use of antibiotics, antibiotic resistance to bacteria is getting worse. The problem of bacterial resistance is getting worse. There is a significantly increasing tendency of multi-resistance to bacteria.The resistance of Escherichiacoli has raised several concerns related to human health and the development of poultry industry. The mechanism of bacterial resistance integron system base on the distribution and characterization of class I integron among Escherichiacoli isolated from animals. The integron of bacterial is DNA system which carry gene cassette encoding antibiotic resistance, and also is the importance molecular foundation of bacteria to capture and disseminate the resistance gene class I integron one of the most important mechaism of bacterial resistance .Examined for bacterial sensitivity to common antimicrobials and detect the integrase gene by PCR,suitable for mechaism of bacteria and clinical studies.In this paper, the sensitivities of 20 resistant E.coli isolated from pigs to 16 antibiotics were assessed with a controlled disk diffusion test;the distribution and tenency of resistance were studied and the resistance characteristic were analyzed.The presence and genetic content of class I integron were examined with specific primers of class 1 integron by PCR and sequencing..The results of the sensitivity test of 20 resistant-E.coli isolates to 16 kinds antibiotics showed that all isolate presented a multiple antibitic resistance, the resistant ratio of E.coli isolates to phytomycin, cidomycin, actinospectacin, amphemycin, furaxone, cotrimoxazole and SMZ-TMP were 100%, the resistant rate of E.coli to fradiomycin and ciprofloxacin were exceeded 90%, the resistance radio to ampligram and amikacin was relative lower, the resistent style of Escherichiacoli to antibiotics was concentrate in 11-15 kinds .Two primers were designed to amplify the gene of class I integron, the transformants were identified by PCR test , and then sequenced. 13 were positive of for Escherichia coli class I integron dihydrofolate reductase (dhfrXIl) and putative protein genes, complete cds, and streptomycin/spectinomycin 3' adenyltransferase (aadA2) pseudogene .The rates of class I integron in E.coli isolated from pig was about 60%.The result shows that the resistance rates of Escherichiacoli is increasing, there is a significantly increasing tendency of multi-resistance ,the problem of bacterial resistance is getting worse .The presence and genetic content of class I integron were examined with specific primers of class I integron by PCR.