The Analysis Of Integron Of Escherichia Coli From Chicken Under The Selection Pressure Of Antibiotic

E. coli is the most of bacteria in animal’s or human’s gut, and is a conditions pathogenic bacteria. It is impossible to feeding drugs to a single animal in the process of animal breeding, drug is usually fed all of the group. Intestinal bacteria and pathogenic bacteria bear the same drug selection pressure, so investigating and monitoring of drug resistance of E. coli, can make us understanding the antibacterial drugs pressure of bacteria which is under the antibacterial drugs. Integron is a bacterial gene which can capture and express genetic unit. There are four types of the integration, and the integron I is more common than others. A literature shows that, the drug resistance of bacteria relates to integron. Therefore, it is necessary to making a further research about the relationship of integron and the drug resistance of E.coli. we collect160feces from three different chicken farms in Nanchang Jiangxi province, A series of microbial diagnosis were undertaken, such as Glanz’dyeing identification, polymerase chain reaction (PCR) identification and medicine sensitivity test. To detect its the existence of integron enzyme and the gene cassette, PCR identification of E.coli was undertaken. A research about the relationship of integron and the drug resistance of E.coli is undertaken, and the results are as follows:1. The establishment and application of polymerase chain reaction (PCR) Amplification of E.coli E.coli are separated from chicken feces by using MacConkey Agar, It’s a G" bacteria. According to rsmC genes in16SrRNA genetic encoding area of E.coli, a specific primer was designed by using the design of primers on NCBI software, and then the PCR detection methods was established. The result shows that the purpose strip can be amplified PCR. The specificity, sensitivity and repeatability of the PCR assay were conducted, the results indicated that all negative to the optimal examination method on other bacterias. The result of PCR detection of160strains shows that the positive rate of E.coli strains was91.25%(146/160).2. The establishment and application of polymerase chain reaction (PCR) Amplification of class I and drug resistance analysis of40bacteria According to class I integron enzyme gene (intll) genes of E.coli, a specific primer was designed by using the design of primers on NCBI software, and then the PCR detection methods was established. In addition, according to conservative end and variable area of class I integron by reference, a specific primer was designed. The variable area was amplified by PCR while integral enzyme was negitive. The results show that the purpose strip can be amplified PCR, The specificity, sensitivity and repeatability of the PCR assay were conducted, the results indicated that all negative to the optimal examination method on other bacterias. The positive rate of class I integron146E.coli strains was84.93%(124/146),and The positive rate of class I integron raises while the feeding day was raising. The positive rate of qacE△1-sull146E.coli strains was80.13%(117/146), and The positive rate of qacE△1-sull also raises while the feeding day was raising.The susceptibilities of40E.coli strains to20antibiotics were detected by disk diffusion test,the results show that the multidrug resistance in the strain was serious. All of bacterias are resistant to at least6drugs, and two strains are resistant to19drugs.40strains bacteria are divided into two groups:group A are bacterias without gene casstte; Group B are bacterias with gene casstte. The drug resisitance of Two groups of bacteria to20drugs show that it isn’t significant in statistics.