A Study On The Disrtibution Of Integrons And Drug Resistance Gene Islands In Proteus Mirabilis

In this study,995 strains of P.mirabilis isolated from the market of fresh meats in Zhongshan meat market and Guangzhou pig farm were studied to test the drug resistance of these strains to 20 antibiotic susceptibility tests,and the positive carrying rates of class I and II integrons and drug resistance gene cassettes,the existence structure and carrying rate of mobile gene island SGI1,explored the relationship between P.mirabilis resistance and integron-gene cassette and gene island.By using the K-B disc diffusion method for bacterial antibiotic resistance susceptibility tests,the producing genus PCR method using the established tuf gene was used to detect the positive carrying rate of class I,class II integrants,drug resistance gene cassettes and gene islands.After sequencing and comparison,the type of genomic island SGI1 was inferred.The experimental results are as follows: 1.Market 569 strains of P.mirabilis were severely resistant to erythromycin(99.47%),florfenicol(89.63%)and trimethoprim(88.05%),and ceftriaxone(70.47%).Enrofloxacin(55.71%)was most sensitive and the lower one was penicillin(53.08%);the P.mirabilis strain isolated from the farm environment was very resistant,specifically,macrolides,chloramphenicol,and β-Amide antibiotics were the most serious.2.The positive carrying rate of class I integron of 995 strains of P.mirabilis was 58.89%,the carrying rate of class II integron was 44.63%,and the number of combined class I and class II integrants was 247,the positive rate was 24.82%.There are 67 drug resistance gene cassettes carried by class I integrons,and 57 drug resistance gene cassettes carried by class II integrons.The drug resistance gene cassettes carried by them were consistent with the drug resistance test results as well.3.The carrying rate of SGI1 was 4.0%.The SGI1 structure of G4 a and pb19 b derived from the market is similar.The drug resistance gene cassette was the same.Three P.mirabilis carried the SGI1 variant SGI1-O and SGI1-Z,but previous scholars have discovered.In summary,995 strains of P.mirabilis showed resistance changes,and one of three antibiotics,cephalosporins,quinolones and aminoglycosides could be used as the first choice for the treatment of P.mirabilis strain infection in Guangzhou pig farm;integrators can be carried the multi-drug resistance gene cassette,the drug-resistant phenotype was basically consistent with the drug resistance gene cassette,and the SGI1 has a low carrying rate and various structures,which was related to the horizontal spread of bacterial resistance.