Isolation And Identification Of A Porcine Escherichia Coli And Analysis Of Drug Resistance

Over the past few years,, a large number of antimicrobial agents were used in intensivepig productio n to combat disease and promote growth. Because antimicrobial agents werelong-term, widespread and irrational used, and of antimicrobial drug selection pressure andother reasons, drug-resistant strains of E. coli were growing, drug resistance spectrumexpanding, and some strains even showed the new antimicrobial agents has not been used inclinical resistance to potency. Therefore, being active in the surveillance of swine E. coli drugresistance and clarify the characteristics of resistance phenotype and genotype, it will help tocontain the development of E. coli resistance to drugs and optimize the reasonable use ofantimicrobial agents. Combination therapy was conducive to the prevention and treatment ofE. coli.Epidemic materials were collected from diseased pig. The bacteria were isolated andpurified. The methods of bacterial culture characteristics test, biochemical test and16s rRNAsequencing were used to identify clinical isolated strain. Kirby-Bauer (K-B) methodrecommended by WHO was used to determine the tolerant drugs of24kides of antimicrobialagents.13pairs of primers were designed according to susceptibility test, respectively, TEM,SHV, CTX-M-1, CTX-M-8, CTX-M-9, OXA-1, OXA-2, CMY-4, OXA-10, of erm, the ant(6)-iv, aac (6’)/aph (2"), of tetM, and the resistant gene of genomes of bacteria wereexpaned. The MIC of gatifloxacin, cefazolin sodium, d amine latter thiazide card that,gentamycin, of fosfomycin and ofloxacin with hydrochloric acid to drug-resistant strains of e.coli from pig was determined used the trace broth dilution method. The joint vitroantibacterial activity of gatifloxacin with the rest of five antibiotics were respectivelymeasured by the method of6×6checkerboard. The results showed that the isolated bacterialwas E. coli from cultural characteristics and biochemical tests.The sequenced result of16s rRNA showed that the homology of isolated bacterial andEscherichia coli E482was99.9%. The drug sensitive test revealed that the isolatedescherichia coli was high resistant(R) to amoxicillin, ampicillin, penicillin, cephalosporins,ceftiofur sodium, neomycin, gentamicin, apramycin, clinafloxacin, ciprofloxacin,enrofloxacin, hydrochloric acid, levofloxacin, doxycycline, oxytetracycline, erythromycin,fosfomycin, fluorobenzene, resistant(R) to piperacillin, Biapenem, Colistin, moderatelysensitive (I) to ceftriaxone, cefotaxime, aztreonam South, and sensitive(S) to meropenem,amikacin. The MIC of gatifloxacin, cefotaxime sodium, amikacin, gentamicin, fosfomycin andhydrochloride levofloxacin to drug-resistant strains of e. coli from pig respectivelywere16ug/ml,64ug/ml,256ug/ml,512ug/ml,512ug/ml,256ug/ml. The FIC of gatifloxacin togentamicin was0.5; The FIC of gatifloxacin to amikacin was0.375; The FIC of gatifloxacinto fosfomycin was0.75.The homology of isolated E. coli with E. coli E482(Escherichia coli E482) was99.9%,and the E. coli was resistant to a variety of drugs. The genome of Escherichia coli existedtetM gene, ant (6)-iv gene, OXA and-a gene, the CTX-M-9gene, TEM genes. The joint drugsusceptibility test showed that there was synergy of gatifloxacin with gentamicin,levofloxacin hydrochloride in vitro. Gatifloxacin with cephalosporins, amikacin, fosfomycinin vitro was additive effect.