Detection On Tetracycline Resistance Gene And Suppressor Screening Of Escherichia Coli In Swine

Escherichia coli is a common pathogen. Escherichia coli can cause disease ofEscherichia coli. Recent studies show that the resistance of Escherichia coli strains isincreasing. Especially, the emergence of multi-drug resistant strains make that veterinaryclinical Escherichia coli disease treatment is very difficult. The problem of antibioticresistance of Escherichia coli is a hot research at home and abroad. In this paper,10Escherichia coli isolated strains as the object of study. Using of BIOLOG identificationsystem and16S rRNA sequencing technology, the10Escherichia coli isolated strains wereidentified. The resistance phenotypes were determined by K-B. Tetracycline resistancegenes of10Escherichia coli isolated strains were tested by PCR. Using the agar diffusionmethod and trace dilution method, tetracycline and Chinese medicine extracts weremeasured on the inhibitory activity of10Escherichia coli isolated strains. Effect oftetracycline and Chinese medicine extract was measured on Escherichia coli infection inmice through the experiment. The main results are as follows:10isolated strains are allEscherichia coli.10Escherichia coli isolated strains to penicillin G, oxacillin,streptomycin, tetracycline, doxycycline, maddie mycin, nalidixic acid, vancomycin,novobiocin and sulfisoxazole are insensitive.10Escherichia coli isolated strains topiperacillin, cephalexin, cefazolin sodium, cefotaxime, ceftriaxone, ceftazidime,ceftriaxone sodium, cefoperazone, amikacin, kanamycin, neomycin, spectinomycin,florfenicol, furazolidone, nitrofurantoin, single cyclosporin, fosfomycin and meropenemare not the same degree of sensitivity. Multidrug resistance phenomenon is obvious:C023(21resistant), SEC470and SEC911(18resistant), SEC298and SEC817(17resistant),C197(15resistant), SEC206(14resistant), C193(12resistant),SEC616and SEC1284(11resistant). All the Escherichia coli isolated strains carry the tetA gene. Two of theEscherichia coli isolated strains carry the tetB gene. And9of the Escherichia coli isolatedstrains carry the tetC gene. The extracts of Fructus Crataegi, Fructus Forsythiae, FlosLonicerae and Fructus Schisandrae had stronger antibacterial activity, while their mixtureswith tetracycline presented the decreased inhibition zone diameter and increased minimalinhibitory concentration.10Escherichia coli isolated strains formulate mix bacteria liquid.Poison attacking the mice which prevents with Chinese herbal aqueous extracts and theirmixtures with tetracycline of two weeks. The result shows that no symptoms of diarrhea inmice. But after3h the mice begin to die. The mice of poison attacking group andtetracycline group are all dead after24h. Survival rate of traditional Chinese medicinegroup is40%. But the group of Chinese herbal aqueous extracts and their mixtures withtetracycline survival rate is only20%.The study shows that resistance of Escherichia coli. The mechanism of drug-resistantto Escherichia coli was explored. And inhibitors of Escherichia coli were screened. Thepaper provides the experimental basis for the research and development of new drugresistant Escherichia coli.