Epidemology And Resistance Analysis Of Avian Pathogenic E.coli In Laizhou Town

Recently years,the viral infection in chickens were controlled with efficient vaccines,however some diseases caused by bacteria,especial E.coli, are more prevalent and have caused numerous losses in chicken industry.Most strains of strains of E.coli are more and more widespread.The spectrum of the resistence becomes wider and wider.Some strains even could resist the new antibiotics which have not been used in animal.Bacteries with drug-resistant plasmid could be transferred from animal to human,so the abuse of large dosage of antibiotics not only makes it difficult to cure the disease,but also makes it latent harm to humankind.In this paper,we report the isolation, purification,indentification and serotype of E.coli in chinkens.The interrelation between drug-resistance and Tetracycline-resistance gene was investigatied.The last experiment was a preventive experiment.The results showed there are the drug- resistant strains of E.coil which caused chicken disease in Laizhou town.In order to investigate and analyze epidemiology of chicken pathogenic E.coli,we collect 60 specimen and separate 48 peccant E.oli from 6different henhouses:Sanyuan,yidao,guojiadian,pinglidian,zhuyou and chengguo henhouse.The studies put emphased on the biology characteristic,drug sensitivity,Tetracycline-resistance gene and protection,so as to find pathogenic characteristics and to set up more reasonable preventive and remedial measures to reduce farmer losses and improve cultivation profit.This study includes three parts:Partâ… :Separation and identification of pathogenica chickens E.coliWe collected 60-bowl specimen from six henhouse in Laizhou town and gain 48 pathogenica E.col.Some of them were identified by culture,staining and biochemical test and pathogenica test.From biochemical test,48 strains were identified as E.coli;The 48 strains were identified from serotype,the prevalent serotypes of E.coli in Lai Zhou town were mainly O₇₈,O₂;The pathogenicity of 48 strains,29 strains were high-virulent,which were 60.42% in the 48 E.coli.Partâ…¡:Inspection of Antibiotic Resistance of pathogenic E.coli from AvianWith 12 kinds of drug sensitivity slips of clinical frequently used antibiotic by routine means to test the drug sensitivity for the isolated 48 strains,we finded that the sensitivity drug of the E.coli isolated from different henhouse was not the same drug,and the sensitivity drug of the E.coli isolated from the same henhouse was not the same drug,too.It perhaps related to the different avian farms use different drugs usually and the serotype was also different.Results showed that isolated strains resist 12 types of drugs.The high sensitive drug of all strains was Cefazolin,Ceftriaxone,Cefoperazone, Amikacin and Rifampicin,and Penicillin,Norfloxacin,Erythromycin, Deoxycyline and Tetracycline were not acting at all.The percentage of the Penicillin,Norfloxacin,Erythromycin,Deoxycyline and Tetracycline in the resistance could reach 72.9%,72.9%,70.8%,64.6%,64.6%.Chickens E.coli was easy to produce antibiotic multi-resistance.The multi-resistance was mainly five-resistance,four-resistance,three-resistance.The percentage of the resistance was 35.4%,29.2%,12.5%,which was all 77.1%in the 48 strains. The drug sensitivity experiments provided scientific experience in producition. It has reference value for prevention E.coli and decrease great loss for henhouse.Partâ…¢:PCR amplification of tetC gene of pathogenic E.coli from AvianThe detection of tetracyclines-resistance of 9 E.coli isolates from Sanyuan henhouse showed the resistance rate was 100%.The tetC gene of 16 E.coli strains was amplified by polymerase chain reaction.7 strains with this gene were located on plasmids compared to the results of the drug-susceptibility tests,the method of PCR showed 77.8%concordance in positive rate.The method of using PCR to detect tetC gene was established, and it could be applied to the molecular epidemiology surveillance of tetracylines-resistance.