Isolation And Identification Of Avian-derived Escherichia Coli And Analysis Of Drug Resistance In Southwest Lu,Shandong

Escherichia coli(E.coli),widely found in nature,is a conditionally pathogenic bacterium that can easily cause serious infections when poultry are in poor sanitation and poor feeding management.With the development of the economy,the human demand for poultry products is increasing,and the environmental pressure of poultry breeding is also increasing,which will cause poultry diseases when the feeding management is poor,causing major losses to the poultry industry.The widespread and inappropriate use of antimicrobials is an important reason for the increasing number of resistant strains of Escherichia coli and the changing mechanism of drug resistance.The emergence of multidrug-resistant Escherichia coli makes veterinary clinical treatment of Escherichiosis coli difficult.Resistance genes,which are the root cause of bacterial resistance,are located on bacterial plasmids or chromosomes and can be transferred horizontally through movable elements,increasing the risk of transmission of resistant bacteria to humans through meat products.Shandong is a major breeding province in China,in order to monitor the overall pollution characteristics and background data of Escherichia coli in poultry farms in many regions of Shandong and investigate the difference between Escherichia coli resistance in large-scale meat duck farms and large-scale broiler farms,isolate and identify the collected strains,detect their virulence gene carrier rate,sensitivity to antibacterial drugs and drug resistance gene carrier rate,analyze the prevalence of Escherichia coli resistance in poultry sources in many regions of Shandong,and explore the relationship between drug resistance phenotype and drug resistance genotype.This paper provides some basic data for the prevention and control of Escherichia coli derived from poultry and the study of the mechanism of drug resistance in Escherichia coli.In this study,a total of 649 duck-source samples and 657 chicken-derived samples were collected from 15 broiler duck and 15 broiler farms in 5 regions of Luxi area.A large number of Escherichia coli were screened through media identification,biochemical identification and PCR identification,and then 11 antimicrobial susceptibility tests were carried out on the isolates,and 17 resistance genes were detected,and finally the prevalence of drug resistance of avianderived Escherichia coli in some parts of Shandong was obtained.In this survey,a total of 253 strains of Escherichia coli duck and 226 strains of Escherichia coli from chickens were isolated from 15 broiler duck and 15 broiler farms in 5 cities in Luxi Prefecture,Shandong Province.The separation rate of different farms varies greatly,and the farms with the highest separation rate are D15 duck farm and C8 chicken farm.From the source of sample separation and collection,the samples with the highest resolution rates were fecal and cloaca samples,respectively.Subsequently,susceptibility tests of 11 antibacterial drugs were carried out on the isolates,and it was found that the resistance rate of Escherichia coli duck to AML reached100%,and the resistance rate of Escherichia coli to TIL,AMP,AML and FLR reached 100%.The highest positive rate of the resistance gene was the aminoglycoside resistance gene ant(3 ? ?)-Ia,and the lowest positive rate was the amide alcohol resistance gene fex A and the macrolide resistance gene erm C.The macrolides had the lowest compliance rate between drug resistance phenotypes and drug resistance genes,and the remaining six classes of drugs had a compliance rate of more than 70%.