Isolation, Identification, And Drug Resistance Analysis Of Canine Oral And Intestinal Bacteria Resistant To Colistin

With the development of society,many families consider dogs as one of their family members.The close contact between humans and dogs increases the risk of pathogen transmission,such as drug-resistant bacteria.Research has shown that drug-resistant bacteria can spread between dogs and humans,and dogs play an important role in the spread of drug-resistant bacteria in humans.Dogs live closely with their owners and inevitably share many bacterial communities with humans,posing a threat to public health.Microbial communication is mainly carried out through the oral and intestinal microbiota,which are complex and diverse.In order to avoid the development of drug resistance and its spread in the oral and intestinal tract,it is necessary to prevent the transfer,colonization,or resistance of resistant genes,which has become one of the urgent issues to be solved in current veterinary public health.Therefore,this study aims to investigate and analyze the situation of drug-resistant bacteria carried in the oral and intestinal cavities of dogs,as well as related drug resistance.The main research content is as follows:1.Isolation and identification of colistin resistant bacteria from canine oral and intestinal mucosaThis study collected 536 oral and intestinal samples of dogs from September 2020 to December 2021,including samples from 23 dog breeds.A total of 1456 drug-resistant strains were isolated from dog feces.After 16 s r DNA sequencing,the bacteria with the highest isolation rate were Escherichia coli(40.73%),Proteus mirabilis(27.4%)and Klebsiella pneumoniae(17.58%).803 drug-resistant strains were isolated from oral cavity,and the highest isolation rate was Proteus mirabilis(67.37%),Escherichia coli(21.92%),and Klebsiella pneumoniae(10.71%).Under different conditions,such as different health conditions,different ages,etc,the proportion of antibiotic resistant isolates is similar,indicating that the dominant antibiotic resistant microbiota carried in the oral and intestinal tracts of dogs are relatively stable.2.Analysis of drug resistance of coliform bacteria resistant to colistin from dogsIn this study,769 strains of colistin resistant Escherichia coli were isolated and tested for the minimal inhibitory concentration(MIC)of nine typical antibiotics.The results showed that the canine drug-resistant Escherichia coli isolates were highly resistant to ampicillin,ceftriaxone,compound sulfamethoxazole and other drugs,and relatively sensitive to myxin,imipenem,meropenem and other new drugs;And there is a certain correlation between bacterial resistance and sampling location,collection area,and history of antibiotic use in dogs.Strains isolated from dog feces in the eastern region and strains from dogs that have taken antibiotics in the past two months have relatively higher resistance.Only 5.98% of the isolated drug-resistant Escherichia coli strains were sensitive to all drugs,and more than 69.96% of the multi drug resistant strains were resistant to two or more drugs.The multi drug resistance of canine drug-resistant Escherichia coli was serious.3.Whole genome sequencing and drug resistance analysis of Klebsiella pneumoniae with colistin resistancePacBio and Illumina whole genome sequencing platforms were used to perform whole genome sequencing analysis on the screened multidrug-resistant strain F0528NT3.The results showed that the entire genome length of F0528NT3 strain was 5260035 bp,containing three plasmids,carrying 167 antibiotic resistance genes from 13 major categories,18 gene islands,and430 virulence genes.By mapping its resistance genes,it was found that five resistance genes were located on plasmid plas3,including TEM-210,NDM-5,H-NS,qac Edelta1,and BRP(MBL),which can mediate β-drug resistance to lactam and glycopeptide drugs,no drug resistance gene mediating tigecycline and lincomycin was found.This study found that drug-resistant canine Escherichia coli and Klebsiella pneumoniae had high drug resistance,and the use of antibiotics would significantly improve the drug resistance of oral and intestinal bacteria.This study investigates and analyzes the distribution and resistance status of dominant bacterial communities in the oral and intestinal tracts of dogs,as well as the formation and transmission mechanisms of bacterial resistance.It provides a certain reference for the risk assessment of clinical drug use and drug resistance transfer in dogs.