Study On Virulence Factors And Drug Resistance Of Escherichia Coli From Different Genetic Lineages In Urine

Background Escherichia coli can be divided into four genetic lineages according to their phylogenetic differences,namely,group A,B1,B2 and D.Studies have shown that bacteria in group A and group B1 of the genetic lineages are related to bacterial infections outside the urinary tract,while bacteria in group D and group A are related to multiple drug resistance.Genotypes of genetic lineages are associated with virulence factors,drug resistance and infection sites,so this grouping is widely used.Bacterial virulence,refers to the ability of bacteria to cause disease,often by a virulence factor or multiple virulence factors,the function of each of the virulence factors produced by the corresponding virulence genes,the virulence genes are usually divided into 6 groups,including adhesion,toxins,theprotection element,iron carrier protein markers and meningitis,pathogenic Island marker.Some studies have found that the drug resistance of Escherichia coli is related to the virulence factors it carries.Therefore,the detection of virulence factors is of great significance for the study of the pathogenic mechanism and drug resistance mechanism of Escherichia coli.In this experiment,Escherichia coli genotypes,drug resistance and 20 virulence factors of urinary tract infection patients were detected to understand the genotype,detection of virulence genes and drug resistance,and to explore the relationship between virulence factors and drug resistance ofEscherichia coli of different genetic lineages in the urinary tract.MethodsCollected in February 2018 to October 2018,the second affiliated hospital of Dalian Medical University clinical diagnosis of acute pyelonephritis,cystitis,urethritis,lower urinary tract infection in patients with urinary tract infection diseases such as urine,160isolated 160 strains of e.coli,adopting multiple polymerase chain reaction(PCR)to detect chuA,YjaA and TspE4C2,genetic lineage classification,detection of 20 strains of virulence factor genes,adhesion of nine types of virulence factor,toxin class 3,protect the element class five,pathogenic island symbol class 1,iron carrier protein class two.The sensitivity of Escherichia coli to commonly used antimicrobial agents was detected by vitek-2 automatic bacterial identification and drug sensitivity analyzer.Results1.The genetic pedigree grouping of 160 Escherichia coli strains was16.3%(26 strains)in group A,30.6%(49 strains)in group B1,0.6%(1 strain)in group B2,and 52.5%(84 strains)in group D.Among the 20 virulence factors,16 virulence factor genes were detected,including 7 adhesion factor virulence factors,1 toxin factor,5 protectors,1 disease-causing island marker and 2 iron carrier protein markers.The virulence factors papA,hlyA(hlyD),rfc and nfaE were not detected.2.Group A compared with group D,the group A virulence factor papGallele?(Internal)detection rate of 8%,D way virulence factor papGallele?(Internal)detection rate of36%,?~2=0.006,p<0.05;Group A virulence factor kpsM?detection rate of 8%,the group D virulence factor kpsM?detection rate of 33%,?~2=0.011,p<0.05;Group A compared with group B1,virulence factor K1 group A detection rate of 4%,virulence factor B1 group K1 detection rate of 22%,?~2=0.048,p<0.05.3.After chi-square test,there was no correlation between 4 groups of genetic pedigree and antimicrobial resistance.4.virulence factor iutA detection rate was 66%,the resistant strains of levofloxacin 112 strains,virulence factor papGallele?(Internal)detection rate was8%,the resistant strains of tobramycin 27 strains,the logistic regression analysisp values were 0.026,0.033,p<0.05.ConclusionThere was no correlation between genetic pedigree grouping and virulence factors.There was no correlation between genetic pedigree grouping and bacterial drug resistance,while the virulence factor was partially correlated with bacterial drug resistance.