Molecular Typing And Whole Genome Sequencing Analysis Of Food-Derived And Human-Derived ESBLs-Producing Escherichia Coli

Escherichia coli is a typical Gram-negative bacteria,and it is a common pathogen of foodborne disease,which is easy to produce drug resistance in the treatment process.The resistance of Escherichia coli to antibiotics has attracted attention and research in China and abroad.In this study,the drug resistance,genotypic characteristics,molecular typing and whole genome sequencing of food-derived and human-derived Escherichia coli were monitored to provide scientific theoretical guidance for clinical medication and control of Escherichia coli disease.In this study,we selected 38 strains of E.coli producing ESBLs from 127 strains and tested the susceptibility of 38 strains of E.coli producing ESBLs to 19 different antibiotics and the detection of 7resistance genes.The results showed that: the resistance rate of 38 strains to cefotaxime and cefepime was the highest(94.74%),and among 38 strains of Escherichia coli,17 strains carried the bla TEM resistance gene.In addition to the resistance genes,virulence genes,plasmid replicon genes,and integron genes were also tested,and the results showed that all 37 strains harbored fim H,Omp A,hly E,and crl virulence genes;Sixteen replicon gene carrying FIB plasmid gene;18 strains carried the Int1 integron gene.Secondly,we also performed phylogenetic grouping and multilocus sequence typing on 38 E.coli strains producing ESBLs.The results showed that 16 of the 38 E.coli strains belonged to Group B1,and nine belonged to Group C;The MLST classification showed that the ST types were relatively dispersed,the similarities among the strains were low,and no new ST type was found.Finally,we measured the biofilm formation ability(BF)of 38 ESBLs-producing E.coli strains,conducted drug resistance metastasis,and sequenced the whole genome of strain 7.The results showed that: There are 28 strains with weak film-forming ability or no film-forming ability;10 strains of E.coli were successfully grafted with zygote,the conjugation rate was 27.78%,and the zygote was also the most resistant to cephalosporins.The whole genome sequencing results of Escherichia coli 7 showed that Escherichia coli 7 was a multi-drug resistant strain,and its genome carried a variety of drug resistance genes,virulence genes and mobile genetic elements,which had the potential of drug resistance transfer.In a word,the research shows that the drug resistance of Escherichia coli producing ESBLs is serious,which poses a serious security threat to social public health.Therefore,measures should be taken immediately and its dynamic development trend should be continuously monitored to ensure that the drug resistance of Escherichia coli will not be further expanded.