Genome Evolution And Transmission Of IncA And IncC Multidrug-resistant Plasmids

IncA and IncC plasmids are important mobile genetic elements(MGEs)of bacteria.They can transfer genes horizontally(HGT)between different species of bacteria by conjugation.Now,the emergence of multidrug-resistant super bacteria has posed a huge threat to human public health.The evolution and diffusion of IncA and IncC plasmids play an important role in the generation and transmission of bacterial resistant phenotypes.As the vector of many drugresistant genes,the evolution and spread of IncA and IncC plasmids are closely related to the spread of drug-resistant phenotypes.Therefore,in order to deal with the potential threat brought by the evolution and spread of the genome of IncA and IncC multi resistant plasmids more effectively,to prevent and control the spread of plasmids more accurately,and to delay the service life of existing antibiotics,we have carried out a systematic study on the evolution and spread of the genome of IncA and IncC plasmids.The typing of IncA and IncC plasmids has always been divergent in the research,and the correct typing is very important for the systematic research of plasmids,so the first part of this paper explores the typing of IncA and IncC plasmids.We collected 279 plasmids,of which 6 were Inca plasmids.By analyzing the replicates of 279 plasmids and the entry rejection genes,we obtained IncA,which is the reason of compatibility and rejection;271 IncC plasmids were divided into four types by using the analysis of the characteristic region fragments of IncC plasmids.We compared and analyzed the resistant islands of reference plasmids and different plasmids.We found a large number of antibiotic resistant genes in the IncC plasmid,which were aggregated into various auxiliary modules in the IncC skeleton.The IncC plasmid contains at least three hot spots integrating the blaCMY carrier region and two antibiotic resistant islands named ARI-A and ARI-B.blaCMY and ARI-A are often found in type 1 plasmids,but not in type 2 plasmids.Both type 1 and type 2 plasmids carry ARI-B,but the frequency is not high.In the second part,we regard the multi resistant plasmid group / family of IncA and IncC as a "species",creatively introduce the research methods of bacterial comparative genomics,phylogeny and molecular evolution,explore the evolution dynamics of IncA and IncC plasmids,reduce their evolution process,and deeply understand the evolution and transmission of IncA and IncC plasmids.We first established a pan genomic model of plasmids,combined with homologous search,we got 44 core genes,and then established a phylogenetic geography model and a global communication network.The results showed that different types of IncA and IncC plasmids had their own evolutionary process and genetic characteristics.Combined with codon bias analysis,positive selection pressure analysis,recombination analysis and amino acid evolution rate analysis of core genes of different types of plasmids,we propose that there is such a "global transmission,regional evolution" mode of transmission and evolution of Inca and IncC multi drug resistant plasmids.In this paper,we collect and obtain all the current IncA and IncC plasmid genomes,make full use of the existing data,and adopt the pan genome model,phylogeny,molecular evolution,phylogenetic geography and other analytical means to build the genetic evolution relationship.The micro evolution events,such as recombination and selection,occurred during the propagation of IncA and IncC plasmids were determined.The origin,evolution and spatiotemporal transmission of IncA and IncC plasmid family were traced.Furthermore,it can reduce the whole evolution process of IncA and IncC genome.In order to prevent and control the spread and spread of bacterial resistance,it is important to clarify the evolution rule and spread mechanism of this type of multidrug resistant plasmid.