The restriction impacts of the Type III restriction-modification system on the transmission dynamics of antimicrobial resistance genes in .

INTRODUCTION

The spread of antibiotic resistance genes among () is a serious problem, and the effects of the restriction-modification (R-M) system on the transmission dynamics of these genes in remain poorly understood.

MATERIALS AND METHODS

Complete genome sequences of strains were extracted from the BV-BRC database until March 25, 2024. The phylogenetic and the resistance analysis were used to analyze the distribution of resistance genes in . The impacts of the R-M systems on the AMR genes transmission between strains and the possible mechanisms were explored through recombination, pangenome and mobile genetic elements analysis.

RESULTS

strains carrying the Type III R-M system have a significantly lower number of antimicrobial resistance (AMR) genes compared to strains without this system ( < 0.0001), with covariance value being -0.0526. The recombination analysis also shows that the median number of the number of AMR genes in the strains not possessing the Type III R-M system increases by 19.38% compared to strains carrying that system ( < 0.0001). We also find that the horizontal gene transfer frequency might have limited relationship with the Type III R-M system in through pangenome and mobile genetic elements analysis.

CONCLUSION

Our research indicates that the Type III R-M system might restrict the transmission of AMR genes potentially by affecting recombination in , which provides a theoretical basis for addressing the drug resistance problem.