Table 5_The restriction impacts of the Type III restriction-modification system on the transmission dynamics of antimicrobial resistance genes in Campylobacter jejuni.xlsx

IntroductionThe spread of antibiotic resistance genes among Campylobacter jejuni (C. jejuni) is a serious problem, and the effects of the restriction-modification (R-M) system on the transmission dynamics of these genes in C. jejuni remain poorly understood.
Materials and methodsComplete genome sequences of C. jejuni 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 C. jejuni. The impacts of the R-M systems on the AMR genes transmission between C. jejuni strains and the possible mechanisms were explored through recombination, pangenome and mobile genetic elements analysis.
ResultsC. jejuni strains carrying the Type III R-M system have a significantly lower number of antimicrobial resistance (AMR) genes compared to strains without this system (p < 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 (p < 0.0001). We also find that the horizontal gene transfer frequency might have limited relationship with the Type III R-M system in C. jejuni through pangenome and mobile genetic elements analysis.
ConclusionOur research indicates that the Type III R-M system might restrict the transmission of AMR genes potentially by affecting recombination in C. jejuni, which provides a theoretical basis for addressing the drug resistance problem.