Study on the effect of allicin in reversing the resistance of NDM-1-type carbapenem-resistant Klebsiella pneumoniae to meropenem

Ruan Haitao; Gao Fanglin; Zhan Wenfang

doi:10.3760/j.issn.1673-4777.2026.02.021

Abstract：Objective To investigate the effect of allicin on reversing the resistance of NDM-1-type carbapenem-resistant Klebsiella pneumoniae(CRKP)to meropenem.Methods Five CRKP strains isolated from clinical specimens of People's Hospital Affiliated to Fujian University of Traditional Chinese Medicine were selected,including 4 blaNDM-1-carrying CRKP strains(CRKP1-CRKP4)and 1 blaNDM-1-non-carrying CRKP strain(CRKP5,negative control).The checkerboard microdilution method was used to screen traditional Chinese medicine monomers(shikonin,myricetin,baicalin,luteolin,allicin)that could reverse the resistance of NDM-1-type CRKP to meropenem,which was further confirmed by concentration cumulative bacteriostatic rate.The standard broth microdilution method was used to verify the reversing effect of allicin on 4 NDM-1-type CRKP strains with different multilocus sequence typing(MLST).Next-generation sequencing technology was employed to detect the MLST typing and antibiotic resistance gene carriage of clinically isolated strains.Results Among the 5 traditional Chinese medicine monomers screened in this experiment,when allicin was combined with meropenem,the fractional inhibitory concentration index(FIC)against CRKP1 was≤0.5,indicating a synergistic effect between allicin and meropenem on CRKP1.Allicin exhibited a reversing effect on 4 NDM-1-type CRKP strains with different MLST types.After the combination of allicin and meropenem,the FIC of the 4 NDM-1-type CRKP strains was≤0.5,suggesting that the combination of allicin and meropenem had a synergistic effect on all 4 NDM-1-type CRKP strains.Antibiotic resistance gene analysis of NDM-1-type CRKP showed that strains CRKP1-4 all carried the blaNDM-1 gene,but their MLST types were different:CRKP1-4 were ST23,ST219,ST63-1 LV,and ST15,respectively,indicating low relatedness among these strains.Conclusion Allicin can reverse the resistance of NDM-1-type CRKP to meropenem,providing a new idea for the clinical treatment of NDM-1-type CRKP infections.