ABSTRACT
Objective To explore the drug resistance mechanisms of carbapenem-resistant Citrobacter freundii (C.freundii) and its treatment strategies.Methods Clinical data of 17 strains of carbapenem-resistant C.freundii from this hospital were collected.Carbapenemase resistant genes were amplifies by polymerase chain reaction (PCR).The agar dilution method and the broth dilution method were used to determine the minimal inhibition concentration (MIC) of single antimicrobial drug and drug combination,the partial inhibitory concentration index (Σ FICI) was calculated.Results Eight strains were found to produce blaNDM-1 and 9 strains produced blaIMP,blaKPC,blaSPM and blaoxA-48 were not detected in the study.Furthermore,the synergistic effect and addictive effect of fosfomycin combined imipenem accounted for 75.00％,in which,the synergistic effect was up to 56.25 ％.the synergistic effect and addictive effect of fosfomycin and cefoperazone/sulbactam accounted for 50.00％.Conclusion Fosfomycin combined with imipenem or cefoperazone/sulbactam has good antibacterial activity in vitro,but imipenem combined with fosfomycin may have better effect.
ABSTRACT
Objective To explore the drug resistance mechanisms of carbapenem-resistant Citrobacter freundii (C.freundii) and its treatment strategies.Methods Clinical data of 17 strains of carbapenem-resistant C.freundii from this hospital were collected.Carbapenemase resistant genes were amplifies by polymerase chain reaction (PCR).The agar dilution method and the broth dilution method were used to determine the minimal inhibition concentration (MIC) of single antimicrobial drug and drug combination,the partial inhibitory concentration index (Σ FICI) was calculated.Results Eight strains were found to produce blaNDM-1 and 9 strains produced blaIMP,blaKPC,blaSPM and blaoxA-48 were not detected in the study.Furthermore,the synergistic effect and addictive effect of fosfomycin combined imipenem accounted for 75.00％,in which,the synergistic effect was up to 56.25 ％.the synergistic effect and addictive effect of fosfomycin and cefoperazone/sulbactam accounted for 50.00％.Conclusion Fosfomycin combined with imipenem or cefoperazone/sulbactam has good antibacterial activity in vitro,but imipenem combined with fosfomycin may have better effect.