Study On Molecular Epidemiology,Risks Factors And Drug Resistance Of Clostridium Difficile

Objectives:Clostridium difficile(C.difficile)infection(CDI)is a neglected and underestimated clinical problem in China and the impact is still not well documented.This study was aimed to quantify the burdens of CDI in Chongqing,Southwest China.Methods:55 isolates of C.difficile were collected,and clinical characteristics and risk factors of CDI were disclosed by a case-case-control study in the First Affiliated Hospital of Chongqing Medical University from June 2014 to March 2016.C.difficile strains were tested for PCR ribotyping(RT)and multilocus sequence typing(MLST),toxin genes and antimicrobial susceptibility.Results:Among the 259 suspicious patients,55 unduplicated strains were isolated and 38 strains producing toxins.35 of 38(92.1%)CDI patients recovered and none developed a recurrence of CDI.Case-case-control study revealed that chronic renal diseases and cephalosporins use prior to the onset of diarrhea were the independent risk factors for patients with diarrheas to acquire CDI.55 unduplicated strains were assigned into 17 STs or 15 ribotypes.ST2(16.4%)and RT449(18.2%)were predominant.35(92.1%)A+B+isolates and one of A+B+isolates was also found haboring binary toxin genes(CDT),3(7.9%)A-B+isolates were found.All RT012 and RT449 strains were A+B+.8(14.5%)isolates were multi-drug resistance(MDR).High resistance to erythromycin and clindamycin were found with rates of 87.3%and 61.8%,respectively.The resistance rate to rifampin and levofloxacin,accounting for 12.7%and 14.5%,respectively.None of isolates were resistant to vancomycin,metronidazole or tigecycline.All RT017 isolates were resistant to erythromycin and clindamycin.Conclusions:The epidemiology of C.difficile in Chongqing differed from other regions in China.RT449 may be a potential prevalent genetype in the region,the surveillance of CDI is necessary.Adequate awareness of patients with chronic renal diseases at high risk of CDI acquisition is advocated and cautious adoption of cephalosporins should be highlighted.No metronidazole,vancomycin and tigecycline resistant strains were found,suggesting that these three antibiotics can be used for empirical treatment of CDI in this region.