| Objective: The aim of this investigation was to explore the genotypes,phynotypes and molecular epidemiology of carbapenem-resistant Klebsiella Pneumoniae(CRKP)isolated from a tertiary hospital in Guizhou Province in order to the infection and outbreak of CRKP with the prevention and strategy theoretically.Methods: 1.The CRKP isolates were collected from sputa,blood,medistream urine and ascitic fluid in patients of a tertiary hospital in Guizhou province from March 2016 to February 2017.2.The phenotypes of CRKP were confirmed by Modified Hodge Test(MHT)and EDTA-imipenem synergistic method.3.Bacteria identification were performed by Phoenixtm-100.According to Clinical and Laboratory Standards Institute(CLSI),the microbroth dilution method was used to determine the MICs of antibiotics.4.The carbapenemase gene of KPC-2,GES,VIM,IMP,NDM-1 and OXA-48 were amplified by PCR with series primers.Consequently,the gynotypes were determined using Basic Local Alignment Search Tool(BLAST)online.5.Seven house-keeping genes were amplified by PCR and analyzed by multilocus sequence typing(MLST).6.The genetic relationship and the population structure of CRKP isolates were analyzed by MEGA sofeware,and eBURST3.0 software respectively.Results: 1.A total of 50 CRKP isolates were collected from the tertiary hospital in Guizhou Province and 37 isolates were enrolled after the confirmation by MHT.2.Three out of the 37 CRKP isolates were detected to be positive by EDTA-imipenem synergistic test.3.The drug susceptibility testing showed the 37 isolates were resistant to carbapenem with MICs ranging from 4μg/ml to 256μg/ml.The CRKP isolates were highly resistant to aminoglycosides,the compound of the third-generation cephalosporin and β-lactamase inhibitor,azithromycin,levofloxacin and piperacillin-tazobactam as well.These isolates showed the lower resistance rate to amikacin(81.1%).The KPC-2 and the NDM-1 were detected in all the 37 strains and 3 strains,respectively.OXA-48 and other gynotypes were not detected in the isolates.5.The genetic relationship analysis revealed the 37 isolates were divided to 8 types including ST11(25/37,67.6%),ST524(2/37,5.4%),ST789(4/37,10.8%),ST35,ST29,ST1066 and ST244(1 of each).Also,a new type(ST2792)was accepted by the PubMlst database.6.CRKP isolates were divided into ST11 group and non-ST11 group based on the clinical data.There was no significant difference between the two groups by analyzed with SPSS17.0 software.However,the patients who infect the strains that carried on KPC-2+NDM-1 had some similar clinical features like severe basic diseases,intrusive operation and multidrug treatments.Conclusion: 1.KPC-2 is the most popular resistant genotype of the CRKP strains in this tertiary hospital.2.The dominant cloning type in this hospital is ST11 which belongs to the same clone group as ST2792 newly detected in our study.CRKP isolates of the same genotype/clone group may cause prevalence at different times in the identical region.The clinical departments should take measures to enhance surveillance in order to avoid the spread of drug-resistant bacteria.3.Bacterial cloning type is not an important factor in determining the drug-resisitance and clinical impacts.4.It is urgent to strengthen the monitoring of drug-resistant strains due to the large range of diversity for resistance. |
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