Analysis Of Resistance Genes And Virulence Factors Of Carbapenems-resistant Klebsiella Pneumonia Of One Hefei Hospital

ObjectiveTo analyze the source and drug sensitivity of clinically isolated klebsiella pneumoniae and the drug resistance mechanism and virulence characteristics of carbapenem-resistant Klebsiella pneumoniae(CRKP)isolated from clinical infection of a hospital of Hefei city MethodsKlebsiella pneumoniae strains isolated from clinical infection in Hefei Binhu Hospital from January 2015 to December 2018 were collected.Vitek-2 Compact was used for identification of bacteria and antimicrobial susceptibility testing.The drug sensitivity test of cefoperazone/sulbactam was analyzed by K-B methods(CLSI2015 as reference).38CRKP strains isolated from clinical bloodstream infection in Hefei Binhu Hospital from January 2015 to December 2017 were collected.The identification and antimicrobial susceptibility testing were done same as above.Additionally,the drug sensitivity test of Tigacycline was detected byMIC strip method,others were evaluated by the K-B methods(CLSI2015as reference).Metallo β-lactamases and carbapenemases screening were conducted by modified Hodge test and imipenem-EDTA double disc synergy test,respectively.PCR was performed to detect the drug resistance gene and virulence associated genes.Those membrane protein-deficient strains were verified by SDS-PAGE method.ResultstsTotally,999 strains of Klebsiella pneumoniae were collected between January 2015 and December 2018.The Klebsiella pneumoniae strains were mainly isolated sputum and urine samples from Geriatric and ICU patients.166 strains of CRKP were detected.It’s worth noting that significant drug resistant characteristics between 2018 and other years.Among these CRKP strains,32(84.2%)strains were carried carbapenemase resistance genes,of which 26(68.4%)were carried KPC-2gene,12(31.6%)were carried NDM-1 gene,6 strains(15.8%)carried both KPC-2 and NDM-1genes,31(81.6%)stains detected ESBLs gene,25(65.8%)strains with membrane pore protein gene deletion,2(5.3%)strains carried ESBLs gene and lacking membrane protein,2(5.3%)stains carried only the SHV+CTX-M+TEM gene,and 2(5.3%)strains carried only the SHV+CTX-M gene.2 membrane protein deletions stains and 2 normalstrains were confirmed by SDS-PAGE and sequencing analysis.Additionally,5 strains of capsular serum K1 type and 1 strain of capsular serum K57 type were detected,and the other 32 strains were not yet classified.There were 16 rmp A positive stains and 12 aerobaction positive stains were detected,of which 10 strains were tested with both rmp A and aerobaction positive.All strains were detected as Fim H-1 positive.ConclusionsIn this study,the Klebsiella pneumoniae strains were mainly isolated sputum and urine samples from Geriatric and ICU patients.Those strains were sensitivity to most antibacterial drugs,while drug resistance rate rise significantly in 2018.The drug resistance genes carried by CRKP in this study were mainly KPC-2.It is noteworthy that strains of CRKP carry a variety of virulence associated capsular serum K1 type should cause clinical attention.