Abstract:

Objective To evaluate the consistency of fluorescent quantitative real-time polymerase chain reaction（RT-PCR） and polymerase chain reaction（PCR） amplification for carbapenem-resistant Klebsiella pneumoniae（CRKP） producing KPC carbapenemase,and to evaluate the performance of RT-PCR for the direct determination of Klebsiella pneumoniae and bla_KPC gene in clinical specimens. Methods Totally,89 clinical isolates of CRKP were collected. The determination rates and consistency of the 2 methods were compared. A total of 226 sputum specimens were collected. The bla_KPC gene and bla_phoE gene of outer membrane phospholipid protein of Klebsiella pneumoniae in clinical specimens were determined by RT-PCR. Traditional culture and drug susceptibility test were carried out to evaluate consistency. Results Among the 89 CRKP isolates,the determination rate of bla_phoE gene was 100%,and 2 isolates did not determinebla_KPC gene by RT-PCR and PCR amplification. The determination rate of bla_KPC was 97.8%,and the consistency of the 2 methods was 100%. In the 226 sputum specimens,for the determination of bla_phoE gene of Klebsiella pneumoniae by RT-PCR,using the results of culture as standard,the sensitivity,specificity and consistency of the 2 methods were 100%,99.38% and 99.56%,respectively. Using the results of drug susceptibility test as standard,for the determination of bla_KPC gene of Klebsiella pneumoniae by RT-PCR,the sensitivity,specificity and consistency of the 2 methods were 95.56%,99.48% and 98.67%,respectively.Conclusions Klebsiella pneumoniae producing _KPC carbapenemase can be rapidly screened by RT-PCR,which can provide a reference for rapid anti-infection treatment in patients with severe infection.

Key words: Klebsiella pneumoniae, Carbapenemase, bla_KPC gene, Molecular determination