CelB is a suitable marker for rapid and specific identification of Klebsiella pneumoniae by the loop-mediated isothermal amplification (LAMP) assay

Abstract

Klebsiella pneumoniae belongs to Enterobacteriaceae, which is the commonest bacterium causing nosocomial respiratory tract infection. It ranks second in bacteremia and urinary tract infection in gram-negative bacteria. Therefore, the rapid and accurate identification of K. pneumoniae was of great significance for the guide of clinical medication, and timely treatment of patients. The purpose of this study was to establish a rapid and sensitive molecular detection method for K. pneumoniae based on loop-mediated isothermal amplification (LAMP) technology. Firstly, local BLAST and NCBI BLAST were used to analyze the genome of K. pneumoniae. According to the principle of interspecific and intraspecific specificity, CelB (GenBank ID 11847805) was selected as the specific gene. Then, the LAMP and PCR identification systems were established with this target gene. Thirty-six clinical isolates of K. pneumoniae and 50 non-K. pneumoniae were used for the specific evaluation, and both LAMP and PCR could specifically distinguish K. pneumoniae from non-K. pneumoniae. A 10-fold series diluted positive plasmids and simulated infected blood samples were used as the templates in the sensitivity assay, and the results showed that the sensitivity could reach 1 copy/reaction. In summary, a rapid, specific, and sensitive LAMP method was established to detect K. pneumoniae in clinics.