Molecular typing of Klebsiella pneumonia by pulse-field gel electrophoresis in combination with multilocus sequence typing

Abstract

To type Klebsiella pneumonia through methods including pulse-field gel electrophoresis (PFGE) in combination with multilocus sequence typing. Four selected different EPs, referring to the Standard Operating Procedure of PulseNet China, were used. The single colony of Klebsiella pneumonia was quantified after enriched culture. Embedding organisms in agarose and genome DNA were lysed with Proteinase K and then digested by restriction endonuclease XbaI, to produce agarose gel. Fingerprint was obtained through PFGE and bands were marked with their molecular weights and then analyzed by BioNumerics software. Using MLST to analyze the strains that were highly similar, by PFGE typing By comparing the four results from each EPs, fk3 (switch time from 6s to 36s, total run time is 18.5 hours) seemed to be better than the others. 59 strains of Klebsiella pneumonia were divided into 47 PFGE types and 19 PFGE clusters. The highly similar strains could be typed into ST-340, ST-342, ST-343, ST-344, ST-345 by MLST. Among them, ST-342, ST-343, ST-344, ST-345 types were all new MLST types that were reported in China. Highly similar Klebsiella pneumonias typed by PFGE could also be typed by MLST.