Molecular strain typing of multidrug-resistant Klebsiella pneumoniae: capsular wzi gene sequencing versus multiple locus variable number tandem repeat analysis.

This study compared genotyping of Klebsiella pneumoniae isolates by 2 molecular methods. Genotyping of 50 multidrug-resistant (MDR) and 10 non-MDR K. pneumoniae subsp. pneumoniae isolates from 2 hospitals was done using multiple locus variable number tandem repeat analysis (MLVA) and capsular typing by wzi gene sequencing. Genotyping of the isolates by the 2 methods showed 100% typeability. Agreement on clustering of the isolates by the 2 methods was 82.6%. Typing by MLVA, however, was more discriminatory (97%) than by wzi gene sequencing (92%). All the 23 K. pneumoniae subsp. pneumoniae isolates randomly selected for wzi gene sequencing showed sequence identity to previously published wzi sequences, which enabled prediction of the K-types of 16 of them. The 2 methods revealed the relatedness of (8/15) isolates from 1 of the 2 hospitals. MLVA may be considered a cheaper and more discriminatory molecular typing method suitable for genotyping of K. pneumoniae isolates in developing countries.