Investigation of clonal relationships of K. pneumoniae isolates from neonatal intensive care units by PFGE and rep-PCR.

Mehmet Koroglu,Taner Hafizoglu,Oguz Karabay,Ahmet Ozbek,Mustafa Altindis,Tayfur Demiray,Ertugrul Guclu,Riza Durmaz

doi:10.3855/jidc.6326

Mehmet Koroglu, Taner Hafizoglu + Show 6 more

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https://doi.org/10.3855/jidc.6326

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Abstract

Clonal relationships of Klebsiella pneumoniae strains obtained during an epidemic and after a one-year post-epidemic (non-epidemic) period in the same neonatal intensive care unit (NICU) using pulsed-field gel electrophoresis (PFGE) and repetitive polymerase chain reaction (rep-PCR) by the DiversiLab (DL) system were investigated, and the results of both molecular techniques were evaluated. Fifteen K. pneumoniae strains were included in this study. All identified bacterial strains were confirmed by 16S rDNA sequencing and analyzed by PFGE and the DL system. According to the PFGE results, 15 isolates showed 10 different band profiles. Nine of these 15 isolates were included in one of the formed clusters, and the remaining six isolates were not included in any of them. According to the DL system results, 15 isolates showed two different clusters, with three strains in one cluster and four strains in the other. The remaining strains could not be placed any one of the clusters. PFGE was used as the gold standard based on its strong genetic discriminatory power. The DL system results showed that PFGE missed the relationship of the two epidemic-related strains and demonstrated one epidemic-unrelated strain to be epidemic related. Both systems may easily be used for clonal relationships of K. pneumoniae strains. The DL system was clearly more rapid and convenient than PFGE, but its discriminatory power seemed to be inferior to that of PFGE based on 15 K. pneumoniae strains.

Highlights

Clonal relationships of Klebsiella pneumoniae strains obtained during an epidemic and after a one-year post-epidemic period in the same neonatal intensive care unit (NICU) using pulsed-field gel electrophoresis (PFGE) and repetitive polymerase chain reaction by the DiversiLab (DL) system were investigated, and the results of both molecular techniques were evaluated
The aims of this study were to analyze the clonal relationships of K. pneumoniae strains obtained during an epidemic and during the one-year post-epidemic period in the same NICU using PFGE and repetitive polymerase chain reaction (rep-PCR) and to evaluate the results of both molecular techniques
Sequencing and neighbor-joining analyses of the 15 K. pneumoniae strains demonstrated that all strains and the reference strain had 91% to 97% similarity

Summary

Introduction

Clonal relationships of Klebsiella pneumoniae strains obtained during an epidemic and after a one-year post-epidemic (nonepidemic) period in the same neonatal intensive care unit (NICU) using pulsed-field gel electrophoresis (PFGE) and repetitive polymerase chain reaction (rep-PCR) by the DiversiLab (DL) system were investigated, and the results of both molecular techniques were evaluated. Traditional techniques for typing K. pneumoniae are based on phenotypic characteristics and include biotyping, antibiogram typing, O-serotyping, and bacteriocin and phage typing; all of these techniques have poor discriminatory power [11] Molecular methods such as plasmid profile analysis, ribotyping, fragment restriction endonuclease analysis, multilocus sequence typing, gene sequencing, pulsed-field gel electrophoresis (PFGE), and repetitive sequence-based polymerase chain reaction (rep-PCR) are available for strain typing [12,13,14,15,16,17,18,19,20].For analysis of an epidemic, strain typing of the isolates should be performed using at least one of these molecular methods

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