TY - JOUR

T1 - Concurrent emergence of multidrug resistance and heat resistance by CTX-M-15-encoding conjugative plasmids in Klebsiella pneumoniae

AU - Bojer, Martin Saxtorph

AU - Hammerum, Anette M

AU - Jørgensen, Steffen Lynge

AU - Hansen, Frank

AU - Olsen, Stefan S

AU - Krogfelt, Karen A

AU - Struve, Carsten

N1 - © 2012 The Authors APMIS © 2012 APMIS.

PY - 2012

Y1 - 2012

N2 - A plasmid-encoded ClpK protein was recently identified as a predictor of a heat-resistant phenotype in the opportunistic pathogen Klebsiella pneumoniae. This study was undertaken to evaluate the presence of the clpK gene in extended-spectrum ß-lactamase (ESBL)-producing K. pneumoniae and to assess the probable co-transfer of multi-resistance with the heat resistance phenotype. A Danish collection of 80 ESBL-producing K. pneumoniae bloodstream infection isolates was screened for clpK by colony hybridization. Nineteen isolates (24%) were positive for clpK; some of them representing major clones identified in Denmark. Among these, nine isolates belonged to a single K. pneumoniae CTX-M-15 clone with sequence type (ST)16 exhibiting a heat-resistant phenotype. This clone has a multi-hospital occurrence and has also been detected outside Denmark. Horizontal co-transfer of multiple antibiotic resistances, including the CTX-M-15 resistance determinant, and the heat resistance phenotype was observed. Thus, the clpK gene is harbored by different ESBL-producing K. pneumoniae isolates including a clone of ST16 internationally spread. The co-localization of clpK on transferable ESBL-encoding plasmids allowing co-dissemination of multiple drug resistance with bacterial heat resistance is a highly interesting phenomenon that may further complicate the prevention of spreading of certain successful clones of multi-resistant K. pneumoniae.

AB - A plasmid-encoded ClpK protein was recently identified as a predictor of a heat-resistant phenotype in the opportunistic pathogen Klebsiella pneumoniae. This study was undertaken to evaluate the presence of the clpK gene in extended-spectrum ß-lactamase (ESBL)-producing K. pneumoniae and to assess the probable co-transfer of multi-resistance with the heat resistance phenotype. A Danish collection of 80 ESBL-producing K. pneumoniae bloodstream infection isolates was screened for clpK by colony hybridization. Nineteen isolates (24%) were positive for clpK; some of them representing major clones identified in Denmark. Among these, nine isolates belonged to a single K. pneumoniae CTX-M-15 clone with sequence type (ST)16 exhibiting a heat-resistant phenotype. This clone has a multi-hospital occurrence and has also been detected outside Denmark. Horizontal co-transfer of multiple antibiotic resistances, including the CTX-M-15 resistance determinant, and the heat resistance phenotype was observed. Thus, the clpK gene is harbored by different ESBL-producing K. pneumoniae isolates including a clone of ST16 internationally spread. The co-localization of clpK on transferable ESBL-encoding plasmids allowing co-dissemination of multiple drug resistance with bacterial heat resistance is a highly interesting phenomenon that may further complicate the prevention of spreading of certain successful clones of multi-resistant K. pneumoniae.

KW - Conjugation, Genetic

KW - Denmark

KW - Drug Resistance, Multiple, Bacterial

KW - Humans

KW - Klebsiella Infections

KW - Klebsiella pneumoniae

KW - Microbial Sensitivity Tests

KW - Nucleic Acid Hybridization

KW - Plasmids

KW - Retrospective Studies

KW - beta-Lactamases

U2 - 10.1111/j.1600-0463.2012.02885.x

DO - 10.1111/j.1600-0463.2012.02885.x

M3 - Journal article

C2 - 22882258

VL - 120

SP - 699

EP - 705

JO - A P M I S. Acta Pathologica, Microbiologica et Immunologica Scandinavica

JF - A P M I S. Acta Pathologica, Microbiologica et Immunologica Scandinavica

SN - 0903-4641

IS - 9

ER -