TY - JOUR

T1 - Heat-resistant, extended-spectrum β-lactamase-producing Klebsiella pneumoniae in endoscope-mediated outbreak

AU - Jørgensen, S.B.

AU - Bojer, Martin Saxtorph

AU - Boll, E.J.

AU - Martin, Y.

AU - Helmersen, K.

AU - Skogstad, M.

AU - Struve, C.

PY - 2016

Y1 - 2016

N2 - BackgroundWe describe an outbreak with an extended-spectrum β-lactamase-producing Klebsiella pneumoniae strain in an intensive care unit in a secondary care hospital in Norway. The outbreak source was a fibreoptic intubation endoscope in which the outbreak strain survived despite chemothermal disinfection in a decontaminator designated for such use. The genetic marker clpK, which increases microbial heat resistance, has previously been described in K. pneumoniae outbreak strains.AimTo investigate the role of clpK in biofilm formation and heat-shock stability in the outbreak strain.MethodsThe outbreak investigation was done by review of clinical records, screening of patients and culture from intubation endoscopes and bronchoscopes. Amplified fragment length polymorphism was used to identify the outbreak strain. clpK detection was performed by polymerase chain reaction, followed by mutant construction and heat-shock assays.FindingsFive patients and one intubation endoscope contained K. pneumoniae with the same amplified fragment length polymorphism pattern. The outbreak strain contained the clpK genetic marker, which rendered the strain its increased heat resistance. The survival rate of the strain grown as biofilm following heat treatment was also strongly dependent on clpK.ConclusionAlthough clpK has been associated with clinical isolates of K. pneumoniae in earlier outbreaks, this is the first time that a ClpK-producing strain has been isolated from an environmental outbreak source. Heat resistance of certain K. pneumoniae strains may facilitate survival in biofilms on medical equipment and hence increase the potential of those strains to persist and disperse in the hospital environment.

AB - BackgroundWe describe an outbreak with an extended-spectrum β-lactamase-producing Klebsiella pneumoniae strain in an intensive care unit in a secondary care hospital in Norway. The outbreak source was a fibreoptic intubation endoscope in which the outbreak strain survived despite chemothermal disinfection in a decontaminator designated for such use. The genetic marker clpK, which increases microbial heat resistance, has previously been described in K. pneumoniae outbreak strains.AimTo investigate the role of clpK in biofilm formation and heat-shock stability in the outbreak strain.MethodsThe outbreak investigation was done by review of clinical records, screening of patients and culture from intubation endoscopes and bronchoscopes. Amplified fragment length polymorphism was used to identify the outbreak strain. clpK detection was performed by polymerase chain reaction, followed by mutant construction and heat-shock assays.FindingsFive patients and one intubation endoscope contained K. pneumoniae with the same amplified fragment length polymorphism pattern. The outbreak strain contained the clpK genetic marker, which rendered the strain its increased heat resistance. The survival rate of the strain grown as biofilm following heat treatment was also strongly dependent on clpK.ConclusionAlthough clpK has been associated with clinical isolates of K. pneumoniae in earlier outbreaks, this is the first time that a ClpK-producing strain has been isolated from an environmental outbreak source. Heat resistance of certain K. pneumoniae strains may facilitate survival in biofilms on medical equipment and hence increase the potential of those strains to persist and disperse in the hospital environment.

KW - Faculty of Health and Medical Sciences

KW - clpK

KW - Extended-spectrum β-lactamase

KW - Intensive care unit

KW - Intubation endoscope

KW - Outbreak

U2 - 10.1016/j.jhin.2016.01.014

DO - 10.1016/j.jhin.2016.01.014

M3 - Journal article

VL - 93

SP - 57

EP - 62

JO - Journal of Hospital Infection

JF - Journal of Hospital Infection

SN - 0195-6701

IS - 1

ER -