Foodborne nosocomial outbreak of SHV1 and CTX-M-15-producing Klebsiella pneumoniae: epidemiology and control

Clin Infect Dis. 2011 Mar 15;52(6):743-9. doi: 10.1093/cid/ciq238.


Background: We describe a foodborne nosocomial outbreak due to extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae.

Methods: An outbreak of ESBL K. pneumoniae was detected in March 2008. Initial control measures included contact isolation and a protocol for routine detection and reinforcement in hand hygiene practices. ESBL producers were screened for the bla(TEM), bla(SHV), and bla(CTX-M) genes. Pulsed-field gel electrophoresis analysis was performed using XbaI as a restriction endonuclease.

Results: One hundred fifty-six colonized and/or infected patients were identified, 35 (22.4%) of whom had infection. The outbreak affected all hospital wards. Fecal carriage was up to 38% of patients in some wards. Of note, investigation revealed a very short delay between admission and colonization. None of the health care workers or environmental surfaces in the wards was found to be colonized. This prompted an epidemiological investigation of a possible foodborne transmission. We found that up to 35% of the hospital kitchen-screened surfaces or foodstuff were colonized and that 6 (14%) of 44 food handlers were found to be fecal carriers. Phenotypic and genotypic analysis of all clinical, environmental, and fecal carrier isolates showed the dissemination of a single strain of SHV-1 and CTX-M-15-producing K. pneumoniae. At that time, structural and functional reforms in the kitchen were performed. These were followed by a progressive reduction in colonization and infection rates among inpatients until complete control was obtained in December 2008. No restrictions in the use of antibiotics were needed.

Conclusions: To our knowledge, this is the first reported hospital outbreak that provides evidence that food can be a transmission vector for ESBL K. pneumoniae.

MeSH terms

  • Aged
  • Bacterial Typing Techniques
  • Cluster Analysis
  • Cross Infection / epidemiology*
  • Cross Infection / microbiology
  • Deoxyribonucleases, Type II Site-Specific / metabolism
  • Disease Outbreaks*
  • Electrophoresis, Gel, Pulsed-Field
  • Female
  • Foodborne Diseases / epidemiology*
  • Foodborne Diseases / microbiology
  • Genotype
  • Humans
  • Klebsiella Infections / epidemiology*
  • Klebsiella Infections / microbiology
  • Klebsiella pneumoniae / classification
  • Klebsiella pneumoniae / enzymology*
  • Klebsiella pneumoniae / genetics
  • Klebsiella pneumoniae / isolation & purification
  • Male
  • Molecular Typing
  • beta-Lactamases / biosynthesis*
  • beta-Lactamases / genetics


  • endodeoxyribonuclease XBAI
  • Deoxyribonucleases, Type II Site-Specific
  • beta-Lactamases