Intermingled Klebsiella pneumoniae Populations Between Retail Meats and Human Urinary Tract Infections

Clin Infect Dis. 2015 Sep 15;61(6):892-9. doi: 10.1093/cid/civ428. Epub 2015 Jul 22.


Background: Klebsiella pneumoniae is a common colonizer of the gastrointestinal tract of humans, companion animals, and livestock. To better understand potential contributions of foodborne K. pneumoniae to human clinical infections, we compared K. pneumoniae isolates from retail meat products and human clinical specimens to assess their similarity based on antibiotic resistance, genetic relatedness, and virulence.

Methods: Klebsiella pneumoniae was isolated from retail meats from Flagstaff grocery stores in 2012 and from urine and blood specimens from Flagstaff Medical Center in 2011-2012. Isolates underwent antibiotic susceptibility testing and whole-genome sequencing. Genetic relatedness of the isolates was assessed using multilocus sequence typing and phylogenetic analyses. Extraintestinal virulence of several closely related meat-source and urine isolates was assessed using a murine sepsis model.

Results: Meat-source isolates were significantly more likely to be multidrug resistant and resistant to tetracycline and gentamicin than clinical isolates. Four sequence types occurred among both meat-source and clinical isolates. Phylogenetic analyses confirmed close relationships among meat-source and clinical isolates. Isolates from both sources showed similar virulence in the mouse sepsis model.

Conclusions: Meat-source K. pneumoniae isolates were more likely than clinical isolates to be antibiotic resistant, which could reflect selective pressures from antibiotic use in food-animal production. The close genetic relatedness of meat-source and clinical isolates, coupled with similarities in virulence, suggest that the barriers to transmission between these 2 sources are low. Taken together, our results suggest that retail meat is a potential vehicle for transmitting virulent, antibiotic-resistant K. pneumoniae from food animals to humans.

Keywords: Klebsiella; antibiotic resistance; food; meat; poultry.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Animals
  • Anti-Bacterial Agents / pharmacology
  • Disease Models, Animal
  • Disease Transmission, Infectious
  • Genome, Bacterial
  • Genotype
  • Humans
  • Klebsiella Infections / epidemiology
  • Klebsiella Infections / microbiology*
  • Klebsiella pneumoniae / classification*
  • Klebsiella pneumoniae / isolation & purification*
  • Meat / microbiology*
  • Mice
  • Microbial Sensitivity Tests
  • Middle Aged
  • Molecular Epidemiology
  • Molecular Sequence Data
  • Multilocus Sequence Typing
  • Sepsis / epidemiology
  • Sepsis / microbiology
  • Sequence Analysis, DNA
  • Urinary Tract Infections / epidemiology
  • Urinary Tract Infections / microbiology*
  • Virulence
  • Young Adult
  • Zoonoses / transmission


  • Anti-Bacterial Agents

Associated data

  • SRA/SRP060821