Multidrug resistant foodborne bug threats on retail meat - Klebsiella, not your usual suspect

In a new paper coming out of Lance Price's George Washington University lab, authors cast light on a new foodborne bug, Klebsiella pneumoniae, which they found on meat commonly found in grocery stores, including chicken, pork, and turkey. K. pneumoniae is very familiar to doctors, known to cause urinary tract and blood infections, among others. A deadly superbug version of this bacterium (resistant to Carbapenem as well as other antibiotics) has been causing havoc in hospitals, including the flagship research hospital for the National Institutes of Health and has been categorized as an urgent threat to public health by the Centers for Disease Control and Prevention.

What's new here and represents a dramatic shift in how we should think about foodborne illness is that the K. pneumoniae studied by the authors were found on meat taken off grocery store shelves and were not very different from K. pneumoniae that had been isolated from hospital patients in the same area.

Here are the main points to take away from the study:

  • K. pneumoniae isolated from retail meat and hospital patients were genetically intermingled, meaning that at the DNA level, bacteria from the two sources were similar and didn't represent two distinct types.
  • K. pneumoniae from retail meat were more likely to be multidrug resistant and some were found to be resistant to cephalosporins, a first line antibiotic in human medicine.
  • Genetically similar K. pneumoniae from retail meat and patients showed similar abilities to cause low level disease in mice.

With this finding, it becomes ever clearer that bacteria don't respect borders, and that finding the original source of a bacterium is unlikely. The evidence presented by the authors suggests that K. pneumoniae from retail meat may very well be responsible for an unknown fraction of infections that afflict humans. Beyond that, like many bacteria, K. pneumoniae, can share their antibiotic resistance with other bacteria that then cause disease.

Scientific and medical organizations agree that antibiotic use in livestock production leads to antibiotic resistance that can threaten public health. This is exactly why antibiotics should be used appropriately and sparingly by veterinarians and doctors alike. This new study only makes the health threat more evident by showing how a known hospital superbug could have started out, in some cases, as a foodborne bug. Or vice versa.