Thursday, July 23, 2015

GWU Study: Klebsiella-Contaminated Food Linked To Urinary Tract Infections



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Just over four years ago, in The Biohazard In Your Butcher’s Case, we looked at a study appearing in the journal Clinical Infectious Diseases produced by the The Translational Genomics Research Institute in Phoenix, Arizona that showed showing that 47% of the meat (beef, chicken, pork and turkey) collected and tested from 26 stores across 5 US Cities (Los Angeles, Chicago, Fort Lauderdale, Flagstaff and Washington, D.C.) were contaminated with Staph aureus.


Of those, 52% were resistant to at least three classes of antibiotics.Giving shoppers about a 1 in 4 chance of selecting a package containing resistant staph from their butcher’s meat case.


Although cooking meat to the proper temperature will kill Staph (and other) bacteria, improper handling and cleanup can expose the preparer (and others)  to potentially dangerous bacteria.


While MSRA is an obvious concern, it is far from being the only rising star in the antibiotic resistance world.  In 2013, in CDC HAN Advisory: Increase In CRE Reports In The United States, we looked at the growing concerns over the incidence of Carbapenem-resistant Enterobacteriaceae (CRE) colonization or infection across the nation.


Enterobacteriaceae comprise a large family of Gram-negative bacteria that range from harmless strains to pathogenic invaders, and includes such familiar names as Salmonella, Escherichia coli, Klebsiella and Shigella.


Klebsiella pneumoniae, is of particular concern as it has a very high mortality rate.  While it can reside harmlessly in in the flora of the human gut, when K. pneumoniae moves beyond the intestinal tract – particularly in people with weakened immune systems – it can cause cause severe pneumonia, urinary tract infections (UTI), septicemia, and soft tissue infections.


Making matters worse, over the past decade doctors have seen the emergence of antibiotic resistant forms of K. pneumoniae known as CRKP or  KPC (K. pneumoniae carbapenemase), that are resistant to the Carbapenem class of antibiotics which are often used as the drug of last resort for treating difficult bacterial infections


K. Pneumoniae’s opportunistic qualities – attacking those with weakened immune systems - makes it an important, and difficult to control, hospital acquired infection.


Today we’ve a  multi-center study from George Washington University Milken Institute School of Public Health, The Translational Genomics Research Institute, Johns Hopkins University School of Medicine, The University of Minnesota, and others that examined grocery store meat in and around Flagstaff, Arizona in 2012 for Klebsiella  and genetically matched some of those strains to local UTI (urinary tract infections).


First a link to  the study’s abstract, followed by some excerpts from the press release.


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

Gregg S. Davis1, Kara Waits2, Lora Nordstrom2, Brett Weaver2, Maliha Aziz1,2, Lori Gauld3, Heidi Grande2, Rick Bigler2, Joseph Horwinski2, Stephen Porter4, Marc Stegger2,5, James R. Johnson4,6, Cindy M. Liu2,7, and Lance B. Price1,2

+ Abstract

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.


The press release from GWU:


This study is the first to suggest that consumers can be exposed to potentially dangerous Klebsiella from contaminated meat,” says lead author Lance Price


Research Suggests Retail Meat is a Potential Vehicle for Disease-Causing Klebsiella

Increasing Antibiotic Resistance Among Klebsiella Poses Serious Public Health Threat; Milken Institute School of Public Health-Led Study Is First To Link Klebsiella-Contaminated Food to Urinary and Blood Infections

Media Contact: Kathleen Fackelmann,, 202-994-8354 and Nicole Tidwell,, 614-309-1293

WASHINGTON, DC (July 23, 2015) — Chicken, turkey and pork sold in grocery stores harbors disease-causing bacteria known as Klebsiella pneumoniae, according to a new study. The research, which was published online today in the journal Clinical Infectious Diseases, shows that contaminated meat may be an important source of human exposure to Klebsiella.

The U.S. food safety system has traditionally focused on a few well-known bacteria like Listeria, Salmonella and Campylobacter, which cause millions of cases of food poisoning every year. The research published today suggests that Klebsiella may need to be added to the list of risky bugs in food products.

“This study is the first to suggest that consumers can be exposed to potentially dangerous Klebsiella from contaminated meat,” said Lance B. Price, PhD, lead author of the study and a professor of environmental and occupational health at Milken Institute School of Public Health (Milken Institute SPH) at the George Washington University. “The U.S. government monitors food for only a limited number of bacterial species, but this study shows that focusing on the ‘usual suspects’ may not capture the full scope of foodborne pathogens.”

The multi-center study was led by Price and scientists at Milken Institute SPH. Other authors on the study include researchers from Translational Genomics Research Institute, Flagstaff Medical Center, the VA Healthcare System-Minneapolis, Statens Serum Institut in Copenhagen, the University of Minnesota, and the Johns Hopkins University School of Medicine.

To better understand potential contributions of foodborne Klebsiella pneumonia to human clinical infections, the multi-center research team compared K. pneumoniae isolates from retail meat products and human clinical specimens to assess their similarity based on whole genome sequencing. They first looked at turkey, chicken and pork products being sold in nine major grocery stores in Flagstaff, Arizona, in 2012. Then the team analyzed urine and blood samples taken from Flagstaff area residents who were suffering from infections during the same time period.

Price and his colleagues found that 47 percent of the 508 meat products purchased from grocery stores in 2012 harbored Klebsiella—and many of the strains recovered were resistant to antibiotics. Agricultural operations often give food animals antibiotics to make them grow faster and to prevent diseases, a practice that can create conditions ideal for the emergence of resistant strains of Klebsiella, Price says.

At the same time, the team found Klebsiella, including resistant strains, comprised 10 percent of the 1,728 positive cultures from patients with either urinary tract or blood infections in the Flagstaff area. The researchers used whole-genome DNA sequencing to compare the Klebsiella isolated from retail meat products with the Klebsiella isolated from patients and found that some isolate pairs were nearly identical.

(Continue . . . )



Although I touch on the problems of antibiotic resistance, the true expert in Flublogia is author, journalist, and renaissance woman Maryn Mckenna, who is the author of two award winning books - Superbug: The Fatal Menace of MRSA   and Beating Back The Devil - is working on a third, and finds time to author  the Germination Blog for National Geographic.


If you haven’t already watched Maryn McKenna’s TED Talk - What do we do when antibiotics don’t work any more?, then I would highly recommend doing so. 


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