A recent study investigated where antibiotic-resistant E. coli strains are found and how they are spread.
Escherichia coli is a common bacterium found naturally in our gut. They can cause diarrhea, food poisoning, urinary tract infections, and infections from gut surgery. Worst case scenario, E.coli can cause infections in the bloodstream with the possibility of mortality.
Some strains of this bacteria produce extended-spectrum b-lactamases (ESBLs). This means that they have special enzymes that destroy drugs in the b-lactam class, specifically penicillins and cephalosporins. This makes antibiotic-resistant E. coli harder to treat. Usually, E. coli cases are mild. However, ESBL-E. coli cases continue to increase and be of concern.
Researchers in the United Kingdom studied how these antibiotic-resistant E. coli are spread and if there is any cross-over between strains in humans and animals. These findings were recently published in The Lancet.
How is antibiotic-resistant E. coli spread? Is there cross-over between strains in humans and animals?
Samples were taken from common reservoirs of ESBL-E. coli, including human feces, sewage, farm slurry, and retail meats, fruits, and vegetables. These isolates were compared to isolates from human bloodstream infections and veterinary isolates. Both the samples and the isolates were taken from various regions across the UK.
No isolates were found in fruits and vegetables. Eleven percent of human feces contained ESBL-E. coli. E. coli was common in sewage and retail chicken (65% found in chicken). It was less common in other meat types.
ESBL-E. coli strain, sequence type 131, predominated in human sources, which included blood, feces, and sewage. In comparison, the food and veterinary isolates were predominately of another strain, concluding that human and animal strains are largely distinct. It has been uncertain to what extent ESBL-E. coli transmission is from food sources to human. This study suggests that food to human transmission is of less importance.
The results from this study suggest that the majority of human infections from ESBL-E. coli aren’t coming from food sources. They are likely being transmitted from human to human through feces to mouth contact. This can happen when someone doesn’t wash their hands after using the bathroom and then goes and eats a sandwich, for example.
Why is this important?
In order to limit serious E. coli infections, we need to focus on proper antibiotic prescribing and good hygiene. Take action by preventing infections! Here are some tips: Proper hygiene measures need to be taken in care homes since most severe infections occur in the elderly. Also, meat should be cooked properly, and appropriate food hygiene practices should be followed.. Remember, hand washing after using the toilet is of upmost importance to avoid fecal-oral transmission.
Written by Kayla Dillon, B.S.
Day, Michaela J et al. Extended-spectrum β-lactamase-producing Escherichia coliin human-derived and foodchain-derived samples from England, Wales, and Scotland: an epidemiological surveillance and typing study. The Lancet Infectious Diseases. 22 Oct 2019. doi: https://doi.org/10.1016/S1473-3099(19)30273-7.
Poor toilet hygiene, not food, spreads antibiotic-resistant E. coli superbugs. EurekAlert!. 22 Oct 2019. https://www.eurekalert.org/pub_releases/2019-10/uoea-pth102219.php.
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