New research published in The Lancet Infectious Diseases indicates that poor toilet hygiene is more likely to spread antibiotic-resistant E. coli than food.

As a news release on the research notes, E. coli has become considerably more antibiotic resistant in recent years in humans and animals. Particularly noteworthy are those strains of the bacteria with extended spectrum beta-lactamases (ESBL), which are enzymes that destroy many important penicillin and cephalosporin antibiotics.

Researchers set out to determine whether antibiotic-resistant E. coli that cause bloodstream infections are passed from person to person or acquired via the food chain. The scientists pursued this research by sequencing the genomes of resistant E. coli from multiple sources across the United Kingdom. These included human bloodstream infections, human feces, human sewerage, animal slurry, and variety of meat, fruit and salad.

The central conclusion: There was little crossover of ESBL-E. coli from animals to humans.

Lead author Prof. David Livermore, from the University of East Anglia's Norwich Medical School, said, in the release: "… the likeliest route of transmission for ESBL-E. coli is directly from human to human, with fecal particles from one person reaching the mouth of another. … We need to carry on cooking chicken well and never to alternately handle raw meat and salad. There are plenty of important food-poisoning bacteria, including other strains of E. coli, that do go down the food chain. But here — in the case of ESBL-E. coli — it's much more important to wash your hands after going to the toilet. … And it's particularly important to have good hygiene in care homes, as the most of the severe E. coli infections occur among the elderly."

The research — titled "Extended-spectrum β-lactamase-producing Escherichia coli in human-derived and foodchain-derived samples from England, Wales, and Scotland: an epidemiological surveillance and typing study" — was published in The Lancet Infectious Diseases on Oct. 22, 2019.