In a global first, scientists have estimated how fast Escherichia coli (E. coli) bacteria can spread between people — revealing that one strain moves as rapidly as the swine flu.
Using genomic data from the UK and Norway, researchers from the Wellcome Sanger Institute, University of Oslo, University of Helsinki, and Aalto University developed a model to calculate bacterial transmission rates. Their findings, published in Nature Communications on November 4, shed new light on how antibiotic-resistant bacteria circulate in communities and hospitals.
The team examined three major E. coli strains found in the UK and Norway — two of which were resistant to multiple antibiotic classes and responsible for most urinary tract and bloodstream infections. The study found that one strain, ST131-A, spreads between people as quickly as some viral pathogens, such as H1N1 swine flu — despite not being airborne.
Researchers achieved this breakthrough by estimating the basic reproduction number (R₀) for gut bacteria for the first time. They used a new modelling platform, ELFI3 (Engine for Likelihood-Free Inference), combining data from the UK Baby Biome Study and national infection surveillance programs.
The results could transform how public health agencies monitor bacterial transmission and respond to outbreaks. The model may also help identify genetic factors that drive bacterial spread, paving the way for targeted treatments and reducing dependence on broad-spectrum antibiotics.
The researchers suggest the same approach could be extended to other pathogens to improve strategies for controlling invasive infections.