Identify what makes certain strains of gut bacteria life-threatening in premature babies

Researchers from the Quadram Institute and the University of East Anglia have identified what makes certain strains of gut bacteria potentially deadly in premature babies.

The results will help identify and track dangerous strains and protect vulnerable newborns.

Necrotizing enterocolitis (NEC) is a major threat to extremely low birth weight newborns.

Rare in full-term babies, this microbial infection exploits vulnerabilities by destroying intestinal tissue, leading to serious complications. Two out of five cases are fatal.

A bacterial species that causes particularly sudden and severe illness is Clostridium perfringens. These are common in the environment and non-pathogenic strains live in healthy human intestines.

So what makes certain strains so dangerous in premature babies?

Professor Lindsay Hall and Dr Raymond Kiu of the Quadram Institute and UEA conducted the first major study on C.perfringens genomes of premature babies, including some babies with necrotizing enterocolitis.

The research team analyzed C.perfringens genomes of faecal samples from 70 babies admitted to five neonatal intensive care units (NICUs) in the UK.

Based on genomic similarities, they found that one set had a lower ability to cause disease. This allowed a comparison with the most virulent strains.

The less virulent group lacked genes responsible for producing a toxin called PFO and other factors needed for colonization and survival.

This study began building genomic signatures for C.perfringens associated with healthy premature babies and those with necrotizing enterocolitis.

Explore the genomic signatures of hundreds of Clostridium perfringens enabled us to distinguish between the “good” bacterial strains that live harmlessly in the intestines of premature infants and the “bad” ones associated with the devastating and deadly disease of necrotizing enterocolitis.

We hope the results will help ‘track’ the deaths C.perfringens strains in a very vulnerable group of patients – premature babies. »

Prof Lindsay Hall, UEA Norwich Medical School and Quadram Institute

Larger studies, at more sites and with more samples may be needed, but this research could help identify better ways to control necrotizing enterocolitis.

The team previously worked alongside Professor Paul Clarke and his clinical colleagues at the NICU at Norfolk and Norwich University Hospital. And they have demonstrated the benefits of providing newborns with probiotic supplements.

The gut microbiota of neonatal enterocolitis is significantly disrupted, making it susceptible to C.perfringens overgrowth.

Professor Hall said: “Our genomic study gives us more data that we can use in the fight against bacteria that cause illness in babies – where we harness the benefits of another microbial resident, Bifidobacteriumto give at-risk babies the best possible start in life.”

Dr Raymond Kiu, from the Quadram Institute, said: “It is important to note that this study highlights whole genome sequencing as a powerful tool for identifying novel bacterial lineages and determining bacterial virulence factors at of the strain, which allows us to better understand the disease.

This research was supported by the Biotechnology and Biological Sciences Research Council, part of UKRI, and the Wellcome Trust.

The study was led by researchers from the Quadram Institute and the University of East Anglia, together with colleagues from Imperial College London, University of Glasgow, University of Cambridge, Newcastle University and Northumbria University.

“Special genomic and virulence traits associated with preterm infant-derived toxigenicity Clostridium perfringens strains” is published in Natural microbiology.