Scientists have discovered that the bacterium that infects the Clostridium difficile intestine is evolving into two separate species, with a highly adapted group to spread to hospitals.
Researchers from the Wellcome Sanger Institute, the Hudson Institute of Medical Research and the London School of Hygiene and Tropical Medicine and collaborators have identified genetic changes in emerging species that allow them to thrive on a diet rich in western sugar, evade the common hospital disinfectants and spread easily. The researchers estimate that this emerging species, which can cause debilitating diarrhea, began to appear thousands of years ago and represents over two-thirds of C. difficile infections in the health sector.
Published in Nature Genetics, the largest genomic study ever conducted on C. difficile shows how bacteria can evolve into a new species and shows that C. difficile continues to evolve in response to human behavior. The results could help inform patients' diet and infection control in hospitals.
C. difficile bacteria can infect the intestine and are the leading cause of antibiotic-associated diarrhea worldwide *. In a healthy person who is not taking antibiotics, millions of "good" bacteria in the intestine keep C. difficile under control. However, antibiotics eliminate normal intestinal bacteria, leaving the patient vulnerable to C. difficile infection in the intestine. This is therefore difficult to treat and can cause intestinal inflammation and severe diarrhea.
Often found in hospital settings, C. difficile forms resistant spores that allow it to remain on the surface and spread easily among people, making it a significant burden on the health system. To understand how this bacterium is evolving, the researchers collected and cultivated 906 strains of C. difficile isolated from humans, from animals, such as dogs, pigs and horses, and from the environment. By sequencing the DNA of each strain and comparing and analyzing all the genomes, the researchers found that C. difficile is currently evolving into two separate species.
The leading expert on bacterial genomics and author of paper articles, Dr. Sam Forster of the Hudson Institute said: "This work provides a new perspective on C. difficile outbreaks and how to manage them, especially in environments such as hospitals and aged care facilities. The study demonstrates how detailed genomic understanding of the Fundamental research can provide important insights into how our behavior shapes the pathogenic bacteria we encounter.
The dott. Nitin Kumar, first joint author of the Wellcome Sanger Institute, said: "Our large-scale genetic analysis has allowed us to discover that C. difficile is currently forming a new species with a group specializing in spreading in hospital environments. This emerging species It has existed for thousands of years, but this is the first time that someone has studied C. difficile genomes in this way to identify it.This particular bacterium has been primed to exploit modern health practices and human diets, even before the hospitals. "
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