Pseudomonas aeruginosa is an environmental bacteria that can cause multidrug-resistant severe infections, especially in people with lung conditions. A new study found that it evolved quickly and spread worldwide over the last 200 years, likely due to changes in human behavior.
“It’s amazing how fast these bacteria evolve and become epidemic, specializing in lung infections,” said Aaron Weimann.
P. aeruginosa causes over 500,000 deaths yearly, with over 300,000 linked to antimicrobial resistance. People with COPD, cystic fibrosis, and similar conditions are most at risk.
An international team led by scientists at the University of Cambridge studied DNA from nearly 10,000 samples to understand how P. aeruginosa evolved into a human pathogen. Their findings are published today in Science.
By mapping the data, the team created ‘family trees’ to show how bacteria samples are related. Almost 70% of infections come from just 21 genetic clones. These clones evolved rapidly by acquiring new genes. They have spread globally over the last 200 years, likely due to people living in densely populated areas with more air pollution.
These clones prefer infecting specific patient types, like those with cystic fibrosis (CF). The bacteria exploit an unknown immune defect in CF patients, allowing them to survive inside macrophages (cells that generally destroy bacteria). Once the bacteria infect the lungs, they become more specialized, with different clones infecting CF and non-CF patients separately.
Professor Andres Floto said, “Our research on Pseudomonas taught us new things about cystic fibrosis and ways to improve immunity against bacteria.”
This study revealed important information about Pseudomonas. It can spread quickly between CF and non-CF patients, affecting hospital infection control. It’s crucial to protect vulnerable patients in open wards.
“At Royal Papworth Hospital, we are fortunate to have single rooms and a new air-handling system to reduce airborne bacteria,” said Professor Andres Floto.
Dr. Aaron Weimann added, “It’s amazing how quickly these bacteria evolve and become epidemic, specializing in lung environments. We need systematic screening of at-risk patients to detect and prevent new epidemic clones.”
In conclusion, scientists have traced the rapid evolution and global spread of deadly bacteria over the last 200 years. This research highlights how changes in human behavior and living conditions have driven the transformation of bacteria into epidemic-causing agents, emphasizing the need for improved infection control and proactive screening to prevent future outbreaks.
Journal reference:
- AARON WEIMANN, ADAM M. DINAN et al., Evolution and host-specific adaptation of Pseudomonas aeruginosa. Science. DOI: 10.1126/science.adi0908.