How Do Bacteria Fighting Against Drugs Spread Infection

The first direct evidence of antibiotic-resistant bacteria migrating from a patient’s gut microbiome to the lungs has been found by the Department of Biology, the University of Oxford in a new study released in Nature Communications. Applying the findings of this study could save lives, as it highlights the importance of preventing pathogenic bacteria from translocating from the gut to other organs where they can cause serious infections.

The study was conducted on a patient that carried the bacterium Pseudomonas aeruginosa as part of their gut microbiome. This species is one of the leading causes of infections in hospitals, and one that is particularly good at resisting antibiotics.

Whilst Pseudomonas is generally not considered to be dangerous when it is embedded in a healthy gut microbiome, it can cause serious infections in the lungs of hospitalized patients.

Antibiotic Resistant Bacteria Travelling from Gut to Lungs Increase Infection Risk?

During their stay in the hospital, the patient was treated with the antibiotic Meropenem for a suspected urinary tract infection (UTI). Meropenem treatment caused non-resistant bacteria in the gut and lung to be killed off, and antibiotic-resistant mutants of Pseudomonas were able to grow and proliferate.

Pseudomonas was then found to translocate from the gut to the patient’s lungs during antibiotic treatment, where it evolved even higher levels of antibiotic resistance.

With AMR being an increasing concern in hospitals, preventing the spread of AMR bacteria to other vital organs such as the lung is critical in vulnerable patients. However, the origin of bacteria that cause these serious infections can be difficult to determine.

This study shows how the gut microbiome can act as a reservoir of AMR pathogens that can translocate to the lung where they have the potential to cause life-threatening illnesses such as pneumonia.

Advertisement

The findings of this study suggest that eliminating AMR pathogens from the gut microbiome of hospitalized patients could help to prevent serious infections, and it highlights how antibiotic use can have profound impacts on bacteria that are not the target of antibiotic treatment.

Researchers tested the patient throughout their time in the hospital to track the duration of their infection with Pseudomonas. They used a genetic approach, creating a time-calibrated bacterial family tree that allowed them to analyze the progression and location of the infection, plus its evolution.

Advertisement

Fortunately, the patient, in this case, had an immune response to the AMR bacteria in their lungs, preventing the infection from causing pneumonia. However, many people in critical conditions, particularly over winter, have a weakened immune system, meaning the body is less able to fight off disease.

AMR policies often focus on reducing infection from external sources, but understanding how AMR can develop and spread within a patient is just as vital. Researchers now intend to assess how frequently gut-to-lung bacterial translocation occurs in vulnerable patients by collecting samples from a much larger population.



Source-Eurekalert