The Department of Biology at the University of Oxford has now published a new study that provides the first concrete proof of the spread of antibiotic-resistant bacteria from a patient’s gut microbiome to the lungs in Nature Communications.
Applying the study’s findings could save lives since it emphasizes how crucial it is to stop pathogenic germs from spreading from the gut to other organs where they can result in dangerous illnesses.
The Pseudomonas aeruginosa bacterium was found in the gut microbiome of the patient for the investigation. One of the most common germs to infect patients in hospitals is this species, which is also highly resistant to antibiotics. Pseudomonas is typically not regarded as harmful when it is incorporated into a healthy gut microbiome, but it can cause life-threatening infections in the lungs of hospitalized patients.
The patient received antibiotic Meropenem during their hospital stay for a possible urinary tract infection (UTI). After receiving meropenem treatment, non-resistant bacteria in the gut and lungs were eliminated, allowing Pseudomonas mutants that are resistant to antibiotics to flourish.
Then, during antibiotic therapy, it was discovered that Pseudomonas translocated from the gut to the patient’s lungs, where it developed even higher levels of drug resistance.
AMR is becoming a bigger problem in hospitals, therefore it’s crucial for patients who are already at risk to stop the germs from spreading to other crucial organs like the lung. It can be challenging to pinpoint the source of the bacteria that cause these dangerous illnesses, though. This work demonstrates how the gut microbiome might serve as a reservoir for AMR infections that can move to the lungs and potentially cause deadly diseases like pneumonia.
There is a clear need to develop new approaches to the challenges that antimicrobial resistance presents. Our study shows how gut-lung translocation and antibiotic use can combine to drive the spread of AMR within a single patient. Insights such as this are needed in order to develop new interventions to prevent resistant infections. For example, our study highlights a potential benefit of eliminating AMR bacteria like Pseudomonas aeruginosa from the gut microbiome of hospitalized patients, even when these bacteria are not actually causing infection.
Professor Craig MacLean
The results of this study demonstrate how antibiotic use can have significant effects on bacteria that are not the real targets of antibiotic treatment and imply that removing AMR pathogens from the gut microbiome of hospitalized patients may assist to prevent serious infections.
To gauge how long the patient had been infected with Pseudomonas, researchers examined them periodically while they were in the hospital. They took a genomic approach, building a time-calibrated bacterial family tree that gave scientists the ability to examine the evolution of the infection as well as its progression and location. They also found high genetic diversity in the gut, which also suggests that the microbiome may be a reservoir for AMR to arise.
The patient in this situation fortunately developed an immunological response to the AMR bacteria in their lungs, preventing pneumonia from developing as a result of the infection. However, a reduced immune system is common in persons in dire situations, especially during the winter, making the body less capable of warding off disease. AMR strategies frequently concentrate on minimizing infection from outside sources, but it’s equally important to comprehend how AMR can arise and spread inside a patient.
By collecting samples from a much larger cohort, the researchers now plan to determine how frequently gut to lung bacterial translocation occurs in susceptible patients.
Professor Craig MacLean, Professor at the Department of Biology, said:
“There is a clear need to develop new approaches to the challenges that antimicrobial resistance presents. Our study shows how gut-lung translocation and antibiotic use can combine to drive the spread of AMR within a single patient. Insights such as this are needed in order to develop new interventions to prevent resistant infections. For example, our study highlights a potential benefit of eliminating AMR bacteria like Pseudomonas aeruginosa from the gut microbiome of hospitalized patients, even when these bacteria are not actually causing infection.”
“AMR pathogens can be difficult to eliminate from patients once they have become established, and our work also underscores the importance of avoiding unnecessary antibiotic use, and in developing antibacterial treatments that only target the bacteria that are actually causing an infection.”
