Researchers have found a key factor that contributes to the spread of hospital-acquired infections (HAIs), shedding light on why these infections are particularly challenging. Their study shows that the dangerous multidrug-resistant pathogen Klebsiella thrives in environments in hospitals where there is a lack of nutrients and a mix of different microorganisms.
HAIs, according to the World Health Organization, pose significant dangers to patients, leading to longer hospital stays, severe health issues, and a mortality rate of around 10%. One of the major challenges in treating HAIs is that the pathogens are resistant to multiple drugs. In a recent study published in the journal Microbiome, researchers at ADA Forsyth Institute (AFI) found that Klebsiella present in healthy individuals not only naturally resist multiple drugs but also become dominant in the bacterial community when there is a lack of nutrients.
Lead researcher Batbileg Bor, Ph.D., associate professor at AFI, explained, “Our study showed that Klebsiella can outcompete other microorganisms in its environment when nutrients are scarce. We examined saliva and nasal samples and noticed that Klebsiella quickly thrived and took over the microbial community as other bacteria died off under starvation conditions.”
Klebsiella is among the top three pathogens responsible for HAIs like pneumonia and irritable bowel disease. While they typically exist harmlessly in the mouths and noses of healthy individuals, they can become harmful under certain circumstances. Dr. Bor added, “Hospitals provide the perfect setting for Klebsiella to spread, with surfaces contaminated by nasal or saliva droplets, sink drains, and the mouths and throats of patients on ventilators, all creating nutrient-deprived environments.”
He further noted, “When patients are on ventilators and not receiving food orally, the bacteria in their mouths lack nutrients, potentially allowing Klebsiella to thrive at the expense of other oral bacteria. This way, the mouth and nose can become reservoirs for various harmful pathogens.”
Klebsiella can also sustain itself by feeding on dead bacteria, enabling it to survive long periods without nutrients. Researchers observed that Klebsiella could persist for more than four months after being deprived of nutrition when present in oral or nasal samples.
Another interesting finding was that Klebsiella from the nasal cavity, a less diverse environment in terms of microbes, was more prevalent and abundant compared to Klebsiella from the oral cavity, which has a more diverse microbial community. This suggests that microbial diversity and specific non-harmful bacteria in saliva may help prevent the excessive growth of Klebsiella species.
The groundbreaking research by AFI scientists provides new insights into how hospital-acquired infections spread, offering potential for improved prevention strategies and treatments.
The study had collaborations with researchers from various institutions, including ADA Forsyth, California Institute of Technology, Sichuan University, Guarulhos University, and Oregon Health & Science University.
Funding:
The research received partial support from grants from the National Institute of Dental and Craniofacial Research of the National Institutes of Health.
