The United States Government’s medical research agency, National Institutes of Health (NIH), investigated new “hypervirulent” bacterial strains Klebsiella pneumoniae (K. pneumoniae), responsible for infections, pneumonia and sepsis, and to which ICU patients are particularly vulnerable, in healthy people in community settings.
The NIH is studying how the human immune system defends itself against infections caused by these multidrug-resistant bacteria. After exposing the evolved strains to immune system components in the laboratory, scientists discovered that some strains are more likely to survive in blood and serum than others and that neutrophils (white blood cells) are more likely to eat and kill certain strains.
“This important study is one of the first to investigate the interaction of these emerging species in Klebsiella pneumoniae that contain components of the human host’s defense,” said acting director of the NIH’s National Institute of Allergy and Infectious Diseases (NIAID), Hugh Auchincloss. “The work demonstrates the strength of NIAID’s Intramural Research Program. “Having strong research teams with established collaborations allows researchers to build on previous work and quickly inform their peers about new and increasingly important public health topics,” he added.
Severe infections
Scientists have known K. pneumoniae more than a century ago as a cause of serious human infection and often fatal, mainly in people who are already sick or have a weak immune system and especially in people who are hospitalized.
Some strains have developed resistance to many antibiotics and become difficult to treat. This bacteria, K. pneumoniae classically, ranks third among the most common pathogens isolated from hospital-acquired bloodstream infections. Some strains of K. pneumoniae cause serious infections in healthy people in community settings (outside hospitals), although they are not multidrug resistant and are known as K. pneumoniae hypervirulent (hvKp). Recently, strains with hypervirulence and multidrug resistance characteristics, the so-called MDR hvKp, have emerged in both environments.
NIAID scientists have studied this phenomenon before. In the early 2000s, they observed and analyzed virulent strains of bacteria Staphylococcus aureus methicillin-resistant strains emerging in US community settings and causing widespread infections in healthy people.
Now, the same research team at NIAID is investigating the same aspects of the new strains. of Klebsiella For example, whether microbes can evade the defenses of the human immune system. Their findings are as follows: hvKp strains are more likely to survive in blood and serum than hvKp MDR strains. And the neutrophils ate less than 5 percent of the hvKp strain, but more than 67 percent of the MDR hvKp strain, most of which died.
Likewise, the researchers found “can” a vaccine procedure for the prevention and treatment of infections caused by these strains.
Now, the research team will determine the Factors associated with susceptibility to MDR hvKp of the body’s immune defenses using mouse infection models. Something that may lead to the possibility of developing treatment strategies to prevent or reduce the severity of the disease.
