Researchers at Washington State University have discovered a new phenomenon that they are calling “bacterial vampirism,” in which some of the world’s deadliest bacteria are attracted to and feed on human blood. The bacteria are specifically drawn to the liquid part of blood, known as serum, which contains nutrients that they can use as food. One of the chemicals that the bacteria seem particularly attracted to is serine, an amino acid that is commonly found in human blood and protein drinks. This research finding, published in the journal eLife, sheds new light on how bloodstream infections occur and could potentially lead to new treatments for these deadly infections.
The team of researchers, led by Professor Arden Baylink and WSU Ph.D. student Siena Glenn, found that bacteria such as Salmonella enterica, Escherichia coli, and Citrobacter koseri are all attracted to human serum. These bacteria are known to be leading causes of death in individuals with inflammatory bowel diseases (IBD), who are at a higher risk of developing bloodstream infections due to intestinal bleeding. Using a specialized microscope system called the Chemosensory Injection Rig Assay, the researchers were able to simulate intestinal bleeding by injecting tiny amounts of human serum and observing how the bacteria quickly navigated towards the source.
In their study, the researchers also discovered that Salmonella has a unique protein receptor called Tsr that enables the bacteria to sense and swim towards serum. By using protein crystallography, the scientists were able to observe the interactions between the atoms of the protein and serine, leading them to believe that serine is one of the chemicals from blood that the bacteria detect and consume. Understanding how these bacteria are able to detect sources of blood could potentially lead to the development of new drugs that block this ability, ultimately improving the lives and health of individuals with IBD who are at high risk for bloodstream infections.
The study was a collaborative effort involving scientists from the University of Oregon and Washington State University, as well as a mathematician from WSU. The research was funded by Washington State University and the National Institute of Allergy and Infectious Diseases. This groundbreaking research provides valuable insights into the mechanisms behind bloodstream infections caused by bacteria that are attracted to human blood, and opens up new possibilities for the development of targeted treatments to prevent these deadly infections in individuals with IBD.
Overall, the discovery of bacterial vampirism sheds new light on the behavior of certain deadly bacteria that seek out and feed on human blood. By understanding how these bacteria are able to sense and consume blood, researchers hope to develop new drugs that can prevent bloodstream infections in high-risk populations such as individuals with inflammatory bowel diseases. This research has the potential to save lives and improve the health outcomes of those who are most vulnerable to these deadly infections. Collaborative efforts and innovative techniques, such as the Chemosensory Injection Rig Assay, have been instrumental in unraveling the mysteries behind bacterial vampirism and providing new insights into the mechanisms of bloodstream infections.
