Recent research conducted by Washington State University has unveiled a startling discovery – some of the world’s deadliest bacteria have a peculiar preference for human blood. Termed as ‘bacterial vampirism’ by the researchers, this phenomenon sheds light on how these pathogens target and consume serum, the liquid component of blood that serves as a rich source of nutrients.
The study, spearheaded by a team of experts led by Professor Arden Baylink from WSU’s College of Veterinary Medicine, highlights the attraction of certain bacteria to serum, particularly drawn to serine, an amino acid abundant in human blood and commonly found in protein beverages. Published in the journal eLife, these findings offer valuable insights into the mechanisms of bloodstream infections and potential avenues for treatment.
Professor Baylink emphasized the severity of bloodstream infections, stating, ‘Bacteria infecting the bloodstream can be lethal. We discovered that some of the bacteria responsible for such infections possess the ability to detect a chemical in human blood and actively move towards it.’
The research identified three bacterial strains – Salmonella enterica, Escherichia coli, and Citrobacter koseri – known to be prevalent causes of mortality among individuals with inflammatory bowel diseases (IBD), affecting approximately 1% of the global population. Patients with IBD often experience intestinal bleeding, creating vulnerable entry points for these bacteria to invade the bloodstream.
Utilizing an advanced microscopic system called the Chemosensory Injection Rig Assay developed by Professor Baylink, the team simulated intestinal bleeding scenarios by introducing minute quantities of human serum and observing the bacteria’s navigation towards the source. Remarkably, the bacteria exhibited swift responsiveness, reaching the serum within seconds.
Furthermore, the study revealed that Salmonella possesses a distinctive protein receptor named Tsr, enabling the bacteria to detect and move towards serum. Through protein crystallography, the researchers visualized the molecular interactions between the protein and serine, indicating the significance of serine as a key nutrient sensed and consumed by the bacteria.
Professor Baylink expressed optimism regarding the potential implications of this research, stating, ‘Understanding how these bacteria detect blood sources may pave the way for the development of novel therapeutics that can disrupt this mechanism.’ By targeting the bacteria’s ability to sense blood components, future medications could offer innovative approaches to combat bloodstream infections effectively.
