Some of the world’s deadliest bacteria seek out and feed on human blood, a newly-discovered phenomenon researchers are calling “bacterial vampirism.”
A team led by Washington State University researchers has found the bacteria are attracted to the liquid part of blood, or serum, which contains nutrients the bacteria can use as food. One of the chemicals the bacteria seemed particularly drawn to was serine, an amino acid found in human blood that is also a common ingredient in protein drinks.
The research finding, published in the journal eLife, provides new insights into how bloodstream infections occur and could potentially be treated.
“Bacteria infecting the bloodstream can be lethal,” said Arden Baylink, a professor at WSU’s College of Veterinary Medicine and corresponding author for the research. “We learned some of the bacteria that most commonly cause bloodstream infections actually sense a chemical in human blood and swim toward it.”
Baylink and the lead author on the study, WSU Ph.D. student Siena Glenn, found at least three types of bacteria, Salmonella enterica, Escherichia coli and Citrobacter koseri, are attracted to human serum. These bacteria are a leading cause of death for people who have inflammatory bowel diseases (IBD), about 1% of the population. These patients often have intestinal bleeding that can be entry points for the bacteria into the bloodstream.

Glenn, working with Assistant Professor Arden Baylink and colleagues, has published research showing
that some of the world’s deadliest bacteria seek out and eat serum, the liquid part of human blood.
Credit: Ted S. Warren, Washington State University College of Veterinary Medicine
Using a high-powered microscope system designed by Baylink called the Chemosensory Injection Rig Assay, the researchers simulated intestinal bleeding by injecting microscopic amounts of human serum and watching as the bacteria navigated toward the source. The response is rapid—it takes less than a minute for the disease-causing bacteria to find the serum.
As part of the study, the researchers determined Salmonella has a special protein receptor called Tsr that enables bacteria to sense and swim toward serum. Using a technique called protein crystallography, they were able to view the atoms of the protein interacting with serine. The scientists believe serine is one of the chemicals from blood that the bacteria sense and consume.
“By learning how these bacteria are able to detect sources of blood, in the future we could develop new drugs that block this ability. These medicines could improve the lives and health of people with IBD who are at high risk for bloodstream infections,” Glenn said.
Scientists Zealon Gentry-Lear, Michael Shavlik, and Michael Harms of the University of Oregon, and Tom Asaki, a mathematician at WSU, contributed to the research.
More information: Siena J. Glenn et al, Bacterial vampirism mediated through taxis to serum, eLife (2024). DOI: 10.7554/eLife.93178.2
Provided by Washington State University
News
Researchers highlight five pathways through which microplastics can harm the brain
Microplastics could be fueling neurodegenerative diseases like Alzheimer's and Parkinson's, with a new study highlighting five ways microplastics can trigger inflammation and damage in the brain. More than 57 million people live with dementia, [...]
Tiny Metal Nanodots Obliterate Cancer Cells While Largely Sparing Healthy Tissue
Scientists have developed tiny metal-oxide particles that push cancer cells past their stress limits while sparing healthy tissue. An international team led by RMIT University has developed tiny particles called nanodots, crafted from a metallic compound, [...]
Gold Nanoclusters Could Supercharge Quantum Computers
Researchers found that gold “super atoms” can behave like the atoms in top-tier quantum systems—only far easier to scale. These tiny clusters can be customized at the molecular level, offering a powerful, tunable foundation [...]
A single shot of HPV vaccine may be enough to fight cervical cancer, study finds
WASHINGTON -- A single HPV vaccination appears just as effective as two doses at preventing the viral infection that causes cervical cancer, researchers reported Wednesday. HPV, or human papillomavirus, is very common and spread [...]
New technique overcomes technological barrier in 3D brain imaging
Scientists at the Swiss Light Source SLS have succeeded in mapping a piece of brain tissue in 3D at unprecedented resolution using X-rays, non-destructively. The breakthrough overcomes a long-standing technological barrier that had limited [...]
Scientists Uncover Hidden Blood Pattern in Long COVID
Researchers found persistent microclot and NET structures in Long COVID blood that may explain long-lasting symptoms. Researchers examining Long COVID have identified a structural connection between circulating microclots and neutrophil extracellular traps (NETs). The [...]
This Cellular Trick Helps Cancer Spread, but Could Also Stop It
Groups of normal cbiells can sense far into their surroundings, helping explain cancer cell migration. Understanding this ability could lead to new ways to limit tumor spread. The tale of the princess and the [...]
New mRNA therapy targets drug-resistant pneumonia
Bacteria that multiply on surfaces are a major headache in health care when they gain a foothold on, for example, implants or in catheters. Researchers at Chalmers University of Technology in Sweden have found [...]
Current Heart Health Guidelines Are Failing To Catch a Deadly Genetic Killer
New research reveals that standard screening misses most people with a common inherited cholesterol disorder. A Mayo Clinic study reports that current genetic screening guidelines overlook most people who have familial hypercholesterolemia, an inherited disorder that [...]
Scientists Identify the Evolutionary “Purpose” of Consciousness
Summary: Researchers at Ruhr University Bochum explore why consciousness evolved and why different species developed it in distinct ways. By comparing humans with birds, they show that complex awareness may arise through different neural architectures yet [...]
Novel mRNA therapy curbs antibiotic-resistant infections in preclinical lung models
Researchers at the Icahn School of Medicine at Mount Sinai and collaborators have reported early success with a novel mRNA-based therapy designed to combat antibiotic-resistant bacteria. The findings, published in Nature Biotechnology, show that in [...]
New skin-permeable polymer delivers insulin without needles
A breakthrough zwitterionic polymer slips through the skin’s toughest barriers, carrying insulin deep into tissue and normalizing blood sugar, offering patients a painless alternative to daily injections. A recent study published in the journal Nature examines [...]
Multifunctional Nanogels: A Breakthrough in Antibacterial Strategies
Antibiotic resistance is a growing concern - from human health to crop survival. A new study successfully uses nanogels to target and almost entirely inhibit the bacteria P. Aeruginosa. Recently published in Angewandte Chemie, the study [...]
Nanoflowers rejuvenate old and damaged human cells by replacing their mitochondria
Biomedical researchers at Texas A&M University may have discovered a way to stop or even reverse the decline of cellular energy production—a finding that could have revolutionary effects across medicine. Dr. Akhilesh K. Gaharwar [...]
The Stunning New Push to Protect the Invisible 99% of Life
Scientists worldwide have joined forces to build the first-ever roadmap for conserving Earth’s vast invisible majority—microbes. Their new IUCN Specialist Group reframes conservation by elevating microbial life to the same urgency as plants and [...]
Scientists Find a Way to Help the Brain Clear Alzheimer’s Plaques Naturally
Scientists have discovered that the brain may have a built-in way to fight Alzheimer’s. By activating a protein called Sox9, researchers were able to switch on star-shaped brain cells known as astrocytes and turn them into [...]















