They discover that human blood attracts some deadly pathogens

Some of the world’s most deadly bacteria seek out and feed on human blood, a newly discovered phenomenon researchers are calling “bacterial vampirism.” The truth is that a team led by researchers at Washington State University (WSU) has discovered that bacteria are attracted to the liquid part of the blood, or serum, which contains nutrients that bacteria can use as food.

According to what was found by EurekAlert!, one of the chemicals that seemed to particularly attract bacteria was serine, an amino acid present in human blood that is also a common ingredient in protein drinks. The results of this study were published on eneLife on April 16. Arden Baylink, a professor at WSU’s Faculty of Veterinary Medicine and one of the corresponding authors of the study, indicated that “the bacteria that infect the bloodstream can be fatal.

Baylink and the study’s lead author, WSU doctoral candidate Siena Glenn, found that at least three types of bacteria, Salmonella enterica, Escherichia coli and Citrobacter koseri, are attracted to human serum. These bacteria are one of the leading causes of death for people suffering from inflammatory bowel disease (IBD), approximately 1% of the population. These patients usually have intestinal bleeding that allows bacteria to enter the bloodstream.

Chemical attraction

In a striking part of the study, the researchers found that Salmonella has a special protein receptor called Tsr, which allows bacteria to detect serum and swim to it. Using a technique called protein crystallography, they were able to see the atoms of the protein that interact with serine. Scientists believe serine is one of the chemicals in the blood that bacteria detect and consume.

“If we learn how these bacteria can detect blood sources, we can in the future develop new drugs that block this ability. These medications can improve the lives and health of people with IBD who are at high risk for bloodstream infections,” Glenn tells EurekAlert!

Scientists Zealon Gentry-Lear, Michael Shavlik and Michael Harms, from the University of Oregon, and Tom Asaki, a mathematician from WSU, participated in the work. The research was funded by WSU and the National Institute of Allergies and Infectious Diseases. Glenn said that “this chemical that is in our blood that we use as food is also something that these pathogenic bacteria recognize as food.” Hence the term ‘bacterial vampirism’, which is responsible for this process of feeding certain bacteria attracted to human blood.

Priority pathogens

The bacteria analyzed by the researchers are called multidrug-resistant Enterobacteriaceae pathogens The World Health Organization (WHO) has labeled the pathogens as ‘priority pathogens’These pathogens belong to a group of 12 bacterial families that are considered the most significant threat to human health due to their resistance to antibiotics, the WHO said.

Enterobacteria can also be “opportunistic pathogens that cause various types of infections, such as urinary tract infections, pyelonephritis, sepsis, pneumonia, and meningitis.”,” according to Health Canada. Baylink explained Global news that people with inflammatory bowel diseases (IBD), such as Crohn’s disease and ulcerative colitis, are particularly vulnerable to these bacteria, which are usually found in the intestines.

For the work, the researchers used a high-powered microscope and simulated intestinal bleeding by injecting microscopic amounts of human serum and observing how the bacteria navigated to the source. ‘Bacteria are microscopic organisms that have no eyes or ears. But they do have something analogous to the sense of smell. Bacteria’s sense of smell is a behavior called chemotaxis. One of the main functions of chemotaxis is the search for food” explains Baylink.