“Bacterial vampirism”

The finding that some of the deadliest bacteria on the planet have an odd hunger for human blood provides new insight into the causes of bloodstream infections and potential therapies.

This behavior, which scientists have dubbed “bacterial vampirism,” was described in a paper that was published on Tuesday in the journal eLife. It indicates that some bacteria are attracted to serum, the liquid portion of blood, where they scavenge for vital nutrients.

This substance found in our blood that we eat is likewise recognized as food by these harmful bacteria. They are swimming for human blood because they are drawn to it, according to Arden Baylink, a professor at Washington State University’s College of Veterinary Medicine and the study’s corresponding author.

Many of the microorganisms in here are presumably well-known to people. Salmonella and E. Coli, he said to Global News.

Multidrug-resistant Enterobacteriaceae pathogens, designated as “priority pathogens” by the World Health Organization, are the type of bacterium that the researchers examined. According to the WHO, these pathogens are members of a group of 12 bacterial families that are thought to pose the greatest threat to human health due to their resistance to antibiotics.

Additionally, according to Health Canada, enterobacterales are “opportunistic pathogens that cause different types of infections such as urinary tract infections, pyelonephritis, sepsis, pneumonia, and meningitis.”

The researchers showed that human blood attracts at least three Enterobacteriaceae pathogen species that are frequently present in people’s digestive tracts: salmonella, E. coli, and Citrobacter koseri.

According to Baylink, those who have inflammatory bowel illnesses (IBD), which include ulcerative colitis and Crohn’s disease, are more susceptible to these bacteria because they usually live in the gut.

“There won’t be much blood exposure in the digestive tract for average, healthy individuals. However, some people are more vulnerable than others,” he stated.

Some patients have intestinal bleeding that occurs on a regular basis. These individuals, which also include patients with inflammatory bowel disease, essentially have tiny, bleeding wounds inside of their intestines. That blood supply might serve as a food source for these infections.

Furthermore, microorganisms entering the bloodstream can ultimately result in death, according to Baylink.

“Bacterial vampirism”: what is it?

Although the increased risk of infection in individuals with inflammatory bowel disease (IBD) is well known, the exact processes by which these bacteria increase the likelihood of bloodstream entry are still poorly understood, he added.

Thus, Washington State University researchers desired to learn more.

The researchers accomplished this by injecting tiny volumes of human serum under a powerful microscope, simulating intestinal bleeding, and observing as the bacteria moved in the direction of the source.

The minuscule creatures known as bacteria are devoid of vision and hearing. However, they do possess a sense that is similar to scent. Therefore, the behavior known as chemotaxis is the sense of smell possessed by bacteria. They search for food as one of chemotaxis’ primary functions, according to Baylink.

Therefore, when you picture these bacteria swimming around, they are utilizing a behavior known as chemotaxis to find nutrition.

It turns out that our blood’s serum, which contains vital metals like iron and zinc as well as carbohydrates and amino acids, provides bacteria with an abundant supply of nutrition. One of the substances that the bacteria appeared to be most attracted to was serine, an amino acid that is frequently included in protein drinks and is present in human blood.

Baylink stated that they were “extremely surprised” by the findings after viewing them under a microscope and noticing that the bacteria seemed to be consuming human blood.

“They are visibly approaching it in a matter of seconds, and at the source in a matter of minutes, there is an overwhelming swarm of them. Thus, it is undeniably true that the serum has a strong attraction on them,” he stated.

The scientists named the bacteria “bacterial vampirism” because of their bloodlust.

What comes next?

The researchers stress the critical necessity for creating novel treatments in the future because the bacteria they studied are known to have strains that are resistant to drugs.

“We need to think of ways that we might be able to stop their infection in order to develop new therapeutics,” stated Baylink.

The theory is that this kind of study may eventually result in novel treatments. And that might make it less likely for these germs to get into the bloodstream.