Bacteria can live in the venoms of snakes and spiders


Recently published research from the University of Northumbria shows that, contrary to popular belief, the venom of snakes and spiders is actually populated by microbes, including bacteria that could cause infection in people. who have been bitten.

For decades, scientists have thought that animal venom is an entirely sterile environment because it’s full of antimicrobial substances — materials that can kill bacteria.

However, new scientific evidence from research led by Sterghios Moschos, associate professor of cell and molecular sciences at Northumbria University, and venom biologist Steve Trim, founder and CSO of biotech company Venomtech, has shown that this it’s not the case.

The work, published today in a scientific journal Microbiological spectrum demonstrates how adaptable microorganisms are. The study provides strong genetic and cultural evidence that bacteria can not only survive in the venom glands of several species of snakes and spiders, but can also mutate to resist the notoriously toxic liquid that is venom.

The findings also suggest that victims of poisonous animal bites may therefore also need treatment for infections, not just antivenom to combat toxins deposited by the bite.

The publication of the study follows news that Northumbria University’s research power continues to grow with results from the Research Excellence Framework (REF2021) showing Northumbria University with the largest increase of the research power ranking of all UK universities. Its search power ranking rose to 23rd, having reached 50th in 2014 from 80th in 2008, making Northumbria the industry’s highest search power ranking for the second time.

Challenging the dogma of the sterility of venom

Seeking to fill a gap in research, Dr. Moschos and his colleagues studied the venom of five species of snakes and two species of spiders. “We found that all of the poisonous snakes and spiders we tested had bacterial DNA in their venom,” Dr. Moschos explained.

“Common diagnostic tools have failed to correctly identify these bacteria – if you were infected with them, a doctor would end up giving you the wrong antibiotics, which could make things worse.

“When we sequenced their DNA, we clearly identified the bacteria and discovered that it had mutated to resist the venom. It’s amazing because the venom is like a cocktail of antibiotics, and it’s so thick with them, you would have thought the bacteria wouldn’t endure. Not only did they have a chance, but they did it twice, using the same mechanisms,” Dr. Moschos added.

“We also directly tested the resistance of Enterococcus faecalisone of the species of bacteria that we found in the venom of black-necked spitting cobras, to the venom itself and compared it to a typical hospital isolate: the hospital isolate was not tolerant of the venom at all, but our two isolates luckily grew in the highest concentrations of venom we could throw at them.”

Implications for clinical treatment

2.7 million poisonous bite injuries occur each year, mostly in Africa, Asia and Latin America. Of these, it is believed that 75% of victims will develop infections in tissue damaged by the venom toxin, along with bacteria Enterococcus faecalis being a common cause of disease.

These infections were previously thought to be the result of an open wound from the bite, as opposed to bacteria causing the infection from the venom itself.

The researchers say their study shows the need for clinicians to consider treating snakebite victims not only for tissue destruction, but also for infection, as quickly as possible.

Venomtech’s Steve Trim added, “By exploring the resistance mechanisms that help these bacteria survive, we can find entirely new ways to attack multi-drug resistance, potentially through the engineering of antimicrobial venom peptides.”


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