U.S – The University of Texas (UT) Southwestern Medical Center’s researchers have figured out how Vibrio parahaemolyticus, a foodborne infection, spreads to humans after they consume raw or undercooked seafood, a development that could result in improved methods for treating diseases brought on by intestinal bacteria.
The work offers a new perspective on how enteric bacteria, when exposed to bile acids, effectively adapt and develop a virulence system. It gives the first visible proof of how a gut bacterial pathogen employs an “assembly method” to form syringe-like structures to inject toxins into intestine cells
V.parahaemolyticus, which is frequently found in warm coastal waters, is a major contributor to food poisoning from seafood. People who are afflicted frequently have chills, fever, cramps, vomiting, and diarrhea.
Experts have called attention to Vibrio as a growing food safety risk as a result of climate change and rising waterways.
Researchers already knew that the type III secretion system 2 (T3SS2), which resembles a syringe, is used by V. parahaemolyticus to inject chemicals into human cells. These 19 separate protein “syringes,” however, are not created or put together until the bacteria are within the intestines. Scientists were unsure of the precise mechanism causing this.
The most recent research expands on earlier discoveries in which fluorescent markers were used to tag specific V. parahaemolyticus T3SS2 components, which were then monitored using super-resolution microscopy as the bacteria were grown under various settings.
The researchers found that bile acids, which are digestive substances found in the intestines, cause V. parahaemolyticus to shift DNA encoding T3SS2 genes close to their membrane.
Then, at the precise location where the T3SS2 is required, V. parahaemolyticus converts the DNA into RNA, translates the RNA into protein, and transerts the T3SS2 components through the membrane.
It was previously believed that the assembly process took place in widely dispersed regions around a cell, but concentrating the machinery in one location on the bacterium’s membrane likely makes it easier for V. parahaemolyticus to construct the T3SS2 and infect cells.
The researchers speculate that the phenomena of transertion may be widely exploited because other intestinal bacteria have molecular components similar to V. parahaemolyticus.
According to the findings, additional gastrointestinal infections may potentially use the transertion mechanism to efficiently assemble complex molecular machines in response to environmental stimuli.
To find out which bacteria employ transertion to create their T3SS structures and whether medications may be created to stop transertion in order to treat infections with V. parahaemolyticus, more research is needed.
