Scientists recently discovered different strains of deadly flesh-eating bacteria working together to spread infection and they now have a better understanding of the role of the toxins they produce. The discovery could change how the illness and other diseases are treated.
The findings are considered a positive step towards development of life-saving therapeutics to treat patients.
Led by Ashok Chopra, professor of microbiology and immunology at the University of Texas Medical Branch at Galveston in partnership with the Federal Drug Administration, CosmosID Inc., the University of Maryland and the Johns Hopkins University, the research studied a human case of necrotizing fasciitis and identified four strains of Aeromonas hydrophila that caused the infection. Three of the strains were closely related but one was different from the others.
Aeromonas hydrophila has been increasingly acknowledged as being responsible for necrotizing fasciitis, a rapidly-progressing skin and muscle tissue infection. The microbe is commonly found in fresh and brackish water, especially during warmer months. The infection can be acquired through cuts and scrapes in the skin.
“We provided evidence that presence of these multiple strains of Aeromonas hydrophila significantly influenced disease progression and outcome, more so than if only individual strains had been involved” said Chopra. “These four strains could be differentiated by using advanced laboratory technology but not by routine clinical procedures. What we found was that although mice were infected with all four strains, only one of the strains spread to the inner organs, namely the spleen and liver.”
This discovery could alter the way medical researchers think about this and other bacterial diseases that are commonly thought to be caused by a single species of bacterium.
This study was the first time scientists were able to determine the role that the ExoA toxin produced by the three similar strains of the bacteria plays in the infection process. Chopra said the plan is to extend analysis of these strains of Aeromonas hydrophila to find ways to prevent or lessen the toxin’s ability to break down muscle tissue.
Image courtesy of CDC, adapted.