A new research technique developed to investigate Strangles in horses has helped scientists in human medicine better understand the bacteria that causes many of us to become hoarse.
World-leading scientists at the Houston Methodist Research Institute, working with the British-based Animal Health Trust, have identified new genes linked to how Streptococcus pyogenes, the infection responsible for a sore throat, survives in saliva from people.
The technique they used to support this discovery was developed by the trust to better understand Streptococcus equi, which causes Strangles, where horses suffer from large pus-filled abscesses in their throat and neck.
With an estimated 600 outbreaks of Strangles each year in Britain alone, the trust has spent many years examining how the bug causes disease, to be able to develop effective vaccines to prevent such outbreaks occurring in the first instance.
To do this, its scientists constructed a new method for identifying the most important genes for the bug’s survival in different conditions. It is this technique that has been shared with human medicine counterparts, enabling the analysis of this human pathogen.
This example of the transfer of knowledge between veterinary and human research under the umbrella of “one medicine” has huge potential to enhance scientific knowledge to the benefit of both animals and humans.
The head of bacteriology with the trust, Dr. Andrew Waller, said he was delighted that a technique developed at the trust to learn more about S. equi and Strangles had provided new results that could benefit people, too.
“We have learnt a huge amount about our bug through following the work being done on human diseases, and it is great to be able to give something back in return.
“This study highlights the similarities of animal and human pathogens. We hope that our technique will also prove useful for the study and prevention of other diseases, regardless of the animal they affect.”
Humans at risk
The number of cases of infections caused by S. pyogenes around the world has increased dramatically over the past 20 years. This bug is responsible for an estimated 600 million cases of pharyngitis (a sore throat) in people each year. The bacteria is also responsible for a further 100 million cases of invasive disease including scarlet fever, acute rheumatic fever and the flesh-eating disease necrotising fasciitis, the onset of which often follows on from initial cases of pharyngitis.
However, despite the cost to human health, relatively little is known about which of the 1800 or so genes in S. pyogenes are required for it to infect people, and persist in their throats.
Helped by horses
The process of unravelling the disease-causing processes of bacteria has traditionally needed to be carried out one gene at a time. However, the new trust technique enables the importance of every gene in the bug to be tested at once.
The Houston scientists were quickly able to identify 92 genes that were needed by S. pyogenes to grow in human saliva in the lab, replicating the critical first stage required on the path it uses to cause disease in people.
“The ability to establish the importance of every gene in Streptococcus pyogenes within one experiment has the potential to accelerate research into this important human pathogen,” explains Dr James Musser, Professor of Pathology and Genome Medicine at the Houston Methodist Research Institute.
“In follow-on tests, we were immediately able to confirm that six of these new genes really did affect growth in human saliva, suggesting that this new information has exciting potential for developing novel therapeutics and vaccines with which to improve human health.”
A paper on the saliva-related research has been published in the open-access journal of the American Society for Microbiology, mSphere.
Novel Genes Required for the Fitness of Streptococcus pyogenes in Human Saliva
Luchang Zhu, Amelia R. L. Charbonneau, Andrew S. Waller, Randall J. Olsen, Stephen B. Beres, James M. Musser