Scientists have identified new genes linked to how Streptococcus pyogenes survives in humans and causes pharyngitis.
Streptococcus pyogenes (group A streptococcus [GAS]) causes 600 million cases of pharyngitis each year. However, the molecular mechanisms used by GAS to infect, cause pharyngitis, and persist in the human oropharynx are poorly understood.
A team from the Animal Health Trust (AHT) and Houston Methodist Research Institute used transposon-directed insertion site sequencing (TraDIS) to learn how GAS survives and proliferates in saliva in order to gain insights into the molecular mechanisms at work in the oropharynx. Their research was published recently in mSphere.
There are approximately 1,800 genes in Streptococcus pyogenes that are required for it to infect humans. The process of unraveling the disease-causing processes of bacteria has traditionally needed to be carried out one gene at a time. However, scientists at the AHT working on Streptococcus equi ,a close relative of Streptococcus pyogenes that causes strangles in horses, developed a new technique that enables every gene in the bug to be tested at once.
This novel technique was used by the researchers in Houston in their study of Streptococcus pyogenes. Using it, the Houston scientists were able to identify 92 genes that were needed by GAS to grow in human saliva in the lab.
“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.”
“We are delighted that a technique developed at the AHT to learn more about Streptococcus equi and strangles in horses has provided new results that could benefit people too,” said Dr. Andrew Waller, head of bacteriology at the AHT. “We have learned 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.”