In their ongoing studies of how yeast (fungi) can infect a host and cause disease, a research team at the Life Sciences and Bioengineering Center at Worcester Polytechnic Institute (WPI) has made an unexpected discovery.
They found that yeast produce a hormone previously known to be made by plants, and that the presence of that hormone in sufficient quantity within the yeast's immediate environment triggers the fungal cells to become more infectious.
The WPI research team led by Reeta Prusty Rao, PhD, assistant professor of biology and biotechnology, working in collaboration with Jennifer Normanly, PhD, associate professor of biochemistry and molecular biology at the University of Massachusetts in Amherst, reported their findings in the paper "Aberrant synthesis of indole-3-acetic acid in Saccharomyces cerevisiae triggers morphogenic transition, a virulence trait of dimorphic pathogenic fungi" published in the May 2010 issue of the journal Genetics. The paper was featured in the "highlights" section of the journal, where the editors called it a "surprising finding."
"This is a well-known plant hormone. In fact, it was first described in plants by Charles Darwin in 1880," Prusty Rao said. "So we were surprised to see it made in yeast, and to see its impact on virulence traits of fungi that cause disease in people."
Commonly called baker's yeast or brewer's yeast, the fungus Saccharomyces cerevisiae (S. cerevisiae) does not cause human disease. It is, however, a model system for studying other fungi like Candida albicans (C. albicans) that do cause diseases like thrush and vaginal yeast infections, which affect millions of people each year and are not easily cleared by the handful of anti-fungal drugs currently available. While most fungal infections do not cause serious harm, if one spreads to the bloodstream it can be deadly. Hospitalized patients with catheters or central intravenous lines are at risk, as the fungi can grow on those devices and enter the body. Because of the lack of an effective treatment, the mortality rate for some systemic fungal infections is nearly 45 percent. Prusty Rao's lab explores the basic biology of yeast to better understand the processes of fungal infections and to identify potential targets for new drug development.
Before fungi begin to infect a host, they first undergo a dramatic physical change and grow filaments that look like twigs on a leafless tree. The hormone indole-3-acetic acid (IAA) regulates how plants grow, causing them to extend shoots towards sunlight. Previous work by Prusty Rao and others has shown that yeast take-up IAA from the environment to stimulate the growth of filaments. In the current study, Prusty Rao's team found that yeast also produce IAA themselves and secrete it into the environment around them. In this manner, the ongoing secretion and uptake of IAA presumably becomes a feedback loop giving the yeast information about the number of yeast nearby. If there are many yeast secreting IAA, then there is more in the environment to take up.
Furthermore, Prusty Rao's team found that when the concentration of IAA reached a certain threshold, the fungus began to change shape and grow filaments (see figure), providing "strong support" for a connection between the yeasts' production of IAA and fungal infection.
"If there is just one yeast cell sitting under your toe nail, then it won't be a problem—but if there are a thousand yeast cells there, then they can begin to filament and cause infection," Prusty Rao noted. "We believe the data show that IAA plays a role in the yeast's ability to know when there are sufficient numbers of them in close enough proximity to try and infect a host, be it a plant or a person."
About Worcester Polytechnic Institute
Founded in 1865 in Worcester, Mass., WPI was one of the nation's first engineering and technology universities. WPI's14 academic departments offer more than 50 undergraduate and graduate degree programs in science, engineering, technology, management, the social sciences, and the humanities and arts, leading to bachelor's, master's and PhD degrees. WPI's world-class faculty work with students in a number of cutting-edge research areas, leading to breakthroughs and innovations in such fields as biotechnology, fuel cells, information security, materials processing, and nanotechnology. Students also have the opportunity to make a difference to communities and organizations around the world through the university's innovative Global Perspective Program. There are more than 20 WPI project centers throughout North America and Central America, Africa, Australia, Asia, and Europe.
Michael Cohen | EurekAlert!
Kidney tumor: Genetic trigger discovered
18.06.2018 | Julius-Maximilians-Universität Würzburg
New type of photosynthesis discovered
18.06.2018 | Imperial College London
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.
Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...
Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...
Water molecules exist in two different forms with almost identical physical properties. For the first time, researchers have succeeded in separating the two forms to show that they can exhibit different chemical reactivities. These results were reported by researchers from the University of Basel and their colleagues in Hamburg in the scientific journal Nature Communications.
From a chemical perspective, water is a molecule in which a single oxygen atom is linked to two hydrogen atoms. It is less well known that water exists in two...
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
18.06.2018 | Earth Sciences
18.06.2018 | Process Engineering
18.06.2018 | Life Sciences