This research award in the Chemistry of Life Processes (CLP) program supports work by Professor Abel-Santos at the University of Nevada Las Vegas to study the mechanism of Clostridium difficile spore germination using kinetic methods and molecular probes. Kinetic analysis of C. difficile spore germination is used to determine how small molecules (germinants) interact with C. difficile spores to induce germination. Using germinant analogs as activators and/or inhibitors of C. difficile spore germination allows defining which parts of the germinant molecules are required for interaction with the C. difficile germination machinery. Finally, photoreactive analogs serve to characterize which spore protein(s) bind to the germinants. These complementary experiments will allow mapping interactions between germinants and C. difficile spores. By using techniques from chemistry, biochemistry, and microbiology, we are able to study a hitherto intractable biological problem. The project has a broader impact on education, as a diverse group of students receives multidisciplinary training in chemistry, biochemistry, and microbiology to provide them with in-depth exposure to both physical and biological sciences.
Since spore germination is the fist step in establishing infection by C. difficile, a molecular-level understanding of how spores germinate could eventually lead to new approaches to prevent C. difficile associated disease. In a more general sense, sporulating bacteria are used beneficially to control agricultural insect pests. Furthermore, some sporulating bacteria species can be used to produce precursors used by the chemical and pharmaceutical industry. Thus, the chemical techniques and knowledge developed in this project will be applicable to understanding the germination process in important bacteria species.
Las Vegas Sun recently found that hospital-acquired C. difficile infection (CDI) is a growing problem in Las Vegas and the major cause of hospital-acquired diarrhea. Las Vegas is not alone; the U.S. experiences approximately 500,000 cases of CDI annually at a cost of more than $3.2 billion. Tragically, approximately 20,000 people succumb to CID annually. C. difficile is a bacterium that produces a very resistant spore that serves as a Trojan horse for infection. In healthy humans, beneficial bacteria in the intestines keep C. difficile spores from germinating and producing toxins. However, in hospitalized patients taking strong antibiotics, the beneficial bacteria are killed, leaving open ground for C. difficile. For the last eight years, the Abel-Santos laboratory at UNLV has been testing a simple hypothesis: since C. difficile spores do not cause disease until they transform into toxin-producing bacteria, blocking spore germination will prevent infections. Hence, rather than trying to cure CDI we want to prevent the infection from happening. An award form NSF has allowed the Abel-Santos laboratory to develop synthetic compounds (anti-germinants) to take the role of our intestinal bacterial defenders. In three recent scientific papers, the Abel-Santos laboratory demonstrated that anti-germinants can inhibit C. difficile spore germination and, as a result, prevent CDI in animals. Based on the data obtained at UNLV, the Abel-Santos laboratory, in collaboration with experts at UNLV, NSC, Wayne State University and the University of Nottingham, received a $3.4M award from the National Institute of Health. The main goal of this five-year drug-discovery grant is to obtain more potent and stable anti-germinants to prevent CDI at lower doses. The best anti-germinants could eventually be used in combination therapies to supplement antibiotic treatments in hospitals. A patient will start taking the anti-germinant simultaneously with each antibiotic dose. While the antibiotic is fighting infections, the anti-germinant will protect from CDI. Once the antibiotic regime is completed, the beneficial intestinal bacteria can grow back and return to the normal function of keeping C. difficile at bay. At this point, anti-germination therapy can also be stopped.
