The Quave Research Group at Emory University focuses on drug discovery efforts to improve treatment options for drug-resistant bacterial infections with natural products derived from medicinal plants. We use the ethnobotanical approach to drug discovery. This involves conducting ethnobotanical field research in which they study and document traditional medical practices for the treatment of infectious disease. The plants used in these traditional remedies are then brought back to the laboratory for chemical extraction followed by testing using a series of anti-bacterial bioassays and tests for mammalian toxicity. In particular, research efforts are focused on blocking pathogenesis and virulence pathways rather than bacterial growth. Simply put, by using natural products to turn off bacterial defense mechanisms (i.e. biofilms), one can make the organisms more susceptible to antibiotic action. Likewise, by turning off bacterial offense mechanisms (i.e. toxins), one can reduce the damage that bacteria do to the host during an infection, enabling the host immune response and antibiotics to clear the infection.
To date, there are no anti-virulence drugs available on the pharmaceutical market for S. aureus infection, though many agree that such drugs are desperately needed. As a graduate student, Quave documented the use of plants in the treatment of skin and soft tissue infection in traditional south Italian folk medicine. She was the first to document the quorum-quenching effects of medicinal plant products in a staphylococcal model. She then spent ~3 years as a postdoctoral fellow at UAMS, where she concentrated on the bioassay-guided fractionation of natural product extracts, testing them against other pathogenesis targets such as biofilms, in particular. This work on staphylococcal pathogenesis targets led to UAMS filing a patent to protect the discovery of an anti-biofilm agent. Dr. Quave then co-founded the start-up biotech company PhytoTEK LLC with Sahil Patel, MBA to continue R&D efforts on this and other anti-pathogenesis drugs.
Dr. Quave and her lab team continue these research efforts at Emory University by developing novel solutions to the issue of antibiotic resistant infections. Their core approach in these efforts is based on the study of medicinal plants for their capacity to target pathogenicity via interruption of bacterial signaling (quorum sensing-mediated toxin production) and interference with biofilm formation. This is truly a non-traditional approach to assessing medicinal plants for potential clinical applications. The advantages of targeting bacterial virulence rather than growth are multifold, and such therapies can work by enhancing the ability of the host immune response to clear an infection while avoiding some of the selective pressures responsible for the development of resistance.
Quave’s emphasis on studying staphylococcal infection as a drug target is deeply personal. She was born with multiple congenital orthopaedic birth defects, which included the lack of her right fibula, several tarsals and metatarsals, an underdeveloped right femur, and hip dysplasia. In an effort to give her better mobility with a prosthetic device, her right leg was amputated below the knee when she was 3 years old. However, following the surgery, she developed a relentless, life-threatening staphylococcal infection at the surgical site. By the time that the infection was detected, she had a severe case of osteomyelitis and had lost most of the fatty tissue that covered the stump. Fortunately, in 1982, MRSA wasn’t as commonplace as it is today, and the MSSA infection was treatable only after vigorous antibiotic therapy, debridement, months of betadine bath treatments, and additional revisions of the distal limb. The reason that the recovery was so difficult is because of the recalcitrant nature of biofilm-associated infections – which are typically impervious to antibiotic treatment regardless of any acquired antibiotic resistant traits.
It is her strong belief that the solution to toxin-mediated and biofilm-associated staphylococcal infection may lay with medicinal plant products, such as those addressed in her work. It is for this reason that she is highly motivated and determined to develop new approaches in the treatment of infectious disease using clues offered by complementary and alternative medicine.
To learn more about our research, please visit the publications page on this website where you can access pdfs of most of our publications. A list of the Quave Research Group’s research funding sources is available on the site. The Quave Lab also accepts charitable donations to support our research program. Click here for more information on how to give to the lab using Emory’s donation site.