Quave to lead workshop and present on research at SEB meetings

June 28-July 2, 2013. Dr. Quave will lead a workshop and present research findings at the annual meeting of the Society for Economic Botany, to be held in Plymouth England. The workshop and paper abstracts are found below:

Getting Our Lessons Across to Students                   Saturday 29 June, 13.45-15.15

Workshop Sponsored by the Open Science Network (OSN)

Cassandra Quave, cquave@emory.edu

This workshop will focus on discussing strategies to get our lessons across to students. First, we will review some of the core concepts and competencies identified in the National Science Foundation’s document Vision and Change in Undergraduate Biology Education (V&C). We will then split into small groups to develop short lesson plans that target these concepts and which incorporate elements of ethnobotany. These lesson plans will include specific learning objectives and action items for educators to follow when engaging students in the study material. The intended audience for the workshop includes educators and researchers who teach ethnobotany courses. During the workshop, participants will (1) develop lesson plans with clear learning objectives and action items to implement in the classroom, (2) engage in problem-based learning approaches, (3) work through a peer-review process for ethnobiology lesson plans, and (4) practice posting the materials on the Open Science Network site. The outcomes of the workshop will be practice in creating lesson plans that address the V&C core concepts and competencies and access to a network of educators interested in promoting and enhancing ethnobotany education, training, and dissemination of ethnobiological knowledge through the Open Science Network.

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Natural product inhibitors of bacterial communication: The next generation of anti-infective drugs from medicinal plants

Sunday 30 June, 8:30-8:45

Cassandra L. Quave, Center for the Study of Human Health, Emory University, 550 Asbury Circle, Candler Library 107, Atlanta, GA 30322.

Jeffrey S. Kavanaugh, Department of Microbiology, University of Iowa, 540F Eckstein Medical Research Bldg., Iowa City, IA 52242

Kate Nelson, Center for the Study of Human Health, Emory University, 550 Asbury Circle, Candler Library 107, Atlanta, GA 30322.

Alexander R. Horswill,  Department of Microbiology, University of Iowa, 540F Eckstein Medical Research Bldg., Iowa City, IA 52242

Introduction

Rates of Staphylococcus aureus infection in both the community and healthcare setting are on the rise, and coupled with its highly antibiotic-resistant nature, this makes it a top public health concern. Nevertheless, the number of new antibiotic leads in the pipeline is diminishing, and many scientists have put out a call for the discovery and development of a new class of drugs which could mediate microbial pathogenicity rather than growth and survival. The staphylococcal quorum-sensing pathway, controlled by the accessory gene regulator (agr) system, is a target for such anti-pathogenic drug discovery efforts, as it serves as a global regulator of staphylococcal virulence.

Following extensive studies on the complementary and alternative medical (CAM) practices of southern Italians in the treatment of skin and soft tissue infection, over 100 plant samples were identified, collected, extracted, and examined for their anti-staphylococcal potential. Among the tests included was a screen for the inhibition of δ-hemolysin, a translational protein product of RNAIII, whose production is regulated through the agr quorum-sensing pathway. Extract 134, which is derived from a popular tree with edible fruits and medicinal leaves and bark, was found to inhibit δ-hemolysin at sub-inhibitory concentrations for growth.

Objectives

To investigate the quorum quenching effects of Extract 134 in staphylococcal models.

Methods

A bioassay-guided fractionation strategy was designed to examine the QSI activity of Extract 134 and its respective fractions. Bioassays employed included fluorescent and luminescent genetic reporter strains for agr (types I-IV), Western blots for delta-toxin, and alpha-toxin red blood cell lysis measurements.

Results

The dose-dependent quorum-quenching effects of Extract 134 were confirmed through all of the bioassays performed. This activity is important based upon previous animal studies with agr knockout mutants that show a diminished capacity to initiate and persist in a skin infection model.

Conclusions

Extract 134 and its fractions have demonstrated significant, dose-dependent activity in disrupting staphylococcal communication pathways, resulting in a decline in toxin production that is independent of any impact on growth. Future efforts will be focused on the identification and structural elucidation of active constituents and investigation of the mechanistic basis for this activity.

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