Inhibitory properties of new polymers against animal and plant bacterial pathogens
Biofilms are structured communities of bacteria that form inside host organisms or inert devices. One of the main threats posed by biofilms to animal and plant health is that pathogenic bacteria inside the biofilm matrix are protected against anti-microbial agents, and therefore are difficult to control. The overall objective of this inter-disciplinary project is to screen a series of newly-fabricated polymers for their potential to prevent biofilm formation of bacterial pathogens. In particular, bacterial attachment to surfaces and subsequent growth/proliferation are the key steps towards formation of biofilms and will be the focus of the specific aims of this research. To test the activity of the polymers against bacterial growth, we are using model animal and plant pathogens. One of our goals is to obtain fundamental information on the activity of different polyurethane polymers with quaternary ammonium compounds against animal and plant pathogenic bacteria. The long-term goal of our research is to use the identified anti-biofilm materials in the manufacturing of devices for health and agricultural industries.
Project Funded By:
- Auburn University Intramural Grants Program
Investigating the development and treatment of plant diseases caused by the bacterium Xylella fastidiosa using theoretical and experimental methods
The goal of this project is to understand the progression and treatment of xylem fouling by bacterial biofilms formed by the plant pathogen Xylella fastidiosa (Xf) using tightly coupled theoretical and experimental techniques. The particular objectives are to determine whether the dominant symptoms of the plant infection, such as leaf scorch, are due to reduced water flux caused by occlusion of the water transport network by the biofilm or whether active plant responses are also implicated. Further, the investigation will focus on non-destructive methods of treatment of the disease. These two objectives will provide fundamental insight into the disease process and treatment.
The collaboration between the theoretical (mathematics) and experimental (biological) methods will validate the mathematical theory and suggest new avenues of disease treatment. The project will initially use experimental data to validate the theoretical modeling. In turn, the modeling and analysis will be used to test various hypotheses on the disease development (e.g. occlusion versus plant responses) that are difficult to test in the laboratory. In addition, the theoretical predictions will point to particular experimental designs (e.g. treatment regimes) that may provide valuable insight into non-destructive disease treatment.
Project Funded By:
- National Science Foundation, Department of Mathematical Sciences
Ionomics of the plant pathogen Xylella fastidiosa: The role of trace elements and nutrients in infection and progression of disease
Xylella fastidiosa is a ubiquitous, xylem-restricted plant pathogen that causes enormous financial losses in commercial crops such as grapes, citrus, peaches, almonds, and blueberries. The aim of this project is to obtain information on how minerals facilitate the infection process of X. fastidiosa. Once X. fastidiosa cells are inside the xylem vessels, they face the challenge of acquiring essential and beneficial mineral nutrients from the xylem sap. These minerals play a role in bacterial processes that lead to disease: growth, biofilm formation, and attachment to surfaces. We are studying this problem through analytical, molecular, and microfabrication approaches. This project is being performed in collaboration with Dr. Paul Cobine’s laboratory in the Department of Biological Sciences (Auburn University).
Project Funded By:
- USDA-AFRI (United States Department of Agriculture – Agriculture and Food Research Initiative)
- HATCH-AAES (Hatch – Alabama Agricultural Experiment Station)
Differentiation of Xylella fastidiosa strains via analysis of environmentally-mediated genes
Attempts so far to elucidate the genetic relationships between strains of Xylella fastidiosa (XF) have shown that genotypes tend to cluster into groups based on the host plant species from which they were isolated. In this project we are investigating the genetic variation of XF isolated from the same host in different geographic areas of the US. Sequence analysis of environmentally-mediated genes (genes thought to be influenced by environmental factors) is being applied to identify strain relationships. Multi-locus sequence analysis (MLSA) is being used for genes related to processes important for establishing XF infections such as surface attachment, biofilm formation, virulence, and nutrient transport and utilization. These types of genes may be more relevant to host-based genetic variability.
Infection traits and growth of “Candidatus Liberibacter asiaticus” inside microfluidic chambers
The bacterium ‘Candidatus Liberibacter asiaticus’ (LAS) is the suspected causal agent of the disease known as citrus greening (or huanglongbin), affecting citrus production worldwide, especially in Florida (US), Brazil, and China. Culturing LAS in the laboratory by traditional bacterial culture methods is extremely difficult. This has caused a knowledge deficit regarding LAS biology that inhibits the generation of well-informed ideas for pathogen control. We are starting a new project based on the use of a novel methodology which uses microfluidic chambers and microscopic observations to improve the culture conditions of LAS and confirm infection traits and nutritional requirements suggested by the recent full genome sequence.
Project Funded By:
- FCPRAC (Florida Citrus Production Research Advisory Council)
Urban Entomology Laboratory
The research of urban entomology Lab focuses on the Development and Implementation of Integrated Pest Management of arthropod pests in urban ecosystem. We are especially interested in behavior, physiology, ecology, biology, and immunology of household and structure insect pests and invasive pests.
Ph.D. Graduate Student – Dissertation Research: Immunology in Subterranean Termites
Leona (Liu) Yang
Ph.D. Graduate Student – Semiochemical-based management stratergy for invasive kudzu bug, M. cribraria
M.S. Graduate Student – Thesis Research: Biology and management of the invasive Kudzu bug
Marta Barba Recreo
M.S. Graduate Student – Resident, Equine Internal Medicine
Thesis: Transmission of Corynebacterium pseudotuberculosis in horse by house flies
Ph.D. Graduate Student – Dissertation Research: Effects of termite behaviors and insecticide application protocol on control efficacy
D.V.M. and M.Ag. Graduate Student -Veterinary Entomology
- Hao Wu, M.S. 2013. Co-advisor. Currently a Technical Assistant at IntelliSurvey in Los Angeles. Thesis Tiel: Instar determination, temperature effects on the growth, and parental care in Dubia Cockroach
- Juliana Xu, M.S. 2012. Co-advisor. Currently a Ph.D. candidate at University of Florida. Thesis Title: Feedign ecology of pest mole crickets (Orthoptera: Gryllotalpidae: Scpteriscus spp.) and associated damage to turfgrass.
- Charles Donald Robert Stephen, M.S. 2012. Major Professor. Currently a Ph.D. candidate at Department of Biology, Auburn University. Thesis Title: Alabama Rhinotermitidae: nomenclature, identification, survey and swarming phenology
- Franklin Quarcoo. Ph.D. 2009. Major Professor. Currently a Research Associate at Tuskegee University, USA. Dissertation Title: Behavioral toxicology of non-repellent termiticides in subterranean termites management.
- Dunlun Song, Ph.D. 2007. Co-Professor. Currently Vice Chair and Associate Professor in Department of Entomology, China Agricultural University, China.
- Edward T. Snoddy, Ph.D. 2012.