Ariena H.C. van Bruggen

Title: Professor of Plant Pathology and EPI plant disease epidemiologist
College: Institute of Food and Agricultural SciencesCollege of Agriculture and Life Sciences
Department: Plant Pathology
Research Interests: Epidemiology, microbial ecology; modeling of enteric and plant pathogens; farming systems; organic farming; emerging pathogens; citrus diseases; Salmonella; cultural control of plant diseases; biological control of plant diseases; biological suppression of root diseases

Curriculum vitae: PDF
Hobbies: Gardening, sailing, hiking, listening to classical music and reading

Dr. Ariena van Bruggen has carried out fundamental and applied research on the health of ecosystems invaded by plant and human pathogens. A healthy ecosystem is characterized by a dynamically balanced and diverse community of organisms, stability and resilience after disturbances, minimal losses of nutrients and energy, and sporadic outbreaks of pests and diseases. Her work is premised on the idea that an ecosystem’s health status is largely determined by limited amounts of easily available carbon sources and mineral nutrients. This concept was developed based upon research on pathogens that reside in animal guts and their survival and spread from manure to soil, plants and other animals. Both plant and animal pathogens are suppressed in environments that have complex and active microbial communities so that easily available nutrients are consumed rapidly and are less available for pathogen survival and growth.

Recent outbreaks of enteric pathogens have prompted van Bruggen to study the pathways through which these pathogens move in farming ecosystems. Research has shown that populations of these pathogens can survive in soils and surface water, which has important implications for best management practices on farms. Specifically, pathogens survived longer in conventionally-managed soils than in organically-managed soils and also in eutrophied water compared to pristine water sources. Accordingly, the probability of a lettuce crop becoming contaminated was higher in conventional farming systems with eutrophied soils, as compared to organic farming systems – though the overall risk remained low – when manure was used as a fertilizer in both systems. In addition, Salmonella survived better in tomato plants grown in conventional than in organic soils, and could move through the phloem into tomato fruits. Once a pathogen arrives inside a fruit, it can multiply and cannot be washed off. However, again, the probability of this happening is very low.

In addition to ecosystem health research, van Bruggen also examined ecological processes and the ability of certain organisms in agroecosystems to disperse over time and across space. Her work has contributed to understanding how certain diseases progress, by taking into account the response time for different developmental stages of a pathogen in relation to its site-specific dynamic environmental conditions (rather than average conditions). This was shown for a plant pathogen (Bremia lactucae and Phytophthora infestans) as well as for two human pathogens (E. coli O157:H7 and S. enterica). She investigated this scale dependency, as well as the similarity of patterns at different scales, for the invasion of a pathogen into previously unoccupied space. On the applied side, van Bruggen’s group studied the epidemiology and spread of emerging plant pathogens like the ones causing citrus huanglongbing, blackspot and laurel wilt and to develop risk assessment models for their spread. In van Bruggen’s laboratory, mathematical and statistical tools have been combined with molecular tools for detecting pathogens and characterizing microbial communities. Van Bruggen also took her research to the classroom, where she taught courses on plant disease epidemiology and statistical analysis of research results.

Contact information: 
Emerging Pathogens Institute
University of Florida
P.O. Box 100009
Gainesville, Florida 32610-0009
Voice: (352) 273-9396
Fax: (352) 273-9399