Peter Bergholz

Assistant Professor

Van Es 118

701 231 5946

Visit the Bergholz Lab Website


  • Ph.D. in Microbiology and Molecular Genetics from Michigan State University (2007)

Professional Experience

  • Research Associate in Food Science at Cornell University (2011)
  • Research Associate in Crop and Soil Sciences at Cornell University (2010-2011)
  • Postdoctoral Associate in Crop and Soil Sciences at Cornell University (2007-2010)
  • National Science Foundation Training Course (2005-2006): Integrative Biology and Adaptation of Antarctic Marine Organisms, McMurdo Station, Ross Island, Antarctica

Teaching Interests

  • MICR 481/681-Microbial Genomics
  • SAFE 401/601-Food Safety Information and Flow of Food
  • SAFE 402/602-Foodborne Hazards
  • SAFE 403/603-Food Safety Risk Assessment

Research Interests

Food and waterborne diseases remain major health concerns worldwide, yet, in the United States, the incidences of these diseases have stagnated and increased, respectively. The consensus is building among food safety researchers that understanding the ecological dynamics of foodborne pathogens will lead to the next breakthrough in reducing foodborne disease incidence. This consensus has been founded on prominent examples from recent outbreaks, e.g. the 2006 E. coli outbreak in spinach and the 2011 L. monocytogenes outbreak in cantaloupe. Likewise, the association of waterborne disease with seasonal and interannual trends in climate is widely recognized, and there is increasing recognition that poorly-understood terrestrial reservoirs of waterborne disease may be playing a role in water contamination in addition to fecal pollution of recreational waters. Therefore, understanding the environmental conditions that promote the formation of disease reservoirs and the landscape connectivity from these reservoirs to food and water is a key strategy to achieve the Healthy People 2020 objectives of 25-50% improvement in foodborne disease incidence and 95% improvement in beach closure rates by 2020. Moreover, untested hypotheses abound regarding the linkages between wildlife reservoirs/transmission vehicles of foodborne pathogens and resulting disease risk. A central goal of the “One World, One Health” initiative is to conduct strong tests of the interactions between human activities, environmental health and environmental conservation.

Research in my laboratory will bring landscape genomics approaches to the problem of food and waterborne disease transmission, because the questions surrounding environmental transmission of foodborne pathogens are fundamentally ecological questions. Landscape genomics combines GIS modeling, population genomics, spatial ecology, and landscape microbial ecology to make new discoveries about disease persistence and the functional linkages across landscapes that drive transmission. This multidisciplinary approach to ecology of food and waterborne disease is necessary for two reasons. First, foodborne and waterborne pathogen populations are diverse, are poorly defined as biological species, and are highly adaptable to new environments into which they are deposited during dispersal. A genomic approach is essential to understanding their diversity and adaptations so that models about their environmental behavior can be calibrated. Second, in addition to environmental persistence, food and waterborne pathogens are not solely transported by environmental vehicles, but also by a variety of biological dispersal vehicles. It is only by accounting for the relative contributions of processes dispersing these pathogens that we can adequately predict connectivity among sources and sinks. The proposed analytical methods are complex, but directly examine how a landscape, in all its variety, dictates movement of organisms within and between environmental reservoirs across a mixed land-use area. The final outcome of my research program is the implementation of pathogen dispersal models that can aid decisions by government and corporate environmental health experts regarding surveillance and intervention to prevent disease.

Most Recent Publications

  • Wongsuntornpoj, S., AI Moreno-Switt, PW Bergholz, M Wiedmann, and S Chaturongakul. Salmonella phages isolated from dairy farms in Thailand show wider host range than a comparable set of pahges isolated from US dairy farms. VETERINARY MICROBIOLOGY. 172 (1-2): 345-352 AUG 2014.
  • Falbo, K, RL Schnieder, DH Buckley, MT Walter, PW Bergholz, and BP Buchanan. Roadside ditches as conduits for fecal indicator organisms and sediment: Implications for water quality management. JOURNAL OF ENVIRONMENTAL MANAGEMENT. 128: 1050-1059 OCT 2013
  • Strawn, LK, ED Fortes, EA Bihn, KK Nightingale, YT Gröhn, RW Worobo, M Wiedmann, PW Bergholz. Landscape and Meterological Factors Affecting Prevalence of Three Foodborne Pathogens in Fruit and Vegetable Farms. APPLIED AND ENVIRONMENTAL MICROBIOLOGY. 79 (2): 588-600 JAN 2013. doi:10.1128/AEM.02491-12.
  • Bergholz, PW, JD Noar, DH Buckley. Environmental patterns are imposed on the population structure of Escherichia coli after fecal deposition. APPLIED AND ENVIRONMENTAL MICROBIOLOGY. 77 (1): 211-219 JAN 2011.
  • Davis, DA, MD Gamble, CE Bagwell, PW Bergholz, CR Lovell. Responses of salt marsh grass diazotroph assemblages to changes in marsh elevation, edaphic conditions, and host-plant species. MICROBIAL ECOLOGY 61 (2): 386-398 FEB 2011.
  • Ayala-del-Río, HL, PS Chain, MA Ponder, JJ Grzymski, N Ivanova, PW Bergholz, G Bartolo, L Hauser, M Land, C Bakermans, D Rodrigues, J Klappenbach, D Zarka, F Larimer, P Richardson, AE Murray, MF Thomashow and JM Tiedje. The genome sequence of Psychrobacter arcticus 273-4, a psychroactive Siberian permafrost bacterium reveals mechanisms for adaptation to low temperature growth. APPLIED AND ENVIRONMENTAL MICROBIOLOGY 76 (7): 2304-2312 APR 2010.
  • Gamble, MM, CE Bagwell, J LaRocque, PW Bergholz, CR Lovell. Seasonal variability of diazotroph assemblages associated with the salt marsh cordgrass, Spartina alterniflora. MICROBIAL ECOLOGY. 59 (2): 253-265 FEB 2010.
  • Bergholz, PW, C Bakermans, and JM Tiedje. Psychrobacter arcticus 273-4 uses resource efficiency and molecular motion adaptations for subzero temperature growth. JOURNAL OF BACTERIOLOGY 191 (7): 2340-2352 APR 2009.
  • Ponder, MA, SJ Gilmour, PW Bergholz, CA Mindock, R Hollingsworth, MF Thomashow, JM Tiedje. Characterization of potential stress responses in ancient Siberian permafrost psychroactive bacteria. FEMS MICROBIOLOGY ECOLOGY 53 (1): 103-115 JUN 2005.