Research Projects

August 1, 2005


Summary of research program at the Food Safety Laboratory: Dean O. Cliver, PhD, Professor of Food Safety, and Maha N. Hajmeer, PhD, Lecturer and Researcher in Food Safety; with guidance from Hans P. Riemann, Professor Emeritus
  • We study infectious diseases that are transmitted via food and water. Some are zoonoses, and others are human-specific. In some instances, we use animal agents as surrogates for human pathogens. Our laboratory is the World Health Organization’s Collaborating Center for Food Virology.

  • Animal feeds are sometimes ammoniated to enhance their nutritional value or to reduce levels of mycotoxins. We are studying the ammoniation process from the standpoint of what it may do to reduce on-farm levels of potentially foodborne bacteria, especially Salmonella.
  • Sprouts made from alfalfa and other seeds have been vehicles in outbreaks of foodborne disease. We are studying ammoniation as a means to kill bacterial pathogens (e.g., Escherichia coli O157:H7 and Salmonella) on the seeds before sprouting, hopefully without interfering with sprouting efficiency.
  • Some of the most important foodborne viruses are detectable only by the reverse transcription-polymerase chain reaction (RT-PCR), which cannot distinguish between infectious and inactivated virus. We have devised a way to eliminate positive RT-PCR results with inactivated virus. We are trying to expand this while adapting it to detection of virus extracted from foods.
  • We are in the process of publishing results of work on the persistence of Listeria monocytogenes, Salmonella spp., and Escherichia coli O157:H7 during production and storage of chorizos, a Mexican-style sausage that is often produced and sold in California without inspection. We are seeking funding to expand this work and to include other ethnic products.
  • We have bacteria from bovine and swine manure that attack human viruses. With the help of off-campus collaborators, we plan to determine whether these bacteria are also effective against prions, foot-and-mouth disease virus, and other pathogens. We are doing similar screening of thermophilic bacteria from composted turkey manure and of fluids from anaerobic sewage sludge digestion, both mesophilic and thermophilic. These results are intended to lead to composting carcasses of food animals infected with exotic disease agents.
  • We are beginning a comparative study, with three other universities, of the incidence of L. monocytogenes in ready-to-eat meat products at retail.
  • We are expecting to receive support for collaborative work with the East Bay Municipal Utilities District on pathogen destruction in modified sewage treatment procedures. We are also supposed to be collaborators in an inter-university project to prevent transmission of animal diseases by terrorists. Various other studies are pending.


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