5. Freie Universität Berlin – Department of Veterinary Medicine • VibrioNet Europe

Vibrio is a ubiquitous, gram negative, rod shaped bacteria originating from estuarine habitats. Worldwide the growing usage of estuarine aquacultures for generation of fish and other seafood is one possible way for spread of Vibrio.

Vibrio is one of the main causes for seafood related, generally enteric infections. The number of human cases of infections caused by Vibrio is constantly rising worldwide. Owing to rising global trade as well as the potentially global climate warming with rising water temperatures the cases increase. Emergence of highly pathogenic V. parahaemolyticus clones in South East Asia and its pandemic spread emphasizes its possible neglected status in Germany and Europe. For a better understanding of the tenacity and spread of Vibrio in the environment as well as in retail foods and the tracking of changes in the spread of Vibrio, surveillance programs of Vibrio cases as well as standardized and validated detection methods are necessary.

The identification and typing of Vibrio strains from food is performed after enrichment via polymerase chain reaction (PCR). Herewith five prevalent species, V. cholerae, V. parahaemolyticus, V. vulnificus, V. alginolyticus and V. mimicus can be determined within one multiplex reaction. The quantification of Vibrio from foods is performed by a combination of microbiological methods, such as isolation on selective agars like TCBS and molecular biological methods as qPCR.

The analysis of tenacity as well as the abilities of Vibrio to contaminate bivalves using storage assays and clearance ponds is one of many projects.

Strategies for reduction of microorganisms in foods e.g. by exposure of UV-C light are in development.

Our research efforts are focused on following topics

  • Qualitative and quantitative analysis of Vibrio spp. in foods
  • Typing of V. parahaemolyticus, Serogroups, toxin testing
  • Characterization of V. cholerae, Serogroups O1/O139, biovar, toxins
  • Molecular epidemiology (MLST)
  • Characterization of the molecular stress-response (RT-qPCR, Microarray)
  • Strategies for rapid detection of microorganisms in food (MALDI)
  • Investigations on bacteria in the “viable but not culturable” VBNC state
  • Strategies for reduction of microorganisms in foods (e. g. UV-C)