Consultant laboratory for vibrios

Vibrios are salt-tolerant bacteria which are prevalent worldwide in maritime waters and estuaries. In many countries, vibrios are the main cause of bacterial diarrhoea, caused by the consumption of shellfish and fishery products (‘seafood’), or by intake of contaminated water. As a result of global warming and higher temperatures of seawater, as well as the rising global trade of seafood, an increase in vibrio infections may be expected.

Consultant laboratory tasks

The task of the consultant laboratory for vibrios at BfR is to develop methods for detection vibrios in shellfish and fishery products for offical monitoring, and to advise and support testing laboratories in the control of food for these bacteria. Furthermore, the consultant laboratory carries out research projects on the occurence of vibrios in the environment and in foods.

Most food-borne Vibrio-infections are caused by the three species Vibrio parahaemolyticus, Vibrio cholerae and Vibrio vulnificus.  Consumers can become infected by consuming contaminated shellfish - in particular, from eating raw oysters and/or shellfish and fish products that have not been sufficiently heated - or from the intake of contaminated water. Studies carried out in Germany on shellfish and fishery products from retail have proven that the three enteropathogenic vibrio species mentioned above occur in these foods.

In addition to food-borne diseases, many vibrios can also induce wound and ear infections, which are triggered by contact with water containing vibrios. One such bacteria is Vibrio vulnificus, which can induce life-threatening blood poisoning (sepsis) in persons with weakened immune systems, especially elderly people. Such infections can occur during very long periods of heat when swimming in the sea or walking in seawater (wash margin). So far, however, the number of infections is low.

Work priorities of the consultant laboratory

• Establishing, evaluating and validating of methods for the detection of vibrios in shellfish and fishery products
• Microbiological diagnosis of Vibrio spp. by phenotypic characterisation, PCR and MALDI-TOF mass spectrometry
• Testing for toxin genes by PCR and DNA sequencing
• Advice on questions of microbiological diagnostics (pathogen and toxin detection) and pathogen typing
• Organizing regular comparative interlaboratory tests for official laboratories for quality assurance
• Research on the occurence and significance of virulence-associated properties of enteropathogenic vibrios using whole genome sequencing, especially in cooperation with laboratories from the VibrioNet network http://www.vibrionet.de/

The basis for microbiological procedures for detection of vibrios in foods is the ISO standard 28172:
Microbiology of the food chain - Horizontal method for the determination of Vibrio spp. - Part 1: Detection of potentially enteropathogenic Vibrio parahaemolyticus, Vibrio cholerae and Vibrio vulnificus (ISO 21872-1:2017).