Pathogens in seawater in times of climate change: the Vibrio case
Vibrio colony on selective medium
Infections, triggered by contact with water or consumption of seafood, represent a problem for healthcare worldwide. In addition to Vibrio cholerae (cholera diseases), particularly the bacteria Vibrio vulnificus and Vibrio parahaemolyticus can be transmitted to humans through contact with seawater or consumption of seafood and frequently lead to severe illnesses.
The German Advisory Council on Global Change (WBGU) states that global climate change has already led to a rise in the surface temperature of the oceans of approx. 1°C. The long-term series conducted by the Helgoland Biological Institute in the German Bight shows that the water temperature of the North Sea has even increased by at least 1.5°C since 1962. This rise in water temperature may now directly influence the growth of vibrios and thus result in a more northern spread of pathogenic Vibrio species.
Hemolytic activity of Vibrio parahaemoylticus on blood agar
There have been few studies on human pathogenic vibrios in northern Europe to date. One of the reasons for this is that, for the most part, infections in Germany have occurred only sporadically up to now. Nevertheless, several studies verify the great influence of temperature on the growth of pathogenic vibrios. It can therefore be assumed that in future human pathogenic vibrios may spread as a consequence of a rise in temperature both in the North Sea and in the Baltic Sea.
The Alfred Wegener Institute is examining this mounting problem within the framework of the zoonosis association VibrioNet of the German Federal Ministry of Education and Research (http://www.vibrionet.de/) so as to enable for the first time a risk assessment for German coasts.
