Austrian Hygiene Award 2017 to Carina Pretzer

Within the frame of the 24th Dosch-Symposium on Hospital Hygiene, which takes place at Velden am Wörthersee from May 15 to 17, the Austrian Hygiene Award 2017 has been awarded to our former diploma student Carina Pretzer. The distinguished publication is a result of our ICC Water & Health Cooperation with the TU Wien.

The Austrian Hygiene Award 2017 has been awarded to Mag. Carina Pretzer, our former diploma student at the Interuniversity Cooperation Centre for Water and Health (ICC Water & Health) from the Department for Water Hygiene, working group of Assoc. Prof. Alexander Kirschner.

The title of the distinguished publication is "High genetic diversity of Vibrio cholerae in the European lake Neusiedler See is associated with intensive recombination in the reed habitat and the long-distance transfer of strains” and was published in January 2017 in the Top-Journal „Environmental Microbiology“*.

With great international participation and in cooperation with a specialist in molecular ecology (Prof. Andreas Farnleitner) and in molecular evolution (Prof. Irina Druzhinina) from the TU Wien, Carina investigated the genetic diversity of Vibrio cholerae strains in Lake Neusiedler See. All of the Vibrio cholerae strains in the lake can be classified as non-cholera vibrios (NCV), as they are not able to cause epidemic cholera due to their genetic background. However, each year they are responsible for several ear and wound infections of bathing guests, with one case of a fatal sepsis of a chemotherapy patient. Currently, NCV infections experience increasing topicality in Europe, because due to climate change and concomitant increase in water temperatures, significant increases of NCV infections have been reported.

In this study, we could show that the Lake Neusiedler See supports a genetically highly diverse population of Vibrio cholerae, which is especially rich in the reed stand. It can be assumed that the unique chemophysical properties of the lake (slight salinity, high pH, rich nutrients and increased water temperature in summer) make it a hot-spot of Vibrio cholerae in the Central Europe. The molecular evolutionary analysis of the strains from the lake and the comparison with the isolates from remote European countries revealed the factors that contribute to the outstanding genetic variability of Vibrio cholerae. First, the intensive genetic recombination in the reed stand makes this habitat a natural ‘bioreactor’ that produces endemic strains. Second, we showed the influx of strains from a variety of European reservoirs of Vibrio cholerae. Isolates from Sweden, the Netherlands, France, and Romania were closely related to the endemic Austrian strains, which can only be explained by the transfer of these bacteria between different European aquatic ecosystems. Because the lake Neusiedler See – and especially the reed belt – is an important habitat for migrating waterfowl species, we propose that birds may play a significant role in the transport of strains over long distances. This study is thus the first which elucidates the main mechanisms for the spreading and evolution of these increasingly emerging pathogens within the European context with the background of climate change. The study was financed by the FWF (project P21625-B20).

*Pretzer C, Druzhinina IS, Amaro C, Benediktsdóttir E, Hedenström I, Hervio-Heath D, Huhulescu S, Schets FM, Farnleitner AH, Kirschner AKT (2017) High genetic diversity of Vibrio cholerae in the European lake Neusiedler See is associated with intensive recombination in the reed habitat and the long-distance transfer of strains. Environmental Microbiology 19(1): 328-344

15.05.2017