29-Oct-2019 - Max-Planck-Institute für terrestrische Mikrobiologie

Pathogens from the sea

A marine pathogenic bacterium forms specialized cells for dissemination

Vibrio parahaemolyticus can be found in the tidal zones in estuarine areas. The marine bacterium causes acute gastroenteritis in humans and is the leading cause for seafood borne illnesses in the world. Researchers from the Max Planck Institute for terrestrial Microbiology in Marburg, Germany, have identified specialized "adventurer" cells that ensure the bacterium's dissemination and prevalence. Their new findings are an important basis for the future management of the disease.

In Central and Northern Europe, Vibrio infections are among the "emerging diseases" whose incidence has recently increased or is likely to increase in the near future. Some reasons for this are global trade and the higher water temperatures caused by global climate change. Mussels, oysters and crabs that are found in our supermarkets from tropical regions are possibly contaminated all year round and to a high percentage. They can cause an infection if eaten raw or are insufficiently cooked.

Vibrio parahaemolyticus forms colonies in the tidal zone of estuarine areas, and its complex life cycle is triggered by the respective conditions of this habitat. But how does the species adapt to environmental changes, and how can it colonize new habitats? "In order to develop any measures against the spread of Vibrio parahaemolyticus and related bacteria, we must first understand the structure and distribution strategy of the bacterial colonies," explains Simon Ringgaard of the Max Planck Institute for Terrestrial Microbiology in Marburg. In their laboratory, he and his team simulate the conditions of the tidal zone and thus investigate the bacterial life cycle and mechanisms of movement.

Swimmer and swarm cells

As many other bacteria, Vibrio parahaemolyticus forms special cell types when environmental conditions require it. While short swimmer cells with a single polar flagellum can move quickly in a liquid environment, the longer swarm cells reside within bacterial populations that are attached to solid surfaces. Swarmer cells are specialized for movement over surfaces and can rapidly colonize new surface areas.

The Vibrio bacterial swarm colonies show a distinct stratification: while the middle of the colony consists of rather shorter cells, the longer swarm cells are found in the outer areas of the colony. As the Max Planck researchers were able to show, if the swarm colony is flooded with water, as in the natural habitat during the tidal rhythms, cells are released from the colony into the liquid surroundings. Surprisingly, however, these released cells are neither the long, swarmer cells nor the very short cells found in the middle, but a completely unexpected and new cell type of medium length. These "adventurer cells" are optimized for living in water and possess particularly good swimming properties.

Spreading disease

The research team showed that once released, the adventurer cells were highly capable of spreading in their new liquid environments and importantly they were able to “smell” and move towards potential nutrient sources such as chitin - an essential component of marine animals to which Vibrio parahaemolyticus attaches. Thus, the release of adventurer cells into the water has the potential to help spread the bacterium in the environment and bring Vibrio parahaemolyticus to new shores, like to the surface of seafood. And thus into our food chains, consequentially likely enhancing the risk of human infections.

The Marburg researchers investigated the life cycle as a function of environmental conditions and time, both morphologically and on the molecular genetic level. Here they found characteristic expression patterns that could also be used for the future detection of the bacterium. But perhaps this involves even something much more far-reaching, says Simon Ringgaard. “Our experiments show that the colony always has a sub-population of adventurer cells that are ready to be released  immediately upon flooding. Adventurer cells would thus be of central importance for the worldwide epidemiology of the disease - and thus also for measures to contain it, for example in industrial aquaculture.”

  • Freitas, C.; Glatter, T.; Ringaard, S.; "The release of a distinct cell type from swarm colonies facilitates dissemination of Vibrio parahaemolyticus in the environment", The ISME Journal; October 17, 2019
Facts, background information, dossiers
  • Vibrio parahaemolyticus
  • bacteria
  • gastroenteritis
More about Max-Planck-Institute für terrestrische Mikrobiologie
  • News

    Environmentally friendly production of mandelic acid

    Sometimes potentially useful enzymes are not easy to discover because their biocatalytic capabilities may go beyond their natural and thus known range of action. By recombining a newly discovered enzymatic capability, a research team from the Max Planck Institute for Terrestrial Microbiolog ... more

    Light drives injection

    When bacteria such as Salmonella or Yersinia cause fever, diarrhoea or abdominal pain, tiny "injection needles" are at work: their type 3 secretion system, or T3SS for short, shoots bacterial virulence proteins directly into the eukaryotic host cells. Researchers have thought of using bacte ... more

    Synchro swimmers under the microscope

    Not only birds, fish and even crowds of people show collective movement patterns, motile bacteria also form currents and vortices when their cell density exceeds a certain size. Researchers at the Max Planck Institute for terrestrial Microbiology in Marburg have now been able to show how sw ... more

More about Max-Planck-Gesellschaft
  • News

    Cells talk at each other to specialize different functions

    During development, cells must specialize their function in a well defined timeline: formation of different tissues must be coordinated from a pile of cells. The research group led by Aneta Koseska (former Max Planck Institute of Molecular Physiology (MPI), CAESAR Bonn) has now developed a ... more

    Neandertal gene variants and Covid-19

    Last year, researchers at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and at Karolinska Institutet in Sweden showed that a major genetic risk factor for severe Covid-19 is inherited from Neandertals. Now the same researchers show, that Neandertals also contri ... more

    Genotoxic E. coli “caught in the act”

    Escherichia coli bacteria are constitutive members of the human gut microbiota. However, some strains produce a genotoxin called colibactin, which is implicated in the development of colorectal cancer. While it has been shown that colibactin leaves very specific changes in the DNA of host c ... more

  • Videos

    Epigenetics - packaging artists in the cell

    Methyl attachments to histone proteins determine the degree of packing of the DNA molecule. They thereby determine whether a gene can be read or not. In this way, environment can influence the traits of an organism over generations. more

    Biomaterials - patent solutions from nature

    Animals and plants can produce amazing materials such as spider webs, wood or bone using only a few raw materials available. How do they achieve this? And what can engineers learn from them? more

    Chaperones - folding helpers in the cell

    Nothing works without the correct form: For most proteins, there are millions of ways in which these molecules, composed of long chains of amino acids, can be folded - but only one way is the right one. Researchers in the department "Cellular Biochemistry" at the Max Planck Institute for Bi ... more

  • Research Institutes

    Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V.

    The research institutes of the Max Planck Society perform basic research in the interest of the general public in the natural sciences, life sciences, social sciences, and the humanities. In particular, the Max Planck Society takes up new and innovative research areas that German universiti ... more