Research on cholera adds to understanding of the social life of bacteria

August 09, 2019

HANOVER, N.H. - August 9, 2019 - Certain strains of cholera can change their shape in response to environmental conditions to aid their short-term survival, according to new research from Dartmouth College.

In the research, some strains of the bacterium Vibrio cholerae transformed themselves from small, comma-shaped cells to long filaments in nutrient-poor environments.

This strategy of changing cell shape supports the growth of bacterial communities and allows the pathogen to compete in environments with a quick turnover of surfaces on which to grow.

According to the study, the formation of the elongated cell shapes allows the rapid formation of communities of bacteria that bind to surfaces - known as biofilms - that are essential in turbulent nutrient environments. These formations come at the expense of being able to compete in the long term with biofilms made from smaller cells that pack together more tightly.

The finding adds to the understanding of how bacteria adapt to their environment.

"Bacteria are normally thought of as solitary organisms, but they are actually highly-social organisms that like to live in groups," said Carey Nadell, an assistant professor of biology at Dartmouth. "This research shows that we can relate cell structure to group behavior in new ways when looking at realistic environments."

When not inside a human host, V. cholerae grows on nutritious pieces of debris in aquatic environments. This debris, known as chitin, comes from the shells of arthropods like plankton and shrimp. Cholera cell growth on the chitin typically takes place in the form of biofilms featuring clusters of organisms.

In the research, strains of cholera were grown in sea water and then observed using 3D microscopy with the aid of fluorescent markers to make the bacteria visible. The researchers found that the altered long-filaments become entangled, providing an advantage that allows the bacteria to quickly colonize nutrient-rich particles in sea water.

The research notes that the formation of the filament-like structure comes at the expense of longer-term competitive ability enjoyed by shorter cells that adhere more strongly to each other and to surfaces.

"This has important consequences for how cells survive in the environment. It shows how bacterial cell shape can be coupled to environmental success during surface occupation, competition within biofilms, and dispersal to new resource patches," said Nadell.

There are many strains of the cholera bacteria. Because the bacteria in the study was grown in sea water, the research does not directly lead to a greater understanding of how cholera acts within the human body.

The discovery of a new way that bacteria form groups on surfaces can, however, help researchers understand more about how bacteria act and associate.

"This kind of behavior is perhaps more widespread than we currently understand in the wild, and that variability in cell shape, like variability in animal body plans, could be a fundamental part of why some bacteria live in certain places but not others."

Predicting microbial community composition is a major frontier of modern microbiology and medicine, given the importance of microbiomes for health, industry, agriculture, and other applications.
This research was funded by the National Science Foundation, the Cystic Fibrosis Foundation, the National Institutes of Health and Dartmouth College.

Researchers at Harvard Medical School, University of Munich, and École Polytechnique Fédéral de Lausanne all contributed to this study.

About Dartmouth

Founded in 1769, Dartmouth is a member of the Ivy League and offers the world's premier liberal arts education, combining its deep commitment to outstanding undergraduate and graduate teaching with distinguished research and scholarship in the arts and sciences and its leading professional schools: the Geisel School of Medicine, the Guarini School of Graduate and Advanced

Dartmouth College

Related Science Articles from Brightsurf:

75 science societies urge the education department to base Title IX sexual harassment regulations on evidence and science
The American Educational Research Association (AERA) and the American Association for the Advancement of Science (AAAS) today led 75 scientific societies in submitting comments on the US Department of Education's proposed changes to Title IX regulations.

Science/Science Careers' survey ranks top biotech, biopharma, and pharma employers
The Science and Science Careers' 2018 annual Top Employers Survey polled employees in the biotechnology, biopharmaceutical, pharmaceutical, and related industries to determine the 20 best employers in these industries as well as their driving characteristics.

Science in the palm of your hand: How citizen science transforms passive learners
Citizen science projects can engage even children who previously were not interested in science.

Applied science may yield more translational research publications than basic science
While translational research can happen at any stage of the research process, a recent investigation of behavioral and social science research awards granted by the NIH between 2008 and 2014 revealed that applied science yielded a higher volume of translational research publications than basic science, according to a study published May 9, 2018 in the open-access journal PLOS ONE by Xueying Han from the Science and Technology Policy Institute, USA, and colleagues.

Prominent academics, including Salk's Thomas Albright, call for more science in forensic science
Six scientists who recently served on the National Commission on Forensic Science are calling on the scientific community at large to advocate for increased research and financial support of forensic science as well as the introduction of empirical testing requirements to ensure the validity of outcomes.

World Science Forum 2017 Jordan issues Science for Peace Declaration
On behalf of the coordinating organizations responsible for delivering the World Science Forum Jordan, the concluding Science for Peace Declaration issued at the Dead Sea represents a global call for action to science and society to build a future that promises greater equality, security and opportunity for all, and in which science plays an increasingly prominent role as an enabler of fair and sustainable development.

PETA science group promotes animal-free science at society of toxicology conference
The PETA International Science Consortium Ltd. is presenting two posters on animal-free methods for testing inhalation toxicity at the 56th annual Society of Toxicology (SOT) meeting March 12 to 16, 2017, in Baltimore, Maryland.

Citizen Science in the Digital Age: Rhetoric, Science and Public Engagement
James Wynn's timely investigation highlights scientific studies grounded in publicly gathered data and probes the rhetoric these studies employ.

Science/Science Careers' survey ranks top biotech, pharma, and biopharma employers
The Science and Science Careers' 2016 annual Top Employers Survey polled employees in the biotechnology, biopharmaceutical, pharmaceutical, and related industries to determine the 20 best employers in these industries as well as their driving characteristics.

Three natural science professors win TJ Park Science Fellowship
Professor Jung-Min Kee (Department of Chemistry, UNIST), Professor Kyudong Choi (Department of Mathematical Sciences, UNIST), and Professor Kwanpyo Kim (Department of Physics, UNIST) are the recipients of the Cheong-Am (TJ Park) Science Fellowship of the year 2016.

Read More: Science News and Science Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to