Publications from the lab of microbiology Fitnat Yildiz reveal mechanisms to understand cholera biofilms and explains why it is so highly infectious.
In finding a way to explain the hyper-infectivity of cholera biofilms, researchers at the University of California Santa Cruz (UCSC) published a series of papers on cholera biofilms. These publications were the work of the Fitnat Yildiz laboratory team and were published in various journals.
Besides its ability to form biofilms, cholera bacteria (Vibrio cholerae) is also water-borne and in regions where cholera is endemic it is able to survive aquatic environments causing periodic and seasonal outbreaks when sources of drinking water becomes contaminated.
Findings in a paper published in April 2020 on PNAS showed that bacteria growing in biofilms activate genes coding for virulence factors such as toxin production, before they infect the host.
The team shared that two of the main virulence factors are the toxin co-regulated pilus for adhesion to the intestine and the cholera toxin which penetrates intestinal cells. This study also demonstrated differences in the colonization patterns of free-swimming or planktonic and biofilm-growing cholera cells in the intestines of infected mice.
Using a new imagine technique the researchers were able to make the intestinal tissue transparent while preserving the spatial integrity of the infected intestines. This enable them to observe the cholera bacteria adhering to the villi in the small intestine.
“Being able to see where the infections are in three dimensions is an important tool for studying intestinal pathogens,” said Jennifer Teschler, a postdoctoral researcher in the Yildiz lab and a co-first author of the paper.
Two papers published in March 2020 on Nature Communications and PLoS Genetics by the same team focused on how free-swimming cholera bacteria attached to surfaces and initiate biofilm formation.
Yildiz shared that through understanding theses mechanisms involved in biofilm formation, it will “pave the way for developing strategies to predict and control cholera epidemics.” This understanding can also go a long way to identifying novel drug targets for inhibiting biofilm formation during infection.
The paper published on Nature Communications explored the cellular signalling pathways that control the attachment process through the regulation of hair-like appendages called pili that grow out from the cell surface.
Findings that were in the PLoS Genetics paper further elucidates that the c-di-GMP signalling pathways promote biofilm formation. Looking particularly at the role of flagellum in this signalling pathway, the researchers found that loss of the flagellum leads to elevated levels of c-di-GMP in the cell and increased expression of biofilm genes. [APBN]