Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Study reveals a way disease bacteria sense antimicrobials and initiate a counter-defense


Many living things, from fruit flies to people, naturally produce disease-fighting chemicals, called antimicrobial peptides, to kill harmful bacteria. In a counter move, some disease-causing bacteria have evolved microbial detectors. The bacteria sense the presence of antimicrobial peptides as a warning signal. The alarm sets off a reaction inside the bacteria to avoid destruction.

University of Washington (UW) and McGill researchers have revealed a molecular mechanism whereby bacteria can recognize tiny antimicrobial peptide molecules, then respond by becoming more virulent. Their studies were done on the bacterium Salmonella typhimurium. The findings were published in the Aug. 12 edition of the journal Cell.

Salmonella typhimurium can contaminate meats such as beef, pork, and chicken, as well as cereals and other foods, and cause severe intestinal illness. Certain strains of the bacteria are difficult to treat, and are behind the increase of salmonellosis in people. Some food science institutes anticipate that virulent strains of salmonella will become more common throughout the food chain. Learning how this sometimes deadly organism fights back against the immune system may lead to treatments that get around bacterial resistance.

Work in this area may also suggest ways other disease-causing Gram-negative bacteria maintain a stronghold in the midst of the body’s attempts to get rid of them.

Strangely enough, the same molecules that the body sends out to help destroy salmonella inadvertently launch bacterial defenses. It is as if missles armed, rather than demolished, the target. The body’s antimicrobial peptides bind to an enzyme, PhoQ, which acts as a watchtower and interceptor near the surface of bacterial cell membranes. The peptide binding activates PhoQ, which sets off a cascade of signals. The signals turn on a large set of bacterial genes. Some of the genes are responsible for products that fortify the bacterial cell surface and protect the bacteria from being killed.

The research was done in the UW laboratory of Dr. Samuel Miller, professor of microbiology and of medicine, Division of Infectious Diseases. The MIller Lab explores the molecular aspects of bacteria-induced illness, and how disease-causing bacteria interact with cells in the host they have infected, and adapt to environments inside the body, such as the airway.

The lead author of the Aug.12 Cell article was Dr. Martin Bader, a UW senior fellow in microbiology and genome sciences. The research team, under the direction of Miller, included Dr. Sarah Sanowar of the Department of Microbiology and Immunology at McGill University; Dr. Margaret Daley, a UW senior fellow in biochemistry; Anna SChneider, a UW undergraduate majoring in mathematics and biochemistry; Uhn Soo Cho, a graduate studenty in biological structure; Dr. Wenqing Xu, assistant professor of biological structure; Dr. Rachel Klevit, professor of biochemistry; and Dr. Herve Le Moual on the McGill Faculty of Dentistry.

Grants from the National Institute of Allergy and Infectious Diseases and from the Canadian Institutes of Health Research funded the study.

Leila Gray | EurekAlert!
Further information:

More articles from Life Sciences:

nachricht First time-lapse footage of cell activity during limb regeneration
25.10.2016 | eLife

nachricht Phenotype at the push of a button
25.10.2016 | Institut für Pflanzenbiochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Ice shelf vibrations cause unusual waves in Antarctic atmosphere

25.10.2016 | Earth Sciences

Fluorescent holography: Upending the world of biological imaging

25.10.2016 | Power and Electrical Engineering

Etching Microstructures with Lasers

25.10.2016 | Process Engineering

More VideoLinks >>>