Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bacteria Responsible for Middle Ear Infections, Pink Eye and Sinusitis May Protect Themselves by Stealing Immune Molecules

18.11.2011
Bacteria responsible for middle ear infections, pink eye and sinusitis protect themselves from further immune attack by transporting molecules meant to destroy them away from their inner membrane target, according to a study from Nationwide Children’s Hospital. The study, published in the November issue of PLoS Pathogens, is the first to describe a transporter system that bacteria use to ensure their survival.

When the body senses an infection, one of the first lines of defense is to send immune molecules called host-derived antimicrobial peptides (AMPs) to target and kill bacteria. However, bacteria have learned to resist AMPs through a series of countermeasures such as remodeling their outer membrane surface to be less permeable. Nontypeable Haemophilus influenzae (NTHI) is such a bacterium.

NTHI resides in the human upper airway, typically without causing any harm. However, NTHI has the ability to change from a non-harmful bacterium to a disease causing pathogen, responsible for pink eye, sinusitis, middle ear infection and complications of cystic fibrosis. “When transitioning to a harmful pathogen, NTHI defends against increased production of AMPs by using the Sap, which stands for sensitivity to antimicrobial peptides, proteins to arm against attack, ” said Kevin M. Mason, PhD, principal investigator in the Center for Microbial Pathogenesis at The Research Institute at Nationwide Children’s Hospital and lead study author. “Yet, it’s unclear just how the Sap transporter complex provides protection against AMPs.”

To help explain the mechanisms that NTHI uses to protect itself from AMPs, Dr. Mason’s team examined an animal model of middle ear infection. They had previously shown that NTHI bacteria lacking the protein SapA were susceptible to AMP attack. In the study, they describe the Sap transporter system that recognizes and transports host immune defense molecules into the bacterial cell. This system is necessary for the bacteria to survive in the host.

“It seems that NTHI senses the presence of these immune molecules, steals them from the host and arms itself to protect against future attacks,” said Dr. Mason. “NTHI imports AMPs into the bacterial cell and then degrades them in the interior of the cell. By remodeling its membranes, the bacterium appears as already attacked, which protects it from being bothered by additional AMPs. Basically, transporting AMPs acts as a counter strategy to evade innate immune defense and ultimately benefits the bacterium nutritionally.” This study provides the first direct evidence that the protein SapA contributes to bacterial survival by providing protection from AMPs in the host.

Dr. Mason says that targeting the Sap transport system may provide a way to use AMP derivatives as alternatives to antibiotics to treat NTHI infections. “Our long-range goal is to block this uptake system and starve the bacterium of essential nutrients. If we could develop a small molecule inhibitor that could block binding and transport, we could render NTHI susceptible to immune attack, while preserving the body’s normal bacteria that are often disrupted by conventional antibiotic use.”

For more information on Dr. Kevin Mason, visit http://www.nationwidechildrens.org/kevin-mason

For more information on the Center for Microbial Pathogenesis, visit http://www.nationwidechildrens.org/microbial-pathogens

Erin Pope | Newswise Science News
Further information:
http://www.nationwidechildrens.org

More articles from Health and Medicine:

nachricht One gene closer to regenerative therapy for muscular disorders
01.06.2017 | Cincinnati Children's Hospital Medical Center

nachricht The gut microbiota plays a key role in treatment with classic diabetes medication
01.06.2017 | University of Gothenburg

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>