Breaking News
May 3, 2019 - Vaping and Smoking May Signal Greater Motivation to Quit
May 3, 2019 - Dementia looks different in brains of Hispanics
May 3, 2019 - Short-Staffed Nursing Homes See Drop In Medicare Ratings
May 3, 2019 - Study of teens with eating disorders explores how substance users differ from non-substance users
May 3, 2019 - Scientists develop new video game that may help in the study of Alzheimer’s
May 3, 2019 - Arc Bio introduces Galileo Pathogen Solution product line at ASM Clinical Virology Symposium
May 3, 2019 - Cornell University study uncovers relationship between starch digestion gene and gut bacteria
May 3, 2019 - How to Safely Use Glucose Meters and Test Strips for Diabetes
May 3, 2019 - Anti-inflammatory drugs ineffective for prevention of Alzheimer’s disease
May 3, 2019 - Study tracks Pennsylvania’s oil and gas waste-disposal practices
May 3, 2019 - Creating a better radiation diagnostic test for astronauts
May 3, 2019 - Vegans are often deficient in these four nutrients
May 3, 2019 - PPDC announces seed grants to develop medical devices for children
May 3, 2019 - Study maps out the frequency and impact of water polo head injuries
May 3, 2019 - Research on Reddit identifies risks associated with unproven treatments for opioid addiction
May 3, 2019 - Good smells may help ease tobacco cravings
May 3, 2019 - Medical financial hardship found to be very common among people in the United States
May 3, 2019 - Researchers develop multimodal system for personalized post-stroke rehabilitation
May 3, 2019 - Study shows significant mortality benefit with CABG over percutaneous coronary intervention
May 3, 2019 - Will gene-editing of human embryos ever be justifiable?
May 3, 2019 - FDA Approves Dengvaxia (dengue vaccine) for the Prevention of Dengue Disease in Endemic Regions
May 3, 2019 - Why Tonsillitis Keeps Coming Back
May 3, 2019 - Fighting the opioid epidemic with data
May 3, 2019 - Maggot sausages may soon be a reality
May 3, 2019 - Deletion of ATDC gene prevents development of pancreatic cancer in mice
May 2, 2019 - Targeted Therapy Promising for Rare Hematologic Cancer
May 2, 2019 - Alzheimer’s disease is a ‘double-prion disorder,’ study shows
May 2, 2019 - Reservoir bugs: How one bacterial menace makes its home in the human stomach
May 2, 2019 - Clinical, Admin Staff From Cardiology Get Sneak Peek at Epic
May 2, 2019 - Depression increases hospital use and mortality in children
May 2, 2019 - Vicon and NOC support CURE International to create first gait lab in Ethiopia
May 2, 2019 - Researchers use 3D printer to make paper organs
May 2, 2019 - Viral infection in utero associated with behavioral abnormalities in offspring
May 2, 2019 - U.S. Teen Opioid Deaths Soaring
May 2, 2019 - Opioid distribution data should be public
May 2, 2019 - In the Spotlight: “I’m learning every single day”
May 2, 2019 - 2019 Schaefer Scholars Announced
May 2, 2019 - Podcast: KHN’s ‘What The Health?’ Bye-Bye, ACA, And Hello ‘Medicare-For-All’?
May 2, 2019 - Study describes new viral molecular evasion mechanism used by cytomegalovirus
May 2, 2019 - SLU study suggests a more equitable way for Medicare reimbursement
May 2, 2019 - Scientists discover first gene involved in lower urinary tract obstruction
May 2, 2019 - Researchers identify 34 genes associated with increased risk of ovarian cancer
May 2, 2019 - Many low-income infants receive formula in the first few days of life, finds study
May 2, 2019 - Global study finds high success rate for hip and knee replacements
May 2, 2019 - Taking depression seriously: What is it?
May 2, 2019 - With Head Injuries Mounting, Will Cities Put Their Feet Down On E-Scooters?
May 2, 2019 - Scientists develop small fluorophores for tracking metabolites in living cells
May 2, 2019 - Study casts new light into how mothers’ and babies’ genes influence birth weight
May 2, 2019 - Researchers uncover new brain mechanisms regulating body weight
May 2, 2019 - Organ-on-chip systems offered to Asia-Pacific regions by Sydney’s AXT
May 2, 2019 - Adoption of new rules drops readmission penalties against safety net hospitals
May 2, 2019 - Kids and teens who consume zero-calorie sweetened beverages do not save calories
May 2, 2019 - Improved procedure for cancer-related erectile dysfunction
May 2, 2019 - Hormone may improve social behavior in autism
May 2, 2019 - Alzheimer’s disease may be caused by infectious proteins called prions
May 2, 2019 - Even Doctors Can’t Navigate Our ‘Broken Health Care System’
May 2, 2019 - Study looks at the impact on criminal persistence of head injuries
May 2, 2019 - Honey ‘as high in sugars as table sugar’
May 2, 2019 - Innovations to U.S. food system could help consumers in choosing healthy foods
May 2, 2019 - FDA Approves Mavyret (glecaprevir and pibrentasvir) as First Treatment for All Genotypes of Hepatitis C in Pediatric Patients
May 2, 2019 - Women underreport prevalence and intensity of their own snoring
May 2, 2019 - Concussion summit focuses on science behind brain injury
May 2, 2019 - Booker’s Argument For Environmental Justice Stays Within The Lines
May 2, 2019 - Cornell research explains increased metastatic cancer risk in diabetics
May 2, 2019 - Mount Sinai study provides fresh insights into cellular pathways that cause cancer
May 2, 2019 - Researchers to study link between prenatal pesticide exposures and childhood ADHD
May 2, 2019 - CoGEN Congress 2019: Speakers’ overviews
May 2, 2019 - A new strategy for managing diabetic macular edema in people with good vision
May 2, 2019 - Sagent Pharmaceuticals Issues Voluntary Nationwide Recall of Ketorolac Tromethamine Injection, USP, 60mg/2mL (30mg per mL) Due to Lack of Sterility Assurance
May 2, 2019 - Screen time associated with behavioral problems in preschoolers
May 2, 2019 - Hormone reduces social impairment in kids with autism | News Center
May 2, 2019 - Researchers synthesize peroxidase-mimicking nanozyme with low cost and superior catalytic activity
May 2, 2019 - Study results of a potential drug to treat Type 2 diabetes in children announced
May 2, 2019 - Multigene test helps doctors to make effective treatment decisions for breast cancer patients
May 2, 2019 - UNC School of Medicine initiative providing unique care to dementia patients
May 2, 2019 - Nestlé Health Science and VHP join forces to launch innovative COPES program for cancer patients
May 2, 2019 - Study examines how our brain generates consciousness and loses it during anesthesia
May 2, 2019 - Transition Support Program May Aid Young Adults With Type 1 Diabetes
May 2, 2019 - Study shows how neutrophils exacerbate atherosclerosis by inducing smooth muscle-cell death
May 2, 2019 - Research reveals complexity of how we make decisions
Scientists discover toxic bullet involved in bacterial competition

Scientists discover toxic bullet involved in bacterial competition

A bacterial toxin that allows an infectious strain of bacteria to defeat its competitors has been discovered by Imperial College London scientists.

The finding provides a better understanding of the mechanisms behind bacterial warfare, which is the first step for the design of improved treatments for microbial diseases.

Bacteria are some of the most abundant organisms on Earth and they are engaged in a relentless fight for the limited food resources available to them. To fend off and eliminate rivals and predators, they have evolved multiple chemical weapons.

Bacterial secretion systems, which can be loaded with bullet-like toxins, are one kind of weapon bacteria use to eliminate their competitors. In a new study, published today in Proceedings of the National Academy of Sciences, Imperial researchers have discovered a new bullet-like toxin produced by Pseudomonas aeruginosa, a bacterium responsible for human diseases such as pneumonia and cystic fibrosis as well as many hospital-acquired infections.

The study, led by Professor Alain Filloux from the Department of Life Sciences, investigated an understudied group of bacterial genes that encode proteins linked to the P. aeruginosa Type 6 secretion system (T6SS). T6SS is a molecular gun responsible for the delivery of multiple toxins which kill or suppress the growth of rival bacteria.

Samples of P. aeruginosa from specific infections are often found to be dominated by a single strain of P. aeruginosa, and the researchers suggest that this newly discovered toxin may help explain why such dominance is possible.

Professor Filloux said: “There is much more to learn about the exact role of T6SS in shaping the composition of bacterial communities in P. aeruginosa infections, which would eventually allow us to use our fundamental understanding of this system to tackle health-related problems.”

Among the T6SS-related genes studied in P. aeruginosa, one was found to encode a protein with an ability to degrade nucleic acids, such as DNA. This protein, which the researchers called Tse7, acts like a toxic bullet, which can be delivered via the T6SS into a competitor cell.

It fits perfectly on the tip of the T6SS gun, making its delivery very efficient. When Tse7 was introduced into different bacteria, it was able to degrade their DNA and ultimately stop their growth, showing its toxic activity.

In the microbial world there is an abundance of different toxins with a variety of functions, from the ones that degrade DNA, like Tse7, to those that cause cell breakdown, by disrupting the essential bacterial membrane of their victims.

However, every bacterium that produces a toxin needs to also somehow protect itself from being destroyed by its own weapon. This is why, along with the toxin, an immunity protein – an antitoxin – is also produced, which makes the toxin-producing bacteria immune to their own weapons. The current study has found that P. aeruginosa possesses a Tse7 immunity protein, called Tsi7, which when introduced to victim cells, protects them from Tse7 toxicity.

The Tsi7 immunity protein was also shown to be very specific to the strain that produces it; that is, different P. aeruginosa strains were found to possess unique versions of Tsi7, which were only protective against the toxin originating from the same strain. This strain specificity of the toxin-immunity pair could explain why samples from P. aeruginosa infections from cystic fibrosis patients tend to be dominated by a single Pseudomonas strain.

Panayiota Pissaridou, a PhD candidate at Imperial and one of the two lead authors in the present study, said: “There are many toxins in P. aeruginosa, which have not yet been studied”. Dr Luke Allsopp, also a lead author on this study, added: “Further research into the T6SS and how it allows bacteria to adapt to different environments is important for understanding the mechanisms that govern clinical infections.”

Source:

http://www.imperial.ac.uk/news/189108/toxic-bullet-involved-bacterial-competition-found/

Tagged with:

About author

Related Articles