About My Health Careers Internship MedBlogs Contact us
Medindia LOGIN REGISTER
Advertisement

New Weapons Discovered Promise to Fight Against Antibiotic Resistance

by Hannah Joy on December 7, 2017 at 4:11 PM
Font : A-A+

New Weapons Discovered Promise to Fight Against Antibiotic Resistance

A bacterium can be increasingly or decreasingly susceptible to an antibiotic, but it depends on the bacterial community it is living in, reveals a new study.

The scientists at the UNC School of Medicine found specifically that the bacterium Pseudomonas aeruginosa can produce specific molecular factors that dramatically increase or decrease an antibiotic's ability to kill Staphylococcus aureus, another bacterium that often co-infects with P. aeruginosa.

Advertisement


The findings, published in PLoS Biology, point to the possibility of new antibiotics employing these factors to enhance antibiotic susceptibility.

The research also shows how understanding the precise mix of bacteria and their interactions could become a standard part of clinical practice in treating bacterial infections, especially the more dangerous infections involving antibiotic resistance. Doctors currently gauge the antibiotic susceptibility of an infecting bacterial species by examining it in isolation from other species.
Advertisement

"The interactions with P. aeruginosa can completely change S. aureus's susceptibility to standard antibiotics," said study senior author Brian P. Conlon, PhD, assistant professor of microbiology and immunology at UNC.

Resistance to antibiotics by bacteria and other microbes is an ongoing public health crisis, contributing to about two million infections and 23,000 deaths per year in the United States, according to the Centers for Disease Control and Prevention. P. aeruginosa, for instance, is a multidrug-resistant pathogen associated with hospital-acquired infections, including ventilator-associated pneumonia. As for S. aureus¬, some strains do not cause disease. Others cause the classic "staph" infections that antibiotics do kill. Other strains, though, are antibiotic-resistant.

Researchers have been racing to find ways to overcome the resistance of these and other bacteria.

One clue in the race to overcome antibiotic resistance that Conlon and colleagues uncovered is that S. aureus sometimes adopts a slow-growing, "low-energy" state that makes it more difficult to kill with antibiotics. Conlon's team hypothesized that this low-energy state might arise from inter-species competition. In other words, a co-infecting bacterial species might have evolved the capability to produce factors that put microbial competitors at a disadvantage. Such factors may include toxins, enzymes, or various bacterial components unique to specific strains.

"We know that P. aeruginosa commonly co-infects with S. aureus and secretes factors that mess with S. aureus's metabolism," Conlon said. "So our hypothesis was that this interaction might be throwing S. aureus into a more antibiotic-resistant state."

Conlon and colleagues, including first author Lauren Radlinski, a graduate student in the Conlon Laboratory who performed most of the experiments, investigated this possibility in the new study. They set up a panel of S. aureus cultures, exposed them to molecules secreted by 14 different P. aeruginosa strains, and then tested the susceptibility of each culture to one of three antibiotics: vancomycin, tobramycin, and ciprofloxacin.

The results were striking and have implications for clinical practice.

The P. aeruginosa factors affected S. aureus's susceptibility to all three antibiotics, in some cases to an enormous extent. Some strains of P. aeruginosa, as expected, significantly reduced S. aureus's susceptibility to tobramycin and ciprofloxacin. Surprisingly, though, many other strains of P. aeruginosa greatly enhanced S. aureus'ssusceptibility to antibiotics used in the experiments.

"Factors secreted by eight of the P. aeruginosa strains, for example, induced 100 to 1000 times more killing of S. aureus by vancomycin, compared to the control culture of S. aureus that was not exposed to P. aeruginosa factors," Conlon said.

The researchers identified three specific P. aeruginosa factors that accounted for these effects:
  • A protein-cutting enzyme called LasA increased vancomycin's ability to kill S. aureus.
  • A set of fat-related molecules called rhamnolipids increased S. aureus's uptake of tobramycin.
  • A small organic molecule called HQNO inhibited the metabolism of S. aureus, shifting it into the low-energy state that made it more antibiotic-resistant.
Conlon and colleagues said it could be possible to create new antibiotics that include the susceptibility-enhancing factors LasA and rhamnolipids and/or block the susceptibility-reducing factor HQNO to build a better arsenal against serious bacterial infections.

Another approach would be to develop simple bacterial genetic tests that enable doctors to detect when a co-infecting bacterium is likely secreting factors that significantly influence antibiotic susceptibility.

Conlon's team is now sequencing P. aeruginosa strains to see how gene sequences vary between strains and how this variance affects the ability of these strains to produce the aforementioned factors Conlon's lab has described.



Source: Eurekalert
Advertisement

Advertisement
News A-Z
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Advertisement
News Category
What's New on Medindia
Top 7 Benefits of Good Oral Hygiene
Healthy and Safer Thanksgiving 2021
Long-Term Glycemic Control - A Better Measure of COVID-19 Severity
View all

Medindia Newsletters Subscribe to our Free Newsletters!
Terms & Conditions and Privacy Policy.

More News on:
MRSA - The Super Bug Drug Resistance - Antibiotic Resistance Antibiotics Eye Infections Natural Antibiotics to Fight Bacterial Infections Vancomycin-Resistant Enterococci (VRE) Boils - Treatment by Drugs Multiple Drug Allergy Syndrome Interaction of Antibiotics with Dairy Products 

Recommended Reading
Frontline Defenders Against Antibiotic Resistance?
Residents often decide which antibiotics to start a patient on, so they could become the first line ...
A Way To Reverse Antibiotic Resistance Discovered
Resistance to antibiotics may be reversed by developing chemicals to inhibit beta-lactamase ......
Drug Use in Animal Farming, Meat Production Causes Antibiotic Resistance
Continuing to use medically important antibiotics for growth promotion in animals is one main ......
In MRSA, Receptor Proteins may Hold Clues to Antibiotic Resistance
At Imperial College London, scientists have identified four new proteins that act as receptors for ....
Antibiotics
Antibiotics are among the most used and abused medications. This article explains some general featu...
Boils - Treatment by Drugs
Diabetes patients have reduced immunity, which makes them more susceptible to skin infections like b...
Drug Resistance - Antibiotic Resistance
Drug resistance is often a problem in malaria, tuberculosis, HIV, sexually transmitted diseases and ...
Eye Infections
Eye infection is a common problem that often causes pain and discomfort to the eyes. Common symptoms...
Interaction of Antibiotics with Dairy Products
Antibiotics like tetracyclines and fluoroquinolones used in the treatment of bacterial infections in...
MRSA - The Super Bug
MRSA infection is the most dreaded hospital or community acquired infection that can become ......
Multiple Drug Allergy Syndrome
Multiple drug allergy syndrome or multiple drug hypersensitivity syndrome is a condition that causes...
Natural Antibiotics to Fight Bacterial Infections
Fighting infections the natural way and preventing them is always more effective than consuming medi...
Vancomycin-Resistant Enterococci (VRE)
Enterococci are a group of gram-negative bacteria that mostly inhabit the human gut. At present ther...

Disclaimer - All information and content on this site are for information and educational purposes only. The information should not be used for either diagnosis or treatment or both for any health related problem or disease. Always seek the advice of a qualified physician for medical diagnosis and treatment. Full Disclaimer

© All Rights Reserved 1997 - 2021

This site uses cookies to deliver our services. By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Use