Low doses of silver make bacteria more susceptible to antibiotic attack, paving the way for new therapies for drug-resistant and recurrent infections
Slipping bacteria some silver could give old antibiotics new life, scientists at the Wyss Institute for Biologically Inspired Engineering at Harvard University reported June 19 in Science Translational Medicine.
Treating bacteria with a silver-containing compound boosted the efficacy of a broad range of widely used antibiotics and helped them stop otherwise lethal infections in mice. It helped make an antibiotic-resistant strain of bacteria sensitive to antibiotics again. And it expanded the power of an antibiotic called vancomycin that is usually only effective in killing pathogens called Gram-positive bacteria, such as Staph and Strep. Silver allowed vancomycin for the first time to penetrate and kill Gram-negative bacteria, a group that includes microbes that can cause food poisoning and dangerous hospital-acquired infections.
Silver also proved useful for two types of stubborn infections that usually require repeated rounds of antibiotic treatment and multiple visits to the clinic: dormant bacteria that lie low during antibiotic treatment and rebound to cause recurrent infections, and microbial slime layers called biofilms that coat catheters and prosthetic joints.
“The results suggest that silver could be incredibly valuable as an adjunct to existing antibiotic treatments,” said Jim Collins, Ph.D., a pioneer of synthetic biology and Core Faculty member at the Wyss Institute, who is also the William F. Warren Distinguished Professor at Boston University, where he leads the Center of Synthetic Biology.
In recent years more disease-causing bacteria have grown resistant to common antibiotics, with serious public health consequences. Yet drug companies have struggled for years to develop new types of antibiotics that target these tough bacteria. That has led scientists to re-examine older methods that were used to fight infection well before penicillin use took off in the 1940s. Silver treatment, which has been used since antiquity to prevent and heal infections, is one of them.
Despite silver’s long history of use in the clinic, no one understood fully how it killed bacteria.To find out, Ruben Morones-Ramirez, Ph.D., a postdoctoral fellow at the Wyss Institute who left recently to become a professor at Universidad Autònoma de Nuevo Leon in Mexico, treated normal and mutant strains of E. coli bacteria with a silver compound. Then he observed them under the electron microscope and ran a series of biochemical tests.
He found that silver compounds cause bacteria to produce more reactive oxygen species – chemically reactive molecules that damage the bacterial cell’s DNA and enzymes, as well as the membrane that encloses the cell. Silver also made the bacteria’s cell membrane leakier.
Although silver was used alone as a therapy in the past, the scientists suspected that both changes might make cells more vulnerable to conventional antibiotics — and they did. A small amount of silver made E. coli bacteria between 10 and 1000 times more sensitive to three commonly used antibiotics: gentamycin, ofloxacin, and ampicillin.
“If you know the mechanism, you can have much more success making combinatorial therapies,” Morones-Ramirez said.
In mice, silver also helped antibiotics fight E. coli-induced urinary-tract infections. It made a previously impervious strain of E. coli sensitive to the antibiotic tetracycline. And it allowed vancomycin to save the lives of 90 percent of mice with life-threatening cases of peritonitis — inflammation caused by infections of the abdominal space surrounding the internal organs. Without silver, only 10 percent of the mice survived.
The scientists also did a series of toxicity studies, showing that the doses of silver needed to help antibiotics kill bacteria were far below what could harm the mice. Nor did they harm cultured human cells, suggesting that oral and injectable silver could be safe for humans as well.
The Latest Bing News on:
Drug-resistant and recurrent infections
- Comeback of drug-resistant neglected tropical disease tracked through genomic surveillanceon October 8, 2020 at 3:56 am
Yaws, caused by the bacterium Treponema pallidum subspecies pertenue (TPP), can cause chronic disfigurement and disability. Most commonly affecting children, infection with the bacteria results in ...
- Morrisville firm scores 'huge' federal contract – up to $77M – for E. coli treatmenton October 1, 2020 at 11:06 am
coli bacteria causing recurrent urinary tract infections (UTIs ... necessarily seeing any data yet that suggested these multi-drug resistant rates are rising but we're certainly seeing a lot ...
- TaiGen Biotechnology Out-Licensed Taigexyn (Nemonoxacin) to Luminarie Canada for Canada, Australia and New Zealandon September 30, 2020 at 1:05 am
PRNewswire/ -- TaiGen Biotechnology Company, Limited ("TaiGen") (Taiwan: 4157) today announced that they have signed an exclusive licensing agreement with Luminarie Canada Inc. ("Luminarie"), a ...
- Infection Surveillance Solution Market Global Industry Analysis and Opportunity Assessment 2020-2025on September 28, 2020 at 12:25 pm
Infection Surveillance Solution Market is valued at USD 322.8 Million in 2018 and expected to reach USD 495.1 Million by ...
- Chronic Infectious Disease and the Future of Health Care Deliveryon September 16, 2020 at 5:00 pm
Extensively drug-resistant tuberculosis is again a case ... claims that treating a chronic infection with a multidrug regimen was impossible in poor settings were invalid. And in 2002, the Global ...
- If You Can't Stop Itching From Recurring Yeast Infections, Read Thison August 19, 2019 at 10:05 am
But after your vagina has been plagued by the uncomfortable, itchy infection, the word yeast will never have the same innocuous ring to it again. And if you get chronic or recurring yeast ...
- Recurrent Urinary Tract Infectionson January 28, 2018 at 4:09 pm
Recurrent urinary tract infections (UTI) are common in dogs compared to cats ... prostatitis), and emergence of drug-resistant pathogens. Common causes of reinfection include failure to eliminate ...
The Latest Google Headlines on:
Drug-resistant and recurrent infections
The Latest Bing News on:
- Poultry Diet Including Menon’s MrFeed Achieves Greater Body Weight and 30% Increase in Egg Yield Without Use of Antibioticson October 13, 2020 at 6:00 am
Eggs Show 10% Higher Albumin Content for Overall Better Nutrition, Yields Beneficial for Vaccine Production San Diego, CA - ( NewMediaWire) - October 13, 2020 - Menon Renewable Products (“Menon” or ...
- Insights on Antibiotics Market within the Pharmaceuticals Sector | Rising Prevalence of Infectious Diseases to Emerge as a Key Driver | Technavioon October 12, 2020 at 1:39 pm
The global antibiotics market is expected to grow at a CAGR of over 3% during 2020-2024, according to the latest market research report by Technavio. The report provides a detailed analysis on the ...
- Wasp toxin inspires new antibiotic that overcomes tough-to-treat sepsis in miceon October 12, 2020 at 12:00 pm
Penn scientists engineered an antibiotic from an ingredient in the venom of the Korean yellow-jacket wasp. In mouse models of sepsis caused by E. coli—an infection that is becoming more and more ...
- Wasp venom peptides show potential as potent antibiotic candidateon October 11, 2020 at 5:00 pm
With antibiotic-resistant bacteria poised to become a huge health problem in the coming decades, the world desperately needs new drugs and treatments. Now, researchers at the University of ...
- CDC launches new plan to tackle antibiotic-resistant infectionson October 9, 2020 at 10:19 am
U.S. Centers for Disease Control and Prevention officials announced Friday what they describe as a "national action plan" to fight antibiotic-resistant infections.
- New approach may give new life to old antibioticon October 8, 2020 at 5:00 pm
Chemists have developed 10 artificial forms of an old antibiotic called gramicidin A, which may be more suitable for use in humans.
- Lawmakers, Drug Companies Cast Lifelines to Antibiotics Industryon October 8, 2020 at 3:07 am
A new bill seeks to spur antibiotic development, while drugmakers plan to invest nearly $1 billion in the struggling sector.
- Antibiotics or Appendectomy? Both Good Optionson October 7, 2020 at 4:14 am
A large, randomized trial finds antibiotics are noninferior to surgery after 30 days. However, experts urge caution in rushing to the medication option for everyone.
- New antibiotics: Turning to dirt in the fight against drug-resistant bacteriaon October 6, 2020 at 1:28 am
Dirt contains an entire microbial ecosystem, with a wealth of intriguing compounds. And while there are major hurdles between discovering a new drug and using it, scientists are hopeful new techniques ...
- 80-year-old antibiotic redesigned for new medical useson October 5, 2020 at 6:45 am
Physicians and scientists have long searched the natural world for chemicals that can improve human health. However, evolutionary selection optimized natural chemicals to benefit their host, not for ...