Wednesday, 8 April 2015

Turning to freshwater sources to fight drug-resistant tuberculosis, other infections





Turning to freshwater sources to fight drug-resistant tuberculosis, other infections


The discovery of antibiotics produced by soil fungi and bacteria gave the world life-saving medicine. But new antimicrobials from this resource have become scarce as the threat of drug resistance grows. Now, scientists have started mining lakes and rivers for potential pathogen-fighters, and they've found one from Lake Michigan that is effective against drug-resistant tuberculosis. Their report on the new compound appears in the journal ACS Infectious Diseases.



Brian T. Murphy and colleagues point out that the emergence of drug-resistant strains of Mycobacterium tuberculosis is a serious, global health threat. In 2013, these bacteria caused 210,000 deaths globally and 480,000 infections, of which more than half were in China, India and Russia, according to the World Health Organization. The development of to fight them has not yet yielded an optimal solution.


Despite a few recent successes, scientists are having a hard time finding new candidates from soil-dwelling microbes. Murphy's team wanted to see whether bacteria that live in freshwater—a habitat that has been largely unexplored for this purpose—could be a new source of antibiotics.


The researchers screened an extensive collection of freshwater bacteria metabolites and identified a new compound that stops the growth of M. tuberculosis. In lab tests, the compound worked at least as well as current treatments for tuberculosis, and it inhibited drug-resistant strains.



More information: Diaza-anthracene Antibiotics from a Freshwater-Derived Actinomycete with Selective Antibacterial Activity toward Mycobacterium tuberculosis ACS Infect. Dis., Article ASAP. DOI: 10.1021/acsinfecdis.5b00005


Abstract

Multidrug- and extensively drug-resistant strains of Mycobacterium tuberculosis are resistant to first- and second-line drug regimens and resulted in 210,000 fatalities in 2013. In the current study, we screened a library of aquatic bacterial natural product fractions for their ability to inhibit this pathogen. A fraction from a Lake Michigan bacterium exhibited significant inhibitory activity, from which we characterized novel diazaquinomycins H and J. This antibiotic class displayed an in vitro activity profile similar or superior to clinically used anti-tuberculosis agents and maintained this potency against a panel of drug-resistant M. tuberculosis strains. Importantly, these are among the only freshwater-derived actinomycete bacterial metabolites described to date. Further in vitro profiling against a broad panel of bacteria indicated that this antibiotic class selectively targets M. tuberculosis. Additionally, in the case of this pathogen we present evidence counter to previous reports that claim the diazaquinomycins target thymidylate synthase in Gram-positive bacteria. Thus, we establish freshwater environments as potential sources for novel antibiotic leads and present the diazaquinomycins as potent and selective inhibitors of M. tuberculosis.


Medical Xpress on facebook


Related Stories


Key to tuberculosis cure could lie underwater


date Mar 08, 2013

The search for a cure for deadly infectious diseases has led Brian Murphy deep underwater. Murphy, assistant professor of medicinal chemistry and pharmacognosy at the University of Illinois at Chicago, is collecting actinomycete ...



Research may yield new ways to treat antibiotic-resistant TB


date Jun 27, 2014

Scientists in the United States and India have successfully modified the precursor to one of the drugs used to treat tuberculosis, an important first step toward new drugs that can transcend antibiotic resistance issues that ...



Researchers discover potential treatment for drug-resistant tuberculosis


date Feb 20, 2015

Researchers at the University of Georgia have developed a new small molecule drug that may serve as a treatment against multi-drug resistant tuberculosis, a form of the disease that cannot be cured with conventional ...



Potential new drug for tuberculosis


date Aug 05, 2013

A new drug capable of inhibiting growth of Mycobacterium tuberculosis is reported this week in Nature Medicine. The findings may improve therapeutic options for the treatment of drug resistant tuberculosis (TB). ...



Improving detection of drug-resistant tuberculosis


date May 02, 2012

(Medical Xpress) -- European researchers are developing new assays to detect drug resistant strains of Mycobacterium tuberculosis.





Recommended for you


Total annual hospital costs could be reduced by rapid candidemia identification


date 2 hours ago

A new study describes a model that estimates the economic consequences of using the T2Candida Panel (a novel diagnostic product that provides Candida detection) as an adjunct to the current blood culture-based diagnostic ...




Plotting the elimination of dengue


date 2 hours ago

Dengue is a viral infection spread between humans by Aedes aegypti mosquitoes. Dengue causes flu-like symptoms, including intense headaches and joint pains.



Searching the microbiome for clues to managing inflammatory bowel disease


date 3 hours ago

Sometimes the best medicine is the most basic. Just ask any of the patients with inflammatory bowel disease who are following a new diet designed to reduce the debilitating symptoms of the illness, developed by Barbara Olendzki, ...



Talking turkey: How bird flu outbreaks are playing out


date 3 hours ago

A deadly strain of bird flu has reached the Midwest, killing or requiring hundreds of thousands of turkeys to be euthanized. Some questions and answers about the outbreak:



WHO sets up emergency rapid response network


date 4 hours ago

The World Health Organization launched a new network of rapid response medical teams Wednesday to react to humanitarian crises across the globe.




Climate change affects where vectors proliferate and also transforms pathogens


date 5 hours ago

Accurate forecasts of a changing climate may not be enough to predict future risk from disease transmission, as the carriers themselves are always changing. In other words, seeing into the future is complicated.




User comments



Please sign in to add a comment. Registration is free, and takes less than a minute. Read more


Click here to reset your password.

Sign in to get notified via email when new comments are made.







Turning to freshwater sources to fight drug-resistant tuberculosis, other infections


The discovery of antibiotics produced by soil fungi and bacteria gave the world life-saving medicine. But new antimicrobials from this resource have become scarce as the threat of drug resistance grows. Now, scientists have started mining lakes and rivers for potential pathogen-fighters, and they've found one from Lake Michigan that is effective against drug-resistant tuberculosis. Their report on the new compound appears in the journal ACS Infectious Diseases.



Brian T. Murphy and colleagues point out that the emergence of drug-resistant strains of Mycobacterium tuberculosis is a serious, global health threat. In 2013, these bacteria caused 210,000 deaths globally and 480,000 infections, of which more than half were in China, India and Russia, according to the World Health Organization. The development of to fight them has not yet yielded an optimal solution.


Despite a few recent successes, scientists are having a hard time finding new candidates from soil-dwelling microbes. Murphy's team wanted to see whether bacteria that live in freshwater—a habitat that has been largely unexplored for this purpose—could be a new source of antibiotics.


The researchers screened an extensive collection of freshwater bacteria metabolites and identified a new compound that stops the growth of M. tuberculosis. In lab tests, the compound worked at least as well as current treatments for tuberculosis, and it inhibited drug-resistant strains.



More information: Diaza-anthracene Antibiotics from a Freshwater-Derived Actinomycete with Selective Antibacterial Activity toward Mycobacterium tuberculosis ACS Infect. Dis., Article ASAP. DOI: 10.1021/acsinfecdis.5b00005


Abstract

Multidrug- and extensively drug-resistant strains of Mycobacterium tuberculosis are resistant to first- and second-line drug regimens and resulted in 210,000 fatalities in 2013. In the current study, we screened a library of aquatic bacterial natural product fractions for their ability to inhibit this pathogen. A fraction from a Lake Michigan bacterium exhibited significant inhibitory activity, from which we characterized novel diazaquinomycins H and J. This antibiotic class displayed an in vitro activity profile similar or superior to clinically used anti-tuberculosis agents and maintained this potency against a panel of drug-resistant M. tuberculosis strains. Importantly, these are among the only freshwater-derived actinomycete bacterial metabolites described to date. Further in vitro profiling against a broad panel of bacteria indicated that this antibiotic class selectively targets M. tuberculosis. Additionally, in the case of this pathogen we present evidence counter to previous reports that claim the diazaquinomycins target thymidylate synthase in Gram-positive bacteria. Thus, we establish freshwater environments as potential sources for novel antibiotic leads and present the diazaquinomycins as potent and selective inhibitors of M. tuberculosis.


Medical Xpress on facebook


Related Stories


Key to tuberculosis cure could lie underwater


date Mar 08, 2013

The search for a cure for deadly infectious diseases has led Brian Murphy deep underwater. Murphy, assistant professor of medicinal chemistry and pharmacognosy at the University of Illinois at Chicago, is collecting actinomycete ...



Research may yield new ways to treat antibiotic-resistant TB


date Jun 27, 2014

Scientists in the United States and India have successfully modified the precursor to one of the drugs used to treat tuberculosis, an important first step toward new drugs that can transcend antibiotic resistance issues that ...



Researchers discover potential treatment for drug-resistant tuberculosis


date Feb 20, 2015

Researchers at the University of Georgia have developed a new small molecule drug that may serve as a treatment against multi-drug resistant tuberculosis, a form of the disease that cannot be cured with conventional ...



Potential new drug for tuberculosis


date Aug 05, 2013

A new drug capable of inhibiting growth of Mycobacterium tuberculosis is reported this week in Nature Medicine. The findings may improve therapeutic options for the treatment of drug resistant tuberculosis (TB). ...



Improving detection of drug-resistant tuberculosis


date May 02, 2012

(Medical Xpress) -- European researchers are developing new assays to detect drug resistant strains of Mycobacterium tuberculosis.





Recommended for you


Total annual hospital costs could be reduced by rapid candidemia identification


date 2 hours ago

A new study describes a model that estimates the economic consequences of using the T2Candida Panel (a novel diagnostic product that provides Candida detection) as an adjunct to the current blood culture-based diagnostic ...




Plotting the elimination of dengue


date 2 hours ago

Dengue is a viral infection spread between humans by Aedes aegypti mosquitoes. Dengue causes flu-like symptoms, including intense headaches and joint pains.



Searching the microbiome for clues to managing inflammatory bowel disease


date 3 hours ago

Sometimes the best medicine is the most basic. Just ask any of the patients with inflammatory bowel disease who are following a new diet designed to reduce the debilitating symptoms of the illness, developed by Barbara Olendzki, ...



Talking turkey: How bird flu outbreaks are playing out


date 3 hours ago

A deadly strain of bird flu has reached the Midwest, killing or requiring hundreds of thousands of turkeys to be euthanized. Some questions and answers about the outbreak:



WHO sets up emergency rapid response network


date 4 hours ago

The World Health Organization launched a new network of rapid response medical teams Wednesday to react to humanitarian crises across the globe.




Climate change affects where vectors proliferate and also transforms pathogens


date 5 hours ago

Accurate forecasts of a changing climate may not be enough to predict future risk from disease transmission, as the carriers themselves are always changing. In other words, seeing into the future is complicated.




User comments



Please sign in to add a comment. Registration is free, and takes less than a minute. Read more


Click here

to reset your password.


Sign in to get notified via email when new comments are made.








Categories:

0 comments:

Post a Comment