Anthrax killer from the sea: Unusual antibiotic from a marine actinomycete is effective against anthrax

July 2, 2013, Angewandte Chemie

Anthrax killer from the sea: Unusual antibiotic from a marine actinomycete is effective against anthrax
(Phys.org) —A new potential drug from a marine microorganism is effective against anthrax and various other Gram-positive bacteria, as reported by American scientists in the journal Angewandte Chemie. A chlorinated analogue kills off Gram-negative bacteria.

Anthrax is a dangerous infectious disease caused by the spore-forming bacterium Bacillus anthracis and transmitted by infected farm animals. For several years now, anthrax has also been feared as a . Attacks with spore-containing letters caused five deaths in 2001.

Infection with anthrax usually requires tedious treatment with various antibiotics. Infections caught through the respiratory system are especially dangerous, often requiring continuous . The search for effective antibiotics is thus correspondingly important.

Researchers working with William Fenical have now isolated a species of Streptomyces from near-shore sediments near Santa Barbara, California. The culture extracts demonstrate significant activity against anthrax. The team from the University of California, San Diego and Trius Therapeutics (San Diego) succeeded in isolating a molecule from this extract that kills off as well as other Gram-positive bacteria like staphylococci, enterococci, and streptococci. However, it is virtually useless against Gram-negative bacteria.

By using a variety of methods of analysis, the researchers were able to determine the structure of this molecule, which they named anthracimycin. Anthracimycin contains an unusual system of rings, one with fourteen and two with six each. This is a macrolide whose biosynthesis very likely occurs by the polyketide pathway. X-ray crystallographic studies allowed the researchers to determine the absolute configurations of the seven asymmetric carbon centers in this compound, identifying the complete 3-dimensional structure.

This class of molecules is completely different from all known antibiotics. An similar carbon skeleton is found in chlorotonil, a metabolite from the terrestrial myxobacterium Sorangium cellulosum. However, chlorotonil differs in its carbon skeleton, contains two chlorine atoms and the stereochemistry of most of its asymmetric carbon centers differs from that of anthracimycin.

In order to examine the effects of the chlorine atoms in the close analogue chlorotonil, the scientists chlorinated anthracimycin. This chlorine-containing analogue proved to be only about half as effective against B. anthracis. However, its activity against a number of Gram-negative pathogens increased significantly. This finding is important because Gram-negative bacteria are often resistant to current antibiotics. Comprehensive studies of this new class of antibacterials could lead to the development of effective new drugs.

Explore further: FDA approves new drug for inhaled anthrax

More information: Fenical, W. Anthracimycin, a Potent Anthrax Antibiotic from a Marine-Derived Actinomycete, Angewandte Chemie International Edition. dx.doi.org/10.1002/anie.201302749

Related Stories

Anthrax targets

August 20, 2012

A trawl of the genome of the deadly bacterium Bacillus anthracis has revealed a clutch of targets for new drugs to combat an epidemic of anthrax or a biological weapons attack. The targets are all proteins that are found ...

Recommended for you

Scientists discover new 'architecture' in corn

January 21, 2019

New research on the U.S.'s most economically important agricultural plant—corn—has revealed a different internal structure of the plant than previously thought, which can help optimize how corn is converted into ethanol.

Targeting 'hidden pocket' for treatment of stroke and seizure

January 19, 2019

The ideal drug is one that only affects the exact cells and neurons it is designed to treat, without unwanted side effects. This concept is especially important when treating the delicate and complex human brain. Now, scientists ...

Artificially produced cells communicate with each other

January 18, 2019

Friedrich Simmel and Aurore Dupin, researchers at the Technical University of Munich (TUM), have for the first time created artificial cell assemblies that can communicate with each other. The cells, separated by fatty membranes, ...

Using bacteria to create a water filter that kills bacteria

January 18, 2019

More than one in 10 people in the world lack basic drinking water access, and by 2025, half of the world's population will be living in water-stressed areas, which is why access to clean water is one of the National Academy ...

0 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.