New antibiotic family discovered in dirt

Authored by bbc.com and submitted by mvea
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US scientists have discovered a new family of antibiotics in soil samples.

The natural compounds could be used to combat hard-to-treat infections, the team at Rockefeller University hopes.

Tests show the compounds, called malacidins, annihilate several bacterial diseases that have become resistant to most existing antibiotics, including the superbug MRSA.

Experts say the work, published in Nature Microbiology, offers fresh hope in the antibiotics arms race.

Drug-resistant diseases are one of the biggest threats to global health.

They kill around 700,000 people a year, and new treatments are urgently needed.

Soil is teeming with millions of different micro-organisms that produce lots of potentially therapeutic compounds, including new antibiotics.

Dr Sean Brady's team at New York's Rockefeller University has been busy unearthing them.

They used a gene sequencing technique to analyse more than 1,000 soil samples taken from across the US.

When they discovered malacidins in many of the samples, they had a hunch it was an important find.

They tested the compound on rats that they had given MRSA and it eliminated the infection in skin wounds.

The researchers are now working to improve the drug's effectiveness in the hope that it can be developed into a real treatment for people.

Dr Brady said: "It is impossible to say when, or even if, an early stage antibiotic discovery like the malacidins will proceed to the clinic.

"It is a long, arduous road from the initial discovery of an antibiotic to a clinically used entity."

Prof Colin Garner, from Antibiotic Research UK, said finding new antibiotics to treat gram-positive infections like MRSA was good news, but would not address the most pressing need.

"Our concern are the so called gram-negative bacteria which are difficult to treat and where resistance is on the increase," he said.

"Gram-negative bacteria cause pneumonia, blood and urinary tract infections as skin infections. We need new antibiotics to treat this class."

Roannoke on February 13rd, 2018 at 14:05 UTC »

I work with MRSA at the CDC. Currently MRSA is still susceptible to vancomycin so that works.

Thread_water on February 13rd, 2018 at 11:29 UTC »

Great news, for those wondering what the catch is, from the article.

"It is impossible to say when, or even if, an early stage antibiotic discovery like the malacidins will proceed to the clinic.

"It is a long, arduous road from the initial discovery of an antibiotic to a clinically used entity."

Still good news though.

mvea on February 13rd, 2018 at 10:29 UTC »

The post title is cut and paste from the linked popular press article here:

New antibiotic family discovered in dirt

And here:

Tests show the compounds, called malacidins, annihilate several bacterial diseases that have become resistant to most existing antibiotics, including the superbug MRSA.

Journal reference:

Culture-independent discovery of the malacidins as calcium-dependent antibiotics with activity against multidrug-resistant Gram-positive pathogens

Bradley M. Hover, Seong-Hwan Kim, Micah Katz, Zachary Charlop-Powers, Jeremy G. Owen, Melinda A. Ternei, Jeffrey Maniko, Andreia B. Estrela, Henrik Molina, Steven Park, David S. Perlin & Sean F. Brady

Nature Microbiology (2018)

doi:10.1038/s41564-018-0110-1

Link: https://www.nature.com/articles/s41564-018-0110-1

Link: https://www.nature.com/articles/s41564-018-0110-1

Published online: 12 February 2018

Abstract

Despite the wide availability of antibiotics, infectious diseases remain a leading cause of death worldwide1. In the absence of new therapies, mortality rates due to untreatable infections are predicted to rise more than tenfold by 2050. Natural products (NPs) made by cultured bacteria have been a major source of clinically useful antibiotics. In spite of decades of productivity, the use of bacteria in the search for new antibiotics was largely abandoned due to high rediscovery rates2,3. As only a fraction of bacterial diversity is regularly cultivated in the laboratory and just a fraction of the chemistries encoded by cultured bacteria are detected in fermentation experiments, most bacterial NPs remain hidden in the global microbiome. In an effort to access these hidden NPs, we have developed a culture-independent NP discovery platform that involves sequencing, bioinformatic analysis and heterologous expression of biosynthetic gene clusters captured on DNA extracted from environmental samples. Here, we describe the application of this platform to the discovery of the malacidins, a distinctive class of antibiotics that are commonly encoded in soil microbiomes but have never been reported in culture-based NP discovery efforts. The malacidins are active against multidrug-resistant pathogens, sterilize methicillin-resistant Staphylococcus aureus skin infections in an animal wound model and did not select for resistance under our laboratory conditions.