Resistance isn’t futile – how to tackle drug-resistant superbugs

Matt Cooper, a medical chemist at the University of Queensland, Australia, puffs out his cheeks and scratches his head. He’s trying to explain why the pipeline for new antibiotics is quite so dry. “The problem,” he says, “is that finding new antibiotics is now really, really hard.”

It’s a worrying concession given how badly we need new drugs. Drug-resistant superbugs already kill hundreds of thousands of people every year and, according to the Antimicrobial Review (AMR) committee chaired by Jim O’Neill (see box), if left unchecked they will kill 10 million of us every year by 2050. That’s more than will be killed by cancer, diarrhoeal disease or road traffic accidents.

One of the reasons drug discovery is so hard, Cooper says, is that it has suffered underinvestment since the late 70s. Big pharma companies, the traditional engine room for drug discovery, started to drop their antibiotics programmes, focusing instead on more profitable drugs that are sold at a higher price and taken for the rest of a patient’s lifetime, such as those for diabetes, cancer and heart disease. The cholesterol-busting drug Lipitor, for instance, at its height raked in a cork-popping $13bn (£8.4bn) a year for pharma giant Pfizer. Antibiotics, cheaper per pill and taken for about a week, could not compete.

Another reason behind the exodus of big pharma was that finding new drugs became difficult. “We took most of the low-hanging fruit in the golden era of antibiotics in the 50s to the 70s,” Cooper says. Most antibiotics came from compounds made by micro-organisms in the soil. Scientists, like children at the beach, needed only a bucket and a spade to collect soil samples, bring them back to the laboratory to be cultured, and try to identify any compounds that could kill bugs. “We were finding 12 antibiotics a year. Nobody worried much about resistance or overuse because we thought there would always be more.”

Nobody worried about resistance or overuse of antibiotics because there were always more. Photograph: Alamy

Scientists have since scoured ocean beds and deep caves for micro-organisms that make new compounds but had come up empty-handed – until, that is, earlier this year when a team from Northeastern University in Boston, US, announced they had discovered 25 potential new compounds in the soil. One of them, teixobactin, showed promise in laboratory tests against otherwise drug-resistant strains of tuberculosis and the hospital superbug MRSA (methicillin-resistant Staphylococcus aureus). Teixobactin is not active against the harder-to-treat type of bacteria called gram-negative bacteria, but its announcement caused much excitement. If approved, as is hoped within the next five years, it will be the first new class of antibiotic developed since 1987.

The researchers used a technology called iChip, currently under exclusive licence to US company NovoBiotic Pharmaceuticals, to tap into the much-prophesied microbial “dark matter” – the roughly 99% of micro-organisms that cannot be cultured in laboratory conditions and were thus unseen by the early antibiotic discoverers.  

Read more https://www.theguardian.com/science/2015/jul/19/antibiotics-new-research-end-of-drug-resistant-superbugs

Courtesy of Guardian News & Media Ltd