Examine, a free newsletter covering science, is sent every Tuesday.
asserted
Examine → cover → science
You’re reading an excerpt – sign up to get the whole newsletter in your inbox.
asserted
You → read → inbox
In 1928, Alexander Fleming left a petri dish unsealed and later found it overgrown with a green fuzz that had partly killed his culture of Staphylococcus aureus.
asserted
that → leave → aureus
He’d discovered penicillin.
asserted
He → discover → penicillin
That was the opening salvo in what would become an evolutionary battle between medical researchers and their pathogenic microbial enemies that have rapidly evolved to outfox antibiotics and kill more than 1.2 million people each year through drug-resistant infections.
asserted
that → open → infections
But recently, an unexpected discovery by scientists at Monash University has unveiled both a new weapon against bacteria and an unexpected defence.
asserted
discovery → unveil → bacteria
“Bacteria are evolving in ways that we’re not anticipating – it’s creating another level of superbug,” says Professor Dena Lyras, director of the Monash Biomedicine Discovery Institute, who focuses on a hospital-haunting bug that can unleash deadly diarrhoea.
asserted
that → evolve → diarrhoea
Hidden yet horrid
Nearly a century after Fleming’s accidental discovery, bacterial researchers found themselves once again flummoxed in the lab.
asserted
themselves → find → lab
Lyras and her colleagues were trying to grow Clostridioides difficile, a bacterium that commonly infects the gut after antibiotic treatment in humans.
asserted
that → try → humans
“Every hospital has a problem with C. difficile.
asserted
hospital → have → difficile
And it’s sort of a bit hidden.
asserted
it → ’ → ?
But we have elderly patients who become very sick and die of it,” Lyras says.
asserted
Lyras → have → it
The researchers’ lab-raised bacterium grew fine, but it couldn’t make spores, which in this species is key to reproduction and infection.
asserted
which → raise → reproduction
“Gosh, they’re tough, I tell you …
asserted
I → ’re → you
You irradiate them for 200 hours and they still aren’t 100 per cent dead.
asserted
they → irradiate → hours
They investigated the batch and discovered the liquid medium they were growing the bacteria in contained a type of substance called a cephamycin.
asserted
they → investigate → substance
They had inadvertently discovered a spore-busting antibiotic – that cephamycins could help treat C. difficile and other spore-forming nasties such as anthrax.
uncertain
cephamycins → discover → anthrax
“A lot of spores are made in the patient as they’re infected.
asserted
they → make → patient
We discovered a group of antibiotics that actually stopped sporulation in its tracks,” Lyras says.
asserted
Lyras → discover → tracks
It wasn’t long, of course, before the bacteria fired back.
asserted
bacteria → fire → course
“In about 10 per cent of the strains that we examined, this sporulation-blocking strategy didn’t work.
asserted
strategy → examine → that
We wondered why it wasn’t working – and that’s where we discovered this subset of strains that have this new resistance gene.”
asserted
that → wonder → gene
Like an ‘armoured truck’: The new discovery
Some bacteria have a “normal” form – where they grow, eat, reproduce and, in C. difficile’s case, gleefully infect people’s colons – and a “spore” form.
asserted
they → have → colons
These spores are extremely hard to kill.
asserted
spores → kill → ?
“Spores are the survival version of the cell,” Lyras says.
asserted
Lyras → say → cell
“They’ve got their DNA packed in the middle, and then they’ve got layers of stuff around them like an armoured truck, tightly packed without that much water.
asserted
they → get → water
So it’s just really tough.”
asserted
it → ’ → ?
What Lyras and her colleagues have now reported in Nature Communications is an antibiotic resistance gene arising in the spore form of bacteria – not the normal form – for the first time.
asserted
reported → report → time
“We hadn’t anticipated that; it’s not been described before, and it’s making that cell type tougher, stronger, more likely to survive in the environment.
asserted
type → anticipate → environment
That’s going to have repercussions in a hospital where you can’t kill these spores off,” Lyras says.
asserted
Lyras → go → spores
“Gosh, they’re tough, I tell you.
asserted
I → ’re → you
You’ve got to have like half an hour of contact with bleach to kill them.
asserted
You → get → them
You irradiate them for 200 hours and they still aren’t 100 per cent dead.
asserted
they → irradiate → hours
In the resistant bacteria, a new gene codes for a protein that can continue making spores, even when hit by antibiotics.
asserted
that → cod → antibiotics
The spores can survive hospital-grade disinfectants and hot laundry temperatures.
asserted
spores → survive → disinfectants
Because they’re already Terminator-tough, spores taking on a drug-resistant gene create the “ultimate superbug”, like a seed that can lie dormant in soil for years before sprouting, Lyras says.
asserted
Lyras → ’re → years
The spores can persist for as long as two years in hospitals.
asserted
spores → persist → hospitals
Off the back of the findings, Lyras asks: “Do we need to rethink our strategies that we’re using to clean the hospitals, to clean the beds, to clean the surfaces, to clean the sheets, to clean the toilets and the sinks?”
asserted
we → ask → toilets
Deaths from infections that were previously treatable with antibiotics will exceed 10 million
-
asserted
that → exceed → million
Antimicrobial resistance (AMR) will result in up to 7.5% global decrease in livestock production
- A decline in global GDP of between 3.8-5%
- An increase in 28.3 million people in extreme poverty
- Global real exports shrinking by 1.1%
- Global healthcare costs increase from $300 billion to >$1 trillion per year.
asserted
costs → result → year
…and 17 more, not listed.
The Aporia
