The tiny killer in your gut

The world's smallest arms race could be happening right now in your gut.
Thomas Crow
Thomas Crow
Freelance science writer
The tiny killer in your gut
Image credit: Ed Uthman via Wikimedia Commons

One of the world’s most dangerous superbugs runs rampant in Perth hospitals, but you’ve likely never heard of it.

Clostridioides difficile (also known as C. diff) is a bacterium that loves your gut. So much so, it infects almost every newborn. The current reasoning for this phenomenon is that newborns most likely have ‘sterile’ guts which means C. diff has no competition. The bacterium makes contact with a newborn via environmental contamination. Around 70% of infants have it in their gut, then eject it after the first 2 years.

View Larger

C. difficile under an electron microscope

Image credit: CDC Public Health Library / Wikimedia Commons
C. difficile under an electron microscope

C. diff can affect anyone, not just babies. While it is thought infants are immune to its toxins because they don’t yet have the cell receptors the toxin attaches to, adults have no such luck. But if you were infected as an infant, you will fare better against the bacterium as an adult.

When disease or antibiotics reduce our normal gut flora, C. diff comes calling. It can cause an infection of the large intestine, with symptoms of the illness ranging from diarrhoea, pain, fever and even death.


Thanks to their endospores, C. diff infections are common and hard to eradicate from hospitals. The endospores protect the bacterium from harsh conditions and low nutrient levels – kind of like a little bacterial space suit.

Tom Riley is a Professor of Public Health at University of Western Australia. He has dedicated much of his career to understanding these superbugs.

“The [bacterial endospores] are highly resistant to conventional disinfectants,” says Tom.

“The only thing that kills them is hydrogen peroxide and hypochlorite.”

As well as being tough to kill, C. diff is gaining resistance to many conventional antibiotics. Half of the strains of C. diff isolated from WA patients aged between 1 and 4 were resistant to one antibiotic. Around 13% were resistant to multiple drugs.


Antibiotics are vital for treating infections. But the our overuse of broad-spectrum antibiotics is making our our guts vulnerable to infection.

Image credit: GIPHY

“Antibiotics are more of a problem in terms of causing rather than curing the disease,” says Tom.

“If you have normal gut flora, you are not susceptible to infection.”

Cephalosporins are a group of broad-spectrum antibiotics. They work by interfering with a bacterial cell’s penicillin-binding proteins. These proteins help glue together cell walls. Without them, the bacterial cell breaks apart and the bacterium dies.

Unfortunately, cephalosporins destroy gut flora and are also associated with C. diff infection. With no other bacteria in the gut to compete with, C. diff can thrive. The wide use of cephalosporins as an antibiotic has changed where people are getting infected.

Tom says that, 20–30 years ago, most infections occurred inside hospitals.

“Now, most cases coming in are from outside the hospital,” says Tom.

“In the 1990s, the US decided it was a good idea to license cephalosporin for animal use. That has facilitated our current wave of C. difficile infections.”

While some governments are trying to remove cephalosporins from livestock medicine, the damage has been done. Most strains of C. diff are inherently resistant to third-generation cephalosporins.

“C. difficile is listed in the [United States Centre for Disease Control] top five urgent threats to public health,” Tom says. “Australians haven’t quite woken up to that fact yet.”

So what can we do?


Recent data suggests that fewer Australian GPs are prescribing broad-spectrum antibiotics.

And while this new trend is welcomed, the prescription of antibiotics is still a hard habit to kick. Antibiotics are one of the most significant advances ever made in medicine. They’re extremely helpful at tackling most bacterial infections.

However, the World Health Organization advises against taking antibiotics for colds and the flu. That’s because they’re viral infections that antibiotics aren’t designed to treat.

According to Tom, we also need to stop using human antibiotics in livestock. It creates a ripe breeding ground for zoonotic diseases (diseases that transfer from animals to humans).

We’re in an arms race with superbugs. It’s not a fight we can ever fully win, but if we adopt the above measures, hopefully we can avoid losing completely.

Thomas Crow
About the author
Thomas Crow
Thomas Crow is an Australian science writer. He has a background in professional writing, biochemistry and genetics. He writes for Australian and New Zealand research institutes and publications like Crikey. He's a horror and gothic fantasy fan. He thinks of himself as a gardener but scores of dead plants beg to differ.
View articles
Thomas Crow is an Australian science writer. He has a background in professional writing, biochemistry and genetics. He writes for Australian and New Zealand research institutes and publications like Crikey. He's a horror and gothic fantasy fan. He thinks of himself as a gardener but scores of dead plants beg to differ.
View articles


We've got chemistry, let's take it to the next level!

Get the latest WA science news delivered to your inbox, every fortnight.


Creative Commons Logo

Republishing our content

We want our stories to be shared and seen by as many people as possible.

Therefore, unless it says otherwise, copyright on the stories on Particle belongs to Scitech and they are published under a Creative Commons Attribution-NoDerivatives 4.0 International License.

This allows you to republish our articles online or in print for free. You just need to credit us and link to us, and you can’t edit our material or sell it separately.

Using the ‘republish’ button on our website is the easiest way to meet our guidelines.


You cannot edit the article.

When republishing, you have to credit our authors, ideally in the byline. You have to credit Particle with a link back to the original publication on Particle.

If you’re republishing online, you must use our pageview counter, link to us and include links from our story. Our page view counter is a small pixel-ping (invisible to the eye) that allows us to know when our content is republished. It’s a condition of our guidelines that you include our counter. If you use the ‘republish’ then you’ll capture our page counter.

If you’re republishing in print, please email us to let us so we know about it (we get very proud to see our work republished) and you must include the Particle logo next to the credits. Download logo here.

If you wish to republish all our stories, please contact us directly to discuss this opportunity.


Most of the images used on Particle are copyright of the photographer who made them.

It is your responsibility to confirm that you’re licensed to republish images in our articles.


All Particle videos can be accessed through YouTube under the Standard YouTube Licence.

The Standard YouTube licence

  1. This licence is ‘All Rights Reserved’, granting provisions for YouTube to display the content, and YouTube’s visitors to stream the content. This means that the content may be streamed from YouTube but specifically forbids downloading, adaptation, and redistribution, except where otherwise licensed. When uploading your content to YouTube it will automatically use the Standard YouTube licence. You can check this by clicking on Advanced Settings and looking at the dropdown box ‘License and rights ownership’.
  2. When a user is uploading a video he has license options that he can choose from. The first option is “standard YouTube License” which means that you grant the broadcasting rights to YouTube. This essentially means that your video can only be accessed from YouTube for watching purpose and cannot be reproduced or distributed in any other form without your consent.


For more information about using our content, email us:

Copy this HTML into your CMS
Press Ctrl+C to copy