The germs lurking in your microwave: Radiation-resistant microbes are breeding inside our home appliances – including several that could prove DEADLY, study warns

Whether it’s heating up a ready meal or warming up a cold cup of tea, many of us use our microwaves multiple times a day.

But a new study might make you think twice before turning to your appliance.

Researchers from Darwin Bioprospecting Excellence SL, a startup based in Paterna, Spain, have discovered radiation-resistant microbes living inside microwaves.

Worryingly, several strains could prove deadly to humans, according to the team.

‘Some species of genera found in domestic microwaves, such as Klebsiella, Enterococcus and Aeromonas, may pose a risk to human health,’ said Daniel Torrent, one of the authors of the study.

Previous studies have discovered microbes living in a range of weird and wonderful habitats, including marine oil spills, industrial brownfields, and even inside the International Space Station.

But until now, it’s been unclear which germs can be found inside microwaves.

In their study, the team sampled microbes from inside 30 microwaves – 10 from single-household kitchens, 10 from shared domestic spaces such as cafeterias, and 10 from scientific laboratories.

An analysis of the samples uncovered 747 different genera of microbes within 25 bacterial phyla.

However, these strains varied significantly between locations.

‘Domestic microwaves have a more “anthropized” microbiome, similar to kitchen surfaces, while laboratory microwaves harbor bacteria that are more resistant to radiation,’ said Mr Torrent.

Researchers from Darwin Bioprospecting Excellence SL, a startup based in Paterna, Spain, have discovered radiation-resistant microbes living inside microwaves. Worryingly, several strains could prove deadly to humans, according to the team (artist’s impression) 

Within the single-household kitchens, the main genera of microbes were Acinetobacter, Bhargavaea, Brevibacterium, Brevundimonas, Dermacoccus, Klebsiella, Pantoea, Pseudoxanthomonas and Rhizobium.

Meanwhile, Arthrobacter, Enterobacter, Janibacter, Methylobacterium, Neobacillus, Nocardioides, Novosphingobium, Paenibacillus, Peribacillus, Planococcus, Rothia, Sporosarcina, and Terribacillus were found only in shared-domestic microwaves.

Worryingly, several of these microbes – Klebsiella, Enterococcus and Aeromonas – can be dangerous to humans.

Klebsiella species can cause a range of healthcare-associated infections, including pneumonia, bloodstream infections, wound or surgical site infections and meningitis.

Enterococcus, meanwhile, have the potential to cause a range of illnesses including urinary tract infections, blood stream infections, and wound infections.

Finally, Aeromonas have been linked to gastrointestinal infections, kidney disease, cellulitis, and meningitis.

Based on the findings, the researchers are urging people to make sure they regularly deep clean their microwaves.

‘We recommend regularly disinfecting microwaves with a diluted bleach solution or a commercially available disinfectant spray,’ Mr Torrent said.

‘In addition, it is important to wipe down the interior surfaces with a damp cloth after each use to remove any residue and to clean up spills immediately to prevent the growth of bacteria.’