BBC: KPC “highly resistant superbug”

Hospital

“Dear BBC, you employ over 20,000 people. Is it too much to ask one of them has a science degree?”

Or – heaven forfend – at least someone with a biology ‘A’ Level? A news story run by the BBC this morning regarding Klebsiella pneumoniae is now being picked up by other meeja. But the BBC gets the basic science completely wrong. Again. KPC is not a superbug. Or even a bug. Grrrr….

“Sixteen people have died in Manchester in the past four years while infected with a highly resistant superbug, figures show. Klebsiella pneumoniae carbapenemase (KPC) is causing increasing concern and a rising number of cases.”

They then add “KPC, which causes urinary tract infections and pneumonia in sick patients…” Except it doesn’t.

OK, so if it’s not a bug, what is KPC?

The clue is in the -ase on the end of carbapenem. It’s not a bug, super or otherwise. It’s an enzyme produced by certain bacteria, including some strains of K. pneumoniae. I realise this is a geeky point and I’m probably the only person on the planet that has OCD re this sort of thing (or CDO – WITH ALL THE LETTERS IN THE CORRECT BLOODY ORDER AS THEY SHOULD BE) but this is a pretty fundamental distinction.

Here’s the biology and why it’s important.

Carbapenems are β lactam antibiotics, similar to the penicillins and cephalosporins. Carbapenem use increased due to rising resistance to cephalosporins in the Enterobacteriaceae (bugs you tend to find in poop). Salmonella, Escherichia coli, Klebsiella, Enterobacter Shigella, Serratia and Proteus are the principal pathogenic genera but this charming family also includes Yersinia pestis – Bubonic Plague – which we don’t see much of nowadays. Which is nice.

So, carbapenem antibiotics were used in response to bacteria becoming resistant to more traditional β lactam antibiotics; now our Microbial Overlords have developed resistance to carbapenems too. Which is entirely unsurprising and not new news by a long chalk. As I’ve said before, bacterial resistance to antibiotics is usually genetic, not intrinsic; and genes are simply instructions that tell cells how to do or make stuff. In this case it’s the recipe for “here’s how you destroy those pesky carbapenems if they get thrown at you“. And the correct term here is ‘plasmid’ – a little ring of genetic material that tells bugs how to do stuff.

The worrying thing about these plasmids (that tell bacteria how to shrug off attack by antibiotic drugs) is that bugs can swap them amongst themselves rather like trading football cards. This is of far more concern than another ‘superbug’ or dirty hospital.

There is a wider trend here. As we rapidly approach the post-antibiotic era, the range of bacteria producing extended spectrum β lactamases (ESBLs – which hydrolyse cephalosporins such as NDM-1 or in this case Klebsiella making short work of carbapenems) is increasing. Carbapenem-resistant enterococci have been around for quite some time.

This is the real germ warfare that goes on constantly; we develop an antibiotic, this applies selective pressure and bugs become resistant so we develop new antibiotic, bugs become resistant to that… and so on.

With respect to Mr Paduano (an excellent journalist on the BBC health beat who rarely gets basic details like this wrong) I think the real story here isn’t the usual ‘health care workers not washing their hands so bugs in poop make folks sick’. Let me stress I do not seek to belittle that story because any preventable death from infection is a tragedy; what I find more worrying is yet another ‘antibiotic of last resort’ is failing. And I can’t see many new ones in the pipeline.

What will be the first pan-resistant bug? My money isn’t on Klebsiella or even MRSA. I’d have a crafty tenner on Neisseria gonorrhoeae. If Paddy Power would take the bet.

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One thought on “BBC: KPC “highly resistant superbug”

  1. No, you are not the only one. I cringed. It’s like a “dog bites man” story where the headline was “Canis lupus familiaris incisor penetrates male’s epidermis!”

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