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An introduction to a new friend (well… acquaintance) Campylobacter

June 22, 2011

If this blog is going to be mainly looking at zoonotic diseases I’m inevitably going to be covering food poisoning bugs a lot.  And as the most common cause of food poisoning in Europe is infection with Campylobacter species (spp) I’ll definitely be talking about these bugs a lot.  Before I start covering any of the recent research into these organisms I thought I’d briefly introduce you guys to them first.

So.

Campylobacter from an article in PLoS Biology: doi:10.1371/journal.pbio.0030040.g001

Campylobacter is a genus of bacteria that includes 18 known species as well as a number of subspecies.  The bugs are small (even for bacteria) and spiral-shaped (see the cool picture – the rings around them are graphical presentations of their genomes).  They’re microaerophilic which means they like to grow in limited oxygen (~5% oxygen is best).  Two species from this genus are especially implicated in human infections: Campylobacter jejuni (C. jejuni) and Campylobacter coli (C. coli) with C. jejuni causing 90% of human infections.

How do we get infected?

Well C. jejuni and C. coli are carried in the intestines of many domestic and wild animals, generally without causing any signs of disease in these animals.  For those of us lucky enough to live in the developed world we are most likely to get infected with these bugs from raw or undercooked poultry.  Now obviously most of us don’t go round eating raw chicken (if you do – you probably should think about stopping…) but if you’ve handled raw chicken and not washed your hands thoroughly or if the utensils you’ve used for the raw chicken are then used for some other food that isn’t cooked you run the risk of accidentally eating the bacteria.  (You can also contract Campylobacter from drinking raw milk or via direct contact with animal faeces but these are less common routes of infection.)

Infection can lead to a whole host of nasty symptoms including vomiting, diarrhoea, stomach cramps and fever that can last from 2-5 days.  You can get even more horrible symptoms including intestinal bleeding, haemolytic uraemic syndrome (which we also encountered in the E coli outbreak post) and toxic megacolon (which is actually something really nasty and not some comic character’s superpower which is what I always think of when I hear it).  Even worse, for a small number of people infection can lead to neurological problems such as Guillain-Barre syndrome, (yes there should be an acute accent over the e but I can’t work out how to do it – sorry!), which involves ascending paralysis and can be life-threatening.  You do not want to get this bug.

Luckily Campylobacter is killed by cooking, so assuming meat is handled, stored and cooked properly it shouldn’t be a problem.  Nevertheless…

Campylobacter infection in the UK is on the rise.

It does rather suggest that, despite all of the food safety campaigns we are exposed to, our kitchen hygiene is still far from perfect.

This has led to some scientists focusing their research on the behaviour of Campylobacter in chickens because if the bacteria could be eliminated from the poultry flock it would greatly decrease our exposure to it and so should dramatically reduce the number of cases.

And so my next post will look at the way this bug interacts with its avian host (aren’t they cute!).

By Earthdirt licenced under[CC-BY-3.0] via Wikimedia Commons

Want to learn more?

Health Protection Agency (UK)

World Health Organisation

patient.co.uk

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4 comments

  1. […] A PhD student's blogging about zoonotic diseases and other cool science « An introduction to a new friend (well… acquaintance) Campylobacter Campylobacter and chickens June 27, 2011 My last post looked at Campylobacter the bug and […]


  2. […] at some very cool research into Campylobacter jejuni (hence the my earlier background posts here and […]


  3. I am going to do a research paper on C. jejuni for Grad school. Any ideas for a topic?


    • I’m hitting a bit of a language barrier as I’m not entirely sure what you mean by a “research paper”. If it’s what I would call a ‘literature review’ (ie. when you write a piece discussing all of the peer-reviewed research on a particular topic) then there’s loads of interesting things about Campy… My esp interests are the argument about whether C. jejuni and some C. colis are converging to form the same spp; whether or not C. jejuni is a commensal in the chicken; the connection between C. jejuni and Guillain Barre syndrome; how C. jejuni varies its surface antigens. I’m not sure how broad your paper has to be but I hope some of these ideas inspire you!

      A really good paper to read if you have access to Nature is: C. jejuni – molecular biology and pathogenesis by Young et al. Nature Reviews Microbiology 5, 665-679 (September 2007) | doi:10.1038/nrmicro1718



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