Tesco have recalled a load of their butter today, after they found listeria in some. But what's listeria? Should we be worried? And why is 'chocolate chip and maple syrup butter' a thing?
Listeria is a bacteria (that's why I'm talking about it!) called Listeria monocytogenes.
It's important (and worth worrying about/recalling weirdly flavoured
butter over) for two key reasons: firstly, it loves the cold. This bug
can happily grow in your fridge! Stopping bacteria grow is the whole
point of fridges so listeria just makes a mockery of that. If it's
growing, the number of bacteria goes up and up increasing the chances of
getting ill if you eat it. So how ill does it make you? It normally
just causes flu-like symptoms (in fact, there's a high chance you've had
it but thought it was just the flu) but the second key reason it's
important is a secondary effect: listeria can cause miscarriage. This is
the reason you're supposed to avoid dairy stuff when pregnant
(especially un-pasteurised cheeses like that fancy smelly french one
you've got tucked away in the fridge). It does that to animals too; if a
breeding herd of cows get fed contaminated food, they all get ill at
once resulting in an 'abortion storm', which is pretty high up on my
list of horrible phrases (right beside de-gloving accident) and
obviously results in farmers losing animals and money, not to mention
how it affects the poor cows.
I don't want to freak you
out or make you stop eating cheese or whatever though (unless you're
pregnant). All dairy food is tested constantly for all sorts of
bacteria, and the tests for listeria are some of the most important. Any
tiny amount of listeria in any product is always treated really
seriously: while Tesco are losing out on the apparently lucrative
flavoured-butter profits, the alternative is much, much worse. As a
result of this, even when there's a scare like today's one you're pretty
safe. Yes, listeria is one to avoid, but don't let the thought of it
ruin your day!
It's not all bad though; listeria is
being used in experiments looking at using it to treat cancer! It's
really clever: normally our immune system recognises cancer cells as
being our own cells, so leave them alone. But these researchers are
modifying listeria cells to show markers for the cancer cells as well as
their own (and to make them not cause disease obviously). When
introduced to the body, the immune system looks at these modified
listeria and starts associating them with the cancer cells. So the
immune system starts thinking the cancer cells are listeria, and attacks
them! Re-wiring the person's immune system to fight the cancer from
within. This is still very much in the experimental phase, but it's a
really exciting idea that I think is pretty promising! Plus it's a way
that bacteria are being used for good (you can't get much more 'good'
than fighting cancer) which I'm really enthused by and passionate about.
Also, I've got a twitter account now! Woo. It's @FriendlyBugBlog (because FriendlyBacteria wouldn't fit), follow me!