Question: is there a way to kill bacteria that has been in a burn or wound for a long time? i don't know if older bacteria is harder to kill than some that has only just formed. if you leave a burn for a long time and it gets really badly infected will it be almost impossible to remove because it has been there so long that it won't go?

Jess Bean answered on 18 Jun 2013:

That’s a really great question Hannah!

When bacteria have been in a wound for a long period of time they form something called a biofilm. This is where all the bacteria all stick together in a thick layer of slime. It is biofilms on your teeth that make them feel dirty at the end of the day.
The problem with biofilms is that they are like a big bacterial city. One bacterium on it’s own is pretty useless, but in a biofilm bacteria are protected (by the slime) and can talk to each other. This is the perfect way of keeping alive, as the slime also stops antibiotics from getting all the way through. So you were right that older and more established bacteria are indeed harder to kill.

In fact in really bad cases the best way to remove bacteria like this is to scrub the wound with a really rough scourer. This is required though as if the infected burn is left, the bacteria can multiply (and give out toxins) and can move into the bloodstream causing something called septicaemia. In this case seriously strong antibiotics need to be given.