Have you ever wondered how on earth vegetative bacteria can survive on dry surfaces for years? Or why when you have an outbreak and you swab the environment you don’t find the outbreak strain even though you’re pretty sure it’s there? Or why a disinfectant that gets a 4-log reduction in the lab can’t eliminate a couple of hundred cfu of bacteria from a dry surface? Dry surface biofilms could be the answer to all these questions! I was involved in a multicentre survey of dry biofilms from across the UK, and we identified dry surface biofilms on 95% of the 61 samples there were tested. Worryingly, viable MRSA was identified on 58% of the surfaces! We need to think carefully about how much of a risk dry surface biofilms present, and whether we need to do more to tackle them.
As the owner of a relatively new beard (see picture below), I was alarmed to hear that my beard is probably as contaminated with faeces as a toilet brush. Fortunately, a Journal of Hospital Infection study from 2014 turns this on its head, showing that those wearing beards are actually less likely to be colonised with staphylococci!
Me and my beard