http://www.popsci.com/technology/article/2010-08/bacteria-survive-553-day-exposure-exterior-iss

Life will often elect to stubbornly establish itself precisely where one wants to curb it, such as a surgery or a place where food is processed. It matters little what one does, life leaks in. Even in space, the adaptability of microorganisms is staggering. And… there’s something analogous about awareness…