The multidrug-resistant A. baumannii pathogen is  unique among the Gram-negative bacteria for its ability to persist in the environment. In a single-hospital study, Kerri A. Thom, from the University of Maryland (Maryland, USA), and colleagues found that over a four-month period, A. baumannii was present in 48% of rooms occupied by a patient who had been colonized or infected with the pathogen.  Moreover, patients with a recent history of A. baumannii were no more likely to contaminate their room than those whose experience with the pathogen was older.  One implication of the finding of this prospective cohort study is that surfaces frequently touched by patients or healthcare workers may be contaminated, the researchers posited. As well, the team submits that it may be useful to take barrier precautions even if a history of A. baumannii colonization or infection is not recent, because it appears that patients may be persistently colonized.