SURVIVAL OF ACINETOBACTER-BAUMANNII ON DRY SURFACES

Acinetobacter spp. have frequently been reported to be the causative a gents of hospital outbreaks, The circumstances of some outbreaks demon strated the long survival of Acinetobacter in a dry, inanimate environ ment, In laboratory experiments, we compared the abilities of five Aci netobacter baumannii strains, three Acinetobacter sp, strains from the American Type Culture Collection (ATCC), one Escherichia coli ATCC st rain, and one Enterococcus faecium ATCC strain to survive under dry co nditions, Bacterial solutions of the 10 strains were inoculated onto f our different material samples (ceramic, polyvinyl chloride, rubber, a nd stainless steel) and stored under defined conditions, We investigat ed the bacterial counts of the material samples immediately after inoc ulation, after drying, and after 4 h, 1 day, and 1, 2, 4, 8, and 16 we eks of storage, A statistical model was used to distribute the 40 resu lting curves among four types of survival curves, The type of survival curve was significantly associated with the bacterial strain but not with the material, The ability of the A. baumannii strains to survive under dry conditions varied greatly and correlated well with the sourc e of the strain, Strains isolated from dry sources survived better tha n those isolated from wet sources, An outbreak strain that had caused hospital-acquired respiratory tract infections survived better than th e strains from wet sources, but not as well as strains from dry source s, Resistance to dry conditions may promote the transmissibility of a strain, but it is not sufficient to make a strain an epidemic one, How ever, in the case of an outbreak, sources of Acinetobacter must be exp ected in the dry environment.