Acinetobacter spp. and Pseudomonas aeruginosa isolates: 1975 and 2003. Shown are the percentages of bacterial isolates associated with (a) Acinetobacter spp. and (b) P. aeruginosa by infection type in the National Nosocomial Infections Surveillance System for 1975 and 2003. Data from 1975 are from hospital-wide surveillance whereas those from 2003 are from intensive care unit surveillance .