BACTERIOLOGY OF PROTECTED BRONCHOPULMONARY SPECIMENS IN RELATION TO THE TIME ELAPSED FROM INTENSIVE-CARE UNIT ADMISSION

lire retrospectively reviewed the variation of the organisms recovered from 403 protected bronchopulmonary specimens in three surgical inten sive cars units according to the time elapsed from admission. The pred ominant pathogens during the four first days were Haemophilus influenc e (33.3%), Staphylococcus aureus (18.2%), mostly methicillin susceptib le strains, and Streptococcus pneumoniae (14.3%). After the fourth day , they were progressively replaced by typical nosocomial bacteria such as methicillin resistant Staphylococcus aureus, Pseudomonas aeruginos na and.Acinctobacter baumannii. For Pseudomonas aeruginosa and cephalo sporinase-producing Enterobacter Enterobacteriacaea, strains resistant to third generation cephalosporins occured significantly later than t he susceptible strains. These results indicate that the time elapsed f rom intensive care unit admission has a major influence on the bacteri ology of respiratory tract infections, but no clear cut-off point betw een early-onset and late onset pneumonia is evident.