[Bacteria isolated from protected bronchopulmonary samples: variation as a function of the previous length of stay in the recovery room]

Abstract

We retrospectively reviewed the variation of the organisms recovered from 403 protected bronchopulmonary specimens in three surgical intensive care units according to the time elapsed from admission. The predominant pathogens during the four first days were Haemophilus influenzae (33.3%), Staphylococcus aureus (18.2%), mostly methicillin susceptible 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 aeruginosa and Acinetobacter baumannii. For Pseudomonas aeruginosa and cephalosporinase-producing Enterobacteriaceae, strains resistant to third generation cephalosporins occurred significantly later than the susceptible strains. These results indicate that the time elapsed from intensive care unit admission has a major influence on the bacteriology of respiratory tract infections, but no clear cut-off point between early-onset and late onset pneumonia is evident.