title: [Lack of specificity of protected distal bronchial samples in the bacteriological diagnosis of nosocomial pneumonia caused by gram negative bacilli].
abstract: Lower respiratory tract secretions (LRS) were sampled during a two year period in patients undergoing mechanical ventilation using a method previously described by Matthew et al. Only those LRS positive for gram-negative bacilli were reported in this study. The patients were separated in two groups: those with nosocomial pneumonia due to gram-negative bacilli (NP+ group) and those without (NP- group). The species most often isolated from LRS were: Pseudomonas aeruginosa (25%), Proteus (20%), Escherichia coli (18%), Klebsiella pneumoniae (10%), Acinetobacter calcoaceticus (8%) and Haemophilus influenzae (7%). The spectrum of gram-negative species was not statistically different in either group of patients. The numbers of gram-negative bacilli isolated from each LRS were more important in the NP+ group (p less than 0.001), but so was the duration of mechanical ventilation before each LRS (p less than 0.01). In this group also, a specific bacteriological diagnosis with only one species was possible in 3 out of the 13 cases; a tentative diagnosis only was possible in 10 cases: in 6 cases, the responsibility of two (or more) species was suggested. The susceptibility to antibiotics of gram-negative bacilli isolated from LRS was moderate. A third generation cephalosporin together with amikacin seemed to be the best choice of antibiotics when no specific bacteriological diagnosis could be made with the LRS.
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001431:Bacteriological Techniques; D001980:Bronchi / Q000382:microbiology*; D003428:Cross Infection / Q000382:microbiology*; D005069:Evaluation Studies as Topic; D006090:Gram-Negative Bacteria / Q000302:isolation & purification*; D006801:Humans; D008826:Microbial Sensitivity Tests; D011014:Pneumonia / Q000382:microbiology*; D012121:Respiration, Artificial; D012189:Retrospective Studies
chemical_list: D000900:Anti-Bacterial Agents
vernacular_title: Absence de spécificité des prélèvements bronchiques distaux protégés dans le diagnostic bactériologique des pneumopathies nosocomiales à bacilles gram négatif.