title: Microbiological considerations of the etiological agents of lower respiratory tract infections.
abstract: One hundred eight-four sputum specimens from the same number of patients with lower respiratory tract infections were examined to determine the bacterial count and the relationship between the microorganisms isolated and the presumptive pathology. The sputa were subdivided into three groups; "high probability", "low probability", and "contaminated sputa", following the criteria of the microscopic readings: sputum with more than 25 white cells and low numbers of squamous epithelial cells represents true lower respiratory tract infections (high probability); those with fewer than 25 white cells represent non-bacterial infections or non-infected sputa (low probability) while sputa with more than 25 squamous cells per field represent contaminated specimens (contaminated sputa). Statistical analysis was carried out to correlate these data. Haemophilus influenzae, Haemophilus parainfluenzae, Streptococcus pneumoniae, and Streptococcus pyogenes showed significant differences in the three groups considered.
authors.affiliation: Institute of Microbiology, University of Catania, Italy.
authors.forename: M B
authors.initials: MB
authors.lastname: Pellegrino
authors.forename: A
authors.initials: A
authors.lastname: Privitera
authors.forename: A
authors.initials: A
authors.lastname: Primavera
authors.forename: M
authors.initials: M
authors.lastname: Puntorieri
authors.forename: A
authors.initials: A
authors.lastname: Nicoletti
authors.forename: S
authors.initials: S
authors.lastname: Stefani
authors.forename: G
authors.initials: G
authors.lastname: Nicoletti
mesh_terms: D006090:Gram-Negative Bacteria / Q000302:isolation & purification; D006193:Haemophilus influenzae / Q000302:isolation & purification; D006801:Humans; D001936:Moraxella catarrhalis / Q000302:isolation & purification; D011336:Probability; D012141:Respiratory Tract Infections / Q000209:etiology* / Q000382:microbiology*; D013183:Sputum / Q000382:microbiology; D013296:Streptococcus pneumoniae / Q000302:isolation & purification; D013297:Streptococcus pyogenes / Q000302:isolation & purification