Table 3– Commonly isolated potentially pathogenic microorganisms: number overall and proportion by sputum colour
MicroorganismTotal isolates nSamples containing specific pathogen# %
Yellow sputumGreen sputumWhite sputumRust sputum
Samples of each colour n23191218353113
Haemophilus influenzae60514.
Streptococcus pneumoniae3137.49.512.42.5
Moraxella catarrhalis3197.311.22.34.4
Haemophilus parainfluenzae2625.
Staphylococcus aureus1583.
Klebsiella pneumoniae1333.
Pseudomonas aeruginosa1052.
Haemophilus spp.+641.
Negative culture§219154.541.181.661.1
  • #: percentage of isolates of each species based on the total number of culture samples; : one sample obtained per patient; +: Haemophilus spp. other than H. influenzae and H. parainfluenzae; §: total number of negative cultures.