The most common organisms which cause lobar pneumonia are Streptococcus pneumoniae, also called pneumococcus, Haemophilus influenzae and Moraxella catarrhalis.
Mycobacterium tuberculosis, the tubercle bacillus, may also cause lobar pneumonia if pulmonary tuberculosis is not treated promptly.
Other organisms that cause lobar pneumonia are Legionella pneumophila and Klebsiella pneumoniae.

Like other types of pneumonia, lobar pneumonia can present as community acquired, in immune suppressed patients or as nosocomial infection.
However, most causative organisms are of the community acquired type.

Pathological specimens to be obtained for investigations include:
Sputum for culture, AAFBS and gram stain
Blood for full hemogram/complete blood count, ESR and other acute phase reactants
Procalcitonin test, more specific
On a posterioanterior and lateral chest radiograph, an entire lobe will be radiopaque, which is indicative of lobar pneumonia.

The identification of the infectious organism (or other cause) is an important part of modern treatment of pneumonia.
The anatomical patterns of distribution can be associated with certain organisms, and can help in selection of an antibiotic while waiting for the pathogen to be cultured.
The most common organisms which cause lobar pneumonia are Streptococcus pneumoniae, also called pneumococcus, Haemophilus influenzae and Moraxella catarrhalis. Mycobacterium tuberculosis, the tubercle bacillus, may also cause lobar pneumonia if pulmonary tuberculosis is not treated promptly. Other organisms that cause lobar pneumonia are Legionella pneumophila and Klebsiella pneumoniae.
Like other types of pneumonia, lobar pneumonia can present as community acquired, in immune suppressed patients or as nosocomial infection. However, most causative organisms are of the community acquired type.
Pathological specimens to be obtained for investigations include:
Sputum for culture, AAFBS and gram stain
Blood for full hemogram/complete blood count, ESR and other acute phase reactants
Procalcitonin test, more specific
On a posterioanterior and lateral chest radiograph, an entire lobe will be radiopaque, which is indicative of lobar pneumonia.
The identification of the infectious organism (or other cause) is an important part of modern treatment of pneumonia. The anatomical patterns of distribution can be associated with certain organisms, and can help in selection of an antibiotic while waiting for the pathogen to be cultured.
Lobar pneumonia