Klebsiella pneumonia

Clinical data

• The patient was a 27 year old man who died in 1948.

• Three days before admission he had sudden onset of pleuritic pain on the right side of his chest.

• He also had a cough with blood-stained sputum.

• On examination he was flushed and pyrexial. His respiratory rate was increased and there were signs of marked consolidation of both the left and right lungs. 

• He died the day after admission despite large doses of penicillin.   

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Post mortem pathology

• The specimen is his left lung which has been partially sectioned to show the grey-white areas of pneumonic consolidation. 

  • These areas are not typically lobar (affecting the whole of a lobe) but rather lobular or segmental, that is affecting parts of the lobes. 

  • This is said to be typical of Klebsiella pneumonia.

  • Another feature is that the affected areas appear to be swollen or bulging, which can give rise to the bulging fissure sign on x-ray. See https://radiopaedia.org/articles/bulging-fissure-sign

• There is a milky-looking fibrinous exudate on the pleural surface of the lung, seen here on the hilar aspect.

• No pneumonia can be accurately identified without microbiological investigation.
• A gram negative bacillus with culture characterisitics of Klebsiella pneumoniae was isolated from both lungs.

• K. pneumoniae produces large, mucoid colonies after 24 hours of aerobic incubation. It is a lactose fermenter so on MacConkey agar the colonies are pink, as shown here.  

• The mucinous quality of Klebsiella would be noted by the pathologist at post mortem; the cut surface of the lungs appears mucinous and the knife used for sectioning would be sticky with mucous.

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• Klebsiella pneumoniae and Klebsiella pneumonia are sometimes still called Friedländer’s bacillus and Friedländer’s pneumonia respectively, after the German physician Carl Friedländer, who described them in the 19^th century.

• Klebsiella pneumonia typically occurs in men over 50 years with an underlying  chronic condition such as alcoholism or diabetes.

• It is an aggressive pneumonia and has a tendency to progress to abscess formation.

• When this patient fell ill in 1948 antibiotic options were limited. Today the first line antibiotic for community acquired Klebsiella pneumonia is coamoxiclav or a 3rd generation cephalosporin (cefotaxime or ceftriaxone).​​​​​​

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