Last Week's Medical Mystery

      You are practicing Telemedicine and are shown the chest x-ray and a video of the sputum of a 57-year-old man from a  homeless shelter who was admitted with fever, rigors, dyspnea, cough, and the smell of alcohol on his breath.
      DIAGNOSIS: Klebsiella pneumoniae pneumonia.
      Klebsiella pneumoniae, also referred to as Friedlander's bacillus, is a Gram negative bacillus notable for it's increasingly prevalent hypervirulence and antibiotic resistance. These features are horizontally transmitted via plasmids carrying the hypervirulence and/or the carbepenem resistance gene. Hypervirulence is associated with the presence in type III and type IV klebsiella of a thick polysaccharide capsule which inhibits phagocytosis and accounts for the hyperviscous sputum seen in patients infected with these serotypes (see inserted video below). Most cases of Klebsiella pneumonia pneumonia are acquired by aspiration, thus accounting for the increased incidence of this disease in alcoholics. The organism can produce biofilms on IV and urinary catheters and on impanted devices making it impossible to cure without first removing the device. 

           
Left upper lobe Klebsiella pneumoniae pneumonia in the presented case (left image). Hyperviscous sputum and consequent "string sign" in the presented case (video, right image). The patient's sputum has a characteristic "current jelly" appearance as described in other patients with Klebsiella pneumoniae pneumonia.