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Experimental Human Pneumococcal Carriage
07:47

Experimental Human Pneumococcal Carriage

Published on: February 15, 2013

STUDIES ON A NON-HEMOLYTIC STREPTOCOCCUS ISOLATED FROM THE RESPIRATORY TRACT OF HUMAN BEINGS : I. BIOLOGICAL

G S Mirick1, L Thomas, E C Curnen

  • 1United States Navy Research Unit at the Hospital of The Rockefeller Institute for Medical Research.

The Journal of Experimental Medicine
|October 30, 2009
PubMed

Insights

Streptococcus MG, a non-hemolytic streptococcus, was identified in fatal pneumonia cases and healthy individuals. This finding suggests it may be a distinct bacterial species previously unrecognized.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Bacteriology

Background:

  • Primary atypical pneumonia is a significant respiratory illness.
  • The causative agent of some pneumonia cases remains elusive.
  • Non-hemolytic streptococci are known human pathogens.

Purpose of the Study:

  • To characterize a specific serological type of non-hemolytic streptococcus, designated Streptococcus MG.
  • To investigate the biological properties of Streptococcus MG strains.
  • To determine if Streptococcus MG represents a distinct bacterial species.

Main Methods:

  • Isolation of Streptococcus MG from clinical samples (fatal pneumonia cases, sputum, respiratory tracts).
  • Bacteriological characterization of 59 isolated strains.
  • Serological typing of the isolates.

Main Results:

  • Streptococcus MG was consistently isolated from fatal primary atypical pneumonia cases and occasionally from healthy individuals.
  • All 59 strains exhibited homogeneous bacteriological characteristics.
  • These characteristics differentiated Streptococcus MG from other known streptococcus species.

Conclusions:

  • Streptococcus MG is a distinct serological type of non-hemolytic streptococcus.
  • The microorganism's unique characteristics suggest it may represent a new, undifferentiated species.
  • Further research is warranted to fully classify Streptococcus MG and its role in respiratory infections.

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