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Clonal basis for resurgence of serious Streptococcus pyogenes disease in the 1980s

P P Cleary1, E L Kaplan, J P Handley

  • 1Department of Microbiology, UMHC, University of Minnesota, Minneapolis 55455.

Lancet (London, England)
|February 29, 1992
PubMed

Insights

A specific Streptococcus pyogenes clone, linked to scarlet fever toxin SPE A, emerged in the 1980s. This highly virulent strain caused severe infections like sepsis and toxic-shock-like syndrome (TSLS) globally.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Genetics

Background:

  • The 1980s saw a rise in severe Streptococcus pyogenes infections, including sepsis and toxic-shock-like syndrome (TSLS).
  • A potential link between the scarlet fever toxin (SPE A) and increased systemic toxicity was investigated.
  • The emergence and global spread of a new, highly virulent Streptococcus pyogenes clone were hypothesized.

Purpose of the Study:

  • To investigate the association between SPE A toxin expression and systemic toxicity in Streptococcus pyogenes.
  • To determine if a new, highly virulent clone of Streptococcus pyogenes emerged and spread worldwide.
  • To analyze serotype M1 strains, commonly linked to severe Streptococcus pyogenes complications.

Main Methods:

  • Restriction-enzyme digestion and electrophoresis were used to analyze 19 isolates from severe infections and 48 from uncomplicated cases.
  • Hybridization with an speA gene probe was performed on 56 isolates (19 severe, 37 uncomplicated).
  • Isolates were categorized based on a characteristic "invasive" (I) restriction-fragment profile.

Main Results:

  • 17 out of 19 (90%) isolates from serious infections exhibited the "invasive" (I) profile and were speA positive.
  • Significantly lower proportions of uncomplicated isolates showed the I profile (44%) and speA gene (54%).
  • The "invasive" profile and speA gene presence were strongly associated with severe Streptococcus pyogenes disease (p < 0.001).

Conclusions:

  • The findings suggest that severe Streptococcus pyogenes infections in the late 1980s were predominantly caused by a unique, highly virulent clone.
  • This clone, characterized by the "invasive" profile and speA gene, became globally prevalent.
  • The study highlights the role of specific genetic factors in the virulence of Streptococcus pyogenes.

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