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La base clonal para el resurgimiento de la enfermedad grave de Streptococcus pyogenes en la década de 1980
P P Cleary1, E L Kaplan, J P Handley
1Department of Microbiology, UMHC, University of Minnesota, Minneapolis 55455.
Lancet (London, England)
|February 29, 1992
Resumen
Un clon específico de Streptococcus pyogenes, vinculado a la toxina de la fiebre escarlata SPE A, surgió en la década de 1980. Esta cepa altamente virulenta causó infecciones graves como sepsis y síndrome similar al choque tóxico (TSLS) a nivel mundial.
Área de la Ciencia:
- Microbiología Microbiología.
- Enfermedades infecciosas Enfermedades infecciosas.
- Genética La genética.
Sus antecedentes:
- La década de 1980 vio un aumento en las infecciones graves por Streptococcus pyogenes, incluida la sepsis y el síndrome similar al shock tóxico (TSLS).
- Se investigó un posible vínculo entre la toxina de la fiebre escarlata (SPE A) y el aumento de la toxicidad sistémica.
- Se planteó la hipótesis de la aparición y la propagación global de un nuevo y altamente virulento clon de Streptococcus pyogenes.
Objetivo del estudio:
- Para investigar la asociación entre la expresión de la toxina SPE A y la toxicidad sistémica en Streptococcus pyogenes.
- Para determinar si un nuevo y altamente virulento clon de Streptococcus pyogenes surgió y se extendió por todo el mundo.
- Para analizar cepas de serotipo M1, comúnmente vinculadas a complicaciones graves de Streptococcus pyogenes.
Principales métodos:
- La digestión de la enzima de restricción y la electroforesis se utilizaron para analizar 19 aislamientos de infecciones graves y 48 de casos sin complicaciones.
- La hibridación con una sonda del gen speA se realizó en 56 aislados (19 graves, 37 sin complicaciones).
- Los aislados se clasificaron en función de un perfil de fragmento de restricción "invasivo" (I) característico.
Principales resultados:
- 17 de 19 (90%) aislamientos de infecciones graves exhibieron el perfil "invasivo" (I) y fueron speA positivos.
- Proporciones significativamente más bajas de aislamientos sin complicaciones mostraron el perfil I (44%) y el gen speA (54%).
- El perfil "invasivo" y la presencia del gen speA se asociaron fuertemente con la enfermedad severa de Streptococcus pyogenes (p < 0,001).
Conclusiones:
- Los hallazgos sugieren que las infecciones graves por Streptococcus pyogenes a fines de la década de 1980 fueron causadas predominantemente por un clon único y altamente virulento.
- Este clon, caracterizado por el perfil "invasivo" y el gen speA, se hizo prevalente en todo el mundo.
- El estudio pone de relieve el papel de factores genéticos específicos en la virulencia de Streptococcus pyogenes.
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