Invasive GAS Infection Clinical Trial
Official title:
Invasive Group A Streptococcus (GAS) Infection in Children: Bacterial Virulence Factors and Detection of Host Immunological and/or Genetic Factors of Predisposition to Infections
The main objective of the study is to characterize the virulence factors of SGA and identify immunological and / or genetic factors predisposing to infections in children hospitalized with invasive GAS infection.
The group A streptococcus (GAS) or Streptococcus pyogenes is a strictly human pathogen ,
which can cause a wide variety of infections. These range from a simple asymptomatic carriage
up to 20 % of children , or minor illnesses such as sore throat or impetigo, to severe
conditions such as necrotizing fasciitis and toxic shock syndrome .
The pathophysiological mechanisms of invasive GAS infections are poorly understood. These
mechanisms could involve not only virulence factors of the bacterium ( M protein determines
the emm genotype , but also super- antigenic exotoxins SpeA , Spe C, Ssa, Sme z or other
virulence genes , SilC , ... Sic ), but also in some cases, factors associated with host
immunity in particular in the absence of risk factors for invasive skin infection such as
cutaneous effraction ( wound , burn , chicken pox ) , corticosteroids or other
immunosuppressive therapy and recent surgery .
The investigators assume that in some invasive GAS infections, especially in children without
risk factors, Mendelian susceptibility to infection may be involved . This hypothesis could
be tested by studying the molecular characteristics of strains isolated SGA and innate and
adaptive immunity in children hospitalised for invasive GAS infection with or without
identified risk factors for infection.
This study could not only lead to a better understanding of the pathophysiological mechanisms
of invasive GAS infections but also to detect in children who underwent invasive GAS genetic
susceptibility to infections requiring specific care . Finally, it could also identify
specific strains of SGA or molecular profiles, whose detection in practice, lead to a
suspicion of hereditary immune deficiency.
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