Role of host genetic factors in susceptibility to group A streptococcal infections.

ABSTRACT

BACKGROUND & OBJECTIVES: Epidemiological evidences indicate that host genetic factors might be critical in determining susceptibility to infection with group A streptococci (GAS). The objective of the present study was to determine the extent to which the genetic background of the mouse strain affected induction and resolution of GAS infection. METHODS: Several inbred mouse strains were intravenously infected with Streptococcus pyogenes strain A20 and the mean survival times of mice was recorded overtime. Bacterial loads were determined in liver and spleen of infected animals at 48 h postinoculation. RESULTS: Different strains of mice exhibited differential susceptibility to GAS infection. After systemic infection with S. pyogenes, inbred mice showed substantial differences in mortality and bacterial loads. INTERPRETATION & CONCLUSION: This study provides further evidences that a genetic component is associated with host susceptibility or resistance to GAS infection.