Survival of Group A Streptococcus (GAS) is Enhanced Under Desiccated Culture Conditions.

Streptococcus pyogenes or Group A Streptococcus (GAS) infections are the leading cause of bacterial tonsillopharyngitis. The bacterium can survive and persist within the human host for a long time as it is observed in up to 40% of the population who are considered as carriers. Recurrent tonsillopharyngitis is a particular problem in children which is caused either by relapses due to failed bacterial clearance or by reinfection.

Hydrogen Peroxide Production of Group A Streptococci (GAS) is emm-Type Dependent and Increased at Low Temperatures.

Group A streptococcus (GAS) is an important human pathogen whose clinical isolates differ in their ability to produce hydrogen peroxide (HO). HO is primarily produced by the enzyme lactate oxidase (LctO), an in depth in silico research revealed that all genome-sequenced GAS possess the required gene lctO. The importance of lctO for GAS is underlined by its highly conserved catabolite control element (cre box) as well as its perfect promotor sequence in comparison to the known consensus sequences of the Gram-positive model organism Bacillus subtilis.

A standardized microdilution susceptibility test to determine the resistance capacity of human pathogenic bacteria towards hydrogen peroxide.

The susceptibility protocol established in this study takes into account that complex media are capable to buffer HO which otherwise may adulterate test results. Furthermore, we demonstrate that clinical isolates of Staphylococcus aureus showed a higher resistance against HO than Streptococcus pyogenes after 30 mins of incubation but not after 24 h.