Group A Streptococcus antibiotic tolerance in necrotizing fasciitis

Group A Streptococcus (GAS) necrotizing fasciitis (NF) is a difficult-to-treat bacterial infection associated with high mortality despite targeted antibiotic treatment. Bacteria surviving prolonged antibiotics exposure without displaying genetic resistance, so-called persisters, fuel difficult-to-treat infections. Here we show for the first time that GAS recovered directly from NF patients are characterized by increased colony-size heterogeneity, indicating the presence of persisters. Corroborating these ex vivo data, we demonstrate that exposure to low pH or nutrient starvation, mimicking NF like environment in vitro, also leads to the same heterogeneity resulting in enhanced antibiotic survival.