Fever temperatures abolish bacterial hemolysis: a microcalorimetry investigation

Hemolysis modulates susceptibility to bacterial infections and predicts poor sepsis outcome. Hemolytic bacteria induce upon infection a reversible fever response from the host that may aid in pathogen clearance. We used high-sensitivity microcalorimetry to measure the evolution of heat production by fever-inducing Escherichia coli and Staphylococcus aureus under isothermal fever conditions, and determined specific aggregation profiles at temperatures equal to or exceeding 38.5{degrees}C. We confirmed these results through bacterial incubation at relevant temperatures revealing the presence or absence of hemolysis. We reveal an additional positive role of febrile temperatures in directly contributing to the immune response, through the abolishment of hemolysis.