Fever temperatures impair hemolysis caused by strains of Escherichia coli and Staphylococcus aureus

Abstract

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. To delineate the role of fever temperatures on the growth and infectivity of two hemolytic bacteria that are known to evoke fever in patients via hemotoxins, we used high-sensitivity microcalorimetry to measure the evolution of heat production by fever-inducing strains of Escherichia coli and Staphylococcus aureus under fever conditions. We determined specific aggregation profiles at temperatures equal to or exceeding 38.5{square}. We confirmed these results through bacterial incubation at relevant temperatures revealing the presence or absence of hemolysis. We thus reveal an additional positive role of febrile temperatures in directly contributing to the immune response, through the abolishment of hemolysis.