Red cell lysis induced by microorganisms as a case of superoxide- and hydrogen peroxide-dependent hemolysis mediated by oxyhemoglobin.

Some bacteria, isolated from the blood of hospitalized patients, have been shown to hemolyze red blood cells through a mechanism which was dependent on the oxygenated state of intracellular hemoglobin, since transformation of hemoglobin into the CO-derivative inhibited the lysis. Hemolysis was also inhibited by superoxide dismutase and catalase, while only catalase prevented the formation of methemoglobin in experiments where isolated oxyhemoglobin was exposed to metabolizing bacteria. Production by bacteria of extracellular superoxide was demonstrated. It is suggested that hemolysis is due to interaction of O-2 and/or H2O2 with intracellular hemoglobin and that some product of such interaction is the lytic agent.