In vitro studies of interaction of rickettsia and macrophages: effect of ultraviolet light on Coxiella burnetii inactivation and macrophage enzymes.

The inactivation of Coxiella burnetii in suspension or in cultures of guinea pig peritoneal macrophages by ultraviolet (UV) light was studied. The effect of UV treatment on the activity of macrophage organelle marker enzymes and their subsequent equilibration in linear sucrose gradients was also determined. It was shown that UV treatment of 600 mu W/cm2 for 15 s at a distance of 10 cm inactivated C. burnetti, either in suspension (10(8) organisms per ml) or within guinea pig peritoneal macrophages. Similar UV treatment had little effect on the activity or equilibration of macrophage organelle marker enzymes in linear sucrose gradients. However, longer exposure caused considerable inactivation of these enzymes.