Phagocytosis of Coxiella burnetii by Hyalomma dromedarii tick haemocytes.

Haemocytes of laboratory bred half-engorged Hyalomma dromedarii ticks phagocytized intracoelomally inoculated Coxiella burnetii organisms. Significantly higher phagocytosis of phase II than phase I C. burnetii was observed, irrespective of whether live, killed untreated or killed organisms treated with chloroform-methanol (CM) mixture were used. However, HCl- or KIO4-treated phase I cells were phagocytized to a similar extent as phase II cells. More consistent results were obtained with haemocytes of male than of female ticks. Phagocytosis of phase I killed and live organisms was significantly increased by their preincubation with phase I but not with phase II immune rabbit sera.