<i>Babesia</i> infection in lions from the 2001 epidemic.

<p>A) Histopathology of <i>Babesia</i> hyperinfection in an adult lion that died during the epidemic. Small intestinal capillaries are occluded by parasitized red blood cells; B) Marked lymphocyte depletion in the lymph node of the same lion, indicating immunosuppression; C) Electron micrograph of intraerythrocytic piroplasms morphologically compatible with <i>Babesia</i> sp. in the deceased lion; D) Results of denaturant gradient gel electrophoresis for previously characterized carnivore hemoparasites and hemoparasites amplified by PCR from lion samples that demonstrated mixed infections. Lane 1, <i>Babesia canis</i>; lane 2, <i>Cytauxzoon felis</i>; lane 3, <i>B. gibsoni</i>; lane 4, mixture of <i>B. canis</i>, <i>C. felis</i>, and <i>B. gibsoni</i> isolates in lanes 1–3; lane 5, no DNA-negative control; lane 6, lion with <i>Babesia sp.</i> most similar genetically to <i>B. gibsoni</i>, <i>B. felis</i> and a previously uncharacterized <i>Babesia sp.</i>; lane 7, lion with <i>Babesia sp.</i> most similar genetically to <i>B. gibsoni</i> and <i>B. felis</i>; lane 8, lion with hemoparasites most similar genetically to <i>B. gibsoni</i> and <i>Hepatozoon felis</i>; lane 9, lion with a hemoparasite most similar genetically to <i>H. felis</i>.