Babesia gibsoni: Detection during experimental infections and after combined atovaquone and azithromycin therapy

• Published in: Experimental parasitology 2007-10, Vol.117 (2), p.115-123
• Main Authors: Jefferies, R., Ryan, U.M., Jardine, J., Robertson, I.D., Irwin, P.J.
• Format: Article
• Language: English
• Subjects: acute course; Acute Disease; Animals; Anti-Infective Agents - pharmacology; Anti-Infective Agents - therapeutic use; Antibodies, Protozoan - blood; antibody detection; antiprotozoal agents; Atovaquone; Atovaquone - pharmacology; Atovaquone - therapeutic use; Azithromycin; Azithromycin - pharmacology; Azithromycin - therapeutic use; Babesia - drug effects; Babesia - genetics; Babesia - immunology; Babesia - isolation & purification; Babesia gibsoni; babesiosis; Babesiosis - diagnosis; Babesiosis - drug therapy; Babesiosis - veterinary; Biological and medical sciences; Canine; canine babesiosis; Chronic Disease; chronic diseases; combination drug therapy; disease detection; DNA, Protozoan - analysis; Dog; Dog Diseases - diagnosis; Dog Diseases - drug therapy; Dog Diseases - parasitology; Dogs; drug efficacy; drug evaluation; Drug Resistance; EDTA; ethylenediamine tetra-acetic acid; Female; FITC; Flinders Technology Associates; fluorescein isothiocyanate; fluorescent antibody technique; Fluorescent Antibody Technique - veterinary; FTA; Fundamental and applied biological sciences. Psychology; haematocrit; haemoglobin concentration; HCT; HGB; IFAT; immunofluorescent antibody test; intravenously; Life cycle. Host-agent relationship. Pathogenesis; MCV; mean corpuscular volume; mean platelet volume; microscopy; MPV; parasitemia; Parasitemia - diagnosis; Parasitemia - parasitology; Parasitemia - veterinary; PBS; PCR; phosphate buffered saline; platelet number; PLT; polymerase chain reaction; Polymerase Chain Reaction - veterinary; Protozoa; RBC; red blood cell count; WBC; white blood cell count
• ISSN: 0014-4894; 1090-2449
• DOI: 10.1016/j.exppara.2007.03.016

Babesia gibsoni is a protozoan parasite of dogs worldwide yet both an effective treatment and a reliable method for detecting subclinical cases of this emerging infection remain elusive. Experimental B. gibsoni infections were established in vivo to investigate the efficacy of combined atovaquone and azithromycin drug therapy and to determine the detection limits of a nested-PCR, IFAT and microscopy during various stages of infection. While atovaquone and azithromycin produced a reduction in parasitaemia, it did not eliminate the parasite and drug resistance appeared to develop in one dog. Polymerase chain reaction was found to be most useful in detecting infection in the pre-acute and acute stages, while IFAT was most reliable during chronic infections. Microscopy is suggested to be only effective for detecting acute stage infections. This study also describes the detection of B. gibsoni in tissue samples during chronic infections for the first time, suggesting possible sequestration of this parasite.