M Sakuma1, A Setoguchi, Y Endo. 1. Laboratory of Veterinary Internal Medicine, Faculty of Agriculture, Kagoshima University, Kagoshima, Japan.
Abstract
BACKGROUND: There is no well-established treatment strategy for Babesia gibsoni infection. A new therapeutic protocol using atovaquone (ATV) and azithromycin (AZM) has been proposed, but there is concern about the possible induction of relapse and the emergence of ATV-resistant variants after treatment. OBJECTIVE: To evaluate the clinical use of combination therapy with ATV and AZM as a first-line treatment of clinical B. gibsoni infection in dogs, and to investigate the emergence of ATV-resistant variants. ANIMALS: Eight B. gibsoni naturally infected dogs showing signs of acute onset of disease. METHODS: Retrospective case study. Eight clinical cases received combination therapy with ATV and AZM at Kagoshima University Veterinary Teaching Hospital during 2007-2008, and their clinical courses and clinicopathological parameters were evaluated. In addition, alterations in the cytochrome b (CYTb) gene of B. gibsoni were analyzed by polymerase chain reaction and DNA sequencing techniques. RESULTS: All of the dogs responded well to the treatment, with rapid improvement in their clinical condition and hematological parameters. However, 5 of the 8 dogs relapsed after treatment. Analysis of the CYTb gene strongly suggested the emergence of ATV-resistant variants after treatment. CONCLUSIONS AND CLINICAL IMPORTANCE: The combination of ATV and AZM can be used as a first-line treatment for dogs with babesiosis, but relapses occur. Attention should be paid to the possible in vivo selection of drug-resistant variants.
BACKGROUND: There is no well-established treatment strategy for Babesia gibsoni infection. A new therapeutic protocol using atovaquone (ATV) and azithromycin (AZM) has been proposed, but there is concern about the possible induction of relapse and the emergence of ATV-resistant variants after treatment. OBJECTIVE: To evaluate the clinical use of combination therapy with ATV and AZM as a first-line treatment of clinical B. gibsoni infection in dogs, and to investigate the emergence of ATV-resistant variants. ANIMALS: Eight B. gibsoni naturally infected dogs showing signs of acute onset of disease. METHODS: Retrospective case study. Eight clinical cases received combination therapy with ATV and AZM at Kagoshima University Veterinary Teaching Hospital during 2007-2008, and their clinical courses and clinicopathological parameters were evaluated. In addition, alterations in the cytochrome b (CYTb) gene of B. gibsoni were analyzed by polymerase chain reaction and DNA sequencing techniques. RESULTS: All of the dogs responded well to the treatment, with rapid improvement in their clinical condition and hematological parameters. However, 5 of the 8 dogs relapsed after treatment. Analysis of the CYTb gene strongly suggested the emergence of ATV-resistant variants after treatment. CONCLUSIONS AND CLINICAL IMPORTANCE: The combination of ATV and AZM can be used as a first-line treatment for dogs with babesiosis, but relapses occur. Attention should be paid to the possible in vivo selection of drug-resistant variants.
Authors: Megan E Schreeg; Henry S Marr; Jaime L Tarigo; Leah A Cohn; Michael G Levy; Adam J Birkenheuer Journal: J Clin Microbiol Date: 2015-05-27 Impact factor: 5.948
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Authors: Adam J Birkenheuer; Henry S Marr; James M Wilson; Edward B Breitschwerdt; Barbara A Qurollo Journal: J Vet Intern Med Date: 2018-10-11 Impact factor: 3.333