Prevalence of the endosymbiont Wolbachia in heartworms (Dirofilaria immitis)
Lee, S-A.; Lee, S-G.; Choi, E-J.; Hyun, C.
Veterinary Record 163(16): 484-486
2008
ISSN/ISBN: 0042-4900 PMID: 18931357 Document Number: 621462
A total of 200 adult heartworms (100 males and 100 females) were collected from 40 dogs with severe heartworm infection randomly selected from eight provinces in Korea . Blood samples were also collected from all dogs for the detection of microfilariae. Combined PCR for Wolbachia and Dirofilaria immitis was carried out. The combined PCR successfully amplified the surface protein gene of D. immitis, producing a 459-bp product and the WSP gene, producing a 619-bp product. All 200 adult D. immitis were found positive for Wolbachia. All dogs had variable degrees of microfilarial infection, with mean number of microfilariae of 641.2/ml blood. Thirty-six of the 40 blood samples (90%) were positive for the WSP gene. The detection of the WSP gene proved to be a quick and efficient method for screening samples for the presence of Wolbachia, with a threshold of detection set at 150 microfilariae/ml whole blood. Since the study was performed on a small population of dogs in one country, a large-scale international survey of the prevalence of Wolbachia in D. immitis is warranted.