• Korean Journal of Clinical Laboratory Science
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• v.51 no.1
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• pp.64-70
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• 2019

Dirofilaria immitis (D. immitis) is a filarial nematode that causes cardiopulmonary dirofilariasis in dogs. In the late stages of infection, infected dogs show one or more symptoms and advanced heart disorder with perivascular inflammation. To detect D. immitis specifically and efficiently in the early stages of infection, a duplex TaqMan qPCR assay was developed based on previous studies using primers and probes specialized to detect D. immitis cytochrome c oxidase subunit I (COI) and dog glyceraldehyde-3-phosphate dehydrogenase (GAPDH). As positive controls, plasmid DNAs were constructed from D. immitis COI or dog GAPDH and a TA-cloning vector. Simplex and duplex TaqMan qPCR assays were performed using the specific primers, probes, and genomic or plasmid DNA. The duplex reaction developed could detect D. immitis COI and dog GAPDH in the same sample simultaneously after optimization of the primer concentrations. The limit of detection was 25 copies for the simplex and duplex assays, and both showed good linearity, high sensitivity, and excellent PCR efficiency. The duplex assays for pathogen detection reduce the costs, labor, and time compared to simplex reactions. Therefore, the duplex TaqMan qPCR assay developed herein will allow efficient D. immitis detection and quantification from a large number of samples simultaneously.

• Korean Journal of Veterinary Service
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• v.32 no.4
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• pp.369-375
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• 2009

This study was attempted to survey the prevalence of heartworm infection among 253 dogs (male 167, female 86) on the 16 breeding farms in southern Gyeongnam area in May to December 2007. The results obtained from this experiment were summarized as follows; Fifty seven (22.5%) of the 253 examined dogs were heartworms-antigen positive, while twenty five dogs were Microfilaria positive by the modified Knott's method. The regional infection rates were of 25% in Tongyeong and 21% in Goseong, and on the breeding environment aspects, infection rates were lower in rural area than urban area farms. The infection rates were higher in female (26/86, 30.2%) than male dog (31/167, 18.6%). The infection rates by breeding size of farms were 31% (11/35) at <20 head, 26%(35/135) at 20~50 head and 13% (11/82) at >50 head. The infection rates of heartworm in examined dogs at the age of <2, 2~4 and >5 were 10.7% (8/75), 26% (40/154) and 37.5% (9/24), respectively. In the microfillaria-infected 25 dogs, identified Dirofilaria immitis of 21 (84%) using PCR. The dogs infected with heartworm showed the increased number of eosinophil.