• Korean Journal of Veterinary Research
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• v.38 no.4
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• pp.823-828
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• 1998

This study was carried out to determine the causative agent and the clinical features of dermatophytosis occurred in 3 dogs from Tae-gu, Korea between 1996 and 1997. Specimens of hair and scale, collected from skin lesions were inoculated on potato dextrose agar and mycobiotic agar supplemented with thiamine and inositol. The agar plates were incubated at $25^{\circ}C$ for 2 weeks. Growing fungi isolated were identified by the morphological and growth characterization on bromocresol purple-milk solids-glucose medium, Christensen urea broth and trichophyton media, and by hair perforation tests. Skin lesions were observed in legs, abdomen, ears, face and head with alopecia of various sizes accompanied by itching and/or inflammation. The causative agent of dermatophytosis in the 3 dogs was identified as Microsprum gypseum and Trichophyton rubrum (mixed infection, dog 1), T rubrum (dog 2) and T raubitschekii (dog 3). The dermatophytosis by T rubrum and T raubitschekii was first found on animals in Korea.

• Korean Journal of Veterinary Research
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• v.42 no.3
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• pp.363-370
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• 2002

For the development of diagnostic polymerase chain reaction (PCR) to fungal infection by dermatophytes Trichophyton and Microsporum, detection of the fungal DNA by PCR and analysis of the DNA pattern were undertaken in the present study. A total of 15 strains were tested and those consisted of 3 reference strains and 12 isolates such as: reference strains of T mentagrophytes (downy type, ATCC 9533), T rubrum (IFO 6204) and M gypseum (ATCC 9083), and each isolate of T mentogrophytes (powdery type), T mentagrophytes (granular type), T mentogrophytes (purple-red type), T rubrum, T raubitschekii, T tonsurans, T equinum, T ajelloi, T verrucosum, M cookei, M nanum and M gypseum. The DNA were purely isolated from all strains of Trichophyton spp. and Microsporum spp. by a simple method partly consisted of disruption of fungal cells by lyophilization and grinding and extraction of fungal DNA without phenol treatment which is a routine procedure in DNA isolation. For the detection of fungal DNAs, optimal condition of PCR was determined as preheating once at $94^{\circ}C$ for 5 min, 35 cycles of denaturation at $94^{\circ}C$ for 1 min, annealing at $38^{\circ}C$ for 1 min and polymerization at $72^{\circ}C$ for 2 min, and 1 cycle of final extension at $72^{\circ}C$ for 5 min. In PCR using arbitrary primers AP-1 (5' ACCCGACCTG3') and AP-2 (5' ACGGGCCAGT3'), DNAs in various numbers and sizes were detected from different species of Trichophyton and Microsporum, while DNAs in similar size were also detected in all strains of Trichophyton spp. and Microsporum spp. There were unique DNAs observed from certain dermatophytes by AP-1 such as 1,900 bases in T rubrum, 950 and 1,100 bases in T raubitscheldi, 2,100 bases in T equinum, 400 bases in T verrucosum and 1,150 bases in M gypseum. The unique DNAs were also observed by AP-2 such as 1,200 bases in T ajelloi, 250 bases in T verrucosum, 1,150 bases in M cookei and 2,000 bases in M nanum. The results indicated that PCR can detect a specific DNA from certain Trychophyton and Microsporum spp, which can be the information for further development of diagoomc PCR to dennatophytes.

• Korean Journal of Veterinary Research
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• v.40 no.1
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• pp.94-100
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• 2000

This study was carried out to determine the causative agent and the epidemiological features of canine dermatitis in Tae-gu, Korea from 1997 to 1998. Specimens of collected from skin lesions were examined mycologically, parasitologically and bacteriologically. In all, 70 dogs of differing ages, gender and living environment were sampled. In mycological examination during this period, pathogenic fungi were cultured from 29(41.3%) of 70 canine specimens. Dermatophytes were cultured from 15(21.4%) and Malassezia pachydermatis were 14(20.0%) of the specimens. The frequent dermatophytes isolated were Microsporum canis (12.9%). Trichophyton mentagrophytes (4.3%), T rubrum (2.9%), T raubitschekii and M gypseum (each 1.4%). There was a high proportion of positive cultures from dogs less than 1 year and over than 3 years of age, and in some long haired breeds, but there was no significant difference between the sexes, and the living environments. Although dermatophytes were more frequently isolated in spring and winter, no significant difference was detected in the seasonal distribution of the canine dermatophytosis. Out of 70 dogs, dermatitis ectoparasites(27.1%; Demodex canis 18.6% and Sarcoptes scabie 8.6%) and bacterial pyoderma(40.4%) were diagnosed. Demodex canis and Sarcoptes scabie were common canine ectoparasites, with a higher incidence in short haired breeds and in summer and winter. Bacterial pyoderma was a higher incidence in long haired breeds, and in summer. In the pathogenic agents isolated from 57 dogs(81.4%), single infection rate was 66.7%(38 dogs) and mixed infection rate was, 35.1%(19 dogs). In the majority of mixed infection cases, Gram positive cocci and Malassezia pachydermatis (in 5 cases, 8.8%), as well as ectoparasites(in 6 cases, 10.5%) were demonstrated simultaneously.