Jae-Ik Han

A Simple and Improved DNA Test for Avian Sex Determination

ABSTRACT. Determining the sex of a bird on the basis of its morphological characteristics is difficult in >50% of avian species; in nestlings, this rate is even higher. Given that male birds have two identical sex chromosomes (ZZ), whereas females are heterogametic (ZW), the development of a DNA-based sexing method has been widely investigated in several species. Griffiths et al. (1998) reported a simple DNA test using intronic size variation; however, this method cannot differentiate birds that have small or nonexistent size variations. We report a simple and novel DNA test for avian sex determination using a novel primer (p0) specific for the unique sequence of the chromohelicase-DNA-binding (CHD)-W gene. Use of a multiplex polymerase chain reaction (PCR) and simple agarose-gel electrophoresis with p0 and with the primers P2 and P8 described by Griffiths et al. (1998) revealed that the P0–P2 combination could amplify the partial CHD-W gene alone. Consequently, we found that p0 could be used to identify only the CHD-W gene. We anticipate that this multiplex PCR will be useful for universal avian sexing, regardless of the intronic size variation.

High prevalence of Theileria sp. in wild Chinese Water Deer (Hydropotes inermis argyropus) in South Korea.

Wild Chinese Water Deer exist in large numbers in Northeast Asia, including South Korea. The deer population is so widespread that they are common even in urban areas, resulting in increased contact with humans and domestic animals. The purpose of this study was to examine the prevalence of Theileria sp. infection in wild Chinese Water Deer in South Korea. Using biomolecular techniques, blood samples taken from 18 wild Chinese Water Deer were examined. Thirteen of the 18 samples (72%) tested positive for infection. In 11 of the deer, a Theileria sp. was detected that is nearly identical to the highly pathogenic Theileria sp. reported in China. Theileria ovis and Theileria capreoli were also detected individually in two deer. These results indicate that there may be a high prevalence of Theileria sp. infection in wild Chinese Water Deer, and that the deer may act as a reservoir for the Theileria sp. infection of domestic animals.

Dysregulation of the Wnt/Β-Catenin Signaling Pathway in Canine Cutaneous Melanotic Tumor

The Wnt/β-catenin signal transduction pathway is important in many developmental processes and during tumorigenesis. β-Catenin acts as a signal transducer. To investigate whether the Wnt/β-catenin signal transduction pathway is involved in canine cutaneous melanomagenesis, 18 formalin-fixed paraffin-embedded canine cutaneous melanotic tumor tissues were examined. For cloning and sequencing of the full-length canine ctnnb1 gene encoding β-catenin, conserved sequences of the human and mouse ctnnb1 gene were used to design the primers. For analysis of expression and translocation of β-catenin in canine cutaneous melanotic tumors, semiquantitative reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry were performed. The canine ctnnb1 sequence showed a high degree of similarity to those of human and mouse. Semiquantitative RT-PCR showed a substantial increase in expression of ctnnb1 mRNA in canine cutaneous melanotic tumors compared to normal canine melanocytes, regardless of whether the tumor was benign or malignant. Immunohistochemistry revealed cytoplasmic accumulation of β-catenin in melanotic tumors. In melanoma tissues, nuclear translocation of β-catenin was also observed. The present study demonstrated that abnormal intracellular accumulation and substantially increased expression of β-catenin are involved in canine cutaneous melanotic tumor.

Molecular Detection of Theileria sp. in Wild Chinese Water Deer (Hydropotes inermis argyropus)

Two cases of Theileria sp. infection in wild Chinese water deer (Hydropotes inermis argyropus) were diagnosed by microscopic examination of thin blood smears and by molecular typing. Two wild Chinese water deer were referred to the Veterinary Medical Center of Chungbuk National University in South Korea, presumably the result of traffic accidents. Thin blood smears, which were stained with Giemsa, revealed intraerythrocytic parasites; however, the deer had no remarkable findings on physical examination. Polymerase chain reaction and direct sequencing indicated that the parasite was nearly identical to the unidentified Theileria sp. previously found in China. Phylogenetic analysis showed that the Theileria sp. identified in these cases are closest to the group of unidentified Theileria spp. previously found in China and Japan.

Asymptomatic Babesia microti-like parasite infection in wild raccoon dogs (Nyctereutes procyonoides) in South Korea

We describe asymptomatic piroplasmosis caused by a Babesia microti–like parasite in wild raccoon dogs (Nyctereutes procyonoides) diagnosed by blood smear and DNA analysis. This is the first description of natural B. microti–like parasite infection in raccoon dogs and suggests that the wild raccoon dog can be a source for B. microti–like parasite infection of domestic dogs and humans.

Dermatitis Caused by Neosartorya hiratsukae Infection in a Hedgehog

ABSTRACT This case report describes the fungal dermatitis caused by Neosartorya hiratsukae infection in a household hedgehog confirmed by microscopic examination of conidiophores and DNA analyses including the internal transcribed spacer region, partial β-tubulin, and the calmodulin gene. It is the first report of a natural N. hiratsukae infection in animals.

Isolation of Staphylococcus simulans from Dermatitis in a Captive African Pygmy Hedgehog

Abstract:  Staphylococcus simulans, a coagulase-negative staphylococcal species, can cause several diseases in humans and animals. This report describes a case of dermatosis characterized by broad, well-circumscribed hyperkeratosis and alopecia on the back of a household pygmy hedgehog (Erinaceous albiventris). Quills and exudates were studied by microscopy. The microscopic examination of the exudates collected from the lesion revealed several leukocytes and numerous gram-positive cocci. An aerobic bacterial culture revealed overgrowth of the same gram-positive bacteria. The bacterium was identified as S. simulans by polymerase chain reaction amplification and direct sequencing targeted to the 16S ribosomal RNA gene. This report is the first to show that S. simulans could be related to the dermatitis of hedgehogs.

Pemphigus-Like Immune-Mediated Dermatosis in a Korean Native Black-Bone Fowl

Abstract A 3-yr-old female Korean native black-bone fowl weighing 1 kg presented with refractory dermatosis characterized by hyperkeratosis and alopecia on the head, neck, and scapular region. Antibiotic therapy before referral had not reduced the severity of lesions. Histopathologic findings revealed hyperkeratosis, acantholysis, heterophil infiltration, and ballooning degeneration in the epidermis. Immunohistochemical analysis showed immunoglobulin G deposits in the intercellular spaces of the intermediate layer of the epidermis. Based on these observations, this case was diagnosed as a pemphigus-like immune-mediated dermatosis. The administration of prednisolone eliminated the lesions, and the feathers grew back partially. Abbreviations: IgG = immunoglobulin G; IHC = immunohistochemistry; PE = pemphigus erythematosus; PF = pemphigus foliaceus; PPP = panepidermal pustular pemphigus Reporte de Caso—Dermatosis auto-inmune parecida a pénfigo en una gallina nativa de hueso negro de Corea. Una gallina de hueso negro de tres años de edad proveniente de Corea con un peso de un kilogramo, fue presentada con dermatosis refractaria caracterizada por hiperqueratosis y alopecia en la cabeza, cuello y región escapular. La antibioterapia aplicada antes de ser referida no redujo la severidad de las lesiones. Los hallazgos histopatológicos revelaron hiperqueratosis, acantólisis, infiltración heterofílica y degeneración vacuolar en la epidermis. El análisis inmunohistoquímico mostró depósitos de inmunoglobulina G en los espacios intercelulares de la capa intermedia de la epidermis. Basado en estas observaciones, este caso se diagnosticó como dermatosis auto-inmune parecida a pénfigo. La administración de prednisolona eliminó las lesiones y las plumas crecieron nuevamente de manera parcial.

A multiplex quantitative real-time polymerase chain reaction panel for detecting neurologic pathogens in dogs with meningoencephalitis

Meningoencephalitis (ME) is a common inflammatory disorder of the central nervous system in dogs. Clinically, ME has both infectious and non-infectious causes. In the present study, a multiplex quantitative real-time polymerase chain reaction (mqPCR) panel was optimized for the detection of eight canine neurologic pathogens (Blastomyces dermatitidis, Cryptococcus spp., Neospora caninum, Borrelia burgdorferi, Bartonella spp., Toxoplasma gondii, Ehrlichia canis, and canine distemper virus [CDV]). The mqPCR panel was subsequently applied to 53 cerebrospinal fluid (CSF) samples collected from dogs with ME. The analytic sensitivity (i.e., limit of detection, expressed as molecules per 1 µL of recombinant vector) was 3.8 for CDV, 3.7 for Ehrlichia canis, 3.7 for Bartonella spp., 3.8 for Borrelia burgdorferi, 3.7 for Blastomyces dermatitidis, 3.7 for Cryptococcus spp., 38 for Neospora caninum, and 3.7 for Toxoplasma gondii. Among the tested CSF samples, seven (15%) were positive for the following pathogens in decreasing order of frequency: Cryptococcus spp. (3/7), Blastomyces dermatitidis (2/7), and Borrelia burgdorferi (2/7). In summary, use of an mqPCR panel with high analytic sensitivity as an initial screen for infectious agents in dogs with ME could facilitate the selection of early treatment strategies and improve outcomes.

What is your diagnosis? Lymph node aspirates from a dog with stillbirth

A 3-year-old female Miniature Schnauzer was presented to Chungbuk National University College of Veterinary Medicine with hyperthermia and vaginal discharge. Symptoms had started 2 days previously when the dog had whelped stillborn puppies. Before the pregnancy, the owner had noticed a symmetric subcutaneous mass in the cervical area, but had not sought treatment because the dog appeared otherwise healthy at the time. At first presentation, symptoms included depression and anorexia. Physical examination revealed hyperthermia (39.9°C), tachypnea, persistent dark-green vaginal discharge, abdominal distention, and generalized peripheral lymphadenopathy. Radiographic and ultrasonographic examinations of the thorax and abdomen revealed systemic lymph node enlargement, splenomegaly, hepatomegaly, ascites, and uterine distention. The CBC results included anemia (PCV 26.1%, reference interval [RI] 37–55%). Fine-needle aspirates (FNA) were obtained from enlarged lymph nodes and the spleen (Figure 1), and smears were prepared for cytologic examination. A