Papers by Kenichi Tamukai
International journal for parasitology. Parasites and wildlife, Dec 1, 2018
Research in Veterinary Science
We examined several aspects of African hedgehog adenovirus (AhAdv-1) that was isolated from an Af... more We examined several aspects of African hedgehog adenovirus (AhAdv-1) that was isolated from an African pygmy hedgehog, including: replication kinetics of, virus-induced cytopathic effect (CPE), activation status of mitogen-activated protein kinase (MAPK) signaling pathways, and possible roles of these signaling pathways in virus replication and virus-induced CPE in MDCK cells. AhAdv-1 efficiently replicated and induced CPE in infected cells and caused accumulation of cleaved caspase-3 at 24 h post-infection (p.i.), suggesting apoptosis induction. Analysis of several intracellular signal transduction pathways, which are involved in apoptosis, showed activation of p38 MAPK, Akt and ERK1/2 pathways at 3 h p.i., and upregulation of phosphorylated SAPK/JNK at 24 h p.i. Although p38 MAPK inhibitor and SAPK/JNK inhibitor suppressed activation of the respective pathways in infected cells, they did not inhibit virus-induced CPE. Treatment of infected cells with inhibitor of the Akt pathway, the p38 pathway, the SAPK/JNK pathway or the ERK pathway revealed that inhibitors of p38 pathway inhibited viral replication by real-time PCR and TCID50 assay in infected MDCK cells, suggesting that AhAdv-1 uses p38 pathway for multiplication in infected cells.
Supplemental material, Supplemental_material for Molecular evidence for vaccine-induced canine di... more Supplemental material, Supplemental_material for Molecular evidence for vaccine-induced canine distemper virus and canine adenovirus 2 coinfection in a fennec fox by Kenichi Tamukai, Shohei Minami, Rio Kurihara, Hiroshi Shimoda, Ikki Mitsui, Ken Maeda and Yumi Une in Journal of Veterinary Diagnostic Investigation
Parasitology International, 2021
This study describes a subcutaneous proliferative cysticercosis in a pet steppe lemming, Lagurus ... more This study describes a subcutaneous proliferative cysticercosis in a pet steppe lemming, Lagurus lagurus (Rodentia: Cricetidae), bred and imported from Czech Republic into Japan. Numerous metacestodes were collected from the subcutaneous cystic lesion of the left medial thigh. Four surgical removals were coupled with anthelmintic treatment but ended with recurrence. Based on morphological features and mitochondrial DNA sequences, the metacestodes were identified as the larval stage of Taenia carassiceps (Zeder, 1800). This is the first case of infection with larval T. crassiceps in rodents of the genus Lagurus, and becomes the third case of the parasite detected from imported animals in Japan. Related public health concerns are discussed.
Journal of Veterinary Medical Science, 2021
Post-import from the Republic of Indonesia to Japan in 2017, two juvenile, captive bred Asian sma... more Post-import from the Republic of Indonesia to Japan in 2017, two juvenile, captive bred Asian small-clawed otters (Aonyx cinereus) exhibited gastrointestinal symptoms, including vomiting, diarrhea, and hematemesis, and died. One of them was examined postmortem. Microscopically, the small intestinal mucosa was necrotic with crypts lined by regenerating large epithelial cells. A gastric cardiac mucosal ulcerative lesion containing fungal yeasts and pseudohyphae morphologically indicated Candida spp. The lymph nodes exhibited marked lymphoid depletion. Canine parvovirus 2 (CPV-2) was isolated from an oral swab, and virus protein 2 (VP2) gene sequencing revealed new CPV-2a. To our knowledge, this is the first new CPV-2a infection report in Asian small-clawed otters. This infection should be considered in gastrointestinal symptom-related cases in this species.
Journal of Veterinary Diagnostic Investigation, 2020
A 61-d-old fennec fox ( Vulpes zerda), 11 d after receiving a multivalent, modified-live virus va... more A 61-d-old fennec fox ( Vulpes zerda), 11 d after receiving a multivalent, modified-live virus vaccine containing canine distemper virus (CDV), canine adenovirus 2 (CAdV-2), parainfluenza virus, parvovirus, and canine coronavirus, developed oculonasal discharge, and subsequently convulsions, and hemoptysis, and died. Microscopic changes in the cerebrum were evident, including neuronal degeneration and necrosis; intracytoplasmic eosinophilic inclusion bodies were observed in astrocytes. CDV was detected in the brain tissue by immunohistochemistry. Pulmonary lesions of multifocal necrotizing bronchopneumonia had Cowdry type A intranuclear inclusions in the bronchial epithelial cells. Electron microscopy revealed crystalline arrays of adenovirus-like particles within the intranuclear inclusions. Additionally, the hemagglutinin gene of CDV and the CAdV-2 DNA polymerase gene were detected in the fennec fox; sequence analysis showed 100% identity with those of the vaccine strain viruses. ...
Archives of Virology, 2019
Feline paramyxovirus (FPaV) is a member of the family Paramyxoviridae that has been reported only... more Feline paramyxovirus (FPaV) is a member of the family Paramyxoviridae that has been reported only in Germany and the United Kingdom. We detected FPaV for the first time in Japan by transcriptome sequencing of cat urine samples. We determined the genome structure of FPaV and conducted a phylogenetic analysis. It was found that FPaV belongs to the genus Jeilongvirus and forms a clade with Mount Mabu Lophuromys virus 1 (MMLV-1). FPaV lacks a small hydrophobic (SH) gene that is found in members of the genus Jeilongvirus; however, some jeilongviruses also do not have this gene. These results provide information about the diversity and evolution of paramyxoviruses.
Veterinary and Animal Science, 2019
An African pygmy hedgehog adenovirus 1 (AhAdV-1) outbreak in a colony of 24 African pygmy hedgeho... more An African pygmy hedgehog adenovirus 1 (AhAdV-1) outbreak in a colony of 24 African pygmy hedgehogs (APHs) with a case of fatal pneumonia occurred in Japan. Thirteen out of a colony of 15 APHs with respiratory symptoms were diagnosed with AhAdV-1 infection based on the detection of AhAdV-1 genome in throat/nasal swabs and further one APH was diagnosed on isolation of the virus. Five infected APHs died during the outbreak and AhAdV-1 caused severe pneumonia and death in one case. After the outbreak, persistent AhAdV-1 infection was suggested in one surviving APH. AhAdV-1 is a novel adenovirus and is suspected to be an emerging pathogen.
Microbiology Resource Announcements, 2019
This study reports the complete genome sequence of an African pygmy hedgehog adenovirus-1 isolate... more This study reports the complete genome sequence of an African pygmy hedgehog adenovirus-1 isolate from an African pygmy hedgehog which displayed respiratory symptoms that included nasal discharge, sniffling, coughing, and respiratory distress. The viral genome is 31,764 bp long and shows four deletion sites compared to that of skunk adenovirus-1.
Diseases of Aquatic Organisms, 2019
In 2017, approximately 40 out of 100 captive Cranwell's horned frogs Ceratophrys cranwelli fr... more In 2017, approximately 40 out of 100 captive Cranwell's horned frogs Ceratophrys cranwelli from several facilities in Japan exhibited protruding facial lesions. Histopathological examination was performed on 6 specimens with such lesions randomly selected from 2 facilities. Lesions consisted of scattered stellate to spindle-shaped cells without atypia in an abundant myxoid matrix and occasional lymphocytic infiltrates. Maxillary bone was resorbed. No etiological organisms were detected using light microscopy or metagenomic analysis of the lesions. Macroscopic and histological assessments indicate that the lesions are associated with nodular facial myxomatous dermatitis, which has never been reported in amphibians.
Parasitology International, 2019
Long-tailed chinchillas Chinchilla lanigera are popular rodent species kept both in households, w... more Long-tailed chinchillas Chinchilla lanigera are popular rodent species kept both in households, where they are hand-raised as pets, and in zoological facilities. From January 2016 to February 2017, 13 juvenile chinchillas from five facilities in Japan were diagnosed with cryptosporidiosis at the animal hospital. Eight of the cases were fatal. All of the animals were imported from the Czech Republic by the same vendor. Histopathological and multilocus sequence analyses using 18S ribosomal RNA, actin, 70-kDa heat shock protein, and 60-kDa glycoprotein genes confirmed Cryptosporidium ubiquitum of subtype XIId as the etiological agent. Multilocus analysis demonstrated the presence of two new sequence types closely related to the C. ubiquitum Xlld strain isolated from a human in the USA. This study indicated that potentially zoonotic Cryptosporidium is widespread and may have caused a high number of deaths among imported juvenile chinchillas. This species has been reported in various countries to infect both wild and domestic ruminants; rodents; carnivores; marsupials; and primates, including many human cases [5-7]. In the present study, we report the clinical, histopathological, and molecular features of cryptosporidiosis caused by C. ubiquitum in juvenile chinchillas imported into Japan. Our results serve to alert veterinarians; workers in the pet trade; animal care and service workers at zoos, animal shelters, and pet stores; and pet owners who may be exposed to imported chinchillas regarding the threat of C. ubiquitum infection and the development of cryptosporidiosis. 2. Materials and methods 2.1. Animals and specimens The animals in the study included 13 juvenile chinchillas (IDs: 1604-1611, 1702-1706) taken to Banquet Animal Hospital, Tokyo, Japan from January 2016 to February 2017. The animals were all imported from the Czech Republic by the same vendor with the intent to be sold as pets and had been housed in five different facilities (Table 1). Fresh feces were collected from each animal and placed in separate vials containing 70% ethanol or 2.5% aqueous potassium dichromate (K 2 Cr 2 O 7) solution, and stored at 4°C. In order to investigate the
JMM Case Reports, 2017
Introduction. Encephalitozoon pogonae is a newly described pathogen belonging to the phylum Micro... more Introduction. Encephalitozoon pogonae is a newly described pathogen belonging to the phylum Microsporidia. In Austria and the USA, this species has been isolated from fatal and disseminated cases of captive-bred inland bearded dragons. Here, we report the case of fatal disseminated microsporidiosis caused by E. pogonae in two bearded dragons in Japan. Case Presentation. The two lizards from different private households in Tokyo, Japan, had been brought to an animal hospital for examination. In both cases, the animal presented with a history of weight loss for several weeks. There were no improvements in clinical symptoms and the lizards deteriorated and finally died. Histopathological examination demonstrated necrotizing granulomatous inflammation attributed to disseminated microsporidian infection. Nucleotide sequencing of the nuclear ribosomal internal transcribed spacer region identified the microsporidian as E. pogonae with sequence identity of 100 %. Conclusion. We report the first case, to our knowledge, of disseminated microsporidiosis caused by E. pogonae in inland bearded dragons in Japan. Although it is difficult to diagnose prenatally since the signs are nonspecific, the disease should be considered in the differential diagnosis of chronic infections that do not respond to antibiotics.
Journal of the Japan Veterinary Medical Association, 2009
Journal of Comparative Pathology, 2016
Disseminated histiocytic sarcoma (HS) was diagnosed on post-mortem examination of a 1.5-year-old ... more Disseminated histiocytic sarcoma (HS) was diagnosed on post-mortem examination of a 1.5-year-old African hedgehog (Atelerix albiventris) that was presented in poor physical condition and with diarrhoea. Leucocytosis and a hypoechoic abdominal mass were noted on haematological and ultrasonographical examinations. Gross pathological, histopathological, immunohistochemical and ultrastructural evaluation of the mass supported a diagnosis of disseminated HS. To our knowledge, this report represents the first documentation of disseminated HS in this species.
Journal of Veterinary Medical Science, 2016
Since there is no available serological methods to detect antibodies to ferret coronavirus (FRcoV... more Since there is no available serological methods to detect antibodies to ferret coronavirus (FRcoV), an enzyme-linked immunosorbent assay (ELISA) using recombinant partial nucleocapsid (N) proteins of the ferret coronavirus (FRcoV) Yamaguchi-1 strain was developed to establish a serological method for detection of FRcoV infection. Many serum samples collected from ferrets recognized both a.a. 1-179 and a.a. 180-374 of the N protein, but two serum samples did not a.a. 180-374 of the N protein. This different reactivity was also confirmed by immunoblot analysis using the serum from the ferret.Therefore, the a.a. 1-179 of the N protein was used as an ELISA antigen. Serological test was carried out using sera or plasma of ferrets in Japan. Surprisingly, 89% ferrets in Japan had been infected with FRcoV. These results indicated that our established ELISA using a.a. 1-179 of the N protein is useful for detection of antibody to FRcoV for diagnosis and seroepidemiology of FRcoV infection. KEY WORDS: enzyme-linked immunosorbent assay (ELISA), ferret coronavirus (FRcoV), nucleocapsid (N)
Journal of Veterinary Medical Science, 2016
Batrachochytrium dendrobatidis (Bd) infects Anuran larvae (tadpole) mouthparts and causes oral ch... more Batrachochytrium dendrobatidis (Bd) infects Anuran larvae (tadpole) mouthparts and causes oral chytridiomycosis, which can be diagnosed in tadpoles by detecting mouthparts deformities. However, oral chytridiomycosis may or may not be observable, depending on species, tadpole stage and season, and has never been reported in Japan. We aimed to observe oral chytridiomycosis characteristics in bullfrog (Lithobates catesbeiana) tadpoles, determine associated pathologic features and investigate the usability of bullfrog tadpoles in Japanese Bd field surveys. Wild-captured bullfrog tadpole mouthparts were examined macroscopically, histopathologically and by molecular biological examination. Macroscopic lesions were observed in 21 of 59 tadpole mouthparts. Lesions were most frequently located in the lower jaw sheaths and were mainly recognized by partial depigmentation (11 tadpoles; some were completely depigmented) and thinning of the pigmented layer (10 tadpoles). Partial defects of the tips and blunt cutting edges of the jaw sheaths were observed with severe jaw sheath depigmentation. Whitened tooth rows were observed in 7 tadpoles. Histologically, the stratified epithelium (pigmented epithelium) showed partial or diffuse hypopigmentation or pigment loss. Irregular stratified epithelium thickening with hyperkeratosis or parakeratosis was observed in the jaw sheaths. Bd infection was confirmed in 20 of 21 tadpoles presenting jaw sheath deformities, by histopathological examination and/or nested polymerase chain reaction. Depigmentation and thinning of the pigmented layers of jaw sheaths were associated with Bd infection. Thus, diagnosis of Bd infection by macroscopic observation of bullfrog tadpole mouthparts is feasible. This is the first report of oral chytridiomycosis in wild bullfrog tadpoles in Japan.
Parasitology Research, 2015
ABSTRACT Sarcocystis nesbitti, using snakes as the definitive host, is a causative agent of acute... more ABSTRACT Sarcocystis nesbitti, using snakes as the definitive host, is a causative agent of acute human muscular sarcocystosis in Malaysia. Therefore, it is important to explore the distribution and prevalence of S. nesbitti in snakes. Nevertheless, epizootiological information of S. nesbitti in snakes remains insufficient because few surveys have assessed Sarcocystis infection in snakes in endemic countries. In Japan, snakes are popular exotic pet animals that are imported from overseas, but the degree of Sarcocystis infection in them remains unclear. The possibility exists that muscular sarcocystosis by S. nesbitti occurs in contact with captive snakes in non-endemic countries. For a total of 125 snake faecal samples from 67 snake species collected at animal hospitals, pet shops and a zoo, this study investigated the presence of Sarcocystis using polymerase chain reaction (PCR) for the 18S ribosomal RNA gene (18S rDNA). Four (3.2 %) faecal samples were positive by PCR. Phylogenetic analysis of the 18S rDNA sequences obtained from four amplification products revealed one isolate from a beauty snake (Elaphe taeniura), Sarcocystis zuoi, which uses rat snakes as the definitive host. The isolate from a Macklot's python (Liasis mackloti) was closely related with unidentified Sarcocystis sp. from reticulated pythons in Malaysia. The remaining two isolates from tree boas (Corallus spp.) were closely related with Sarcocystis lacertae, Sarcocystis gallotiae and unidentified Sarcocystis sp. from smooth snakes, Tenerife lizards and European shrews, respectively. This report is the first of a study examining the distribution of Sarcocystis species in captive snakes in Japan.
Medical mycology, 2015
A dematiaceous hyphomycete, isolated from frogs, was determined as the possible etiologic agent o... more A dematiaceous hyphomycete, isolated from frogs, was determined as the possible etiologic agent of a case of systemic chromomycosis this cold-blooded animal. The fungus was identified as Veronaea botryosa on the basis of morphological features observed in histopathological examination and molecular phylogenetic evidence. Although V. botryosa is known to be distributed widely in litter and as a human pathogen, this is the first confirmed report of its involvement in a lethal infection in a cold-blooded animal, including an anuran.
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Papers by Kenichi Tamukai