title: Localization of the rabies virus antigen in Merkel cells in the follicle-sinus complexes of muzzle skins of rabid dogs.
abstract: The direct fluorescent antibody test (dFAT) on fresh brain tissues is the gold standard for rabies virus antigen detection in dogs. However, this method is laborious and holds a high risk of virus exposure for the experimenter. Skin biopsies are useful for the diagnosis of humans and animals. In mammals, the tactile hair, known as the follicle-sinus complex (FSC), is a specialized touch organ that is abundant in the muzzle skin. Each tactile hair is equipped with more than 2,000 sensory nerve endings. Therefore, this organ is expected to serve as an alternative postmortem diagnostic material. However, the target cells and localization of rabies virus antigen in the FSCs remain to be defined. In the present study, muzzle skins were obtained from 60 rabid dogs diagnosed with rabies by dFAT at the Research Institute of Tropical Medicine in the Philippines. In all dogs, virus antigen was clearly detected in a part of the outer root sheath at the level of the ring sinus of the FSCs, and the majority of cells were positive for the Merkel cell (MC) markers cytokeratin 20 and CAM5.2. Our results suggest that MCs in the FSCs of the muzzle skin are a target for virus replication and could serve as a useful alternative specimen source for diagnosis of rabies.
authors: Department of Veterinary Pathology, School of Veterinary Medicine, Kitasato University, 23-35-1, Higashi, Towada, Aomori 034-8628, Japan.
authors: Taichi
authors: T
authors: Shimatsu
authors: Department of Veterinary Pathology, School of Veterinary Medicine, Kitasato University, 23-35-1, Higashi, Towada, Aomori 034-8628, Japan.
authors: Harumi
authors: H
authors: Shinozaki
authors: Department of Veterinary Pathology, School of Veterinary Medicine, Kitasato University, 23-35-1, Higashi, Towada, Aomori 034-8628, Japan.
authors: Kazunori
authors: K
authors: Kimitsuki
authors: Department of Veterinary Pathology, School of Veterinary Medicine, Kitasato University, 23-35-1, Higashi, Towada, Aomori 034-8628, Japan.
authors: Nozomi
authors: N
authors: Shiwa
authors: Veterinary Research Department, Research Institute for Tropical Medicine, Department of Health, 9002 Research Drive, Filinvest Corporate City, Alabang, Muntinlupa City 1781, Philippines.
authors: Daria L
authors: DL
authors: Manalo
authors: Veterinary Research Department, Research Institute for Tropical Medicine, Department of Health, 9002 Research Drive, Filinvest Corporate City, Alabang, Muntinlupa City 1781, Philippines.
authors: Rodolfo C
authors: RC
authors: Perez
authors: Veterinary Research Department, Research Institute for Tropical Medicine, Department of Health, 9002 Research Drive, Filinvest Corporate City, Alabang, Muntinlupa City 1781, Philippines.
authors: Joselito E
authors: JE
authors: Dilig
authors: Research Promotion Project, Oita University, 1-1 Idaigaoka, Hasama-machi, Yufu, Oita 879-5593, Japan.
authors: Kentaro
authors: K
authors: Yamada
authors: Department of Veterinary Pathology, Faculty of Veterinary Medicine, Mahanakorn University of Technology, 140 Cheum-Sampan Road, Nong-Chok, Bangkok, 10530 Thailand.
authors: Hassadin
authors: H
authors: Boonsriroj
authors: Department of Veterinary Science, National Institute of Infectious Diseases, Toyama 1-23-1, Shinjuku-ku, Tokyo 162-8640 Japan.
authors: Satoshi
authors: S
authors: Inoue
authors: Department of Veterinary Pathology, School of Veterinary Medicine, Kitasato University, 23-35-1, Higashi, Towada, Aomori 034-8628, Japan. Electronic address: baku@vmas.kitasato-u.ac.jp.
authors: Chun-Ho
authors: CH
authors: Park
mesh_terms: D000818:Animals; D000956:Antigens, Viral / Q000276:immunology / Q000302:isolation & purification* / Q000648:ultrastructure; D003933:Diagnosis; D019937:Diagnostic Techniques and Procedures; D004283:Dog Diseases / Q000175:diagnosis* / Q000821:virology; D004285:Dogs; D018859:Hair Follicle / Q000648:ultrastructure / Q000821:virology*; D007150:Immunohistochemistry / Q000379:methods*; D018862:Merkel Cells / Q000648:ultrastructure / Q000821:virology*; D011818:Rabies / Q000175:diagnosis / Q000662:veterinary* / Q000821:virology; D011820:Rabies virus / Q000276:immunology / Q000302:isolation & purification* / Q000648:ultrastructure; D012867:Skin / Q000473:pathology / Q000821:virology*; D013194:Staining and Labeling
chemical_list: D000956:Antigens, Viral
keywords: Follicle-sinus complexes; Immunohistochemistry; Merkel cells; Postmortem diagnosis; Rabies