Pathological and microbiological studies of Japanese Hare (Lepus brachyurus angustidens) naturally infected with Francisella tularensis subsp. holarctica.
An adult male hare (Lepus brachyurus angustidens) was discovered in a moribund condition in the bush in the mountains of Aomori prefecture in Japan. Upon gross inspection, many ticks were found on the neck and the external ear regions, and more than half the ticks contained blood in the intestine. The skin around the tick bite wounds was alopecic and mildly thickened. At necropsy, enlargement of the cervical lymph nodes and spleen were observed. Histologically, acute necrotizing splenitis, lymphadenitis, hepatitis, pneumonia, myelitis, adrenalitis, and encephalitis with bacterial organisms were observed. The cutaneous lesions were chronic and cysts had formed in the areas marked by tick bites. Immunohistochemically, the organisms in the skin, liver, spleen, lymph nodes, lungs, adrenal glands, brain, bone marrow, and ticks were positive for F. tularensis antigen. Microbiological and polymerase chain reaction results were consistent with F. tularensis subsp. holarctica. Because the cutaneous lesions were more chronic than those in the visceral organs and F. tularensis was detected in the ticks, we inferred that F. tularensis was transmitted to the hare via tick bites.
Park
Chun-Ho
CH
Department of Veterinary Pathology, School of Veterinary Medicine, Kitasato University, Towada, Aomori 034-8628, Japan. baku@vmas.kitasato-u.ac.jp
Nakanishi
Ataru
A
Hatai
Hitoshi
H
Kojima
Daisuke
D
Oyamada
Toshifumi
T
Sato
Hisaaki
H
Kudo
Noboru
N
Shindo
Junji
J
Fujita
Osamu
O
Hotta
Akitoyo
A
Inoue
Satoshi
S
Tanabayashi
Kiyoshi
K
D000818:Animals; D000907:Antibodies, Bacterial; D005604:Francisella tularensis; D034621:Hares; D007299:Insect Bites and Stings / Q000473:pathology; D007564:Japan / Q000453:epidemiology; D008099:Liver / Q000382:microbiology / Q000473:pathology; D008297:Male; D012867:Skin / Q000382:microbiology / Q000473:pathology; D013987:Ticks / Q000382:microbiology; D014406:Tularemia / Q000453:epidemiology / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*
D000907:Antibodies, Bacterial