First report of the isolation of Balamuthia mandrillaris in the northern region of Japan

• Published in: Parasitology research (1987) Vol. 117; no. 9; pp. 2895 - 2900
• Main Authors: Yamanouchi, Kanako, Arima, Hiroaki, Sakamoto, Yamato, Kanto, Kazuki, Kasai, Kosuke, Ito, Koichi, Inaba, Takashi
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-09-2018; Springer; Springer Nature B.V
• Subjects: Adult; Aged; Aged, 80 and over; Amebiasis - epidemiology; Amebiasis - pathology; Amebiasis - transmission; Amoeba; Amoebas; Analysis; Animals; Balamuthia mandrillaris; Balamuthia mandrillaris - isolation & purification; Biomedical and Life Sciences; Biomedicine; Climate change; Encephalitis; Encephalitis - epidemiology; Encephalitis - parasitology; Female; Genetic aspects; Human settlements; Humans; Immunology; Japan - epidemiology; Male; Medical Microbiology; Microbiology; Middle Aged; Nose; Original Paper; Sequence Analysis, DNA; Soil - parasitology; California; Japan; Soil; Free-living amoeba; Japan; 16S rRNA gene; Balamuthia mandrillaris; Balamuthia 16S rRNA gene
• ISSN: 0932-0113; 1432-1955
• DOI: 10.1007/s00436-018-5980-x

Balamuthia mandrillaris
is a free-living amoeba that lives in soil and water near human settlements.
B. mandrillaris
was first isolated from a mandrill baboon that died at the San Diego Zoo Wildlife Park in California in 1986, and the first human infection was reported in 1990. Although reported
B. mandrillaris
infections are often not properly characterized, it appears that
B. mandrillaris
invades the living body from the soil and water, either via a wound or the nasal cavity. Most confirmed infections have originated in South and North America.
B. mandrillaris
inhabits warm climates and is recognized as a pathogen in warm areas such as desert climates and tropical climates.
B. mandrillaris
has been isolated from environmental samples since 2000, most of which originated from warm areas such as step climates, tropical climates, and desert climates. However,
B. mandrillaris
may survive in diverse environments, although fewer granulomatous amebic encephalitis patients have been reported in colder Japanese and Northern European regions. In the present study, we conducted a survey of 13 soil samples in Aomori Prefecture located at the northernmost tip of Japan Honshu and successfully isolated one strain of
B. mandrillaris
from soil for the first time in Japan. In addition,
B. mandrillaris
gene was detected from several soils. This confirms that
B. mandrillaris
is capable of spreading to a wider climatic region.