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Researcher Information

last modified:2021/07/25

Associate Professor TOKORO Masaharu

Mail Laboratory Website

Faculty, Affiliation

Faculty of Medicine, Institute of Medical, Pharmaceutical and Health Sciences Departmet of Parasitology

College and School Educational Field

Division of Medical Sciences, Graduate School of Medical Science
Division of Health Sciences,Graduate School of Medical Science
School of Medicine, College of Medical, Pharmaceutical and Health Sciences


Department of parasitology TEL:076-265-2821 FAX:076-234-4242

Academic Background

【Academic background(Doctoral/Master's Degree)】
Keio University Doctor Graduate School, Division of Medicine 200103 Accomplished credits for doctoral program
【Academic background(Bachelor's Degree)】
Akita University 199703


Kanazawa University Department of Parasitology,(2003/04/01-2005/03/31)
Kanazawa University Department of Parasitology(2005/04/01-)

Year & Month of Birth


Academic Society

The Japanese Society of Clinical Parasitolgoy

Society of Evolutionary Studies, Japan


○Kanehara-Ichiro Memorial Medical Foundation(2004/03/01)
○Japan Antibiotic Research Organization& Pfizer(2004/09/10)
○Honjin Ryouhei basic medical research fund(2004/08/25)
○Kurozumi Medical Foundation(2007/10/19)
○Ooyama Health Foundation(2008/03/06)


Parasitology (including sanitary zoology)

Speciality Keywords

molecular epidemiology,molecular evolution,drug development,tropical medecine,intestinal protozoan parasites,Parasitology

Research Themes

The challenges of chemotherapy against a pathogenic protozoon, Cryptpsporidium

Demonstrate unique metabolic regulations in protozoal pathogens, which may provide suitable targets for novel chemotherapeutic regimens against the parasites.

Analysis of intra-species diversity in intestinal protozoan parasites using molecular taxonomy

Reveal the intra-species diversity within the population of each intestinal protozoan parasite from an evolutionary viewpoint to construct a novel prevention approach using selection pressures against the spread of drug-resistant parasites.

Epidemiologic analysis regarding parasitic burdens in endemic areas

To maintain the international co-operational relationships with partners in endemic tropical countries, and to fight against expected pandemics of protozoal infectious diseases, several field works in those areas are ongoing.



  •  Lower prevalence of Entamoeba species in children with vertically transmitted HIV infection in Western Kenya. Matey EJ, Tokoro M, Nagamoto T, Mizuno T, Saina MC, Bi X, Oyombra JA, Okumu P, Langat BK, Sang WK, Songok EM, Ichimura H. AIDS. 30 5 803-805 2016/03/13
  •  Positive correlation of HIV infection with Giardia intestinalis assemblage B but not with assemblage A in asymptomatic Kenyan children.  Matey EJ, Tokoro M, Mizuno T, Matsumura T, Nagamoto T, Bi X, Oyombra JA, Sang WK, Songok EM, Ichimura H. AIDS. 30 15 2385-2387 2016/12/24
  •  Adenovirus-prime and baculovirus-boost heterologous immunization achieves sterile protection against malaria sporozoite challenge in a murine model. Yoshida K, Iyori M, Blagborough A, Salman A, Dulal P, Sala K, Yamamoto D, Khan S, Janse C, Biswas S, Yoshii T, Yusuf Y, Tokoro M, Hill A, and Yoshida S. Scientific Reports. 8 3896 2018/03/01
  •  In vitro assessment of anticryptosporidial efficacy and cytotoxicity of adenosine analogues using a SYBR Green real-time PCR method Journal of Antimicrobial Chemotherapy. JOURNAL OF ANTIMICROBIAL CHEMOTHERAPY 66 3 560-563 2011/03
  •  Extra-gastrointestinal anisakidosis caused by Pseudoterranova azarasi manifesting as strangulated inguinal hernia. Mitsuboshi A, Yamaguchi H, Ito Y, Mizuno T, Tokoro M, Kasai M. Parasitol Int. 66 6 810-812 2017/12/01

show all

  •  Split introns in the genome of a divergent eukaryote Giardia intestinalis are excised by spliceosome-mediated trans-splicing CURRENT BIOLOGY 21 4 311-315 2011/03
  •  Genotyping of Giardia Isolates from Human in Japan Using the Small Subunit Ribosomal RNA and Glutamate Dehydrogenase Gene Sequences JAPANESE JOURNAL OF INFECTIOUS DISEASES 58 57-58 2005/03
  •  A case of cerebral toxoplasmosis after bonemarrow transplantation Tomoko Arai, Yukio Kondo, Kohei Hosokawa, Yasunori Sato, Masaharu Tokoro Clinical Parasitology 21 1 16-19 2010/12
  •  Current status of molecular taxonomy in pathogenic protozoan parasites 117 2 53-57 2008/06
  •  Detection and Identification of Cyclospora cayetanensis by a Clinical Parasitology 17 1 145-148 2006/03
  •  免疫低下にともなうMAC感染症に合併した呼吸器クリプトスポリジウム症の一例 Clinical Parasitology 19 1 55-58 2008/03
  •  Multiple-subgenotype infections of Giardia intestinalis detected in Palestinian clinical cases using a subcloning approach.  Parasitology International 58 3 258-262 2009/09
  •  New strategy for the development of chemotherapy drugs against Cryptosporidium infection 81-84 2008/09
  •  Giardia intestinalis Genotyping to Where? 74-78 2008/09
  •  Intraspecies diversity of intestinal protozoan parasites: How did they evolve into human pathogens? 33-37 2008/09
  •  Assemblage-Dependent Genetic Features of Giardia intestinalis in Humansh.  Hussein A, Nakamoto K, Arai T, Tokoro M. Palestinian Medical and Pharmaceutical Journal  1 2 49-58 2016
  •  A case of giardiasis expressing severe systemic symptoms and marked hypereosinophilia. Parasitology International 59 3 487-489 2010/09
  •  Identification and Characterization of Two Isoenzymes of Methionine gamma-lyase from Entamoeba histolytica A KEY ENZYME OF SULFUR-AMINO ACID DEGRADATION IN AN ANAEROBIC PARASITIC PROTIST THAT LACKS FORWARD AND REVERSE TRANS-SULFURATION PATHWAYS JOURNAL OF BIOLOGICAL CHEMISTRY 278 43 42717-42727 2003/10
  •  A refractory case of Acanthamoeba keratitis. Tetsushi Mizuno, Kazuki Nakazawa, Hideaki Yokogawa, Akira Kobayashi, Masaharu Tokoro Clinical Parasitology 30 1 28-30 2019/12/01
  •  Detections of gastrointestinal parasites, including Giardia intestinalis and Cryptosporidium spp., in cattle of Banten province, Indonesia. Sawitri DH, Wardhana AH, Martindah E, Ekawasti F, Dewi DA, Utomo BN, Shibahara T, Kusumoto M, Tokoro M, Sasai K, Matsubayashi M.  J Parasit Dis. 44 1 174-179 2020/03
  •  Molecular identification of Eimeria hestermani and Eimeria prionotemni from a red-necked wallaby (Macropodidae; Macropusrufogriseus) in Japan.  Ekawasti F, Kitagawa K, Domae H, Wardhana AH, Shibahara T, Uni S, Tokoro M, Sasai K, Matsubayashi M. Parasitol Res. 2020/02
  •  Extremely diversified haplotypes observed among assemblage B population of Giardia intestinalis in Kenya. Mizuno T, Matey EJ, Bi X, Songok EM, Ichimura H, Tokoro M. Parasitol Int. 75 102038 2020/04
  •  Human case of subcutaneous nodule because of a novel genetic variation of Dirofilaria sp. Nakao M, Okamura A, Mizuno T, Takehara K, Tokoro M, Matsushita T. J Dermatol. 46 10 914-916 2019/10
  •  Molecular characterization of highly pathogenic Eimeria species among beef cattle on Java Island, Indonesia.  Ekawasti F, Nurcahyo W, Wardhana AH, Shibahara T, Tokoro M, Sasai K, Matsubayashi M. Parasitol Int. 72 101927 2019/10
  •  A Case of Giardiasis Expressing Severe Systemic Symptoms and Marked Hypereosinophilia. Yuhko Suzuki, Takeshi Nakamura, Masaharu Tokoro et al. Clincal Parasitology 21 1 12-15 2010/12
  •  Two human cases of entamoebiasis: A Brazilian with Entamoeba dispar, Blastocystis hominis and Endolimax nana infection and a Japanese with an asymptomatic ilocecal ulcer with E. histolytica infection Minoru Yamada, Tatsuya Tegoshi, Mari Tanigawa, Hiroko Yashiro, Masayo Hamahata, Hisao Yoshikawa, Hiroshi Tachibana, Masaharu Tokoro, Eisai Cho Clincal Parasitology 23 1 82-85 2012/12
  •  Ex vivo laser confocal microscopy findings of cultured Acanthamoeba trophozoites. Yamazaki N,Kobayashi A,Yokogawa H,Ishibashi Y,Oikawa Y,Tokoro M,Sugiyama K Clin Ophthalmol 6 1365-8 2012/08
  •  Genetic identification of Entamoeba polecki subtype 3 from pigs in Japan and characterisation of its pathogenic role in ulcerative colitis. Matsubayashi M, Murakoshi N, Komatsu T, Tokoro M, Haritani M, Shibahara T.  Infect Genet Evol. 36 8-14 2015/12/01
  •  An atypical presentation of Trichomonas tenax in liver abscesses associated with gallbladder carcinoma. Clinical Parasitology 28 1 90-92 2017/12/01
  •  Etra-gastrointestinal anisakidosis caused by Pseudoterranova azarasi identified by molecular analysis. Clinical Parasitology 28 1 28-31 2017/12/01
  •  A case of amebic liver abscess confirmed by PCR Clinical Parasitology 27 1 84-86 2016/12/01
  •  Ancylostoma ceylanicum hookworm infection in Japanese traveler who presented chronic diarrhea after return from Lao People's Democratic Republic. Kaya D, Yoshikawa M, Nakatani T, Tomo-Oka F, Fujimoto Y, Ishida K, Fujinaga Y, Aihara Y, Nagamatsu S, Matsuo E, Tokoro M, Ouji Y, Kikuchi E. Parasitol Int. 65 737-740 2016/12/01
  •  Possible pathogenicity of commensal Entamoeba hartmanni revealed by molecular screening of healthy school children in Indonesia Matsumura T, Hendarto J, Mizuno T, Syafruddin D, Yoshikawa H, Matsubayashi M, Nishimura T, Tokoro M. Trop Med Health. 47 7 2019/01/15
  •  Molecular characterization of various trichomonad species isolated from humans and related mammals in Indonesia Kamaruddin, Mudyawati; Tokoro, Masaharu; Moshiur Rahman, Md; Arayama, Shunsuke; Hidayati, Anggi Pn N; Syafruddin, Din; Asih, Puji Bs S; Yoshikawa, Hisao; Kawahara, Ei Korean Journal of Parasitology 52 5 471-478 2014/01/01 
  •  Molecular survey of Blastocystis sp. from humans and associated animals in an Indonesian community with poor hygiene. Yoshikawa H, Tokoro M, Nagamoto T, Arayama S, Asih PB, Rozi IE, Syafruddin D. Parasitol Int. 65 780-784 2016/12/01
  •  Impact of HIV Infection and Anti-Retroviral Therapy on the Immune Profile of and Microbial Translocation in HIV-Infected Children in Vietnam.  Bi X, Ishizaki A, Nguyen LV, Matsuda K, Pham HV, Phan CT, Ogata K, Giang TT, Phung TT, Nguyen TT, Tokoro M, Pham AN, Khu DT, Ichimura H.  Int J Mol Sci. 17 8 pii: E1245 2016/08/02
  •  First molecular identification of Entamoeba polecki in a piglet in Japan and implications for aggravation of ileitis by coinfection with Lawsonia intracellularis. Matsubayashi M, Kanamori K, Sadahiro M, Tokoro M, Abe N, Haritani M, Shibahara T. Parasitol Res. 114 8 3069-3073 2015/08/01
  •  Giardiasis in a patient undergoing chemotherapy for retinoblastoma and acute myelogenous leukemia Otsubo, Keisuke; Sakaki-Nakatsubo, Hisano; Taneichi, Hiromichi; Nomura, Keiko; Miyawaki, Toshio; Tokoro, Masaharu; Kanegane, Hirokazu Pediatrics International 55 4 524-527 2013/08/01 
  •  Progressive HIV-associated Cholangiopathy in an HIV Patient Treated with Combination Antiretroviral Therapy. Imai K, Misawa K, Matsumura T, Fujikura Y, Mikita K, Tokoro M, Maeda T, Kawana A. Intern Med. 55 19 2881-2884 2016/08/10
  •  A case of giardiasis with hypereosinophilia after percutaneous endoscopic gastrostomy Takahiro Matsumura, Tomoji Yuno, Yasuyuki Nishimura, Masaharu Tokoro Clincal Parasitology 23 1 86-89. 2012/12
  •  Bowman's layer encystment in cases of persistent Acanthamoeba keratitis. Yokogawa H, Kobayashi A, Yamazaki N, Ishibashi Y, Oikawa Y, Tokoro M, Sugiyama K Clin Ophthalmology 6 1245-1251 2012/08
  •  Genetic characterization of clinical Acanthamoeba isolates from Japan using nuclear and mitochondrial small subunit ribosomal RNA Rahman, Md Moshiur; Yagita, Kenji; Kobayashi, Akira; Oikawa, Yosaburo; Hussein, Amjad I A; Matsumura, Takahiro; Tokoro, Masaharu Korean Journal of Parasitology 51 4 401-411 2013/08/01 
  •  In vivo imaging of radial keratoneuritis in patients with acanthamoeba keratitis by anterior-segment optical coherence tomography Yamazaki, Natsuko; Kobayashi, Akira; Yokogawa, Hideaki; Ishibashi, Yasuhisa; Oikawa, Yosaburo; Tokoro, Masaharu; Sugiyama, Kazuhisa Ophthalmology 121 11 2153-2158 2014/01/01 
  •  Trichomonads detected by microscopic examination of urine sedimentation: high enedemicity of sexually transmitted protozoan infection among elderly population. Hideaki Hatanaka,Hisaji Arai,Masaharu Tokoro,Joko Hendarto Tukimin, Takehiro Nagamoto,Tetsushi Mizuno Clinical Parasitology 29 1 24-26 2018/12/01
  •  A case of giardiasis diagnosed by the presence of trophozoites in pancreatic juice. Satoru Kawai, Masaharu Tokoro, Atsuhito Fukushima, Akira Hishinuma, Keiichiro Abe, Hideyuki Hiraishi, Haruka Furumai, Hiromi Machida, Yasuo Imai, Masato Kato, Yuki Sakuraoka, Keiichi Kubota, Yuichi Chigusa Clinical Parasitology 29 1 33-36 2018/12/01
  •  Molecular phylogeny of Blastocystis isolates from wild rodents captured in Indonesia and Japan. Katsumata M, Yoshikawa H, Tokoro M, Mizuno T, Nagamoto T, Hendarto J, Asih PBS, Rozi IE, Kimata I, Takami K, Syafruddin D.  Parasitol Res. 117 9 2841-2846 2018/07/02
  •  Three monophyletic clusters in Retortamonas species isolated from vertebrates. Hendarto J, Mizuno T, Hidayati APN, Rozi IE, Asih PBS, Syafruddin D, Yoshikawa H, Matsubayashi M, Tokoro M. Parasitol Int. 69 93-98 2019/04/01
  •  Histopathologically detected Anisakis pegreffii in gastrectomy tissue of stomach cancer: carcinogenesis or tropism of the parasite? Masaharu Tokoro,Kenichi Harada,Tetsushi Mizuno Clinical Parasitology 29 1 80-82 2018/12/01

Conference Presentations

  • Africa: The geographical origin of Giardia intestinalis assemblage B, but not assemblage A(conference:15th International Congress of Protistology)(2017/08/01)
  • 寄生虫感染症(2014/02/01)
  • インドネシアの辺境地域で人獣から検出される多様な寄生原虫(2015/10/25)


  •  Sulfur-containing amino acid metabolism in parasitic protozoa Ali V, Tokoro M 60 1 1-99 2005/10
  •  Genotyping of Cryptosporidium species: current status and future direction. Nakamoto K, Hussein AIA Sankei-sha Co., Ltd. 1 1 3-7 2006/12
  •  Technical notes for the genotyping of Giardia intestinalis. Nakamoto K, Yamaguchi T, Tokoro M Sankei-sha Co., Ltd. 1 1 10-13 2006/12
  •  Pathogenesis and virulence factors associated with intestinal protozoan parasites 65 3 470-473 2007//3
  •  Intestinal and urogenital protozoal diseases 2008//1

show all

  •  Amebiasis and Cryptosporidiosis 34 4 329-334 2007//7
  •  New strategy for the development of chemotherapy drugs against Cryptosporidium infection Hussein AIA,Iseki M, Tokoro M 1,81 84 2008/09
  •  Giardia intestinalis Genotyping to Where? Yamaguchia T, Tanaka M, Tokoro M 1 74-78 2008/09
  •  Intraspecies diversity of intestinal protozoan parasites: How did they evolve into human pathogens? 1  33-37 2008/09

Arts and Fieldwork


Theme to the desired joint research

○Development of drugs against novel anti-protozoan parasites
○Intra-species diversity of intestinal protozoan parasites

Grant-in-Aid for Scientific Research

○Festering Joint International Research (B)「Study on the dynamics of initial infections and colonizations with intestinal protozoan parasites」(2019-2022) 

Competitive research funding,Contribution

Collaborative research,Consignment study

Classes (Bachelors)


Classes (Graduate Schools)

○Lectures on Protozoal & Helminthic Diseases(2017)
○Lectures on Protozoal & Helminthic Diseases(2017)
○Environment and Health -Introductory Various intestinal protozoan parasites in developing areas(2017)
○Introduction to Basic Medical Science(2016)
○Environment and Health -Introductory(2016)
○Lectures on Protozoal & Helminthic Diseases(2016)
○Lectures on Protozoal & Helminthic Diseases(2016)
○Lectures on Protozoal & Helminthic Diseases(2016)

International Project

International Students

Lecture themes

○Drug developments for neglected diseases
○To fight against endemic diseases

Others (Social Activities)

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