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• Identification of Shiga Toxin-Producing Escherichia Coli (STEC) Adhesins

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• Degradation of p0071 and p120-catenin during adherens junction disassembly by Leptospira interrogans

  Romina Tokumon, Isabel Sebastian, Bruno M. Humble, Nobuhiko Okura, Hidenori Yamanaka, Tetsu Yamashiro, Claudia Toma

  Frontiers in cellular and infection microbiology ( Frontiers )  13   2023.09 [ Peer Review Accepted ]

  Type of publication: Research paper (scientific journal)

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• Analysis of human clinical and environmental Leptospira to elucidate the eco-epidemiology of leptospirosis in Yaeyama, subtropical Japan.

  Sato Y, Hermawan I, Kakita T, Okano S, Imai H, Nagai H, Kimura R, Yamashiro T, Kajita T, Toma C

  PLoS neglected tropical diseases ( PLoS Neglected Tropical Diseases )  16 ( 3 ) e0010234 - e0010234   2022.03 [ Peer Review Accepted ]

  Type of publication: Research paper (scientific journal)

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  Background Leptospirosis, a zoonosis caused by species in the spirochete genus Leptospira, is endemic to the Yaeyama region in Okinawa, subtropical Japan. Species of the P1 subclade “virulent” group, within the genus Leptospira, are the main etiological agents of leptospirosis in Okinawa. However, their environmental persistence is poorly understood. This study used a combination of bacterial isolation and environmental DNA (eDNA) metabarcoding methods to understand the eco-epidemiology of leptospirosis in this endemic region. Findings Polymerase chain reaction (PCR) characterized twelve human clinical L. interrogans isolates belonging to the P1 subclade “virulent” subgroup and 11 environmental soil isolates of the P1subclade “low virulent” subgroup (genetically related to L. kmetyi, n = 1; L. alstonii, n = 4; L. barantonii, n = 6) from the Yaeyama region targeting four virulence-related genes (lipL32, ligA, ligB and lpxD1). Clinical isolates were PCR positive for at least three targeted genes, while all environmental isolates were positive only for lipL32. Analysis of infected renal epithelial cells with selected clinical and environmental strains, revealed the disassembly of cell-cell junctions for the Hebdomadis clinical strain serogroup. Comparison of leptospiral eDNA during winter and summer identified operational taxonomic units corresponding to the species isolated from soil samples (L. kmetyi and L. barantonii) and additional P2 subclade species (L. licerasiae, L. wolffii-related, among others) that were not detected by soil cultivation. Total Leptospira read counts were higher in summer than in winter and the analysis of leptospiral/animal eDNA relationship suggested Rattus spp. as a potential reservoir animal. Conclusion Our study demonstrated high environmental Leptospira diversity in the Yaeyama region, particularly during summer, when most of the leptospirosis cases are reported. In addition, several Leptospira species with pathogenic potential were identified that have not yet been reported in Yaeyama; however, the environmental persistence of P1 subclade species previously isolated from human clinical cases in this region was absent, suggesting the need of further methodology development and surveillance.

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• Disassembly of the apical junctional complex during the transmigration of Leptospira interrogans across polarized renal proximal tubule epithelial cells.

  Sebastián I, Okura N, Humbel BM, Xu J, Hermawan I, Matsuura C, Hall M, Takayama C, Yamashiro T, Nakamura S, Toma C

  Cellular microbiology ( Cellular Microbiology )  23 ( 9 ) e13343   2021.09 [ Peer Review Accepted ]

  Type of publication: Research paper (scientific journal)

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• Understanding leptospirosis eco-epidemiology by environmental DNA metabarcoding of irrigation water from two agro-ecological regions of Sri Lanka

  Chandika D. Gamage, Yukuto Sato, Ryosuke Kimura, Tetsu Yamashiro, Claudia Toma

  PLOS Neglected Tropical Diseases   14 ( 7 ) e0008437   2020.07 [ Peer Review Accepted ]

  Type of publication: Research paper (scientific journal)

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• Evaluation of Intracellular Trafficking in Macrophages.

  Toma C, Suzuki T

  Methods in molecular biology (Clifton, N.J.) ( Methods in Molecular Biology )  2134   199 - 206   2020 [ Peer Review Accepted ]

  Type of publication: Research paper (scientific journal)

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Other Papers 【 display / non-display 】

Other Papers 【 display / non-display 】

• Vibrio cholerae type IV pili

  Toma C., Nakasone N., and Iwanaga M

  Recent Res. Devel. Infection ( その他の出版社 )  1 ( 1 ) 167 - 178   2003.03

   

  DOI

Presentations 【 display / non-display 】

Presentations 【 display / non-display 】

• Environmental DNA metabarcoding to understand the ecology of leptospirosis

  Claudia Toma

  World Congress on Leptospirosis  (Port Blair, Andaman and Nicobar Islands, India)  2019.11  -  2019.11 

• Leptospira interrogans translocation across renal proximal tubule epithelial cells

  Toma C, Sebastian I, Okura N.

  The 18th International Forum on Infection and Immunity  (Awaji Yumebutai International Conference Center, Hyogo, Japan)  2019.09  -  2019.10 

• Evaluation of a leptospiral enzyme for diagnosis of acute leptospirosis

  Toma C, Koizumi N, Kakita T, Kyan H, Hermawan I, Higa N, Yamashiro T.

  10th International Leptospirosis Society Conference  (Parlmerston North, New Zealand)  2017.11  -  2017.12 

• Analysis of the bacterial factors involved in Leptospira interrogans-macrophage interactions

  Toma C, Murray GL, Higa N, Nakasone N, Nohara T, Takaesu G, Koizumi N, Adler B, Suzuki T.

  8th Scientific Meeting of International Leptospirosis Society  (Fukuoka, Japan)  2013.10  -  2013.10 

• Mechanism of macrophage infection by Leptospira interrogans

  Toma C, Koizumi Y, Okura N, Nakasone N, Higa N, Ogura Y, Takayama C, Suzuki T.

  Gordon Research Conference, Biology of Spirochetes,   (Ventura, CA, USA)  2010.01  -  2010.02 

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Industrial Property 【 display / non-display 】

Industrial Property 【 display / non-display 】

• Antibodies to detect a leptospiral antigen for the diagnosis of leptospirosis

  Industrial Property No 2017-226148  (2017.11.24)

  Unexpectedly No 2018-127442  (2020.07.02)

  Claudia Toma

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• Editor's Choice

  2021.09   Cellular Microbiology  

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• Grant-in-Aid for Scientific Research(B)

  Project Year: 2021.04  -  2024.03 

  Direct: 12,800,000 (YEN)  Overheads: 16,640,000 (YEN)  Total: 3,840,000 (YEN)

• Grant-in-Aid for Scientific Research(B)

  Project Year: 2018.04  -  2021.03 

• Grant-in-Aid for Scientific Research(C)

  Project Year: 2015.04  -  2018.03 

  Direct: 3,700,000 (YEN)  Overheads: 1,110,000 (YEN)  Total: 4,810,000 (YEN)

• Grant-in-Aid for Scientific Research(C)

  Project Year: 2012  -  2013 

  Direct: 2,210,000 (YEN)  Total: 2,210,000 (YEN)

• Grant-in-Aid for Scientific Research(C)

  Project Year: 2009  -  2011 

  Direct: 4,250,000 (YEN)  Total: 4,250,000 (YEN)

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SDGs 【 display / non-display 】