2023年10月, 第9回北海道大学部局横断シンポジウム, 奨励賞　　　　　　　　　　　　　　　
マダニの化学物質に対する誘引活性と誘引時の行動解析

2018年09月, 6th Sapporo Summer Symposium for One Health (SaSSOH), BEST POSTER AWARD　　　　　　　　　　　　　　　
Analysis of symbionts and parasites for vector-borne disease control

Experimental demonstration of the transmission of Spiroplasma between different arthropod taxa
Shohei Ogata, Naoki Hayashi, Yuki Eshita, Yasuha Nagasawa, Nariaki Nonaka, Ryo Nakao
Journal of Medical Entomology, Oxford University Press (OUP), 2024年02月21日, ［査読有り］, ［筆頭著者］
研究論文（学術雑誌）, Abstract

Spiroplasma (Mycoplasmatales: Spiroplasmataceae) is one of the most widely distributed symbionts of arthropods. Spiroplasma species can infect their hosts via vertical or horizontal transmission. However, the mode of transmission of Spiroplasma between different arthropod taxa has not been elucidated. In this study, we investigated the potential for the transmission of Spiroplasma to non-native arthropod species, using 2 Spiroplasma spp. isolated from ticks, namely Spiroplasma ixodetis and Spiroplasma mirum, and 3 species of mosquito laboratory colonies, namely Aedes albopictus, Aedes aegypti, and Culex pipiens pallens (Diptera: Culicidae). After feeding the adult mosquitoes with Spiroplasma-containing artificial meals, they were kept at 25 °C for 10 days. Homogenates prepared from Spiroplasma-fed mosquitoes were used to re-isolate Spiroplasma using the in vitro culture method. Nine weeks after culture initiation, the presence of Spiroplasma was tested using the polymerase chain reaction (PCR). The results revealed that only S. ixodetis was detected from all 3 species of mosquitoes and re-isolated from 2 of them. The differences in the infection ability of different Spirolasma species could be attributed to several factors, including environmental effects. Nevertheless, this is the first experimental demonstration of Spiroplasma transmission among different arthropod taxa. Further studies are needed to elucidate the evolutionary mechanism that supports the survival of Spiroplasma in nature.

Investigation of vertical and horizontal transmission of Spiroplasma in ticks under laboratory conditions
Shohei Ogata, Rika Umemiya-Shirafuji, Kodai Kusakisako, Keita Kakisaka, Elisha Chatanga, Naoki Hayashi, Yurie Taya, Yuma Ohari, Gita Sadaula Pandey, Abdelbaset Eweda Abdelbaset, Yongjin Qiu, Keita Matsuno, Nariaki Nonaka, Ryo Nakao
Scientific Reports, 13, 1, Springer Science and Business Media LLC, 2023年08月15日, ［査読有り］, ［筆頭著者］
研究論文（学術雑誌）, Abstract

Many arthropods harbour bacterial symbionts, which are maintained by vertical and/or horizontal transmission. Spiroplasma is one of the most well-known symbionts of ticks and other arthropods. It is still unclear how Spiroplasma infections have spread in tick populations despite its high prevalence in some tick species. In this study, Ixodes ovatus, which has been reported to harbour Spiroplasma ixodetis at high frequencies, was examined for its vertical transmission potential under experimental conditions. Next, two isolates of tick-derived Spiroplasma, S. ixodetis and Spiroplasma mirum, were experimentally inoculated into Spiroplasma-free Haemaphysalis longicornis colonies and the presence of Spiroplasma in their eggs and larvae was tested. Our experimental data confirmed that S. ixodetis was transmitted to eggs and larvae in a vertical manner in the original host I. ovatus. In the second experiment, there was no significant difference in engorged weight, egg weight, and hatching rate between Spiroplasma-inoculated and control H. longicornis groups. This suggested that Spiroplasma infection does not affect tick reproduction. Spiroplasma DNA was only detected in the eggs and larvae derived from some individuals of S. ixodetis-inoculated groups. This has demonstrated the potential of horizontal transmission between different tick species. These findings may help understand the transmission dynamics of Spiroplasma in nature and its adaptation mechanism to host arthropod species.

Comparative mitogenomics elucidates the population genetic structure of Amblyomma testudinarium in Japan and a closely related Amblyomma species in Myanmar
Wessam Mohamed Ahmed Mohamed, Mohamed Abdallah Mohamed Moustafa, May June Thu, Keita Kakisaka, Elisha Chatanga, Shohei Ogata, Naoki Hayashi, Yurie Taya, Yuma Ohari, Doaa Naguib, Yongjin Qiu, Keita Matsuno, Saw Bawm, Lat Lat Htun, Stephen C. Barker, Ken Katakura, Kimihito Ito, Nariaki Nonaka, Ryo Nakao
Evolutionary Applications., 15, 7, 1062, 1078, Wiley, 2022年06月, ［査読有り］, ［国際誌］
英語, 研究論文（学術雑誌）

High infection rate of tick-borne protozoan and rickettsial pathogens of cattle in Malawi and the development of a multiplex PCR for Babesia and Theileria species identification
Elisha Chatanga, Emmanuel Maganga, Wessam Mohamed Ahmed Mohamed, Shohei Ogata, Gita Sadaula Pandey, Abdelbaset, Eweda Abdelbaset, Kyoko Hayashida, Chihiro Sugimoto, Ken Katakura, Nariaki Nonaka, Ryo Nakao
Acta Tropica, 231, 106413, 106413, 2022年03月, ［査読有り］, ［国際誌］
英語, 研究論文（学術雑誌）, Malawi has an estimated cattle population of 1,884,803 heads, the indigenous Malawi zebu breed accounts for 91.2%, while the exotic and crossbred accounts for the remaining 8.8%. Although ticks and tick-borne diseases are widespread in Malawi, no molecular study has been conducted to investigate the tick-borne Anaplasmataceae and piroplasms infecting cattle. To provide an insight into the current status of tick-borne pathogens (TBPs) of cattle, a molecular survey was conducted in the central and southern regions of Malawi. A total of 191 cattle of which 132 were Malawi zebu, 44 were Holstein Friesian and 15 were Holstein-Friesian/ Malawi zebu crosses were screened for Anaplasmataceae and piroplasms using the heat shock protein groEL gene and 18S rDNA, respectively. A new 18S rDNA multiplex PCR assay was designed for Babesia and Theileria species identification without sequencing. Overall, 92.3% (n = 177) of the examined animals were infected with at least one TBP. Anaplasmataceae-positive rate was 57.6% (n = 110) while for piroplasms it was 80.1% (n = 153). The detected Anaplasmataceae were Anaplasma bovis 2.6% (n = 5), Anaplasma marginale 24.6% (n = 47), Anaplasma platys-like 13.6% (n = 26), uncharacterized Anaplasma sp. 14.1% (n = 27), and uncharacterized Ehrlichia sp. 16.2% (n = 31). The detected piroplasms were Babesia bigemina 2.6% (n = 5), Theileria mutans 73.8% (n = 141), Theileria parva 33.0% (n = 63), Theileria taurotragi 12.6% (n = 24), and Theileria velifera 53.4% (n = 102). Mixed infection rate was found in 79.6% (n = 152) of the samples analyzed. This study has shown a high burden of TBPs among cattle in Malawi which highlights the need to conceive new methods to control ticks and TBPs in order to improve animal health and productivity. The newly developed multiplex PCR assay would be a useful tool especially in resource limited settings where sequencing is not available and when mixed infections are expected.

Molecular survey of Babesia and Anaplasma infection in cattle in Bolivia.
Shohei Ogata, Juan Antonio Cristian Pereira, Loza Vega Ariel Jhonny, Herbas Perez Gladys Carolina, Keita Matsuno, Yasuko Orba, Hirofumi Sawa, Fumihiko Kawamori, Nariaki Nonaka, Ryo Nakao
Veterinary Sciences, 8, 9, 188, 188, MDPI AG, 2021年09月07日, ［査読有り］, ［筆頭著者］, ［国際誌］
英語, 研究論文（学術雑誌）, Latin American countries produce more than a quarter of the world’s beef and are a major global supplier of livestock protein. Tick-borne diseases (TBDs) are a major constraint to the livestock industry worldwide, including in Latin America. The aim of this study was to detect and characterise tick-borne pathogens in cattle from Santa Cruz, Bolivia, where no detailed epidemiological data are available. Blood samples were collected from 104 cattle. Apicomplexan parasites were detected by nested PCR amplification of the 18S ribosomal RNA gene (rDNA), and Anaplasmataceae was screened by the PCR amplification of 16S rDNA, followed by characterisation based on the heat shock protein and citrate synthase gene sequences. Babesia infection was observed in nine cattle (one Babesia bovis and eight Babesia bigemina), while Anaplasmataceae infection was detected in thirty-two cattle. A sequencing analysis confirmed the presence of Anaplasma marginale and Anaplasma platys-like. These results provide the first molecular evidence for the four above-mentioned tick-borne pathogens in cattle in Bolivia. This information improves our understanding of the epidemiology of TBDs and will help in formulating appropriate and improved pathogen control strategies.

ボリビア多民族国サンタクルス県の牛におけるBabesiaおよびAnaplasmaの感染状況　　　　　　　　　　　　　　　
小方 昌平, Pereira Juan Antonio, 松野 啓太, 大場 靖子, 澤 洋文, 川森 文彦, 野中 成晃, 中尾 亮
日本獣医学会学術集会講演要旨集, 164回, [CO, 40], (公社)日本獣医学会, 2021年09月
日本語

Applications of blocker nucleic acids and non-metazoan PCR improves the discovery of the eukaryotic microbiome in ticks.
Yurie Taya, Gohta Kinoshita, Wessam Mohamed Ahmed Mohamed, Mohamed Abdallah Mohamed Moustafa, Shohei Ogata, Elisha Chatanga, Yuma Ohari, Kodai Kusakisako, Keita Matsuno, Nariaki Nonaka, Ryo Nakao
Microorganisms, 9, 5, 2021年05月13日, ［査読有り］, ［国際誌］
英語, 研究論文（学術雑誌）

Spiroplasma infection among ixodid ticks exhibits species dependence and suggests a vertical pattern of transmission.
Shohei Ogata, Wessam Mohamed Ahmed Mohamed, Kodai Kusakisako, May June Thu, Yongjin Qiu, Mohamed Abdallah Mohamed Moustafa, Keita Matsuno, Ken Katakura, Nariaki Nonaka, Ryo Nakao
Microorganisms, 9, 2, 2021年02月08日, ［査読有り］, ［筆頭著者］, ［国際誌］
英語, 研究論文（学術雑誌）

Amblyomma testudinarium infestation on a brown bear (Ursus arctos yesoensis) captured in Hokkaido, a northern island of Japan.
Ryo Nakao, Kohei Shinjo, Tomoki Sakiyama, Shohei Ogata, Kodai Kusakisako, Gohta Kinoshitaa, Doaa Naguiba, Elisha Chatanga, Wessam Mohamed Ahmed Mohamed, Mohamed Abdallah Mohamed Moustafa, Keita Matsuno, Takuya Itoi, Nariaki Nonaka, Mariko Sashika, Toshio Tsubota, Michito Shimozuru
Parasitology International, 80, ELSEVIER IRELAND LTD, 2021年02月, ［査読有り］, ［国際誌］
英語, 研究論文（学術雑誌）, The tick Amblyomma testudinarium Koch, 1844 (Acari: Ixodidae) is known as a vector of several pathogens such as Rickettsia tamurae and severe fever with thrombocytopenia syndrome (SFTS) virus. This tick species is present in many Asian countries, including Japan, where its distribution is limited to the warm areas of Kanto region and the southwestern region. The present study reports the recovery of a partially engorged A. testudinarium from a wild brown bear captured in Shari town, Hokkaido. In addition to morphological identification, the specimen was genetically characterized by the complete mitochondrial genome sequencing. The results showed that the length of the obtained mitogenome is 14,835 bp that encodes 13 protein-coding, two ribosomal RNA (rRNA) (12S and 16S), and 22 transfer RNA genes with two non-coding control regions. The phylogenetic analysis indicated that our sample clustered with A. testudinarium from Nara, Japan, but separated from A. testudinarium from China. Although the introduction of the tick through livestock transportation cannot be ruled out, the detection of A. testudinarium in Hokkaido prefecture, which is separated from the main island where A. testudinarium is present in the south, may suggest the introduction by migratory birds. This study provides important insights on the distribution and host range of A. testudinarium. This will be useful for the future taxonomic analysis of ticks based on the complete mitogenome sequencing. To our knowledge, this is the northernmost detection point of the tropical tick A. testudinarium.

Complete genome sequence of Rickettsia asiatica strain Maytaro1284, a member of spotted fever group rickettsiae isolated from an Ixodes ovatus tick in Japan.
May June Thu, Yongjin Qiu, Junya Yamagishi, Kodai Kusakisako, Shohei Ogata, Mohamed Abdallah Mohamed Moustafa, Norikazu Isoda, Chihiro Sugimoto, Ken Katakura, Nariaki Nonaka, Ryo Nakao
American Society for Microbiology, 8, 37, American Society for Microbiology, 2019年09月12日, ［査読有り］, ［国際誌］
英語, 研究論文（学術雑誌）, This is the first report of the complete genome sequence of
Rickettsia asiatica
strain Maytaro1284, isolated from an
Ixodes ovatus
tick in Japan. The genome contains a 1,344,324-bp circular chromosome and one plasmid of 74,761 bp. There was no outer membrane protein A (
ompA
) gene encoded in the genome.

Preventive Effects of Houttuynia cordata Extract for Oral Infectious Diseases
Yasuko Sekita, Keiji Murakami, Hiromichi Yumoto, Takashi Amoh, Natsumi Fujiwara, Shohei Ogata, Takashi Matsuo, Yoichiro Miyake, Yoshiki Kashiwada
BioMed Research International, 2016, 2016年06月20日, ［査読有り］
英語

北海道斜里町においてエゾヒグマより採集されたタカサゴキララマダニの一例　　　　　　　　　　　　　　　
下鶴 倫人, 新庄 康平, 崎山 智樹, 小方 昌平, 草木迫 浩大, 木下 豪太, Mohamed Wessam Mohamed Ahmed, Moustafa Mohamed Abdallah Mohamed, 松野 啓太, 伊東 拓也, 野中 成晃, 佐鹿 万里子, 坪田 敏男, 中尾 亮, 日本獣医学会学術集会講演要旨集, 163回, 327, 327, 2020年10月
(公社)日本獣医学会, 日本語

Understanding the vertical and horizontal transmission potential of Spiroplasma in ticks　　　　　　　　　　　　　　　
Shohei Ogata, Rika Umemiya-Shirafuji, Kodai Kusakisako, Keita Kakisaka, Elisha Chatanga, Naoki Hayashi, Yurie Taya, Yuma Ohari, Gita Sadaula Pandey, Abdelbaset Eweda Abdelbase, Yongjin Qiu, Keita Matsuno, Nariaki Nonaka, Ryo Nakao
11th Tick & Tick-borne Pathogen Conference, 2024年09月02日, 英語, ポスター発表
2024年09月01日 - 2024年09月06日, キューバ共和国, ［国際会議］

Zoonosis surveillance in Zambia and academic contribution to foster zoonosis experts under the One Health concept.　　　　　　　　　　　　　　　
3rd International Conference on Public Health in Africa (CPHIA 2023), 2023年11月, シンポジウム・ワークショップパネル（公募）
2023年11月27日 - 2023年11月30日

マダニ × ファッション - 従来のマダニ感染症の啓蒙活動に対する問題へのファッションを取り入れた試み -　　　　　　　　　　　　　　　
小方昌平, 西晃平
超異分野学会 東京大会2023, 2023年03月04日, 日本語, ポスター発表
2023年03月03日 - 2023年03月04日

ボリビア多民族国サンタクルス県の牛におけるBabesiaおよびAnaplasmaの感染状況　　　　　　　　　　　　　　　
小方昌平、Juan Antonio Pereira、松野啓太、大場靖子、澤洋文、川森文彦、野中成晃、中尾亮
第164回日本獣医学会学術集会, 2021年09月, 日本語, 口頭発表（一般）
2021年09月07日 - 2021年09月13日, ［国内会議］

人への病原性が示唆されるマダニ共生細菌の検出および⼆酸化炭素誘引法による⽇本産マダニ採集への挑戦　　　　　　　　　　　　　　　
小方昌平、Wessam Mohamed Ahmed Mohamed、草木迫浩大、May June Thu、邱永晋、Mohamed Abdallah Mohamed Moustafa、松野啓太、片倉賢、野中成晃、中尾亮
第２８回ダニと疾患のインターフェイスに関するセミナー, 2021年09月, 日本語
［国内会議］

Molecular analysis of Babesia and Anaplasma in cattle in Bolivia.　　　　　　　　　　　　　　　
Shohei Ogata, Loza Vega Ariel Jhonny, Juan Antonio C. Pereira, Keita Matsuno, Nariaki Nonaka, Ryo Nakao
The 8th Sapporo Summer Symposium for One Health 2020, 2020年09月, 英語, 口頭発表（一般）
2020年09月16日 - 2020年09月17日, ［国際会議］

The diversity of Spiroplasma sp. in ticks.　　　　　　　　　　　　　　　
Shohei Ogata, Ryo Nakao, Nariaki Nonaka
The 7th Sapporo Summer Symposium for One Health 2019, 2019年09月, 英語, ポスター発表
2019年09月19日 - 2019年09月20日

マダニが保有するスピロプラズマ属細菌の多様性　　　　　　　　　　　　　　　
小方昌平、中尾亮、野中成晃、片倉賢
第162回日本獣医学会学術集会, 2019年09月, 日本語, 口頭発表（一般）
2019年09月10日 - 2019年09月12日, ［国内会議］

Analysis of symbionts and parasites for vector-borne disease control.　　　　　　　　　　　　　　　
Shohei Ogata, Yuki Eshita, Ryo Nakao
The 6th Sapporo Summer Symposium for One Health 2018, 2018年09月, 英語, ポスター発表
2018年09月20日 - 2018年09月21日