IUMS2017-1178 A study on the origin of bovine rotavirus strains detected from the children of the Nasu district, Tochigi, Japan 2018/5/19 Kei Numazaki,

Presentation on theme: "　　　　　 IUMS2017-1178 A study on the origin of bovine rotavirus strains detected from the children of the Nasu district, Tochigi, Japan 2018/5/19 Kei Numazaki,"— Presentation transcript:

1 　　　　　 IUMS A study on the origin of bovine rotavirus strains detected from the children of the Nasu district, Tochigi, Japan 2018/5/19 Kei Numazaki, MD, PhD Division of International Infectious Diseases, Graduate School International University of Health and Welfare Nasu-shiobara, Tochigi, Japan 　

2 No commercial relationship or potential conflict of interest related to this presentation

3 Background 　 Serious gastrointestinal infection of rotavirus (RV) is usually prevalent during winter months and often seen in infants and young children. While at least 11 G genotypes have been isolated from humans, G1, G2, G3, G4, and emerging G9 are major genotypes of human RV. Although G6 human rotavirus is quite rare, it is the major type among rotaviruses from cattle. In a study of Japanese cows, 59.1% of isolates belonged to G6. Usually, bovine G6 strains were combined with P[5], P[1], and P[11] worldwide. Studies on genotypes of prevalent RV strains are quite important for preventing infection, developing vaccines, and its evaluation. We investigated the characteristics of RV infections of the Nasu district of Tochigi, Japan and to compare to the other region before introduction of rotavirus vaccines.

4 Materials and Methods 　　　We examined the clinical findings in 147 patients who attended to the Department of Pediatrics at International University of Health and Welfare Hospital in Nasu-shiobara City, Tochigi, Japan during the time of April 1, 2008 to March 31, We analyzed the clinical findings of the 37 patients with a fecal sample positive for RV antigen on VP6, NSP4 gene RT-PCR genotyping. Ｖｉｒａｌ ｇｅｎｏｔｙｐｅｓ were determined using rotavirus-positive samples from 27 of these 37 patients. 　　　 　 Nasu-Shiobara Tochigi 対象です。2008年4月1日から2010年3月31日までのあいだに栃木県那須塩原市の国際医療福祉大学病院小児科を受診し、臨床的に急性ウイルス性胃腸炎を疑った147例を対象としました。なお、栃木県那須塩原市は首都圏から約150kmの栃木県北部に位置し、酪農が盛んで生乳の粗生産額が本州では第1位となっております。

5 Results 　 In 37 cases in VP6, NSP4 gene-based RT-PCR 24 samples were positive and the genotypes were determined as G1P [8] in 5 samples, G3P [8] in 5 samples, G9P [8] in 3 samples, and G6P [9] in 2 samples. Of particular note, we detected G6P [9] which were extremely rare in human beings but common in cattle. KF 17 strain of a patient showed G6 type of bovine strains and P [9] was admitted to reconcile with human strains. Per match ratio in each gene of VP6, VP1, VP2, VP3, and NSP4 showed a high match rate ( %) with DS-1 type. Per match ratio in each gene of VP4, NSP1, NSP3, NSP4 and NSP5 also showed a high match rate ( %) with AU-1 type. Bovine type strain gene segments become reassortant rotaviruses major two genes in these stocks.

6 Summary of genotypes of rotavirus A (RVA)
Viral proteins Genotypes Common Genotypes in Human VP G G1, G2, G3, G4, G9, G12 VP P P[4], P[6], P[8] VP I I1, I2 VP R R1, R2 VP C C1, C2 VP M M1, M2 NP A A1, A2 NP N N1, N2 NP T T1, T2 NP E E1, E2 NP H H1, H2

7 遺伝子型別検索結果につき提示します。VP6, NSP4遺伝子に基づくRT-PCRでは23検体が陽性となりました。ウイルス量の少ない検体ではVP6, NSP4陽性でもG,P-typeが決定できませんでした。検体番号10から13は検体番号7の生後1か月の入院患者の両親および祖父母の便検体でした。また、髄液および血液からは検出されませんでした。ダイレクトシークエンスによる遺伝子型別ではG1P[8]IIが5検体、G3P[8]IIが5検体、G9P[8]IIが3検体、G6P[9]Iが2検体と判定されました。赤文字は入院症例です。

8 Phylogenetic trees of the VP7 gene segments of the KF17 strain from Case 24
検体番号24番(KF17株)のVP7遺伝子型の系統解析です。

9 Genomic constellations of G6 P[9] rotavirus (KF17) and prototype strains (Numazaki and Ichikawa, 2014). 検体番号24番(KF17株)と他株との比較のスライドになります。ヒトの株との一致点も多いですがNCDV-Lincoln株、WC3株といったウシの株との一致点も認められました。

10 Phylogenetic analysis of VP7 genes of G6P[9] (M72S11)
Infectious Agents Surveillance Reports IASR Vol. 35 p : 2014

11 Phylogenetic analysis of VP4 genes of G6P[9] (M72S11)
Infectious Agents Surveillance Reports IASR Vol. 35 p : 2014

12 Distribution and genotypes of feline rotaviruses isolated from all FRV-positive Cats Protection Adoption Centers in the United Kingdom during German, AC et al. J. Clin. Microbiol. February 2015 vol. 53 no. 2  Center No. with genotype a Total no. of positives G6P[9] G6P[X] G3P[9] G3P[X] GXP[9] GXP[X] Birmingham 9 4 2 3 18 Bridgend 1 Chelmsford Derby Downham Market Exeter Axhayes Glasgow Haslemere Isle of Wight Mansfield NCAC Nottingham Truro 21 Total FRVs 11 5 17 57 a X indicates G or P rotavirus genotypes that were unable to be elucidated.

13 Molecular Epidemiology of Rotavirus in Cats in the United Kingdom German, AC et al. J. Clin. Microbiol. February 2015 vol. 53 no. 2  Two G and P genotype combinations, G3P[9] and G6P[9], were identified carried by RV circulating in cats population in the United Kingdom in 2012, G3P[9] is a recognized feline genotype (AU-1-like and BA222-like genotype constellations). G6 was the more prevalent genotype (84%) and was detected in Scotland, the Midlands, and Cornwall.  Both G3P[9] and G6P[9] genotypes have been isolated from people in other parts of the globe.  It was strongly suggested that G6P[9] genotypes are examples of zoonotic or anthropozoonotic transmission between cats and people. 

14 Discussion and Conclusion
In the phylogenetic analysis the gene of a strain KF17 of G6P [9] was located in a human lineage including　other human G6 strains. Similarly, all other genes of the strain except for the NSP3 gene were relatively closely　related to at least one of the human G6 RVs reported in Europe and the U.S. In a study in Miyagi Prefecture G6P [9] (M72S11) per sample was found from a 2-year-old toddler in Also G6P [9] have been detected from more than 3 cats of Mie Prefecture. These findings suggest that human G6 RVs which had occurred by reassortment between human and bovine RVs are distributed worldwide, despite low prevalence. G6 RV may occur independently in different areas through reassortment among local strains.