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Koizumi N.,Japan National Institute of Infectious Diseases | Muto M.M.,Japan National Institute of Infectious Diseases | Akachi S.,11 Health | Okano S.,Okinawa Prefectural Institute of Health and Environment | And 5 more authors.
Journal of Medical Microbiology | Year: 2013

Canine leptospirosis, which is caused by infection with pathogenic Leptospira species, occurs worldwide, but information regarding the causative Leptospira serotypes and genotypes and their effects on virulence in dogs remains limited. Monitoring acute leptospirosis in dogs as sentinels can also aid in estimating the risk of human leptospirosis, particularly when the disease is rare, as it currently is in Japan. Among 283 clinically suspected cases of leptospirosis diagnosed from August 2007 to March 2011 in Japan, 83 cases were laboratory diagnosed as leptospirosis by blood culture, a rise in antibody titres in paired sera using a microscopic agglutination test (MAT) and/or DNA detection using flaB-nested PCR. The infected dogs comprised hunting dogs (31 dogs) and companion animals (50 dogs) and two unknown; 63.4% of the infected dogs were males. The mortality rate was 53.2%. A rise of at least fourfold in MAT titre was detected in 30 dogs whose paired serum samples were obtained, and the predominant reactive serogroup was Hebdomadis (53.3 %), followed by Australis (16.7%) and Autumnalis (16.7 %). Leptospira interrogans was isolated from 45 dogs of the following serogroups: Australis (16), Autumnalis (six), Canicola (one), Hebdomadis (21) and Icterohaemorrhagiae (one). All of these serogroups caused lethal infections (57.1-100 %). Genetic heterogeneity was demonstrated in serogroups Australis, Autumnalis and Hebdomadis by multilocus sequence typing (MLST) and/or RFLP analysis based on PFGE. In serogroup Hebdomadis, each genotype determined by MLST had a unique mortality rate in the infected dogs. Although classic canine leptospirosis is associated with serovars Canicola and Icterohaemorrhagiae, serogroup Hebdomadis has become the predominant serogroup causing high mortality in Japan. This study suggests that the virulence of members of serogroup Hebdomadis in dogs may be associated with the genotypes in this serogroup. © 2013 SGM. Source


Inafuku M.,Saga University | Nagao K.,Saga University | Nomura S.,Saga University | Shirouchi B.,Saga University | And 5 more authors.
British Journal of Nutrition | Year: 2012

Non-alcoholic fatty liver disease (NAFLD) is emerging as the most common liver disease in industrialised countries. Various mushrooms have been used in Eastern folk medicine for the treatment of lifestyle diseases. We previously found that the dietary intake of powdered whole Panellus serotinus (Mukitake) alleviates NAFLD in obese, diabetic db/db mice. In the present study, we investigated the influence of Mukitake fractional extracts on the development of NAFLD in db/db mice. A significant reduction in the hepatic TAG content, macrovesicular hepatocytes and activities of key enzymes for de novo synthesis of the fatty acid was observed in both the water-soluble Mukitake extract (WE) diet and the ethanol-soluble Mukitake extract (EE) diet groups compared with the control diet group of the db/db mice. The serum level of monocyte chemoattractant protein-1 (MCP-1), which is known to exacerbate insulin resistance, was significantly decreased in the WE group. On the other hand, the serum level of adiponectin, which plays a protective role against the metabolic syndrome, was significantly increased in the EE group. Additionally, differential analysis between Mukitake and Shiitake, mycelia from the same family, using liquid chromatography time-of-flight MS technology revealed that only seven and five compounds exist in WE and EE from Mukitake, respectively. In conclusion, the present study demonstrated that Mukitake displays at least two different physiological actions that alleviate NAFLD: one through the reduction in inflammatory damage by its suppression in MCP-1 production and the other through an increase in level of serum adiponectin and the prevention of visceral fat accumulation. © The Authors 2011. Source


Yoshikawa T.,Japan National Institute of Infectious Diseases | Shimojima M.,Japan National Institute of Infectious Diseases | Fukushi S.,Japan National Institute of Infectious Diseases | Tani H.,Japan National Institute of Infectious Diseases | And 25 more authors.
Journal of Infectious Diseases | Year: 2015

Background. Severe fever with thrombocytopenia syndrome (SFTS) is a tick-borne acute infectious disease caused by the SFTS virus (SFTSV). SFTS has been reported in China, South Korea, and Japan as a novel Bunyavirus. Although several molecular epidemiology and phylogenetic studies have been performed, the information obtained was limited, because the analyses included no or only a small number of SFTSV strains from Japan. Methods. The nucleotide sequences of 75 SFTSV samples in Japan were newly determined directly from the patients' serum samples. In addition, the sequences of 7 strains isolated in vitro were determined and compared with those in the patients' serum samples. More than 90 strains that were identified in China, 1 strain in South Korea, and 50 strains in Japan were phylogenetically analyzed. Results. The viruses were clustered into 2 clades, which were consistent with the geographic distribution. Three strains identified in Japan were clustered in the Chinese clade, and 4 strains identified in China and 26 in South Korea were clustered in the Japanese clade. Conclusions. Two clades of SFTSV may have evolved separately over time. On rare occasions, the viruses were transmitted overseas to the region in which viruses of the other clade were prevalent. © 2015 The Author 2015. Source


Yoshikawa T.,Japan National Institute of Infectious Diseases | Fukushi S.,Japan National Institute of Infectious Diseases | Tani H.,Japan National Institute of Infectious Diseases | Fukuma A.,Japan National Institute of Infectious Diseases | And 25 more authors.
Journal of Clinical Microbiology | Year: 2014

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease with a high case fatality risk and is caused by the SFTS virus (SFTSV). A retrospective study conducted after the first identification of an SFTS patient in Japan revealed that SFTS is endemic to the region, and the virus exists indigenously in Japan. Since the nucleotide sequence of Japanese SFTSV strains contains considerable differences compared with that of Chinese strains, there is an urgent need to establish a sensitive and specific method capable of detecting the Chinese and Japanese strains of SFTSV. A conventional one-step reverse transcription-PCR (RT-PCR) (cvPCR) method and a quantitative one-step RT-PCR (qPCR) method were developed to detect the SFTSV genome. Both cvPCR and qPCR detected a Chinese SFTSV strain. Forty-one of 108 Japanese patients suspected of having SFTS showed a positive reaction by cvPCR. The results from the samples of 108 Japanese patients determined by the qPCR method were in almost complete agreement with those determined by cvPCR. The analyses of the viral copy number level in the patient blood samples at the acute phase determined by qPCR in association with the patient outcome confirmed that the SFTSV RNA load in the blood of the nonsurviving patients was significantly higher than that of the surviving patients. Therefore, the cvPCR and qPCR methods developed in this study can provide a powerful means for diagnosing SFTS. In addition, the detection of the SFTSV genome level by qPCR in the blood of the patients at the acute phase may serve as an indicator to predict the outcome of SFTS. Copyright © 2014, American Society for Microbiology. All Rights Reserved. Source


Fukuma A.,Japan National Institute of Infectious Diseases | Fukushi S.,Japan National Institute of Infectious Diseases | Yoshikawa T.,Japan National Institute of Infectious Diseases | Tani H.,Japan National Institute of Infectious Diseases | And 19 more authors.
PLoS Neglected Tropical Diseases | Year: 2016

Background: Severe fever with thrombocytopenia syndrome (SFTS) is a tick-borne infectious disease with a high case fatality rate, and is caused by the SFTS virus (SFTSV). SFTS is endemic to China, South Korea, and Japan. The viral RNA level in sera of patients with SFTS is known to be strongly associated with outcomes. Virological SFTS diagnosis with high sensitivity and specificity are required in disease endemic areas. Methodology/Principal Findings: We generated novel monoclonal antibodies (MAbs) against the SFTSV nucleocapsid (N) protein and developed a sandwich antigen (Ag)-capture enzyme-linked immunosorbent assay (ELISA) for the detection of N protein of SFTSV using MAb and polyclonal antibody as capture and detection antibodies, respectively. The Ag-capture system was capable of detecting at least 350–1220 TCID50/100 μl/well from the culture supernatants of various SFTSV strains. The efficacy of the Ag-capture ELISA in SFTS diagnosis was evaluated using serum samples collected from patients suspected of having SFTS in Japan. All 24 serum samples (100%) containing high copy numbers of viral RNA (>105 copies/ml) showed a positive reaction in the Ag-capture ELISA, whereas 12 out of 15 serum samples (80%) containing low copy numbers of viral RNA (<105 copies/ml) showed a negative reaction in the Ag-capture ELISA. Among these Ag-capture ELISA-negative 12 samples, 9 (75%) were positive for IgG antibodies against SFTSV. Conclusions: The newly developed Ag-capture ELISA is useful for SFTS diagnosis in acute phase patients with high levels of viremia. © 2016 Fukuma et al. Source

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