Rare toxin A-negative and toxin B-positive strain of Clostridioides difficile from Japan lacking a complete tcdA gene.

INTRODUCTION: Clostridioides difficile (C. difficile) produces three kinds of toxins: toxin A (enterotoxin), toxin B (cytotoxin), and C. difficile transferase (CDT), a binary toxin. Some strains show positivity only for toxin B. These strains reportedly possess a gene for toxin A, tcdA. However, toxin A production is inhibited due to a mutated stop codon and/or deletion within the tcdA gene. Here for the first case in Japan, we describe toxin genomes and proteins of a strain possessing only toxin B and lacking a complete tcdA gene, along with clinical manifestations. METHODS: C. difficile was isolated from the bloody stool of a 60-year-old female patient treated with meropenem. Although a rapid detection kit of toxins (C. DIFF QUIK CHEK COMPLETE®, TechLab, Blacksburg, VA, USA) showed positivity, Western blotting detected no toxins. Therefore, we explored the strain's toxin genes and their sequences to determine whether the strain possessed a toxin. RESULTS: Polymerase chain reaction did not identify toxin genes. Whole-genome sequencing analysis showed that a gene for toxin A, tcdA, was completely deleted in the strain. Moreover, 701 mutations and some deletions/insertions were identified on the tcdB gene. CONCLUSIONS: We isolated a rare strain of C. difficile producing only toxin B and lacking a complete tcdA gene herein Japan. The possibility of a false negative needs to be considered with a genetic method for a diagnose of C. difficile infection.

Pathogenicity Characterization of Prevalent-Type Streptococcus dysgalactiae subsp. equisimilis Strains.

Streptococcus dysgalactiae subsp. equisimilis (SDSE) is an emerging human pathogen that causes severe invasive streptococcal diseases. Recent reports have shown that SDSE exhibits high pathogenicity with different mechanisms from that of Streptococcus pyogenes, although the two streptococci possess some common virulence factors such as streptolysin, streptokinase, and cell-binding proteins. To date, only a few studies have examined the variety of mechanisms expressing the pathogenicity of SDSE. Among nine SDSE clinical isolates sequenced in this study, we present in vitro and in vivo analyses of KNZ01 and KNZ03, whose emm and multilocus species types (MLSTs) are prevalent in Japan and other countries. For the comparison of pathogenicity, we also utilized the ATCC 12394 strain. The whole-genome analysis showed that KNZ03 and ATCC 12394 are categorized into an identical clonal complex by MLST and are phylogenetically close. However, the three strains exhibited different characteristics for pathogenicity in vitro; ATCC 12394 showed significant cytotoxicity to human keratinocytes and release of streptolysin O (SLO) compared to KNZ01 and KNZ03; KNZ03 exhibited significantly high hemolytic activity, but did not secrete SLO. KNZ01 and KNZ03 adhered to human keratinocytes at a higher rate than ATCC 12394; KNZ03 showed a higher rate of survival after a brief (30 min) incubation with human neutrophils compared to the other two strains; also, KNZ01 grew more rapidly in the presence of human serum. In vivo subcutaneous infection commonly resulted in ulcer formation in the three strains 7 days after infection. KNZ01-infected mice showed significant body weight loss 2 days after infection. Besides, on post-infection day 2, only KNZ01 remained in the cutaneous tissues of mice. Scanning electron microscopy analysis revealed that KNZ01 formed an extracellular structure (biofilm), which was probably composed of cell wall-anchoring proteins, in the presence of glucose and human serum. The extracellular structure of ATCC 12394 was also changed dramatically in response to culture conditions, whereas that of KNZ03 did not. Our study proposed that each SDSE strain possesses different virulence factors characteristics for mediating pathogenicity in humans.

Clinical usefulness of library and information services in Japan: The detailed use and value of information in clinical settings.

OBJECTIVES: Considering that there is a lack of evidence regarding the contribution of library and information services to evidence-based medicine in actual clinical practice in Japan, the purpose of the study is to explore the current status of use and value of library and information services in clinical settings to examine the usefulness of information in implementing evidence-based medicine (EBM) into practice. METHODS: A Web-based survey was conducted at seven sites (hospitals with 300-1,200 beds) and interviews conducted at five sites to investigate information behavior among health professionals (physicians, residents, and nurses) in 2016, replicating the Value Study carried out in the United States in 2010 and 2011. Using a critical incident technique, respondents answered questions about their information topics, information resources used, search location, access points, and evaluation of the information. RESULTS: Analysis from 598 valid responses (275 physicians, 55 residents, and 268 nurses) revealed the characteristics of information use and recognition of the value of information. Physicians and residents showed their information needs regarding clinical care using PubMed (80.4%, 65.5%), Ichushi-Web (61.8%, 63.6%), and UpToDate (40.4%, 65.5%). While physicians rely more on electronic journals (37.8%), residents use more hybrid resources including Japanese print books (38.2%) and online books (30.9% for Japanese, 32.7% for English) to confirm their knowledge. Nurses need more information close to patients and explore a wider variety of information resources such as Japanese print books (60.4%), Ichushi -Web (40.3%), Japanese online books (20.5%), and websites of academic organizations (19.0%). Although the overall recognition of the value of information was relatively modest, concrete changes in clinical practice were found in some areas. Environments with insufficient information and availability of electronic resources should be improved to increase the use of library and information services for implementing EBM.

Fabrication and characterization of an all-solid tellurite-phosphate photonic bandgap fiber.

We present an all-solid tellurite-phosphate photonic bandgap fiber (PBGF) with two layers of high-index rods (TeO2-Li2O-WO3-MoO3-Nb2O5, TLWMN) in the cladding (TeO2-ZnO-Li2O-K2O-Al2O3-P2O5, TZLKAP). TLWMN and TZLKAP glasses have good compatibility for fabricating the all-solid PBGF. Photonic bandgap (PBG) properties are calculated by the plane wave expansion method (PWM), and the results agree well with the measured transmission spectrum. Furthermore, the modal field patterns are measured at ∼1300 and 1520 nm, respectively. The light is confined to the core at ∼1300 nm and lost in the cladding at ∼1520 nm, which match well with the calculated modal field intensities.

International trends in health science librarianship part 11: Japan and Korea.

This is the 11th in a series of articles exploring international trends in health science librarianship. The previous article in this series looked at the Far East (Greater China, Hong Kong and Taiwan). The current issue surveys developments in Japan and Korea. The next issue will explore trends in South Asia (India, Pakistan, Bangladesh and Sri Lanka). Next year all four issues will be devoted to trends in four regions in Africa (Southern Africa, East Africa, West Africa and North Africa.

The role of readability in effective health communication: an experiment using a Japanese health information text on chronic suppurative otitis media.

OBJECTIVES: This study identifies the most significant readability factors and examines ways of improving and evaluating Japanese health information text in terms of ease of reading and understanding. METHODS: Six different Japanese texts were prepared based on an original short text written by a medical doctor for a hospital web site intended for laypersons regarding chronic suppurative otitis media. Four were revised for single readability factor (syntax, vocabulary, or text structure) and two were modified in all three factors. Using a web-based survey, 270 high school students read one of the seven texts, including the original, completed two kinds of comprehension tests, and answered questions on their impressions of the text's readability. RESULTS: Significantly higher comprehension test scores were shown in the true or false test for a mixed text that presented important information first for better text structure. They were also found in the cloze test for a text using common vocabulary and a cohesive mixed text. CONCLUSIONS: Vocabulary could be a critical single readability factor when presumably combined with better text structure. Using multiple evaluation methods can help assess comprehensive readability. The findings on improvement and evaluation methods of readability can be applied to support effective health communication.

Health information seekers in Japan: a snapshot of needs, behavior, and recognition in 2008.

OBJECTIVES: The purpose of this study was to explore the latest information-seeking behavior among health care consumers in Japan and to compare these behaviors with those recorded in similar surveys administered in Japan and the United States after 2000. METHOD: The authors conducted a randomized, population-based, door-to-door survey in 2008. A total of 1,200 Japanese adults over 15 years of age completed the questionnaire. MAIN RESULTS: The results from 1,189 valid responses indicated that slightly more than half the number of participants had actively sought health information during the previous 2 years. Most seekers looked for information on a specific disease. "Physicians" remained the respondents' first choice as an information source, while "Internet" has gained greater popularity as a resource since the previous survey in 2000. Half the number of participants stated that they were willing to read academic or professional medical journal articles if written in Japanese and provided free of charge. CONCLUSION: The evidence indicates that Japanese health care consumers are now proactively seeking health information. These consumers feel reassured by the information they can access and would like to read clinical research in their native language.

Status of open access in the biomedical field in 2005.

OBJECTIVES: This study was designed to document the state of open access (OA) in the biomedical field in 2005. METHODS: PubMed was used to collect bibliographic data on target articles published in 2005. PubMed, Google Scholar, Google, and OAIster were then used to establish the availability of free full text online for these publications. Articles were analyzed by type of OA, country, type of article, impact factor, publisher, and publishing model to provide insight into the current state of OA. RESULTS: Twenty-seven percent of all the articles were accessible as OA articles. More than 70% of the OA articles were provided through journal websites. Mid-rank commercial publishers often provided OA articles in OA journals, while society publishers tended to provide OA articles in the context of a traditional subscription model. The rate of OA articles available from the websites of individual authors or in institutional repositories was quite low. DISCUSSION/CONCLUSIONS: In 2005, OA in the biomedical field was achieved under an umbrella of existing scholarly communication systems. Typically, OA articles were published as part of subscription journals published by scholarly societies. OA journals published by BioMed Central contributed to a small portion of all OA articles.

Purification and biochemical characterization of a membrane-bound [NiFe]-hydrogenase from a hydrogen-oxidizing, lithotrophic bacterium, Hydrogenophaga sp. AH-24.

Membrane-bound [NiFe]-hydrogenase from Hydrogenophaga sp. AH-24 was purified to homogeneity. The molecular weight was estimated as 100+/-10 kDa, consisting of two different subunits (62 and 37 kDa). The optimal pH values for H(2) oxidation and evolution were 8.0 and 4.0, respectively, and the activity ratio (H(2) oxidation/H(2) evolution) was 1.61 x 10(2) at pH 7.0. The optimal temperature was 75 degrees C. The enzyme was quite stable under air atmosphere (the half-life of activity was c. 48 h at 4 degrees C), which should be important to function in the aerobic habitat of the strain. The enzyme showed high thermal stability under anaerobic conditions, which retained full activity for over 5 h at 50 degrees C. The activity increased up to 2.5-fold during incubation at 50 degrees C under H(2). Using methylene blue as an electron acceptor, the kinetic constants of the purified membrane-bound homogenase (MBH) were V(max)=336 U mg(-1), k(cat)=560 s(-1), and k(cat)/K(m)=2.24 x 10(7) M(-1) s(-1). The MBH exhibited prominent electron paramagnetic resonance signals originating from [3Fe-4S](+) and [4Fe-4S](+) clusters. On the other hand, signals originating from Ni of the active center were very weak, as observed in other oxygen-stable hydrogenases from aerobic H(2)-oxidizing bacteria. This is the first report of catalytic and biochemical characterization of the respiratory MBH from Hydrogenophaga.

Isolation and characterization of a new facultatively autotrophic hydrogen-oxidizing Betaproteobacterium, Hydrogenophaga sp. AH-24.

A hydrogen-oxidizing bacterium strain AH-24 was isolated, which was classified in the genus Hydrogenophaga, based on the 16S rRNA gene sequence. The isolate possessed a typical yellow pigment of Hydrogenophaga species. Its closest relative was Hydrogenophaga pseudoflava, but the assimilation profile of sugar compounds resembled that of no species of Hydrogenophaga. The optimum temperature and pH for autotrophic growth were, respectively, 33-35 degrees C and 7.0. Most hydrogenase activity (benzyl viologen reducing activity) was localized in the membrane fraction (MF), but NAD(P)-reducing hydrogenase activity was detected in neither the membrane nor the soluble fractions. Cytochromes b561 and c551 were present in MF; both were reduced when hydrogen was supplied to the oxidized MF, suggesting involvement in respiratory H2 oxidation as electron carriers. Cytochrome b561 was inferred to function as the redox partner of the membrane-bound hydrogenase.

Expression and significance of a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)-1 in an animal model of renal interstitial fibrosis induced by unilateral ureteral obstruction.

To evaluate the pathological roles of a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)-1 in rat renal interstitial fibrosis, we examined the expression, localization and effect on growth of ADAMTS-1 in a normal rat kidney cell line (NRK-49F). Increased ADAMTS-1 mRNA expression was observed in the kidney by in situ hybridization after induction of unilateral ureteral obstruction (UUO) in male Wistar rats, the mRNA was localized in the renal tubular epithelial cells in the outer stripe of the outer medulla in the UUO kidney. On the other hand, no positive signals were observed in the sham-operated-kidney. Western-blot analysis of stable human embryonic kidney 293 (HEK293) transformant cells expressing rat ADAMTS-1 containing the V5 tag using anti-V5 tag monoclonal antibody revealed the presence of two post-translationally processed bands in the cells: an 87-kDa band with a metalloproteinase motif and 65-kDa band with a thrombospondin motifs. On the other hand, secretion of the 65-kDa protein into the culture supernatants from the transformant cells was confirmed. Treatment with the culture supernatant of the transformant cells potently reduced the uptake of 3H-thymidine in the NRK-49F cells, no such inhibitory effect was observed with the culture medium of the HEK293 cells. These results suggest that the UUO-induced expression of ADAMTS-1 in the rat renal tubular epithelial cells may actively contribute to the inhibition of DNA synthesis in the renal interstitial fibroblasts via the 65-kDa moiety with thrombospondin motifs.

Molecular pathological evaluation of clusterin in a rat model of unilateral ureteral obstruction as a possible biomarker of nephrotoxicity.

In the present study, to determine the validity of considering clusterin as a possible biomarker of nephrotoxicity, the expression and distribution of clusterin in the rat UUO kidney were investigated. Real-time RT-PCR revealed an immediate increase in the clusterin mRNA level in the kidney, within 6 hours after UUO, and also maintenance of the mRNA expression level from day-1 to day-3 was 60-fold higher in the UUO kidney than in the sham kidney. ISH analysis revealed clusterin mRNA signals in the UUO renal tubular epithelium, whereas no signal was observed in the sham kidney. Detection of clusterin-alpha and -beta was conducted using the subtype-specific antibodies, by both of western blotting and immunohistochemistry. Although clusterin-alpha was predominant in the UUO urine, only faint signals were noted at the brush border of the tubular epithelium or intraductal. On the other hand, strong signals of clusterin-beta were detected in the UUO kidney homogenate, and the molecule was localized in the renal tubular epithelium. These results suggest that clusterin was translated in the renal tubular epithelium after de novo expression induced by renal injury. Thus, detection of clusterin mRNA and clusterin-beta in the kidney or clusterin-alpha in the urine may be useful for predicting nephrotoxicity.