No single microbial source tracking (MST) marker can be applied to determine the sources of fecal pollution in all water types. This study aimed to validate a high-throughput quantitative polymerase chain reaction (HT-qPCR) method for the simultaneous detection of multiple MST markers. A total of 26 fecal-source samples that had been previously collected from human sewage (n = 6) and ruminant (n = 3), dog (n = 6), pig (n = 6), chicken (n = 3), and duck (n = 2) feces in the Kathmandu Valley, Nepal, were used to validate 10 host-specific MST markers, i.
View Article and Find Full Text PDFCryoconite is a granular structure present on the glaciers and ice sheets found in polar regions including the Himalayas. It is composed of organic and inorganic matter which absorb solar radiations and reduce ice surface albedo, therefore impacting the melting and retreat of glaciers. Though climate warming has a serious impact on Himalayan glaciers, the biodiversity of sub-glacier ecosystems is poorly understood.
View Article and Find Full Text PDFRecent studies have highlighted the presence of antibiotic resistance genes (ARGs) in Antarctica, which are typically indicative of human activity. However, these studies have concentrated in the Antarctic Peninsula region, and relatively less is known about ARG prevalence in East Antarctica, where human activity levels are lower compared to the Antarctic Peninsula. In addition, the mechanisms of ARG transmission to Antarctica through natural or anthropogenic pathways remain unclear.
View Article and Find Full Text PDFThe brown bear () is one of the survivors of the Late Quaternary megafauna extinctions. However, despite being widely distributed across the Holarctic, brown bears have experienced extensive range reductions, and even extirpations in some geographical regions. Previous research efforts using genetic data have provided valuable insights into their evolutionary history.
View Article and Find Full Text PDFBackground: Gorham-Stout disease (GSD) is a form of lymphangiomatosis of unknown etiology, characterized by abnormal distribution of lymphatic vessels. Platelets and lymphangiogenesis are closely related via C-type lectin-like receptor 2 (CLEC-2)/podoplanin.
Key Clinical Question: Despite similarities between abnormal lymphatic vessels in CLEC-2-deficient mice and patients with GSD, whether CLEC-2 on platelets is involved in GSD pathogenesis is unknown.
Recent studies of microbial biogeography have revealed the global distribution of cosmopolitans and dispersal of regional endemics, but little is known about how these processes are affected by microbial evolution. Here, we compared DNA sequences from snow/glacier algae found in an 8000-year-old ice from a glacier in central Asia with those from modern snow samples collected at 34 snow samples from globally distributed sites at the poles and mid-latitudes, to determine the evolutionary relationship between cosmopolitan and endemic phylotypes of snow algae. We further applied a coalescent theory-based demographic model to the DNA sequences.
View Article and Find Full Text PDFVariants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are continuously emerging, highlighting the importance of regular surveillance of SARS-CoV-2 and other epidemiologically significant pathogenic viruses in the current context. Reverse transcription-quantitative PCR (RT-qPCR) is expensive, time-consuming, labor-intensive, requires a large reagent volume, and only tests a few targets in a single run. High-throughput qPCR (HT-qPCR) utilizing the Biomark HD system (Fluidigm) can be used as an alternative.
View Article and Find Full Text PDFExtranodal NK/T-cell lymphoma, nasal type (ENKTL) is an Epstein-Barr virus-positive, aggressive lymphoma with a heterogeneous cell of origin and variable clinical course. Several clinical prognostic indices have been proposed for ENKTL; however, there are few pathological biomarkers. This multi-institutional study sought to identify histologically assessable prognostic factors.
View Article and Find Full Text PDFLittle is known about the spatiotemporal dynamics of gray wolves in the Pleistocene across low-latitude regions of Eurasia. In Japan, a small-bodied endemic subspecies of Japanese wolves existed and went extinct in the early 1900s. The fossil record indicates that a giant wolf, which reached 70 cm in body height, inhabited Japan during the Pleistocene, but its evolutionary relationship, if any, with the Japanese wolf remains uncertain.
View Article and Find Full Text PDFMigratory geese could influence the microbiological water quality; however, their impacts on pathogen dynamics remain largely unknown. In this study, we analyzed the population dynamics of Campylobacter and Arcobacter group bacteria (AGB) in a freshwater lake in Japan over two years. The bacteria were quantified by using both culture-dependent and -independent methods.
View Article and Find Full Text PDFBackground: Cryoconite granules are mineral-microbial aggregates found on glacier surfaces worldwide and are hotspots of biogeochemical reactions in glacier ecosystems. However, despite their importance within glacier ecosystems, the geographical diversity of taxonomic assemblages and metabolic potential of cryoconite communities around the globe remain unclear. In particular, the genomic content of cryoconite communities on Asia's high mountain glaciers, which represent a substantial portion of Earth's ice masses, has rarely been reported.
View Article and Find Full Text PDFAims: In-situ follicular neoplasia (ISFN) is a histologically recognizable neoplastic proliferation of follicular lymphoma (FL)-like B cells confined to the germinal centres. While some ISFNs are associated with overt FL, others are incidentally identified as isolated or pure forms in individuals without evidence of overt FL. The prevalence of incidentally found isolated ISFN is approximately 3% in Europe; however, no screening study has been conducted in Asia.
View Article and Find Full Text PDFLittle is known about how mammalian biogeography on islands was affected by sea-level fluctuations. In the Japanese Archipelago, brown bears () currently inhabit only Hokkaido, the northern island, but Pleistocene fossils indicate a past distribution throughout Honshu, Japan's largest island. However, the difficulty of recovering ancient DNA from fossils in temperate East Asia has limited our understanding of their evolutionary history.
View Article and Find Full Text PDFBackground And Purpose: Glaucoma, the leading cause of blindness, damages the retinal ganglion cells. Elevated intraocular pressure (IOP) is a high-risk factor for glaucoma, so topical hypotensive drugs are usually used for treatment. Because not all patients do not respond adequately to current treatments, there is a need to identify a new molecular target to reduce IOP.
View Article and Find Full Text PDFSnow algae are photosynthetic microbes that inhabit the melting snow surface in alpine and polar regions. We analyzed the pigment and species composition of colored snow collected on Mt. Tateyama in Japan during the melting seasons of 2015 and 2016.
View Article and Find Full Text PDFCryoconite granules are naturally occurring microbial structures on glacier surfaces worldwide. They play a key role in carbon and nitrogen cycling in glacier ecosystems and can accelerate the melting of snow and ice. However, detailed mechanism of nitrogen cycling in cryoconite granules remains unclear.
View Article and Find Full Text PDFLiu et al. reported the cultivation and DNA sequencing of 69 fungal isolates (Ascomycota and Basidiomycota) from ancient subseafloor sediments, suggesting that they represent living fungal populations that have persisted for over 20 million years. Because these findings could bring about a paradigm shift in our understanding of the spatial breadth of the deep subsurface biosphere as well as the longevity of ancient DNA, it is extremely important to verify that their samples represent pure ancient fungi from 20 million years ago without contamination by modern species.
View Article and Find Full Text PDFDespite the essential role of in health-promoting gut bacteria in humans, little is known about their functions in wild animals, especially non-human primates. It is difficult to determine in vivo the function of Bifidobacterium in wild animals due to the limited accessibility of studying target animals in natural conditions. However, the genomic characteristics of obtained from the feces of wild animals can provide insight into their functionality in the gut.
View Article and Find Full Text PDFClostridium tagluense strain A121 was isolated from a permafrost core in the Canadian High Arctic. This endospore-forming strain is a strictly anaerobic, Gram-positive, and psychrotolerant bacterium. This article describes the draft genome sequence of C.
View Article and Find Full Text PDFCurrent approach to identify sources of human pathogens is largely dependent on the cultivation and isolation of target bacteria. For rapid pathogen source identification, culture-independent strain typing method is necessary. In this study, we designed new primer set that broadly covers short variable region (SVR) of various species, and applied the SVR sequencing method to examine the diversity of spp.
View Article and Find Full Text PDFThe glacier stonefly Andiperla willinki is the largest metazoan inhabiting the Patagonian glaciers. In this study, we analysed the gut microbiome of the aquatic nymphs by 16S rRNA gene amplicon and metagenomic sequencing. The bacterial gut community was consistently dominated by taxa typical of animal digestive tracts, such as Dysgonomonadaceae and Lachnospiraceae, as well as those generally indigenous to glacier environments, such as Polaromonas.
View Article and Find Full Text PDFRed-snow algae are red-pigmented unicellular algae that appear seasonally on the surface of thawing snow worldwide. Here, we analyse the distribution patterns of snow algae sampled from glaciers and snow patches in the Arctic and Antarctica based on nuclear ITS2 sequences, which evolve rapidly. The number of phylotypes is limited in both polar regions, and most are specific to either the Arctic or Antarctica.
View Article and Find Full Text PDFDetection and genotyping of pathogenic RNA viruses in human and environmental samples are useful for monitoring the circulation and prevalence of these pathogens, whereas a conventional PCR assay followed by Sanger sequencing is time-consuming and laborious. The present study aimed to develop a high-throughput detection-and-genotyping tool for 11 human RNA viruses [Aichi virus; astrovirus; enterovirus; norovirus genogroup I (GI), GII, and GIV; hepatitis A virus; hepatitis E virus; rotavirus; sapovirus; and human parechovirus] using a microfluidic device and next-generation sequencer. Microfluidic nested PCR was carried out on a 48.
View Article and Find Full Text PDFAlthough nitric oxide (NO) emissions from anaerobic ammonium oxidation (anammox)-based processes were reported previously, the NO production pathways are poorly understood. Here, we investigated the NO production pathways in anammox granules in detail by combining N-stable isotope tracer experiments with various inhibitors, microsensor measurements, and transcriptome analysis for key genes of NO reduction. NO was emitted from the anammox granules, which account for 0.
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