Changes in bacterial diversity and community structure in drinking water distribution system revealed by high throughput sequencing.

For microbiological management of water quality, it is important to identify bacteria and to understand the community structure. To analyze the community structure during water purification and distribution, we selected a distribution system in which water from other water treatment facilities was not mixed with the target water. Changes in the bacterial community structure during treatment and distribution processes in a slow filtration water treatment facility were analyzed using 16S rRNA gene amplicon sequencing with a portable sequencer MinION.

Microbial Water Quality Assessment of Private Wells Using 16S rRNA Gene Amplicon Sequencing with a Nanopore Sequencer.

Private wells are used daily worldwide as convenient household water sources. In Japan, where water supply coverage is high, well water is occasionally used for non-potable purposes, such as irrigation and watering. Currently, the main microbiological test of well water is designed to detect Escherichia coli, which is an indicator of fecal contamination, using culture methods.

Bacterial bioburden and community structure of potable water used in the International Space Station.

The control of microbes in manned spaceflight is essential to reducing the risk of infection and maintaining crew health. The primary issue is ensuring the safety of a potable water system, where simultaneous monitoring of microbial abundance and community structure is needed. In this paper, we develop a flow cytometry-based counting protocol targeting cellular flavin autofluorescence as a tool for rapid monitoring of bacterial cells in water.

Microbial Monitoring in the International Space Station and Its Application on Earth.

The space habitat is a confined environment with a simple ecosystem that consists mainly of microorganisms and humans. Changes in the pathogenicity and virulence of bacteria, as well as in astronauts' immune systems, during spaceflight may pose potential hazards to crew health. To ensure microbiological safety in the space habitat, a comprehensive analysis of environmental microbiota is needed to understand the overall microbial world in this habitat.

Culture independent approach reveals domination of human-oriented microbes in a pharmaceutical manufacturing facility.

Strict microbial control is required in pharmaceutical manufacturing facilities, for which environmental microbial monitoring is fundamental. Appropriate microbial control is based on understanding the abundance and community structure of the microbes in the target environment, but most microbes are not culturable by conventional methods. Here, we determined the bacterial abundance and assessed the environmental microbiome in a pharmaceutical manufacturing facility using rRNA gene-targeted quantitative PCR (qPCR) and high-throughput sequencing of rRNA gene fragments.

Effects of Asian dust events on atmospheric bacterial communities at different distances downwind of the source region.

Aeolian dust particles arising from arid and semiarid zones are known to carry microbes by air currents. The effect of wind-borne bacteria on atmospheric bacterial population at various downwind distances from the dust source regions must be clarified, but has not yet been reported. This study monitored the bacterial abundance and community composition in outdoor aerosol samples in Beijing, China, which is close to the Asian dust source regions, and compared them with the results obtained in a distant region (Osaka, Japan).

Investigation of bacterial effects of Asian dust events through comparison with seasonal variability in outdoor airborne bacterial community.

Atmospheric bacterial dispersion with aeolian dust has been reported to have a potential impact on public health and ecosystems. Asian dust is a major aeolian event that results in an estimated 4 million tons of Asian dust particles falling in Japan annually, 3,000-5,000 km away from their source regions. However, most studies have only investigated the effects of Asian dust during dust seasons.

Four-year bacterial monitoring in the International Space Station-Japanese Experiment Module "Kibo" with culture-independent approach.

Studies on the relationships between humans and microbes in space habitation environments are critical for success in long-duration space missions, to reduce potential hazards to the crew and the spacecraft infrastructure. We performed microbial monitoring in the Japanese Experiment Module "Kibo", a part of the International Space Station, for 4 years after its completion, and analyzed samples with modern molecular microbiological techniques. Sampling was performed in September 2009, February 2011, and October 2012.

Abundance and Community Structure of Bacteria on Asian Dust Particles Collected in Beijing, China, during the Asian Dust Season.

Approximately 180 t/km(2) of Asian dust particles are estimated to fall annually on Beijing, China, and there is significant concern about the influence of microbes transported by Asian dust events on human health and downwind ecosystems. In this study, we collected Asian dust particles in Beijing, and analyzed the bacterial communities on these particles by culture-independent methods. Bacterial cells on Asian dust particles were visualized first by laser scanning microscopy, which demonstrated that Asian dust particles carry bacterial cells to Beijing.

Distribution and respiratory activity of mycobacteria in household water system of healthy volunteers in Japan.

The primary infectious source of nontuberculous mycobacteria (NTM), which are known as opportunistic pathogens, appears to be environmental exposure, and it is important to reduce the frequency of exposure from environmental sources for preventing NTM infections. In order to achieve this, the distribution and respiratory activity of NTM in the environments must be clarified. In this study, we determined the abundance of mycobacteria and respiratory active mycobacteria in the household water system of healthy volunteers using quantitative PCR and a fluorescent staining method, because household water has been considered as one of the possible infectious sources.

Microbial monitoring of crewed habitats in space-current status and future perspectives.

Previous space research conducted during short-term flight experiments and long-term environmental monitoring on board orbiting space stations suggests that the relationship between humans and microbes is altered in the crewed habitat in space. Both human physiology and microbial communities adapt to spaceflight. Microbial monitoring is critical to crew safety in long-duration space habitation and the sustained operation of life support systems on space transit vehicles, space stations, and surface habitats.

Changes in the airborne bacterial community in outdoor environments following Asian dust events.

Bacterial abundance and community compositions have been examined in aeolian dust in order to clarify their possible impacts on public health and ecosystems. The influence of transcontinentally transported bacterial cells on microbial communities in the outdoor environments of downwind areas should be determined because the rapid influx of a large amount of bacterial cells can disturb indigenous microbial ecosystems. In the present study, we analyzed bacteria in air samples (approximately 100 m(3) d(-1)) that were collected on both Asian dust days and non-Asian dust days over 2 years (between November 2010 and July 2012).

Microchip-based terminal restriction fragment length polymorphism for on-site analysis of bacterial communities in freshwater.

Assessing microbiological quality assurance by monitoring bacteria in various sources of freshwater used for human consumption, recreation, and food preparation is important for a healthy life. Bacterial number and their community structure in freshwater should be determined as quickly as possible, and "real-time" and "on-site" microbiological methods are required. In this study, we examined the protocol for microchip-based terminal restriction fragment length polymorphism (T-RFLP) analysis, which uses microchip electrophoresis for rapid microbial community analysis.

Bacterial monitoring with adhesive sheet in the international space station-"Kibo", the Japanese experiment module.

Microbiological monitoring is important to assure microbiological safety, especially in long-duration space habitation. We have been continuously monitoring the abundance and diversity of bacteria in the International Space Station (ISS)-"Kibo" module to accumulate knowledge on microbes in the ISS. In this study, we used a new sampling device, a microbe-collecting adhesive sheet developed in our laboratory.

Global dispersion of bacterial cells on Asian dust.

The atmospheric dispersion of bacteria over long distances is an important facet of microbial ecology. Certain groups of dispersed bacteria can adapt to their new location and affect established ecosystems. Aeolian dust particles are known to be carriers of microbes but further research is needed to expand our understanding of this field of microbiology.

Break down of asian dust particle on wet surface and their possibilities of cause of respiratory health effects.

Asian dust (called 'Kosa' in Japan) is comprised of a large number of soil particles originating from the arid regions and deserts of China and Mongolia and dispersed long-range to Japan. A major public concern about Asian dust is its impact on human health. We collected Asian dust particles over the Japan Sea at an altitude of 900 m to directly estimate their effects on health.

High prevalence of qnr and aac(6')-Ib-cr genes in both water-borne environmental bacteria and clinical isolates of Citrobacter freundii in China.

We investigated the prevalence of qnr and aac(6')-Ib-cr genes in water-borne environmental bacteria and in clinical isolates of Enterobacteriaceae, as well as the subtypes of qnr. Environmental bacteria were isolated from surface water samples obtained from 10 different locations in Hangzhou City, and clinical isolates of Citrobacter freundii were isolated from several hospitals in four cities in China. qnrA, qnrB, qnrS, and aac(6')-Ib-cr genes were screened using PCR, and the genotypes were analyzed by DNA sequencing.

A ten years (2000-2009) surveillance of resistant Enterobacteriaceae in Zhejiang Province, China.

Objective: In Zhejiang Province, there are several highly developed cities near the coast and several relatively under-developed mountain areas. Analysis of the composition of bacteria isolated from patients as well as their antibiotic resistance profile from various areas of this province, and tracing of such data year-by-year, will help to delineate the bacterial resistance profile of these areas and to understand how the stage of socio-economical development impacts on the composition of clinical micro-flora and their resistance profile.

Methods: In order to investigate variation in resistance rates and isolation rates of Enterobacteriaceae, from 2000 to 2009 in Zhejiang Province, China, Enterobacteriaceae isolated from 15 hospitals located in different regions of the province were surveyed.

Rapid enumeration of respiratory active mycobacteria with fluorescent double staining.

A new method for rapid enumeration of physiologically active mycobacteria was developed by acid-fast bacilli staining (Auramine O) following formazan reduction. Results can be obtained within 90 min by the optimized procedure, while more than one week is required for the widely used culture-dependent approach.