Waterborne diseases due to pathogen contamination in water are a serious problem all over the world. Accurate and simultaneous detection of pathogens in water is important to protect public health. In this study, we developed a method to simultaneously detect various pathogenic Escherichia coli by sequencing the amplicons of multiplex PCR.
View Article and Find Full Text PDFClimate change and anthropogenic activities are affecting the hydrological conditions of rivers and may have altered nutrient and suspended sediments released into coastal seas. However, testing this hypothesis is difficult, confounded by the lack of observational data and the unavailability of globally accepted suspended sediment concentration (SSC) algorithms. Here, we analyzed the trends in SSC (2000-2020) at the mouths of 10 major Asian rivers using 10 available satellite-SSC algorithms.
View Article and Find Full Text PDFThere is a need for developing a simple and easy-to-maintain disinfection technique for sewage treatment for use in developing countries and disaster-affected areas. We propose a novel disinfection technology that inactivates bacteria in wastewater via sunlight irradiation under high salt concentration by mixing with seawater. The disinfection efficiency of the proposed method was quantitatively evaluated and examined using fecal indicator bacteria.
View Article and Find Full Text PDFRotaviruses are the major cause of severe acute diarrhea in infants and young children. Rotaviruses exhibit zoonosis and thereby infect both humans and animals. Viruses detected in urban rivers possibly reflect the presence of circulating viruses in the catchment.
View Article and Find Full Text PDFSci Total Environ
August 2020
The quantification of pathogens is important for assessing water safety and preventing disease outbreaks. Culture-independent approaches, such as quantitative PCR (qPCR) and digital PCR (dPCR), are useful techniques for quantifying pathogens in water samples. However, since pathogens are usually present at low concentrations in water, it is necessary to concentrate microbial cells before extracting their DNA.
View Article and Find Full Text PDFThe lectin family is composed of mono- and oligosaccharide binding proteins that could activate specific cellular activities, such as cell-cell attachment and toxin production. In the present study, the effect of the external addition of lectins to culture media containing the freshwater cyanobacterium Microcystis aeruginosa on its metabolic activities, such as iron uptake and toxin production was investigated. Among the three lectins examined in this study (concanavalin A [Con A], wheat germ agglutinin [WGA] and peanut agglutinin [PNA]), PNA substantially increased the accumulated intracellular and extracellular iron content.
View Article and Find Full Text PDFNumerous bacterial genetic markers are available for the molecular detection of human sources of fecal pollution in environmental waters. However, widespread application is hindered by a lack of knowledge regarding geographical stability, limiting implementation to a small number of well-characterized regions. This study investigates the geographic distribution of five human-associated genetic markers (HF183/BFDrev, HF183/BacR287, BacHum-UCD, BacH, and Lachno2) in municipal wastewaters (raw and treated) from 29 urban and rural wastewater treatment plants (750-4 400 000 population equivalents) from 13 countries spanning six continents.
View Article and Find Full Text PDFWaterborne human enteric viruses, such as noroviruses and adenoviruses, are excreted in the feces of infected individuals and transmitted via the fecal-oral route including contaminated food and water. Since viruses are normally present at low concentrations in aquatic environments, they should be concentrated into smaller volumes prior to downstream molecular biological applications, such as quantitative polymerase chain reaction (qPCR). This review describes recent progress made in the development of concentration and detection methods of human enteric viruses in water, and discusses their applications for providing a better understanding of the prevalence of the viruses in various types of water worldwide.
View Article and Find Full Text PDFHuman activities during recent decades have led to increased degradation of the river water environment in South Asia. This degradation has led to concerns for the populations of the major cities of Nepal, including those of the Kathmandu Valley. The deterioration of the rivers in the valley is directly linked to the prevalence of poor sanitary conditions, as well as the presence of industries that discharge their effluents into the river.
View Article and Find Full Text PDFSewage samples have been investigated to study the norovirus concentrations in sewage or the genotypes of noroviruses circulating in human populations. However, the statistical relationship between the concentration of the virus and the number of infected individuals and the clinical importance of genotypes or strains detected in sewage are unclear. In this study, we carried out both environmental and clinical surveillance of noroviruses for 3 years, 2013 to 2016.
View Article and Find Full Text PDFSelecting the best quantitative PCR assay is essential to detect human norovirus genome effectively from clinical and environmental samples because no cell lines have been developed to propagate this virus. The real-time PCR methods for noroviruses GI (4 assays) and GII (3 assays) were evaluated using wastewater (n = 70) and norovirus-positive stool (n = 77) samples collected in Japan between 2012 and 2013. Standard quantitative PCR assays recommended by the U.
View Article and Find Full Text PDFQuantitative microbial risk assessment (QMRA) is a powerful decision analytics tool, yet it faces challenges when modeling health risks for the indoor environment. One limitation is uncertainty in fomite recovery for evaluating the efficiency of decontamination. Addressing this data gap has become more important as a result of response and recovery from a potential malicious pathogen release.
View Article and Find Full Text PDFIn order to study the epidemiology of human parechovirus (HPeV) infections and to evaluate the feasibility of environmental surveillance, we analyzed 281 stool samples, 265 nasopharyngeal swab samples, and 79 municipal wastewater samples for HPeV. The samples were collected in Miyagi Prefecture, Japan, between April 2012 and March 2014. HPeV was detected by reverse-transcription-PCR targeting the partial 5'-untranslated region and was genotyped by sequencing the capsid VP1 region.
View Article and Find Full Text PDFNorovirus is a leading etiological agent of viral gastroenteritis. Because of relatively mild disease symptoms and frequent asymptomatic infections, information on the ecology of this virus is limited. Our objective was to examine the genetic diversity of norovirus circulating in the human population by means of genotyping the virus in municipal wastewater.
View Article and Find Full Text PDFCurrently in Japan, the only approved influenza vaccine is the inactivated vaccine which is injected subcutaneously. On the other hand, there is a live vaccine available elsewhere in the world. Flumist, an intranasal influenza live vaccine which contains four strains of infectious viruses, has been used in the United States for more than 10 years; the vaccine has been found effective in clinical trials, while it has some limitations such as those on subjects for the administration, strict storage conditions, relatively short expiration date etc.
View Article and Find Full Text PDFRiver water samples were taken from 32 locations around the basin of Chaophraya River and its four major tributaries in Thailand to investigate resistance ratios of Escherichia coli isolates to eight antibiotic agents of amoxicillin, sulfamethoxazole/trimethoprim, tetracycline, doxytetracycline, ciprofloxacin, levofloxacin, norfloxacin and ofloxacin. Principal component analysis was performed to characterize resistance patterns of the samples. Relevancy of the obtained principal components with urban land use and fecal contamination of the river were examined.
View Article and Find Full Text PDFTwo novel G3P[4] rotavirus strains were detected from children with acute diarrhea in Sendai, Japan, identified as a G3-P[4]-I2-R2-C2-M2-A2-N2-T2-E2-H2 genotype constellation by whole-genome sequence analysis. The VP7 gene of the two strains displayed the highest nucleotide sequence identity (91 %) and showed a close genetic relationship (99 % bootstrap value) to an equine rotavirus reported in India. The other gene segments were related to human group A rotaviruses.
View Article and Find Full Text PDFBackground: Water contamination with human enteric viruses has posed human health risks all over the world. Reasonable and facile methodologies for recovering and quantifying infectious enteric viruses in environmental samples are needed to address the issues of waterborne viral infectious diseases. In this study, a bacterial protein that has a binding capability with several enteric viruses is discovered, and its binding characteristics were investigated for utilizing it as a viral adsorbent in virus recovery and detection technologies.
View Article and Find Full Text PDFRecreational outbreaks associated with sprayparks are well recognized, and may be partly due to the engineering designs used for their water reclamation systems are problematic to control. This work is based on an outbreak of cryptosporidiosis linked to a spraypark in New York State, where it was determined, specifically that the spraypad (the main attraction) was the primary exposure point. We first determined the likely dose the spraypad users were exposed to, then modeled the efficacy of the treatment system and used this to inform a Monte Carlo method to estimate the probability of infection and illness for the users of the spraypad.
View Article and Find Full Text PDFThe kinetics of ligand exchange between ferric citrate and desferrioxamine B (DFB) was investigated at pH 8.0 and high citrate/Fe molar ratios (500-5000) with particular attention given to understanding the precise mechanism of ligand exchange. Ferric citrate complexes present in a test solution and therefore involved in the reaction with the incoming ligand (DFB) were initially examined by evaluating ferric citrate speciation on the basis of published thermodynamic constants.
View Article and Find Full Text PDFNine approaches to recover viral RNA from environmental silty sediments were newly developed and compared to quantify RNA viruses in sediments using molecular methods. Four of the nine approaches employed direct procedures for extracting RNA from sediments (direct methods), and the remaining five approaches used indirect methods wherein viral particles were recovered before RNA extraction. A direct method using an SDS buffer with EDTA to lyse viral capsids in sediments, phenol-chloroform-isoamyl alcohol to extract RNA, isopropanol to concentrate RNA, and magnetic beads to purify RNA resulted in the highest rate of recovery (geometric mean of 11%, with a geometric standard deviation of 0.
View Article and Find Full Text PDFThe excess growth of cyanobacteria in semi enclosed water areas caused by eutrophication brings about coagulation inhibition in drinking water treatment processes. In this study, coagulation inhibitor proteins produced by Microcystis aeruginosa, a major cyanobacterium in algal bloom, were acquired by a phage display technique, an aluminum-immobilized affinity chromatography and a protein expression technique using Escherichia coli cells. Two cyanobacterial peptides with a high ratio of metallophilic amino acids were recovered, which were a part of homologues of a thiol oxidase enzyme Ero1p and a trans-acting repressor ArsR.
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