scholarly journals Detection of Helminth Ova in Wastewater Using Recombinase Polymerase Amplification Coupled to Lateral Flow Strips

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 691
Author(s):  
Vivek B. Ravindran ◽  
Basma Khallaf ◽  
Aravind Surapaneni ◽  
Nicholas D. Crosbie ◽  
Sarvesh K. Soni ◽  
...  

Ascaris lumbricoides is a major soil-transmitted helminth that is highly infective to humans. The ova of A. lumbricoides are able to survive wastewater treatment, thus making it an indicator organism for effective water treatment and sanitation. Hence, Ascaris ova must be removed from wastewater matrices for the safe use of recycled water. Current microscopic techniques for identification and enumeration of Ascaris ova are laborious and cumbersome. Polymerase chain reaction (PCR)-based techniques are sensitive and specific, however, major constraints lie in having to transport samples to a centralised laboratory, the requirement for sophisticated instrumentation and skilled personnel. To address this issue, a rapid, highly specific, sensitive, and affordable method for the detection of helminth ova was developed utilising recombinase polymerase amplification (RPA) coupled with lateral flow (LF) strips. In this study, Ascaris suum ova were used to demonstrate the potential use of the RPA-LF assay. The method was faster (< 30 min) with optimal temperature at 37 °C and greater sensitivity than PCR-based approaches with detection as low as 2 femtograms of DNA. Furthermore, ova from two different helminth genera were able to be detected as a multiplex assay using a single lateral flow strip, which could significantly reduce the time and the cost of helminth identification. The RPA-LF system represents an accurate, rapid, and cost-effective technology that could replace the existing detection methods, which are technically challenged and not ideal for on-site detection in wastewater treatment plants.

Plant Disease ◽  
2020 ◽  
Vol 104 (11) ◽  
pp. 2774-2778
Author(s):  
Xinyu Lu ◽  
Ying Zheng ◽  
Fan Zhang ◽  
Jia Yu ◽  
Tingting Dai ◽  
...  

Late blight, caused by the oomycete Phytophthora infestans, is a major constraint on the production of potatoes and tomatoes as well as a constant threat to global food security. An early diagnostic tool is important for the effective management of late blight in the field. Here, in combination with a simplified DNA extraction method, we developed a lateral flow strip-based recombinase polymerase amplification (LF-RPA) assay for the rapid, equipment-free detection of P. infestans. This assay targets the Ras-related protein (Ypt1) gene and can be performed over a wide range of temperatures (25 to 45°C). All 12 P. infestans isolates yielded positive detection results using the LF-RPA assay, and no cross-reaction occurred with related oomycetes or fungal species. With this assay, the detection limit was 500 fg of genomic DNA in optimized conditions. Furthermore, by combining a simplified polyethylene glycol-NaOH method for extracting DNA from plant samples, the entire LF-RPA assay enabled the detection of P. infestans within 30 min with no specialized equipment. When applied to field samples, it successfully detected P. infestans in naturally diseased potato plants from eight different fields in China. Therefore, the LF-RPA assay is simple, rapid, and cost-effective and has potential for further development as a kit for diagnosing late blight in resource-limited settings or even on-site.


mSystems ◽  
2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Pamela Y. Camejo ◽  
Ben O. Oyserman ◽  
Katherine D. McMahon ◽  
Daniel R. Noguera

“CandidatusAccumulibacter phosphatis” is widely found in full-scale wastewater treatment plants, where it has been identified as the key organism for biological removal of phosphorus. Since aeration can account for 50% of the energy use during wastewater treatment, microaerobic conditions for wastewater treatment have emerged as a cost-effective alternative to conventional biological nutrient removal processes. Our report provides strong genomics-based evidence not only that “Ca. Accumulibacter phosphatis” is the main organism contributing to phosphorus removal under microaerobic conditions but also that this organism simultaneously respires nitrate and oxygen in this environment, consequently removing nitrogen and phosphorus from the wastewater. Such activity could be harnessed in innovative designs for cost-effective and energy-efficient optimization of wastewater treatment systems.


Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1414 ◽  
Author(s):  
I-Tae Kim ◽  
Young-Seok Yoo ◽  
Young-Han Yoon ◽  
Ye-Eun Lee ◽  
Jun-Ho Jo ◽  
...  

The development of cost-effective methods, which generate minimal chemical wastewater, for methanol production is an important research goal. In this study, treated wastewater (TWW) was utilized as a culture solution for methanol production by mixed methanotroph species as an alternative to media prepared from commercial or chemical agents, e.g., nitrate mineral salts medium. Furthermore, a realistic alternative for producing methanol in wastewater treatment plants using biogas from anaerobic digestion was proposed. By culturing mixed methanotroph species with nitrate and phosphate-supplemented TWW in municipal wastewater treatment plants, this study demonstrates, for the first time, the application of biogas generated from the sludge digester of municipal wastewater treatment plants. NaCl alone inhibited methanol dehydrogenase and the addition of 40 mM formate as an electron donor increased methanol production to 6.35 mM. These results confirmed that this practical energy production method could enable cost-effective methanol production. As such, methanol produced in wastewater treatment plants can be used as an eco-friendly energy and carbon source for biological denitrification, which can be an alternative to reducing the expenses required for the waste water treatment process.


2020 ◽  
Vol 15 (1) ◽  
pp. 160-169 ◽  
Author(s):  
Yeshi Cao ◽  
M. C. M. Van Loosdrecht ◽  
Glen. T. Daigger

Abstract Since about the 1990s China has achieved remarkable progress in urban sanitation. The country has built very extensive infrastructure for wastewater treatment, with 94.5% treatment coverage in urban areas and legally mandated nation-wide full nutrient removal implemented. However, municipal wastewater treatment plants (WWTPs) in China are still confronted with issues rooted in the unique sewage characteristics. This study compares energy recovery, cost of nutrient removal and sludge production between Chinese municipal WWTPs and those in countries with longer wastewater treatment traditions, and highlights the cause-effect relationships between Chinese sewage characteristics – high inorganic suspended solids (ISS) loads, and low COD and C/N ratio, and municipal WWTP process performance in China. Integrated design and operation guidelines for municipal WWTPs are imperative in relation to the unique sewage characteristics in China. Cost-effective measures and solutions are proposed in the paper, and the potential benefits of improving the sustainability of municipal WWTPs in China are estimated.


2013 ◽  
Vol 68 (7) ◽  
pp. 1440-1453 ◽  
Author(s):  
Peta A. Neale ◽  
Åsa K. Jämting ◽  
Beate I. Escher ◽  
Jan Herrmann

Engineered nanomaterials (ENMs) are increasingly found in a wide range of products and processes, and consequently increasing loads are expected to reach wastewater treatment plants (WWTPs). To better assess the potential risk of ENMs to the environment via input through WWTP effluents, this review considers ENM detection methods, fate in WWTPs and potential effects on biota exposed to wastewater associated ENMs. Characterising ENMs in complex matrices presents many challenges, especially at low concentrations. Combining separation methods with techniques to assess particle size and chemical composition appears to be the most suitable approach for wastewater. In a range of studies, the majority of ENMs are removed from the aqueous phase by flocculation and sedimentation and remain in the sludge. However, ENM surface coating and the presence of organic matter and surfactants can alter removal. ENMs may affect biota via discharge of treated effluent to the aquatic environment or by application of sewage sludge to soil, although observed effects in laboratory studies only occurred at concentrations several orders of magnitude higher than the expected environmental levels. More realistic experimental designs with improved quantification of ENM properties under the selected test conditions are required to better understand the fate and effect of ENMs associated with WWTPs.


2021 ◽  
Vol 12 ◽  
Author(s):  
Jia Xie ◽  
Xiaohan Yang ◽  
Lei Duan ◽  
Keyi Chen ◽  
Pan Liu ◽  
...  

Hand, foot, and mouth disease (HFMD) is a common infectious disease affecting mainly children under 5 years of age. Coxsackievirus A6 (CVA-6), a major causative pathogen of HFMD, has caused outbreaks in recent years. Currently, no effective vaccine or antiviral treatments are available. In this study, one-step reverse-transcription recombinase polymerase amplification (RT-RPA), combined with a disposable lateral flow strip (LFS) assay, was developed to detect CVA-6. This assay can be performed in less than 35 min at 37°C without expensive instruments, and the result can be observed directly with the naked eye. The sensitivity of the RT-RPA-LFS was 10 copies per reaction, which was comparable to that of the conventional real-time quantitative polymerase chain reaction (qPCR) assays. Moreover, the assay specificity was 100%. The clinical performance of the RT-RPA-LFS assay was evaluated using 142 clinical samples, and the coincidence rate between RT-RPA-LFS and qPCR was 100%. Therefore, our RT-RPA-LFS assay provides a simple and rapid approach for point-of-care CVA-6 diagnosis.


Toxins ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 136 ◽  
Author(s):  
Zhilei Zhao ◽  
He Wang ◽  
Wenlei Zhai ◽  
Xiaoyuan Feng ◽  
Xia Fan ◽  
...  

Type-B aflatoxins (AFB1 and AFB2) frequently contaminate food, especially nuts and fried figs, and seriously threaten human health; hence, it is necessary for the newly rapid and sensitive detection methods to prevent the consumption of potentially contaminated food. Here, a lateral flow aptasensor for the detection of type-B aflatoxins was developed. It is based on the use of fluorescent dye Cy5 as a label for the aptamer, and on the competition between type-B aflatoxins and the complementary DNA of the aptamer. This is the first time that the complementary strand of the aptamer has been used as the test line (T-line) to detect type-B aflatoxins. In addition, the truncated aptamer was used to improve the affinity with type-B aflatoxins in our study. Therefore, the lengths of aptamer and cDNA probe were optimized as key parameters for higher sensitivity. In addition, binding buffer and organic solvent were investigated. The results showed that the best pair for achieving improved sensitivity and accuracy in detecting AFB1 was formed by a shorter aptamer (32 bases) coupled with the probe complementary to the AFB1 binding region of the aptamer. Under the optimal experimental conditions, the test strip showed an excellent linear relationship in the range from 0.2 to 20 ng/mL with a limit of detection of 0.16 ng/mL. This aptamer-based strip was successfully applied to the determination of type-B aflatoxins in spiked and commercial peanuts, almonds, and dried figs, and the recoveries of the spiked samples were from 93.3%−112.0%. The aptamer-complementary strand-based lateral flow test strip is a potential alternative tool for the rapid and sensitive detection of type-B aflatoxins in nuts and dried figs. It is of help for monitoring aflatoxins to avoid the consumption of unsafe food.


1990 ◽  
Vol 22 (7-8) ◽  
pp. 145-152 ◽  
Author(s):  
Jan Maarschalkerweerd ◽  
Rory Murphy ◽  
Gail Sakamoto

Pilot and full-scale studies of UV disinfection of wastewater have demonstrated that the process could consistently meet an effluent fecal coliform standard of 200/100 mL or less, depending on suspended solids and UV transmission. Since 1984 over three hundred systems have been installed at municipal wastewater treatment plants in North America. The majority of these are in treatment plants which have been using chlorination. The UV systems have been retrofitted into the existing chlorine contact tanks or existing channels. The capital costs of retrofitting compare favourably to the costs of upgrading chlorination systems, especially when de-chlorination equipment is required. As experience is gained in the operation of these UV systems, their performance has been monitored for their disinfection efficiency and cost of operation. Several installations are examined and their performance and costs analyzed. The evidence to date supports the premise that UV disinfection can meet demands for reliable effluent disinfection in a cost effective manner.


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