Pathogen Pollution Research Articles

Design, Synthesis and Fungicidal Activity of N-(5-Phenyl-1,3,4-Thiadiazol-2-yl)-N-((1-Phenyl-1H-1,2,3-Triazol-4-yl) Methyl) Benzamide Derivatives

Objective: Plant pathogens are serious hazards to agricultural production, but existing drugs have problems such as increased resistance of pathogenic bacteria and environmental pollution, and there is a need to find high-efficiency, low-toxicity fungicides with novel chemical structures. Methods: 5-phenyl-1,3,4-thiadiazol-2-amine was used as the starting material, and 20 new thiadiazole-linked compounds were designed and synthesized. Their in vitro inhibitory activities against plant pathogenic fungi were tested using a mycelium growth inhibition assay, and the relationship between the antifungal activity of the target compounds and their molecular structures was preliminarily discussed. Results: Bioassay results revealed that most of the title compounds exhibited excellent in vitro fungicidal activity, in which compound D16 showed the highest activity against Rhizoctonia solani (EC50 = 0.0028 μmol·L−1), D12 against Botrytis cinerea (EC50 = 0.0024 μmol·L−1), and D5 against Stemphylium lycopersici and Curvularia lunata (EC50 = 0.0105 μmol·L−1, 0.005 μmol·L−1). The structure activity relationship (SAR) was also discussed and the results are of great significance for the structural optimization and development of more effective thiadiazole antibacterial compounds. Conclusion: The results of this study are important for structural optimization and development of more potent thiadiazole antimicrobial compounds.

Extreme Weather Events and Pathogen Pollution Fuel Infectious Diseases: The 2024 Flood-Related Leptospirosis Outbreak in Southern Brazil and Other Red Lights

Extreme Weather Events and Pathogen Pollution Fuel Infectious Diseases: The 2024 Flood-Related Leptospirosis Outbreak in Southern Brazil and Other Red Lights

Polyamide microplastics can mitigate the effects of pathogenic bacterium on the health of marine mussels

Vibrio parahaemolyticus and microplastics are prevalent in the ocean. Bacteria attach onto plastic particles, forming harmful biofilms that collectively threaten bivalve health. This study investigates the interaction between polyamide microplastics (PA: particle size 38 ± 12 µm) and V. parahaemolyticus, as well as their combined impact on thick-shelled mussels (Mytilus coruscus). We introduced 1011 CFU/L of V. parahaemolyticus into varying PA concentrations (0, 5, 50, and 500 particles/L) to observe growth over 14 h and biofilm formation after 48 h. Our findings indicate that microplastics suppress biofilm formation and virulence gene expression. Four treatments were established to monitor mussel responses: a control group without PA or V. parahaemolyticus; a group with 50 particles/L PA; a group with 1011 CFU/L V. parahaemolyticus; and a co-exposure group with both 50 particles/L PA and 1011 CFU/L V. parahaemolyticus, over a 14-day experiment. However, combined stress from microplastics and Vibrio led to immune dysregulation in mussels, resulting in intestinal damage and microbiome disruption. Notably, V. parahaemolyticus had a more severe impact on mussels than microplastics alone, yet their coexistence reduced some harmful effects. This study is the first to explore the interaction between microplastics and V. parahaemolyticus, providing important insights for ecological risk assessments.

Rational design of ROS scavenging and fluorescent gold nanoparticles to deliver siRNA to improve plant resistance to Pseudomonas syringae

Bacterial diseases are one of the most common issues that result in crop loss worldwide, and the increasing usage of chemical pesticides has caused the occurrence of resistance in pathogenic bacteria and environmental pollution problems. Nanomaterial mediated gene silencing is starting to display powerful efficiency and environmental friendliness for improving plant disease resistance. However, the internalization of nanomaterials and the physiological mechanisms behind nano-improved plant disease resistance are still rarely understood. We engineered the polyethyleneimine (PEI) functionalized gold nanoparticles (PEI-AuNPs) with fluorescent properties and ROS scavenging activity to act as siRNA delivery platforms. Besides the loading, protection, and delivery of nucleic acid molecules in plant mature leaf cells by PEI-AuNPs, its fluorescent property further enables the traceability of the distribution of the loaded nucleic acid molecules in cells. Additionally, the PEI-AuNPs-based RNAi delivery system successfully mediated the silencing of defense-regulated gene AtWRKY1. Compared to control plants, the silenced plants performed better resistance to Pseudomonas syringae, showing a reduced bacterial number, decreased ROS content, increased antioxidant enzyme activities, and improved chlorophyll fluorescence performance. Our results showed the advantages of AuNP-based RNAi technology in improving plant disease resistance, as well as the potential of plant nanobiotechnology to protect agricultural production.

Allosteric probe-initiated double rolling circle amplification in tandem for sensitive whole-cell detection of E. coli O157:H7

The development of facile, reliable nucleic acid amplification assays for pathogenic bacteria is paramount but still poses a challenge. Here we present a molecular amplification system that integrates the whole-cell recognition of allosteric probes with cascaded rolling circle amplification. Allosteric probe-initiated double rolling circle amplification (AID-RCA) assay involves a three-step process that utilizes allosteric probes, dumbbell templates, and circular templates to recognize, amplify, and detect target bacteria, E. coli O157:H7. The allosteric probes are designed to recognize E. coli O157:H7 without bacterial isolation and nucleic acid extraction. Subsequently, the two-stage in-tandem amplification, that is, dumbbell template-based exponential-rolling circle amplification (DT-RCA) and circular template-based linear-rolling circle amplification (CT-RCA), is initiated and yields powerful fluorescence signals using molecular beacon as a signal probe. The symmetric structure of the dumbbell template endows the AID-RCA assay with good specificity. Cascaded signal amplification boosts its sensitivity. The AID-RCA assay demonstrated high sensitivity in the quantitative detection of E. coli O157:H7(limit of detection 1.6 CFU·mL−1). Compared to real-time PCR, the AID-RCA system exhibited higher sensitivity for low concentrations of E. coli O157:H7. Furthermore, the AID-RCA system can selectively differentiate E. coli O157:H7 from other pathogenic bacteria in complex samples such as drinking water and milk. In a blind validation study using milk samples, the AID-RCA system effectively distinguished between contaminated and pasteurized milk samples. Our method is expected to hold great potential for developing precise, reliable, and efficient analytical platforms to combat pathogenic bacterial pollution and safeguard human health.

Household dog fecal composting: Current issues and future directions.

Dog feces are a known source of nutrient, pathogen, and plastic pollution that can harm human and ecosystem health. Home composting may be a more environmentally sustainable method of managing dog feces and reducing this pollution. While composting is an established method for recycling animal manures into low-risk soil conditioners for food production, few studies have investigated whether household-scale compost methods can safely and effectively process dog feces for use in backyard edible gardens. A broad range of literature on in situ composting of dog feces is evaluated and compared according to scale, parameters tested, and compost methods used. Studies are analyzed based on key identified knowledge gaps: appropriate compost technologies to produce quality soil conditioner on small scales, potential for fecal pathogen disinfection in mesophilic compost conditions, and biodegradation of compostable plastic dog waste bags in home compost systems. This review also discusses how existing methods and quality standards for commercial compost can be adapted to dog fecal home composting. Priorities for future research are investigation of household-scale aerobic compost methods and potential compost amendments needed to effectively decompose dog feces and compostable plastic dog waste bags to produce a good-quality, sanitized, beneficial soil conditioner for use in home gardens. Integr Environ Assess Manag 2024;20:1876-1891. © 2024 The Author(s). Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Spatially limited pathogen pollution in an invasive tick and host system

Expansion of global commerce has facilitated pathogen pollution via the transportation and translocation of invasive species and their associated parasites and pathogens. In Florida, imported cane toads (Rhinella horribilis) were accidentally and intentionally released on multiple occasions. Early populations were found to be infested with the invasive tick, Amblyomma rotundatum, yet it is unknown if these ticks dispersed with their hosts as cane toads spread throughout much of the state. The objectives of our investigation were to (1) determine if there are fewer tick infestations on toads at the periphery than at the core of their distribution as predicted by founder effect events, and (2) identify if ticks were infected with exotic pathogens. We captured toads from 10 populations across Florida. We collected ticks, vent tissue, and tick attachment site tissue from each toad, then tested samples for bacteria in the genus, Rickettsia. We found that 3/10 populations had toads that were infested with A. rotundatum, and infested individuals were in the earliest introduced populations at the core of their distribution. Pathogen testing confirmed Rickettisa bellii in ticks, but not in toad tissues. Haplotype networks could not clearly distinguish if R. bellii in Florida was more closely related to North or South American strains, but host-tick associations suggest that the pathogen was exotic to Florida. Our investigation demonstrated that an invasive species facilitated the introduction of parasites and pathogens into Florida, yet the invasive tick species encountered limitations to dispersal on this host species.

Rapid detection method of bacterial pathogens in surface waters and a new risk indicator for water pathogenic pollution

In this study, a accurate, rapid quantitative PCR method for the simultaneous detection of 4 kinds of pathogenic bacteria in water was established, and the distribution of pathogenic bacteria in surface waters with different levels of pollution (Yulin region, China) was detected. The results showed that the detection accuracy was 94%; the detection limit was 2.7 in bacterial cells. Salmonella enterica subsp. enterica serovar typhimurium and Salmonella dysenteria were always present in water when the universal primer for pathogenic bacteria abundance detection was greater than 104 copies 100 mL−1. When the detection value is lower than 104 copy 100 mL−1, the bacteria in the water are rarely pathogenic bacteria, so the detection value of 104 copy 100 mL−1 can be used as a new indicator of waterborne pathogen pollution.

The role of species ecology in predicting Toxoplasma gondii prevalence in wild and domesticated mammals globally.

Macroecological approaches can provide valuable insight into the epidemiology of globally distributed, multi-host pathogens. Toxoplasma gondii is a protozoan that infects any warm-blooded animal, including humans, in almost every habitat worldwide. Toxoplasma gondii infects its hosts through oocysts in the environment, carnivory of tissue cysts within intermediate host prey and vertical transmission. These routes of infection enable specific predictions regarding the ecological and life history traits that should predispose specific taxa to higher exposure and, thus infection rates of T. gondii. Using T. gondii prevalence data compiled from 485 studies representing 533 free-ranging wild mammalian species, we examined how ecological (habitat type, trophic level) and life history (longevity, vagility, gestation duration and torpor) traits influence T. gondii infection globally. We also compared T. gondii prevalence between wild and domesticated species from the same taxonomic families using data compiled from 540 studies of domestic cattle, sheep, and pigs. Across free-ranging wildlife, we found the average T. gondii prevalence was 22%, which is comparable to the global human estimate. Among ecological guilds, terrestrial species had lower T. gondii prevalence than aquatic species, with freshwater aquatic taxa having an increased prevalence compared to marine aquatic species. Dietary niches were also influential, with carnivores having an increased risk compared to other trophic feeding groups that have reduced tissue cyst exposure in their diet. With respect to influential life history traits, we found that more vagile wildlife species had higher T. gondii infection rates, perhaps because of the higher cumulative risk of infection during movement through areas with varying T. gondii environmental loads. Domestic farmed species had a higher T. gondii prevalence compared to free-ranging confamilial wildlife species. Through a macroecological approach, we determined the relative significance of transmission routes of a generalist pathogen, demonstrating an increased infection risk for aquatic and carnivorous species and highlighting the importance of preventing pathogen pollution into aquatic environments. Toxoplasma gondii is increasingly understood to be primarily an anthropogenically-associated pathogen whose dissemination is enhanced by ecosystem degradation and human subsidisation of free-roaming domestic cats. Adopting an ecosystem restoration approach to reduce one of the world's most common parasites would synergistically contribute to other initiatives in conservation, feline and wildlife welfare, climate change, food security and public health.

Pathogen Pollution: Viral Diseases Associated with Poor Sanitation in Brazil

Brazil faces many types of pollution, including atmospheric CO2 pollution due to Amazon deforestation, pollution by heavy metals, microplastics, pesticides, pathogens, and other classes of environmental contaminants. Pathogen pollution refers to (I) the introduction of a pathogen to a new host species or population and (II) a concept used in the study of pathogenic organisms in water or terrestrial ecosystems. Anthropogenic activities are the leading forces of pathogen pollution in both contexts previously cited. In this Opinion article, we discuss the impacts of pathogen pollution on public health, infectious diseases emergence, and ecosystems using mosquito- and water-borne viral diseases in Brazil as case studies. Finally, we advocate improvements and expansion in sanitation systems, considering sewage treatment and soil waste management, as an umbrella factor to minimize risks and spreading of pathogen pollution in Brazil.

ANCIENT PRACTICE TO MODERN TECHNOLOGY: RIVERBANK FILTRATION (RBF) FOR DRINKING WATER

ABSTRACT This study focuses on applying riverbank filtration (RBF) in Malaysia, aiming to address water quality challenges caused by river water pollution, particularly the presence of harmful pathogens that can lead to waterborne diseases. Malaysia heavily relies on surface water as its primary source of potable water, making it crucial to explore practical and sustainable technologies for water treatment. Riverbank filtration is a promising low-cost, environmentally friendly technology that has shown significant potential in reducing the concentration of harmful bacteria and contaminants in water supplies. However, research into RBF's effectiveness in Malaysia has been limited, warranting further investigation and understanding of its application. The study emphasizes the importance of protecting surface water from contamination and conducting risk assessments of microorganisms in groundwater, particularly in the context of RBF implementation. A thorough understanding of the movement and retention of pathogenic bacteria in the aquifer is vital for optimizing RBF's efficiency and ensuring drinking water safety. Moreover, the study highlights the significance of considering soil properties and characteristics to determine suitable sites for RBF application. By providing valuable insights into RBF's potential benefits and capacity to address water quality issues, this research contributes to the advancement of sustainable water resource management in Malaysia, offering a promising solution for safeguarding public health and water security in the country. KEYWORDS: Riverbank filtration (RBF), drinking water, pathogenic pollutants

Melatonin targets MoIcl1 and works synergistically with fungicide isoprothiolane in rice blast control.

Melatonina natural harmless molecule-displays versatile roles in human health and crop disease control such as for rice blast. Rice blast, caused by the filamentous fungus Magnaporthe oryzae, is one devastating disease of rice. Application of fungicides is one of the major measures in the control of various crop diseases. However, fungicide resistance in the pathogen and relevant environmental pollution are becoming serious problems. By screening for possible synergistic combinations, here, we discovered an eco-friendly combination for rice blast control, melatonin, and the fungicide isoprothiolane. These compounds together exhibited significant synergistic inhibitory effects on vegetative growth, conidial germination, appressorium formation, penetration, and plant infection by M. oryzae. The combination of melatonin and isoprothiolane reduced the effective concentration of isoprothiolane by over 10-fold as well as residual levels of isoprothiolane. Transcriptomics and lipidomics revealed that melatonin and isoprothiolane synergistically interfered with lipid metabolism by regulating many common targets, including the predicted isocitrate lyase-encoding gene MoICL1. Furthermore, using different techniques, we show that melatonin and isoprothiolane interact with MoIcl1. This study demonstrates that melatonin and isoprothiolane function synergistically and can be used to reduce the dosage and residual level of isoprothiolane, potentially contributing to the environment-friendly and sustainable control of crop diseases.

Mechanism of eugenol inhibiting the growth of vegetative cells and spores of Bacillus cereus and its application in rice cakes

Recently, natural active substance has been widely concerned and researched because of its potent effect in the control of foodborne pathogen pollution. In this study, we explored the mechanism of eugenol (EL) against Bacillus cereus (B. cereus) and its spores and the potential of EL in controlling the growth of B. cereus in rice cakes. The results of antibacterial activity showed that EL performed potent antibacterial activity against B. cereus (MIC=0.4 mg/mL, MBC=0.8 mg/mL). EL could increase the permeability of cell membrane, increase the leakage of intracellular protein and disturb the balance of ion exchange within bacteria. Molecular docking and competitive fluorescence experiments revealed that EL interacted with DNA through grooving binding. Under the above multiple effects, the normal metabolic activities within bacteria were severely affected and even leading to death. EL treatment resulted in the decrease of multiple toxin synthesis genes (nheA, nheB, nheC, hblC, hblD, hblA, and cytK) expression levels, and significantly reduced the hemolysis activity of toxins through hydrophobic interactions and hydrogen bonding forces. EL was proved to be effective in inhibiting the growth of B. cereus in rice cakes. The inhibition on spore germination and the improvement of spore thermal sensitivity by EL would also provide a valid method for spore control. This study revealed the antibacterial mechanisms of EL against B. cereus and its spores, and laid a theoretical foundation for expanding its application in the control of foodborne pathogens contamination.

Fungal-Based Remediation in the Treatment of Anthropogenic Activities and Pharmaceutical-Pollutant-Contaminated Wastewater

Pharmaceutical personal care products (PPCPs) have increased in consumption due to the worldwide post-pandemic situation, marking them as chemical and pathogenic pollutants in significantly higher concentrations than ever in the ecosystem. Considering the inexplicable levels of these chemical residues discharged into the environment, concerns have been raised regarding their probable ecotoxicity to marine and terrestrial life. A further concern is the potential for developing and spreading antibiotic-resistant microorganisms and genes in aquatic ecosystems due to antibiotic exposure. Hence, knowing how these compounds impact aquatic ecosystem functioning is imperative, and thus is a critical area of research. The ecological risk analysis of PPCPs in aquatic ecosystems has been carried out using various strategies. Previous studies have reported numerous approaches for eliminating these PPCPs, including conventional treatment methods, activated sludge processes, generated wetlands, biological remediation, sequencing batch reactors, phytoremediation, and membrane bioreactors. In terms of green biotechnology approaches, the current research aims to discover effective procedures for removing PPCPs and their emerging resources as pollutants. Therefore, this review focuses on the over-extensive utilization of PPCPs and their emergent sources responsible for the contamination and environmental threat for future wastewater purposes. Further, as fungi and their enzymes and derivatives can remove pharmaceuticals and personal care products from wastewater through oxidation and several processes, they have attracted the attention of the scientific community due to their ability to remove PPCPs as pollutants and their status as emerging resources in wastewater. This review examines the fundamental approach and progress of the bioremediation of pharmaceutical- and personal-care-contaminated wastewater using fungal-based systems. It also discusses mechanistic approaches through hybridizing cultures and other biological systems with fungal strains, current technologies, and prospects for future research on PPCPs in wastewater treatment.

A novel, efficient and economical alternative for the removal of toxic organic, inorganic and pathogenic water pollutants using GO-modified PU granular composite

Multicomponent wastewater treatment utilising simple and cost-effective materials and methods is an important research topic. This study has reported the fabrication and utilisation of graphene oxide (GO) embedded granular Polyurethane (PU) (GOPU) adsorbent for the treatment of lead ion (Lead ion (Pb(II)), Methylene blue (MB), and E. coli. PU granules were wrapped with GO flakes to improve hydrophilicity, interaction with polluted water, cation-exchange reaction, and binding of pollutants on its surface. Synthesised GOPU granules were characterised by X-Ray Diffraction (XRD), Raman, Fourier transform infrared (FTIR) spectroscopy, and Scanning electron microscopy (SEM) analysis to ensure the successful synthesis of GO and fabrication of GOPU granules. Further, batch and continuous adsorption processes were studied in different operating conditions to evaluate the performance of GOPU granules in practical applications. The kinetic and isotherm analyses revealed that the adsorption of Lead (Pb(II)) ion and Methylene Blue (MB) dye followed the Freundlich and Langmuir isotherm models, respectively, and they showed good agreement with the Pseudo-second-order kinetic model. The adsorption capacities of GOPU granules for the elimination of Pb(II) and MB dye were about 842 mg/g and 899 mg/g, respectively.Additionally, investigations into the fixed bed column revealed that the adsorption column performed best at a flow rate of 5 mL/min and a bed height of 6 cm. Pb(II) adsorption had a bed uptake capacity (qbed) of 88 mg/g and percentage removal efficiency (%R) of 76%. Similarly, MB adsorption had a bed uptake capacity of 202 mg/g and a percentage removal efficiency of 71%. A systematic invention on antibacterial activity toward E. coli showed that The GOPU granules have a removal efficiency of about 100% at an exposure of 24 h. These findings indicated the possible use of GOPU granules as promising adsorbents for various water pollutants.

Assessing relationships between onsite wastewater treatment system maintenance patterns and system-level variables

Globally, millions of households rely on onsite wastewater treatment systems (OWTSs), such as septic systems, to safely treat and dispose of wastewater. Conventional subsurface OWTSs are a common and affordable option for many landowners, and effectively remove pathogenic and nutrient pollution from wastewater when properly sited and maintained. However, OWTSs can also be a source of nonpoint pollution in watersheds when they are not functioning properly. To better understand the drivers of OWTS maintenance and failure, we explored relationships between OWTS age, environmental characteristics (edaphic conditions, topographic wetness index, and distance to stream), and repair and pumping records for OWTSs in Athens-Clarke County, Georgia, USA. Repair records indicated that 7.8 % of the 8826 OWTSs in the study were repaired over a 78-year period and that the median age of a repaired OWTSs was 65 years old. Pumping records showed that 12.2 % of the OWTSs were pumped in a 38-month period (an annualized rate of 5.7 %). The suite of widely available environmental variables we used as predictors were likely not granular enough to detect patterns of individual system maintenance at this scale. However, we found that the oldest OWTSs (>50 years) had the highest probabilities of being repaired and exhibiting signs of hydraulic failure. Notably, new OWTSs (2–10 years) were nearly as likely as the oldest systems to exhibit signs of hydraulic failure. These findings suggest that repair and replacement efforts should target older systems that are at or near the end of their serviceable life, and, in addition to continually monitoring older systems, all OWTSs should be inspected one year after installation. By leveraging data that may already exist, practitioners in other localities can use this reproducible approach to estimate the performance of OWTSs. Our data and methods will support efforts to prioritize wastewater infrastructure investments and policies.

Fluorescent Probe Combined with Photoelectric Analysis Technology for Detection of Escherichia coli.

Food safety is facing great challenges in preventing foodborne diseases caused by pathogenic pollution, especially in resource-limited areas. The rapid detection technique of microorganisms, such as immunological methods and molecular biological methods, plays a crucial key in timely bioanalysis and disease treatment strategies. However, it is difficult for these methods to simultaneously meet the criteria of simple operation, high specificity, and sensitivity, as well as low cost. Coconut water is known as the "water of life" in Hainan. It is a refreshing and nutritious beverage which is widely consumed due to its beneficial properties to health. Coconut water processing is an important pillar industry in Hainan. The detection of pathogenic microorganisms, such as Escherichia coli, in coconut water has become an important factor which has restricted the upgrading and development of this industry. Based on the needs of industrial development, we developed a microbial photoelectric detection system which was composed of a fluorescent probe detection reagent and a photoelectric sensor detection device. This system combined microbial enzyme targets, selective fluorescent substrate metabolism characteristics, and a photoelectric sensor signal transduction mechanism, which produce a strong signal with a high signal-to-noise ratio. The microbial detection system developed here has a simple structure, simple and convenient operation, short detecting time (≥2 h), and high sensitivity (1 CFU/mL). This system may also enable early warning and monitoring programs for other pathogenic microorganisms in order to promote the overall competitiveness of the Hainan coconut water industry.

Current wastewater treatment targets are insufficient to protect surface water quality

The quality of global water resources is increasingly strained by socio-economic developments and climate change, threatening both human livelihoods and ecosystem health. With inadequately managed wastewater being a key driver of deterioration, Sustainable Development Goal (SDG) 6.3 was established to halve the proportion of untreated wastewater discharged to the environment by 2030. Yet, the impact of achieving SDG6.3 on global ambient water quality is unknown. Addressing this knowledge gap, we develop a high-resolution surface water quality model for salinity as indicated by total dissolved solids, organic pollution as indicated by biological oxygen demand and pathogen pollution as indicated by fecal coliform. Our model includes a novel spatially-explicit approach to incorporate wastewater treatment practices, a key determinant of in-stream pollution. We show that achieving SDG6.3 reduces water pollution, but is still insufficient to improve ambient water quality to below key concentration thresholds in several world regions. Particularly in the developing world, reductions in pollutant loadings are locally effective but transmission of pollution from upstream areas still leads to water quality issues downstream. Our results highlight the need to go beyond the SDG-target for wastewater treatment in order to achieve the overarching goal of clean water for all.

Simulation of experimental synthetic DNA tracer transport through the vadose zone

Although multiple experimental studies have proven the use of free synthetic DNA as tracers in hydrological systems, their quantitative fate and transport, especially through the vadose zone, is still not well understood. Here we simulate the water flow and breakthrough of deuterium (D) and one free synthetic DNA tracer from a 10-day experiment conducted in a transient variably saturated 1m3 10° sloped lysimeter using the HYDRUS-2D software package. Recovery and breakthrough flux of D (97.78%) and the DNA tracer (1.05%) were captured well with the advection-dispersion equation (R2 = 0.949, NSE = 0.937) and the Schijven and Šimůnek two-site kinetic sorption model recommended for virus transport modeling (R2 = 0.824, NSE = 0.823), respectively. The degradation of the DNA tracer was very slow (estimated to be 10% in 10 days), because the “loamy sand” porous media in our lysimeter was freshly crushed basaltic tephra (i.e., crushed rocks) and the microbes and DNase that could potentially degrade DNA in regular soils were rare in our “loamy sand”. The timing of the concentration peaks and the HYDRUS-2D simulated temporal and spatial distribution of DNA in the lysimeter both revealed the role of the solid-water-air contact lines in mobilizing and carrying DNA tracer under the experimental variably saturated transient flow condition. The free DNA was nearly non-selectively transported through the porous media, and showed a slightly early breakthrough, possibly due to a slight effect of anion exclusion or size exclusion. Our results indicate that free DNA have the potential to trace vadose zone water flow and solute/contaminant transport, and to serve as surrogates to trace viral pathogen pollution in soil-water systems. To our knowledge, this study is the first to simulate transport mechanisms of free synthetic DNA tracers through real soil textured porous media under variably saturated transient flow condition.

Microbial pollution challenges for the Pharmaceutical Plants in Sikkim, India

Quality is a predominant theme in pharmaceutical production. As the most important raw material used inpharmaceutical industry, water quality remains central to the efforts to build quality in final products.Sikkim, the latest hub of pharmaceutical industries, has water streams the main source of water for them.This study had been undertaken to ascertain the magnitude of pathogenic microbial pollution to whichPharmaceutical industries in Sikkim are exposed to, and the challenges this poses to their water purificationprocess. Our conclusions in this respect are that presence of pathogenic microbes in feed water topharmaceutical country is extremely high. While ranking the water purification process steps using riskpriority number, determined on the basis of expert opinion of quality assurance managers. Missing ofSodium Hypochlorite dosing emerged as the most critical step in this respect, followed by Pipe inducedmicrobial growth and malfunctioning Reverse Osmosis (RO) membrane malfunctioning. Implications forthe quality professionals and regulatory authorities are that the extent of microbial pollution is extremelyhigh and that some steps in purification process are highly critical and validation process should take thisinto consideration.