High Risk Of Contamination Research Articles

Effectiveness of integrated prophylactic antibiotics prescription in patients undergoing radiofrequency and microwave ablation of liver tumors: a retrospective cohort study

An institutionalised in-house antibiotic prophylaxis (AP) guideline was developed in May 2019 to standardize AP prescription. This retrospective cohort study evaluated the effectiveness and clinical outcomes of the newly launched AP guideline on patients undergoing radiofrequency (RFA) and microwave (MWA) ablation of the liver from November 2018 to March 2020. Patients without high risk of biliary tree contamination were recommended a single dose of 2g IV cefazolin (or 600mg IV clindamycin in cases of beta-lactam allergy). Univariate analysis was conducted to evaluate the clinical outcomes.
 
 The study included 87 patients who underwent 93 procedures consisting of 18 RFAs and 75 MWAs for liver tumours. Concordance with AP guidelines improved significantly (38.5% vs. 87.0%; p<0.001). There were no ablation-related infections and mortality within 30 days post-ablation, and post-procedural nausea and vomiting were significantly reduced (15.4% vs. 1.9%; p=0.020). No significant difference in post-procedural fever (7.7% vs. 5.6%; p-value=0.693), chest and/or abdominal pain (5.1% vs. 7.4%; p=1.000) were noted.
 
 The newly implemented in-house antibiotic prophylaxis guideline streamlined AP prescribing in patients undergoing RFA and MWA. Additional research is needed to determine the effects on infection and mortality in patients with high-risk factors such as bile duct stents, sphincterotomies, and biliary-enteric anastomoses.

Antimicrobial Surface for Devices Used in Stem Culture Manipulation and In Vitro Biofabrication of Tissues.

Cell therapy and engineered tissue creation based on the use of human stem cells involves cell isolation, expansion, and cell growth and differentiation on the scaffolds. Microbial infections dramatically can affect stem cell survival and increase the risk of implant failure. To prevent these events, it is necessary to develop new materials with antibacterial properties for coating scaffold surfaces as well as medical devices, and all other surfaces at high risk of contamination. This chapter describes strategies for obtaining antibacterial blends for coating inert surfaces (polymethylmethacrylate, polycarbonate, Carbon Fiber Reinforced Polymer (CFRP)). In particular, the procedures for preparing antibacterial blends by mixing polymer resins with two types of antibacterial additives and depositing these blends on inert surfaces are described.

Infecção e uso de equipamentos de proteção individual entre trabalhadores da Atenção Primária à Saúde durante a pandemia da COVID-19

Abstract Objective: to analyze the frequency and associated risk factors for COVID-19 infection and the availability of Personal Protective Equipment used by primary healthcare workers. Method: a cross-sectional study was conducted over six months in Rio Grande do Sul. Descriptive analysis was performed, with the comparison of independent samples using Pearson’s Chi-square test and Fisher’s Exact test (p<.05). Results: the study included 206 (27%) healthcare workers who presented COVID-19 symptoms. There was a statistical association for the following variables: availability of surgical masks (p=.003), seeking information on the correct use of personal protective equipment (p=.045), having attended people with flu-like syndrome (p=.024), and believing that the highest risk of contamination is when attending a patient positive for coronavirus disease (p=.001). Conclusion: the availability of personal protective equipment is indispensable for COVID-19 prevention, with special emphasis on the use of surgical masks. Furthermore, the study highlighted the importance of providing Personal Protective Equipment in conjunction with guidance on its use.

Water Safety Practices Along the Water Service Chain in Addis Ababa: A Cross-Sectional Study in a Cosmopolitan City.

This study investigated water safety practices and risk levels along Addis Ababa's water supply service chain. The data came from 23 random woredas, 384 random households, 115 microbiological water quality tests, and diagnostic inspections from source to point of use. Findings from this study indicate that the surface water sources (53%) and the water source catchments (62%) are characterized by very high-risk and high risk contamination levels respectively. Conversely, the water treatment process (5%) and temporary reservoir (20%) indicates a low risk level. Whereas the water distribution system (40%), water source boreholes (44%), and Household level (29%) water safety practices are identified as medium risk levels. The microbial analysis of the drinking water at the source and point of use indicated low (<11 CFU/100 ml) to high levels (>100 CFU/100 ml) of risk with significant levels of contamination at the household level. Moreover, the household-level water safety practice assessment revealed intermediate to very high levels of risks. The Chi2 test shows that water supply type is significantly associated with occupation(X2(12,384) = 23.44, P < .05) and education(X2(8,384) = 15.4, P < .05). Multinomial regression analysis also showed better occupation is associated with increased access to safe bottled water compared to safe piped water on premises. It can be concluded that the water safety practice encountered low to very high levels of risk of contamination at different components along the water supply service chain and the household level. This study suggests ways to improve Addis Ababa residents' health and well-being through water safety interventions. These include safeguarding water sources, supporting local safe water businesses, providing household water treatment, and handling options, and addressing the barriers and incentives for adopting safe water practices.

Urbanization and land use regulate soil vulnerability to antibiotic contamination in urban green spaces

The presence of antibiotics in environment is an emerging concern because of their ubiquitous occurrence, adverse eco-toxicological effects, and promotion of widespread antibiotic resistance. Urban soil, which plays a noticeable role in human health, may be a reservoir of antibiotics because of intensive human disturbance. However, little is understood about the vulnerability of soil to antibiotic contamination in urban areas and the spatial–temporal characteristics of anthropogenic and environmental pressures. In this study, we developed a framework for the dynamic assessment of soil vulnerability to antibiotic contamination in urban green spaces, combining antibiotic release, exposure, and consequence layers. According to the results, soil vulnerability risks shown obvious spatial–temporal variation in urban areas. Areas at a high risk of antibiotic contamination were usually found in urban centers with high population densities and in seasons with low temperature and vegetation coverage. Quinolones (e.g., ofloxacin and norfloxacin) were priority antibiotics that posed the highest vulnerability risks, followed by tetracyclines. We also confirmed the effectiveness of the vulnerability assessment by correlating soil vulnerability indexes and antibiotic residues in urban soils. Furthermore, urbanization- and land use-related parameters were shown to be critical in regulating soil vulnerability to antibiotic contamination based on sensitivity analysis. These findings have important implications for the prediction and mitigation of urban soil contamination with antibiotics and strategies to improve human health.

Microbial and potentially toxic elements risk assessment in high Andean river water based on Monte Carlo simulation, Peru

The study evaluated microbial and Potentially Toxic Elements—PTEs risks in high Andean river water in Peru using Monte Carlo simulation. A total of 144 water samples were collected from four rivers and evaluated for physicochemical parameters, PTEs and bacterial pathogens. The microbial risk analysis for exposure to pathogens present in the water was based on the probability of occurrence of diseases associated with Escherichia coli, Pseudomonas aeruginosa and enterococci. PTEs risk analysis was performed using a Monte Carlo simulation approach. The results showed that the highest microbial risk due to exposure to water contaminated by E. coli, P. aeruginosa and enterococci was recorded in the Miraflores and Chia rivers. Meanwhile, the analysis of carcinogenic and non-carcinogenic risk by PTEs in adults and children revealed that the Chia river presents a high risk of contamination by PTEs, especially the carcinogenic risk for children. The Monte Carlo simulation indicated a 56.16% and 94.85% probability of exceeding the limit value of 0.0001 for carcinogenic risk in adults and children, respectively. It can be concluded that children consuming the waters of the Chia river are potentially at risk of As toxicity.

Toxigenic Escherichia coli with high antibiotic resistance index recovered from sands of recreational beaches of Mumbai, India

Mumbai, India's seven-island city, is known for its sandy beaches as a major tourist attraction, but urbanization and industrialization have weakened the environment. Unregulated sewage disposal and untreated effluents off the coast have made the beach environment vulnerable. Therefore, monitoring water and sand quality at beaches should be mandatory. This study was thus designed to determine the microbiological status of selected sandy beaches, viz. Versova, Juhu, and Girgaon. The study found fecal coliforms in the sand, with stx1 and stx2 genes specific for Shiga toxin-producing E. coli pathotypes in 5.5 % of isolates, whereas the presence of eaeA gene specific for enteropathogenic E. coli pathotype was detected in 12.2 % of isolates, and the presence of the LT and ST genes specific for enterotoxigenic E. coli pathotype was detected in 6.6 % of isolates. Multiple antibiotic-resistant indices indicated high-risk contamination sources. The study suggests routine monitoring of pollution levels at coastal cities' beaches.

A machine learning-based approach to predict groundwater nitrate susceptibility using field measurements and hydrogeological variables in the Nonsan Stream Watershed, South Korea

Identifying and predicting the nitrate inflow and distribution characteristics of groundwater is critical for groundwater contamination control and management in rural mixed-land-use areas. Several groundwater nitrate prediction models have been developed; in particular, a nitrate concentration model that uses dissolved ions in groundwater as an input variable can produce accurate results. However, obtaining sufficient chemical data from a target area remains challenging. We tested whether machine learning models can effectively determine nitrate contamination using field-measured data (pH, electrical conductivity, water temperature, dissolved oxygen, and redox potential) and existing geographic information system (GIS) data (lithology, land cover, and hydrogeological properties) from the Nonsan Stream Watershed in South Korea, an area where nitrate contamination occurs owing to intensive agricultural activities. In total, 183 groundwater samples from different wells, mixed municipal sites, and agricultural activities were used. The results indicated that among the four machine learning models (artificial neural network (ANN), classification and regression tree (CART), random forest (RF), and support vector machine (SVM)), the RF (R2: 0.74; RMSE: 3.5) and SVM (R2: 0.80; RMSE: 2.8) achieved the highest prediction accuracy and smallest error in all groundwater parameter estimates. Land cover, aquifer type, and soil drainage were the primary RF and SVM model input variables, representing agricultural activity-related and hydrogeological infiltration effects. Our research found that in rural areas with limited hydro-chemical data, RF and SVM models could be used to identify areas at high risk of nitrate contamination using spatial variability, GIS-aided visualization, and easily accessible field-measured groundwater quality data.

Challenges for estimating human norovirus infectivity by viability RT-qPCR as compared to replication in human intestinal enteroids

Viability RT-qPCR, a molecular detection method combining viability marker pre-treatment with RT-qPCR, has been proposed to infer infectivity of viruses which is particularly relevant for non-culturable viruses or sophisticated cell culture systems. Being human noroviruses (HuNoV) most frequently associated with foodborne outbreaks, this study compared different viability techniques and infectivity in human intestinal enteroids (HIE) to ultimately determine whether the molecular approaches could serve as rapid assays to predict HuNoV inactivation in high-risk food. To this end, the performance of three viability RT-qPCR assays with different intercalating markers ((Viability PCR Crosslinker Kit (CL), propidium monoazide (PMAxx™), and platinum chloride (PtCl4)) in estimating survival of HuNoV exposed to thermal and high pressure (HPP) treatments was compared to replication tested in the HIE cell culture model. A nearly full-length genomic molecular assay coupled with PMAxx™ to infer HuNoV thermal inactivation was also assessed. The experimental design included HuNoV genogroup I.3 [P13], GII.4 Sydney [P16], GII.6 [P7], along with Tulane virus (TV) serving as surrogate. Finally, viability RT-qPCR was tested in HPP-treated strawberry puree, selected as a food matrix with high viral contamination risk. PMAxx™ and CL performed evenly, while PtCl4 affected HuNoV infectivity. Taking all experimental data together, viability RT-qPCR was demonstrated to be an improved method over direct RT-qPCR to estimate viral inactivation at extreme thermal (95 °C) and HPP (450 MPa) exposures, but not under milder conditions as amplification signals were detected. Despite its complexity and limitations, the HIE demonstrated a more robust model than viability RT-qPCR to assess HuNoV infectivity.

Access to water, sanitation and hygiene (WASH) services and drinking water contamination risk levels in households of Bishoftu Town, Ethiopia: A cross-sectional study.

Access to safe drinking water, sanitation, and hygiene is a fundamental human right and essential to control infectious diseases. However, many countries, including Ethiopia, do not have adequate data to report on basic water, sanitation, and hygiene (WASH) services. Although contaminated drinking water spreads diseases like cholera, diarrhea, typhoid, and dysentery, studies on drinking water contamination risk levels in households are limited in Ethiopia. Therefore, closing this gap needs investigation. A community-based cross-sectional study was conducted. A total of 5350 households were included. A systematic, simple random sampling technique was used to select the participants. The information was gathered through in-person interviews using a standardized questionnaire. Furthermore, 1070 drinking water samples were collected from household water storage. This investigation revealed that 9.8%, 83.9%, and 4.9% of households used limited, basic, and safely managed drinking water services, respectively. Besides, 10.2%, 15.7% and 59.3% of households used safely managed, basic and limited sanitation services, respectively. Yet, 10.6% and 4.2% of households used unimproved sanitation facilities and open defecation practices. Also, 40.5% and 19.4% of households used limited and basic hygiene services. On the other hand, 40.1% of households lacked functional handwashing facilities. In this study, 12.1%, 26.3%, and 42% of households' drinking water samples were positive for Escherichia coli, fecal coliforms, and total coliforms, respectively. Also, 5.1% and 4.5% of households' drinking water samples had very high and high contamination risk levels for E. coli, respectively. We found that 2.5% and 11.5% of households and water distributors had unacceptable fluoride concentrations, respectively. The majority of households in Bishoftu town lack access to safely managed sanitation, drinking water, and basic hygiene services. Many households' water samples had very high and high health risk levels. Hence, the government and partner organizations should implement water and sanitation safety plans.

Study on the Antibacterial Rule in Fermented Feed with Different Amounts of CaCO3 by Quantitative Real-Time Polymerase Chain Reaction

Fermented feed is needed to maintain the vitality of probiotics and cannot be sterilized. Fermented feeds, especially those with added CaCO3, have a high risk of contamination with pathogens. Escherichia coli, Staphylococcus aureus, and Shigella flexneri are the main pathogenic bacteria threatening animal breeding. This study developed a new microbial quantitative real-time PCR analysis method to investigate the antibacterial rule in fermented feed with different amounts of CaCO3. Moreover, using the qPCR method, we found that the feed pH decreased slowly with the increase of CaCO3 addition. In the early stage of fermentation, CaCO3 addition promoted three pathogenic bacteria growth. In the middle and late fermentation, CaCO3 addition inhibited the growth of Escherichia coli and Shigella flexneri, and the greater the CaCO3 addition, the stronger the inhibitory effect. The CaCO3 addition reduced the growth inhibition of Staphylococcus aureus, and the inhibition effect was weaker with the increase of CaCO3 addition. From the inhibitory effect on intestinal pathogenic bacteria such as Escherichia coli and Shigella flexneri, the optimal addition amount of CaCO3 was 12%. At this level of addition, the number of Lactiplantibacillus plantarum subsp. plantarum, Lacticaseibacillus rhamnosus, and Bacillus subtilis were also the highest, and the content of organic acids with antibacterial effects was also the highest. The addition of CaCO3 had an inhibitory effect on the growth of pathogenic bacteria, mainly attributed to the promotion of the growth of Lactiplantibacillus plantarum subsp. plantarum and Lacticaseibacillus rhamnosus, and the organic acid of its fermentation product had an inhibitory effect on pathogenic bacteria. This study provides theoretical guidance for the antibacterial rule of high-pH fermented feed with different amounts of CaCO3.

Data-Sparse Prediction of High-Risk Schools for Lead Contamination in Drinking Water: Examples from Four U.S. States.

Childhood lead exposure through drinking water has long-term effects on cognition and development, and is a significant public health concern. The comprehensive lead testing of public schools entails high expense and time. In prior work, random forest modeling was used successfully to predict the likelihood of lead contamination in the drinking water from schools in the states of California and Massachusetts. In those studies, data from 70% of the schools was used to predict the probability of unsafe water lead levels (WLLs) in the remaining 30%. This study explores how the model predictions degrade, as the training dataset forms a progressively smaller proportion of schools. The size of the training set was varied from 80% to 10% of the total samples in four US states: California, Massachusetts, New York, and New Hampshire. The models were evaluated using the precision-recall area under curve (PR AUC) and area under the receiver operating characteristic curve (ROC AUC). While some states required as few as 10% of the schools to be included in the training set for an acceptable ROC AUC, all four states performed within an acceptable ROC AUC range when at least 50% of the schools were included. The results in New York and New Hampshire were consistent with the prior work that found the most significant predictor in the modeling to be the Euclidean distance to the closest school in the training set demonstrating unsafe WLLs. This study further supports the efficacy of predictive modeling in identifying the schools at a high risk of lead contamination in their drinking water supply, even when the survey data is incomplete on WLLs in all schools.

Prevalence and identification of Corynebacterium pseudotuberculosis in slaughtered sheep in central Algeria

Caseous lymphadenitis, also called abscess disease, is an infectious, cosmopolitan disease. The causative agent is a Gram-positive bacillus, Corynebacterium pseudotuberculosis that is resistant to antibiotic treatment. Humans become infected with this bacillus, but the disease is considered a neglected zoonosis. The objective of this study was to estimate the prevalence and to identify Corynebacterium pseudotuberculosis in sheep slaughtered in central Algeria. For this purpose, 897 animals were examined and samples (pus) were taken from 12 sheep with abscesses to perform bacteriological study. Sex, age, and location of the abscess were noted. The results obtained showed an overall prevalence of 1.33%. The highest rate (50%) was observed in animals aged between 8 months and 1 year. Males were more affected by abscesses (66.7%) than females (33.3%). As for localisation, 41% of abscesses were found in the pulmonary lymph nodes and 25% in the submandibular region. Infection by Corynebacterium was estimated at a rate of 25%, lower than that obtained for Staphylococcus (41.7%). Regarding the zoonotic nature of the disease, the bacteria’s ability to survive in the external environment, and the high risk of contamination, management measures should be implemented for better disease control and prevention.

Campylobacter jejuni Outbreak Linked to Raw Oysters in Rhode Island, 2021

Oysters and other shellfish are not a food that is commonly highlighted as high risk for Campylobacter contamination. The Rhode Island Department of Health (RIDOH) conducted a multiagency investigation of a Campylobacter jejuni outbreak that was linked to the consumption of raw oysters; the first such outbreak was detected in Rhode Island. The environmental investigation identified birds as the likely source of contamination of the aquacultured oysters. As a result of this outbreak response, several investigative processes and best practice recommendations are offered. 1) RIDOH will be including exposure to raw shellfish as a question on their case report forms to better identify future oyster-related Campylobacter clusters. 2) It is important that shellfish aquaculture farms be aware of the risks of using floating gear to hold oyster cages and of the importance of using bird abatement to keep birds off floating aquaculture gear to prevent contamination of oysters from bird feces. 3) It should be recognized that fecal coliform water samples collected near an oyster aquaculture farm may not act as an adequate indicator for the presence of Campylobacter. 4) For the first time, Rhode Island has developed guidelines for the closure and reopening of oyster harvest areas due to contamination with Campylobacter. It is hoped that increased awareness and mitigation of the described risk factors will help prevent future similar outbreaks of illness.

Remote sensing as a key tool for assessing war-induced damage to soil cover in Ukraine (the case study of Kyinska territorial hromada)

&#x0D; &#x0D; &#x0D; The war is damaging one of Ukraine’s main assets its soil resources. Soil takes the brunt of military operations, suffers the most contamination and, as an inert ecosystem com- ponent, can bear the consequences of war for a long time. Thus, the assessment of the degree of soil disturbance and contamination enables us to estimate the consequences of the ecocide carried out by the Russian Federation on the territory of Ukraine. The article presents preliminary research on the impact of the war on the soil cover of arable land in the Kyinska territorial hromada (Chernihiv region), where warfare lasted only a month, but during this short time, they caused irreparable damage to the environment. The study was conducted based on the analysis of high-resolution satellite imagery by Maxar. 4914 craters were identified in the Kyinska hromada, including 2912 craters within arable land, ranging in diameter from 0.5 to 13.8 m. According to the morphometric parameters of the craters, the probable caliber of the ammunition and the volume of soil displaced were estimated, which is 3136 m3. It is proposed to distinguish bombturbation and contamination zones aroundthe craters, which differ in the degree and nature of their impact on the soil. In the bombturbation zone, the soil was redeposited, ejected, displaced, compacted, deformed, and heavily contaminated, whereas in the contamination zone, the soil was mostly physically undisturbed, however, slightly contaminated by explosives, shells, and bomb fragments. The estimated area of both zones was determined to be 44.3 hectares for the bombturbation zone and 386.9 hectares for the contamination zone. Areas of possible soil compaction and deformation due to the maneuvers of heavy military vehicles were identified. Moreover, the issue of the high risk of soil contamination with heavy metals as a result of shells and bombs exploding was considered. The contamination is apparently limited to the contamination zone. Over time, vertical and horizontal migration of heavy metals can lead to secondary risk of contamination with heavy metals. Furthermore, geomorphological hazards can occur on the slopes and at the bottom of craters, leading to engineering complications of the territory, unfavorable physical and chemical processes in the soil, and an expansion of the contamination zone. In accordance with the Methodology set out in the Order of the Ministry of Environmental Protection and Natural Resources of Ukraine No. 167 dated 04.04.2022, the amount of damage from soil contamination of arable land in the Kyinska territorial hromada was calculated at 192.2 million UAH.&#x0D; &#x0D; &#x0D;

Automated production of gene-modified chimeric antigen receptor T cells using the Cocoon Platform

Autologous cell-based therapeutics have gained increasing attention in recent years because of their efficacy at treating diseases with limited therapeutic options. Chimeric antigen receptor (CAR) T-cell therapy has demonstrated clinical success in hematologic oncology indications, providing critically ill patients with a potentially curative therapy. Although engineered cell therapies such as CAR T cells provide new options for patients with unmet needs, the high cost and complexity of manufacturing may hinder clinical and commercial translation. The Cocoon Platform (Lonza, Basel, Switzerland) addresses many challenges, such as high labor demand, process consistency, contamination risks and scalability, by enabling efficient, functionally closed and automated production, whether at clinical or commercial scale. This platform is customizable and easy to use and requires minimal operator interaction, thereby decreasing process variability. We present two processes that demonstrate the Cocoon Platform's capabilities. We employed different T-cell activation methods—OKT3 and CD3/CD28 Dynabeads (Thermo Fisher Scientific, Waltham, MA, USA)—to generate final cellular products that meet the critical quality attributes of a clinical autologous CAR T-cell product. This study demonstrates a manufacturing solution for addressing challenges with manual methods of production and facilitating the scale-up of autologous cell therapy.

Single-cell detection of DMSO promoted HL-60 differentiation toward granulocyte based on DC-iDEP for medicine screening.

The most common form of leukemia in adults is acute leukemia. Drug differentiation control is an extremely critical treatment for acute leukemia. Unfortunately, current techniques detecting differentiation control experience long time and complex steps of verification hindering the pace of medicine discovery: flow cytometry and RT-PCR are highly accurate and efficient at a cost of inconvenient fluorescent labeling or a high risk of contamination; conventional staining leads to cell death unavailable for further pharmacological tests. There is a great interest in developing simple, fast, and non-invasive techniques to screen medicine. DC-iDEP is an emerging label-free identification technique taking advantage of the whole cell native biophysical property for sorting cell populations. Here, HL-60 cell line has been used as a model to study the differentiation process toward granulocytes and medicine efficacy. The results showed that DEP succeeded in detecting the DMSO promoted HL-60 differentiation degree by the weighted average characterization factor. This factor is related to the single cell biophysical property, which accumulates to generate differences in each population with distinct constitutions. Furthermore, cichoric acid was investigated to be capable of promoting DMSO-induced differentiation efficiently. Using the change induced by cichoric acid, the HL-60 medicine screening application has been first attempted based on DEP. A rapid, label-free medicine screening method has been established to monitor HL-60 differentiation toward granulocyte and has great potential for medicine screening.

Omics integration for in-depth understanding of the low-carbon co-culture platform system of Chlorella vulgaris-Escherichia coli

Many fuels and chemicals can be commercially produced by microbial processes to substitute the petrochemical processes. However, the microbial processes suffer from the instability, low efficiency or discontinuous cultures. The continuous culture can greatly increase the productivity and reduce costs for the microbial production. The challenges for the application of continuous culture in industry are high contamination risk and strain degeneration. The co-culture system of photoautotrophs and heterotrophs is probably able to solve bottlenecks of microbial culture. The micro-ecological balance can be achieved for the continuous microbial culture by the co-culture of photoautotrophs and heterotrophs. Here, a system for the co-cultivation of Chlorella vulgaris and Escherichia coli was established for the biosynthesis of isoprene. Compared with axenic culture, the isoprene production in the co-culture process was improved 10-fold to 0.6 g/L and the fermentation was prolonged from 100 h to 350 h. C. vulgaris promoted the isoprene synthesis and E. coli growth, while E. coli restricted C. vulgaris growth. The interactions between E. coli and C. vulgaris were closely associated with oxidative pressure from photomixotrophic metabolism. The consumption of exogenous glucose resulted in excess photomixotrophic electrons and subsequently resultant toxic reactive oxygen species (ROS). The oxidative pressure was reflected by the high activity of intracellular antioxidative (CysK, CysE, SerA, AhpC, AhpF) and repair (YtfE, NfuA, YebG) systems. C. vulgaris might protect E. coli against the oxidative pressure and improve the growth of E. coli through the inter-species cross-feeding. The biosynthesis of cysteine was greatly up-regulated in C. vulgaris to reduce ROS, and the cysteine necessary for antioxidation in E. coli might be provided by C. vulgaris. This study on the co-culture of C. vulgaris and E. coli is significant for revealing the common interactions between photoautotrophs and heterotrophs for the continuous culture.

Deep mining of reported emerging contaminants in China's surface water in the past decade: Exposure, ecological effects and risk assessment.

The identification and management of high-risk contaminants have raised great concern from governments. Facing the growing amount of data on the occurrence of emerging contaminants (ECs) in surface water, a deep mining and quality control strategy was developed to integrate data on all reported ECs in Chinese surface water over the past decade, and an exposure and effect database was further built. In addition, multilevel risk characterization was carried out to prioritize high-risk areas, contaminants and endpoints. A total of 1038 ECs, mainly pharmaceutical and personal care products (PPCPs) and industrial chemicals, were curated, with concentrations ranging from 0.02 pg/L to 533µg/L. For individual risk, all the provinces had acceptable risks except for Henan, which was characterized with a medium chronic risk. Nine ECs, including 4-nonylphenol and estrone, dominated individual risks. Conversely, for multisubstance risk, 76.20% and 73.87% of aquatic organisms were affected acutely and chronically at the national level, with acute and chronic risks exceeding the safety threshold of 5% in 11 and 19 provinces, respectively. Nineteen ECs, including sitosterol and chyfluthrin, dominated the multisubstance risk. In addition, 9 MoAs mainly inducing electron transfer inhibition, neurotoxicity and narcosis toxicity are high-risk endpoints. The study revealed the ecological risk status and key risk entities of Chinese surface waters, which provided the latest data to support the control of ECs in China.

Race, Racism, and Drinking Water Contamination Risk From Oil and Gas Wells in Los Angeles County, 2020.

Objectives. To evaluate the potential for drinking water contamination in Los Angeles (LA) County, California, based on the proximity of supply wells to oil and gas wells, and characterize risk with respect to race/ethnicity and measures of structural racism. Methods. We identified at-risk community water systems (CWSs) as those with supply wells within 1 kilometer of an oil or gas well. We characterized sociodemographics of the populations served by each CWS by using the 2013-2017 American Community Survey. We estimated the degree of redlining in each CWS service area by using 1930s Home Owners' Loan Corporation security maps, and characterized segregation by using the Index of Concentration at the Extremes. Multivariable regression models estimated associations between these variables and CWS contamination risk. Results. A quarter of LA County CWSs serving more than 7 million residents have supply wells within 1 kilometer of an oil or gas well. Higher percentages of Hispanic, Black, and Asian/Pacific Islander residents and a greater degree of redlining and residential segregation were associated with higher contamination risk. Conclusions. Redlining and segregation predict drinking water contamination risks from oil development in LA County, with people of color at greater risk. (Am J Public Health. 2023;113(11):1191-1200. https://doi.org/10.2105/AJPH.2023.307374).