ABSTRACT
Since the outbreak of the COVID-19 global pandemic in 2019, monitoring COVID-19 infection status and trend through wastewater, known as wastewater-based epidemiology (WBE), has been widely used in many countries and regions. WBE consists of five steps:wastewater sample collection, viral concentration, viral nucleic acid extraction, quantification of virus using quantitative RT-PCR, and dissemination of the wastewater surveillance results. This method could be used for early warning of COVID-19 outbreak in a population, monitoring COVID-19 distributions and epidemic trend, prediction of COVID-19 prevalence rate, understanding of temporal trend of SARS-COV-2 variants, and simultaneous surveillance of multiple pathogens. WBE and clinical surveillance can be used concurrently and the former is a good complement to the latter.
ABSTRACT
Monitoring SARS-CoV-2 in wastewater is a valuable approach to track COVID-19 transmission. Designing wastewater surveillance (WWS) with representative sampling sites and quantifiable results requires knowledge of the sewerage system and virus fate and transport. We developed a multi-level WWS system to track COVID-19 in Atlanta using an adaptive nested sampling strategy. From March 2021 to April 2022, 868 wastewater samples were collected from influent lines to wastewater treatment facilities and upstream community manholes. Variations in SARS-CoV-2 concentrations in influent line samples preceded similar variations in numbers of reported COVID-19 cases in the corresponding catchment areas. Community sites under nested sampling represented mutually-exclusive catchment areas. Community sites with high SARS-CoV-2 detection rates in wastewater covered high COVID-19 incidence areas, and adaptive sampling enabled identification and tracing of COVID-19 hotspots. This study demonstrates how a well-designed WWS provides actionable information including early warning of surges in cases and identification of disease hotspots.
ABSTRACT
SARS-CoV-2 is a respiratory virus but it is also detected in a significant proportion of fecal samples of COVID-19 cases. Recent studies have shown that wastewater surveillance can be a low-cost tool for management of COVID-19 pandemic and tracking COVID-19 outbreaks in communities but most studies have been focusing on sampling from wastewater treatment plants. Institutional level of wastewater surveillance may serve well for early warning purposes since cases can be tracked and immediate action can be executed in the event of positive signal. In this study, a novel Moore swab method was developed and used for wastewater surveillance of COVID-19 at institutional level. Among the 219 swab samples tested, 28 (12.8%) swabs collected from the three campuses and two buildings were positive for SARS-CoV-2. Further individual clinical diagnosis validated the wastewater results and indicated that this method was sensitive enough to detect 1-2 cases in a building. In addition, comparison between grab and Moore swab methods from the hospital sewage line indicated that Moore swab method was more sensitive than the grab sampling method. These results suggest that the Moore swab is a sensitive, practical, and easy to use early warning tool for COVID-19 surveillance especially in low-resource settings and at an early stage of infection in communities.
ABSTRACT
Through studying the process of glycerol fermentation to 1, 3-propanediol(1, 3-PD) by Klebsiella pneumoniae, it was found that the cell growth and product (or by-product) production were under salt stress. Cell growth and product formation kept high rate at low salt concentration. High salt concentration led to low growth of cells, final concentration of 1, 3-PD and conversion from glycerol to 1, 3-PD, and, 1, 3-propanediol oxidoreductase activity decreased. When the salt concentration in 5 m3 bioreactor was controlled under appropriate manner, the concentration of 1, 3-PD production was markedly enhanced. The final 1, 3-PD concentration ,the conversion of glycerol to 1, 3-PD and productivity were 64 g/L, 61% and 2.1 g/(L x h).
Subject(s)
Alcohol Dehydrogenase , Alcohol Oxidoreductases , Metabolism , Culture Media , Culture Techniques , Fermentation , Glycerol , Metabolism , Klebsiella pneumoniae , Metabolism , Physiology , Propylene Glycols , Metabolism , Sodium Chloride , Pharmacology , Stress, PhysiologicalABSTRACT
cDNA microarray was used to compare the gone expression profiles of multiple myeloma cell line RPMI8226 24 h before and after treatment with arsenic trioxide. Two eDNA probes were prepared by mRNA reverse transcription of both arsenic trioxide-treated and untreated RPMI8226 cells. The probes were labeled with Cy3 and Cy5 fluorescence dyes separately, hybridized with cDNA microarray representing 4096 different human genes, and scanned for fluorescence intensity. The differences in gene expression were calculated on the basis of the ratios of signal intensity of treated and untreated samples. The up- and down-regulated genes were screened through the analysis of gene expression ratios. The results showed that 273 genes were differentially altered at mRNA level, 121 genes were up-regulated and 152 were down-regulated. It is concluded that the treatment with arsenic trioxide can induce a variety of gene changes in RPMI8226 cell line. Many genes may be involved in the pathogenesis of multiple myeloma. ALK-1 and TXNIP genes may play an impor- tant role in the apoptosis and partial differentiation of RPMI8226 cells.
ABSTRACT
cDNA microarray was used to compare the gene expression profiles of multiple myeloma cell line RPMI8226 24 h before and after treatment with arsenic trioxide. Two cDNA probes were prepared by mRNA reverse transcription of both arsenic trioxide-treated and untreated RPMI8226 cells. The probes were labeled with Cy3 and Cy5 fluorescence dyes separately, hybridized with cDNA microarray representing 4096 different human genes, and scanned for fluorescence intensity. The differences in gene expression were calculated on the basis of the ratios of signal intensity of treated and untreated samples. The up-and down-regulated genes were screened through the analysis of gene expression ratios. The results showed that 273 genes were differentially altered at mRNA level, 121 genes were up-regulated and 152 were down-regulated. It is concluded that the treatment with arsenic trioxide can induce a variety of gene changes in RPMI8226 cell line. Many genes may be involved in the pathogenesis of multiple myeloma. ALK-1 and TXNIP genes may play an important role in the apoptosis and partial differentiation of RPMI8226 cells.
Subject(s)
Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Arsenicals/pharmacology , Gene Expression Profiling , Multiple Myeloma/genetics , Multiple Myeloma/pathology , Oxides/pharmacology , Tumor Cells, CulturedABSTRACT
OBJECTIVE: To compare the changes of gene expression profiles of multiple myeloma cell line RPMI 8226 before and after 24-hour intervention of arsenic trioxide. METHODS: The responses of the RPMI 8226 cells to arsenic trioxide were determined with cDNA microarray which included 4,096 different human genes. RESULTS: Of these 4,096 genes, the expressions of 273 genes were altered significantly at mRNA level. The expressions of 121 genes were up-regulated while the expressions of 152 genes were down-regulated. CONCLUSION: The effect of arsenic trioxide on RPMI 8226 cells is related to changing the expression levels of a number of genes. ZFYVE16, ALK1 and TXNIP genes may play important roles in apoptosis and differentiation of RPMI 8226 cells.
