scholarly journals Evaluation of electropositive filtration for recovering norovirus in water

2011 ◽  
Vol 9 (1) ◽  
pp. 27-36 ◽  
Author(s):  
Heetae Lee ◽  
Misoon Kim ◽  
Soon-Young Paik ◽  
Chan Hee Lee ◽  
Weon-Hwa Jheong ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Recovery Rate ◽  
Detection Method ◽  
Tween 80 ◽  
Environmental Water ◽  
Murine Norovirus ◽  
Virus Adsorption ◽  
Concentration Methods ◽  
Electropositive Filtration ◽  
Surface And Groundwater

The virus adsorption-elution (VIRADEL) technique has been widely used in the recovery of various enteric viruses in water, and an electropositive filter such as 1 MDS has been commonly applied. However, effective methods of monitoring waterborne norovirus (NoV) have not yet been well characterized and optimized. Hence, in this study, the VIRADEL technique was evaluated and optimized for effectively detecting NoV in water by two commonly used electropositive filters (1MDS and NanoCeram filter). Various elution and concentration methods were evaluated by using both murine norovirus (MNV) and human NoV. Among the tested elution buffers, the most effective was 1.5% beef extract plus 0.01% Tween 80 for both 1MDS (67.5%) and NanoCeram (85.7%) microfilters. The recovery rate of GII-4 human NoV was higher by organic flocculation (86.6%) than by polyethylene glycol (PEG) precipitations (11.6~73.6%). When both 1MDS and NanoCeram filters were tested to detect NoV in surface and groundwater, the sensitivity of NoV recovered by these filters appeared to depend on the types and conditions of environmental water. The results of this study will help to set a standard of detection method for NoV in water.

Evaluation of Various Methods for Recovering Human Norovirus and Murine Norovirus from Vegetables and Ham

2010 ◽  
Vol 73 (9) ◽  
pp. 1651-1657 ◽  
Author(s):  
HYEONJIN PARK ◽  
MINJUNG KIM ◽  
GWANGPYO KO
Keyword(s):  
Molecular Weight ◽  
Polyethylene Glycol ◽  
Hollow Fiber ◽  
Significant Positive Correlation ◽  
Recovery Efficiency ◽  
Murine Norovirus ◽  
Human Norovirus ◽  
Ph Values ◽  
Elution Buffer ◽  
Concentration Methods

We evaluated and optimized each step in an analytical method for detecting norovirus from various foods. We characterized the buffers needed for eluting norovirus from foods such as ham and lettuce. Two different concentration methods, polyethylene glycol (PEG) precipitation and hollow fiber ultrafiltration (HUF), were compared using both murine norovirus (MNV) and human norovirus (HuNoV). For PEG precipitation, an elution buffer containing 3% beef extract (pH 7.1) was more suitable than 0.05 M glycine plus 0.14 M NaCl (pH 7.5), and the recovery efficiency increased with increasing molecular weight of PEG. To determine the optimal buffer for concentrating norovirus by HUF, glycine buffers with different pH values and ionic strengths were examined as elution buffers. Overall, HUF was more efficient for norovirus recovery than was PEG precipitation. Because there was a significant positive correlation between MNV and HuNoV results, MNV could be a useful surrogate for detecting HuNoV in foods.

Determination of Free Polyethylene Glycol in Cross-Linked Sodium Hyaluronate Gel

2014 ◽  
Vol 881-883 ◽  
pp. 918-922
Author(s):  
Yong Liang Zhao ◽  
Tian Tian Meng ◽  
Wei Guo Wang ◽  
Jia Li Wan
Keyword(s):  
Quality Control ◽  
Polyethylene Glycol ◽  
Standard Deviation ◽  
Linear Relationship ◽  
Recovery Rate ◽  
Detection Method ◽  
Sodium Hyaluronate ◽  
Liquid Samples ◽  
Excellent Stability

Abstract: In this study we present a method for the determination of free polyethylene glycol in a gel. We detect the PEG residues of cross-linked sodium hyaluronate gel by spectrophotometry. The pretreatment of cross-linked sodium hyaluronate gel is special and the plot of working curve is unconventional. The precision, the recovery rate with marker, the reliability and repeatability of this method are tested and verified. The results indicated that the method has an excellent linear relationship in the range of 0-40.5µg mL-1. The regression equation is Y=0.0108X+0.2047 (R2=0.9994). The standard deviation of the detection method is 1.10% (n=9). The recovery rate with marker is 97.8% and the repeatability is perfect. In conclusion, the method possesses the properties of simple operation, quickness, excellent stability. Moreover this method can be applied for the quality control of gel products cross-linked by PEG and liquid samples containing PEG.

scholarly journals Polyethylene glycol (PEG) methods are superior to acidification for secondary concentration of Adenovirus and MS2 in water

2021 ◽  
Author(s):  
Nicole Lynn McLellan ◽  
Susan C Weir ◽  
Hung Lee ◽  
Marc B Habash
Keyword(s):  
Polyethylene Glycol ◽  
Plaque Assay ◽  
Human Adenovirus ◽  
Cost Effective ◽  
Viral Pathogens ◽  
Virus Adsorption ◽  
Cost Effective Approach ◽  
Acidic Conditions ◽  
Concentration Methods ◽  
Poor Stability

The most common and cost-effective approach to concentrating viruses from water samples involves virus adsorption and elution procedures, followed by secondary concentration. There is a lack of consistency in how secondary concentration methods are practiced and some methods may have better recovery for particular groups of viruses. Secondary concentration methods typically involve precipitation and the most common methods employ organic flocculation (OF) by acidification at a pH of 3.5, or precipitation by polyethylene glycol (PEG) in combination with NaCl. In this study, the recovery of coliphage MS2 using the plaque assay and human adenovirus strain 41 (HAdV41) using cell-culture and qPCR assays were evaluated by OF and PEG secondary concentration of spiked samples of wastewater, surface water, and groundwater. Recovery of MS2 and HAdV41 by PEG precipitation was significantly higher than OF (p<0.0001) when viruses were detected by culture based methods and marginally better when HAdV41 was enumerated by qPCR (p<0.019). The recovery of HAdV41 by qPCR ranged from 75.3% to 94.4% (n=36). The mean recovery of MS2 by OF was 4.4% (0.9%-7.7%; n=14) and ranged from 57.1% to 87.9% (n=28) for the PEG methods. Poor recovery of MS2 by OF was attributed to inactivation or poor stability at acidic conditions as MS2 were not recovered in the supernatant following OF and centrifugation. The inconsistency and lack of justification for method selection in many studies calls for a systematic study to inform guidance and standardization with respect to the application of concentration methods for various water types and viral pathogens.

Improving Mycobacterium spp. detection in water: a new methodological proposal

2004 ◽  
Vol 4 (2) ◽  
pp. 103-106
Author(s):  
R. Santos ◽  
S. Gonçalves ◽  
F. Macieira ◽  
F. Oliveira ◽  
R. Rodrigues ◽  
...  
Keyword(s):  
Water Samples ◽  
Recovery Rate ◽  
Opportunistic Infections ◽  
Environmental Water ◽  
Environmental Water Samples ◽  
Sample Treatment ◽  
Detection Time ◽  
Fast Detection ◽  
Enrichment Step ◽  
Mycobacterium Spp

In recent years, non-tuberculous mycobacteria (NTM), once considered merely environmental saprophytes, have emerged as a major cause of opportunistic infections. There is no evidence of human-to-human transmission but they have been found in several environmental water samples. It is, therefore, of the utmost importance to develop methods of rapidly and accurately detecting non-tuberculous mycobacteria in water samples. To obtain a maximum recovery rate and a reduction of Mycobacterium spp. detection time in water samples, different decontamination, enrichment procedures and antibiotics supplements were tested before the inoculation into the Bactec® system. The proposed method of sample treatment (decrease in the decontamination time, followed for a peptone pre-enrichment step and an aztreonam and cefepime supplement) before the inoculation into the Bactec® system proved to be a good option for reliable and fast detection of Mycobacterium spp. in water samples.

scholarly journals FORMULATION AND EVALUATION OF ATORVASTATIN CALCIUM NANOCRYSTALS CONTAINING P-GLYCOPROTEIN INHIBITORS FOR ENHANCING ORAL DELIVERY

2021 ◽  
pp. 19-23
Author(s):  
SARAH LABIB ◽  
MOHAMED NASR ◽  
MOHAMED NASR
Keyword(s):  
Polyethylene Glycol ◽  
Oral Drug Delivery ◽  
Tween 80 ◽  
Degree Of Crystallinity ◽  
Oral Drug ◽  
Tween 20 ◽  
Atorvastatin Calcium ◽  
Peg 400 ◽  
P Glycoprotein ◽  
Saturated Solubility

Objective: The main objective of this study was to develop atorvastatin calcium (ATR) as an oral drug delivery system for a P-glycoprotein (P-gp) substrate drug using different pharmaceutical excipients that inhibit P-glycoprotein and evaluate the influence of nanocrystals on the dissolution characteristics and bioavailability compared to the plain drug. Methods: A nanosuspension was prepared by Solvent-antisolvent precipitation method using a solvent containing stabilizer that act as a p-gp inhibitor dissolved in distilled water as polyethylene glycol 300, polyethylene glycol 400 (PEG 300, PEG 400), tween 20 and tween 80 while the solvent selected for atorvastatin calcium was methanol. The concentrations were as follows: PEG 300 and 400 = 0.25% w/v, tween 20 and 80 = 0.75% v/v. Nanocrystals were extracted from the suspension and characterized. Results: Particle size of the drug was 1307±127.79 nm while the formulas prepared ranged from 223±17.67 to 887±58.12 nm. Pure ATR had a saturated solubility of 0.059±0.005 mg/ml and the prepared nanocrystals ranged from 0.32±0.021 to 0.88±0.019 mg/ml. The Percentage of drug released of plain atorvastatin calcium reached 41.49% while the formula ranged from 44.32 to 61.5%. Both XRD and SEM discussed the degree of crystallinity as follows: F1<F2<F4<F3<ATR. Conclusion: 0.3% of PEG 300 and PEG 400 were not enough to formulate proper nanocrystals while 0.75% tween 20 and tween 80 achieved acceptable formulas. F4 which is prepared with tween 80 exhibited the highest enhancement in saturated solubility, dissolution rate and subsequently expected to have improved oral bioavailability.

scholarly journals Recovery and Detection of Enteric Viruses from Non-Traditional Irrigation Water Sources

2019 ◽  
Vol 2 (3) ◽  
pp. 55 ◽  
Author(s):  
Brienna L. Anderson-Coughlin ◽  
Kalmia E. Kniel
Keyword(s):  
Irrigation Water ◽  
Water Samples ◽  
Hepatitis A Virus ◽  
Enteric Viruses ◽  
Environmental Water ◽  
Water Sources ◽  
Aichi Virus ◽  
Water Types ◽  
Virus Adsorption ◽  
Traditional Irrigation

The variability of environmental water samples impacts the allowance of one method to be universally ideal for all water types and volumes. Surface and reclaimed waters can be used for crop irrigation and may be referred to as non-traditional irrigation waters as these water types may be associated with a higher risk of microbial contamination compared to groundwater. These waters are typically more microbially and chemically complex than groundwater and have a higher risk of viral contamination. To detect viruses in these water types, an infinite number of variations can be made to traditional recovery methods. This protocol was developed based on a commonly used virus adsorption and elution (VIRADEL) method. Additional steps were included to simplify and efficiently reduce particulates in the viral concentrate and remove DNA from eluted nucleic acids prior to detection. Method alterations allow for volumes up to 40 liters to be processed with consistent recovery of enteric viruses including Aichi virus, hepatitis A virus, and noroviruses belonging to genogroups GI and GII. No inhibition was observed among either surface or reclaimed water samples. This protocol could be utilized in the monitoring of a wide array of irrigation water sources throughout irrigation processes.

Purification of Hepatitis B Surface Antigen Using Polyethylene Glycol, Pepsin and Tween 80

Vox Sanguinis ◽  
1976 ◽  
Vol 31 (1) ◽  
pp. 84-95
Author(s):  
Nrapendra Nath ◽  
Scott Mazzur ◽  
Robert Ledman ◽  
Chyang T. Fang
Keyword(s):  
Polyethylene Glycol ◽  
Hepatitis B ◽  
Surface Antigen ◽  
Hepatitis B Surface Antigen ◽  
Tween 80

scholarly journals Comparative Recoveries of Naegleria fowleri Amoebae from Seeded River Water by Filtration and Centrifugation

1998 ◽  
Vol 64 (3) ◽  
pp. 955-959 ◽  
Author(s):  
P. Pernin ◽  
M. Pélandakis ◽  
Y. Rouby ◽  
A. Faure ◽  
F. Siclet
Keyword(s):  
Environmental Water ◽  
Most Probable Number ◽  
Naegleria Fowleri ◽  
Probable Number ◽  
Cystic Form ◽  
Low Concentrations ◽  
The Difference ◽  
Nægleria Fowleri ◽  
Concentration Methods ◽  
Amoebic Meningoencephalitis

ABSTRACT Detection of pathogenic Naegleria fowleri in environmental water samples, which is necessary for the prevention of primary amoebic meningoencephalitis, generally requires concentrating the samples. Two concentration techniques, filtration and centrifugation, were used to study the recovery of N. fowleri, in vegetative or cystic form, that had been mixed with the two other thermotolerant Naegleria species, N. lovaniensis and N. australiensis. Counting of amoebae was performed by the most probable number method on 10 water replicates of 100 ml and 10 ml each. With both concentration methods, recovery was better for cysts than for trophozoites (53% ± 21% versus 5% ± 5% by filtration and 57% ± 25% versus 22% ± 5% by centrifugation). The recovery of Naegleria trophozoites by filtration was very low, and centrifugation was significantly better than filtration in recovery of Naegleria trophozoites (22% ± 5% versus 5% ± 5%; P < 0.001). For cysts, however, filtration appeared as efficient as centrifugation, with equivalent values for recovery (53% ± 21% versus 57% ± 25%;P > 0.7). Although the recovery of cysts of N. fowleri obtained by filtration (51% ± 24%) appeared higher than that by centrifugation (36% ± 23%), the difference was not significant (P > 0.1). Both concentration methods have highly variable recovery rates, making accurate quantification of low concentrations (<100/liter) of N. fowleri in the environment difficult.

Comparison of Two Methods for the Recovery of Rotavirus from Mussels and Oysters

1991 ◽  
Vol 24 (2) ◽  
pp. 423-426 ◽  
Author(s):  
S. Boher ◽  
C. Beril ◽  
D. Terver ◽  
L. Schwartzbrod
Keyword(s):  
Polyethylene Glycol ◽  
Borate Buffer ◽  
Cover Slip ◽  
Beef Extract ◽  
Second Procedure ◽  
Virus Recovery ◽  
Concentration Methods ◽  
Polyethylene Glycol 6000

Two extraction-concentration methods for recovering rotavirus from mussels and oysters are compared. Molluscs are artificially contaminated by a one hour stay in seawater seeded with rotavirus SA 11. Results show that the first procedure using a glycine-NaCl pH 10 solution and an organic flocculation gives quite similar virus recovery from mussels and oysters, whatever the quantities of rotavirus in seawater are. The second procedure using a borate buffer - 3 % beef extract pH 9 and a double precipitation with Polyethylene glycol 6000 leads in most cases to a more efficient virus recovery, based on immunofluorescent foci counts on cover slip cultures of MA 104.

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