Parameters Affecting Spore Recovery from Wipes Used in Biological Surface Sampling

ABSTRACTThe need for the precise and reliable collection of potential biothreat contaminants has motivated research in developing a better understanding of the variability in biological surface sampling methods. In this context, the objective of this work was to determine parameters affecting the efficiency of extractingBacillus anthracisSterne spores from commonly used wipe sampling materials and to describe performance using the interfacial energy concept. In addition, surface thermodynamics was applied to understand and predict surface sampling performance. Wipe materials were directly inoculated with known concentrations ofB. anthracisspores and placed into extraction solutions, followed by sonication or vortexing. Experimental factors investigated included wipe material (polyester, cotton, and polyester-rayon), extraction solution (sterile deionized water [H2O], deionized water with 0.04% Tween 80 [H2O-T], phosphate-buffered saline [PBS], and PBS with 0.04% Tween 80 [PBST]), and physical dissociation method (vortexing or sonication). The most efficient extraction from wipes was observed for solutions containing the nonionic surfactant Tween 80. The increase in extraction efficiency due to surfactant addition was attributed to an attractive interfacial energy between Tween 80 and the centrifuge tube wall, which prevented spore adhesion. Extraction solution significantly impacted the extraction efficiency, as determined by statistical analysis (P< 0.05). Moreover, the extraction solution was the most important factor in extraction performance, followed by the wipe material. Polyester-rayon was the most efficient wipe material for releasing spores into solution by rank; however, no statistically significant difference between polyester-rayon and cotton was observed (P> 0.05). Vortexing provided higher spore recovery in H2O and H2O-T than sonication, when all three wipe materials and the reference control were considered (P< 0.05).

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Impact of Processing Method on Recovery of Bacteria from Wipes Used in Biological Surface Sampling

Applied and Environmental Microbiology ◽

10.1128/aem.00873-12 ◽

2012 ◽

Vol 78 (16) ◽

pp. 5872-5881 ◽

Cited By ~ 20

Author(s):

Autumn S. Downey ◽

Sandra M. Da Silva ◽

Nathan D. Olson ◽

James J. Filliben ◽

Jayne B. Morrow

Keyword(s):

Tween 80 ◽

Surface Sampling ◽

Risk Characterization ◽

Processing Methods ◽

Content Type ◽

Biological Surface ◽

Sources Of Variation ◽

Physical Dissociation ◽

Performance Results ◽

Phosphate Buffered Saline

ABSTRACTEnvironmental sampling for microbiological contaminants is a key component of hygiene monitoring and risk characterization practices utilized across diverse fields of application. However, confidence in surface sampling results, both in the field and in controlled laboratory studies, has been undermined by large variation in sampling performance results. Sources of variation include controlled parameters, such as sampling materials and processing methods, which often differ among studies, as well as random and systematic errors; however, the relative contributions of these factors remain unclear. The objective of this study was to determine the relative impacts of sample processing methods, including extraction solution and physical dissociation method (vortexing and sonication), on recovery of Gram-positive (Bacillus cereus) and Gram-negative (Burkholderia thailandensisandEscherichia coli) bacteria from directly inoculated wipes. This work showed that target organism had the largest impact on extraction efficiency and recovery precision, as measured by traditional colony counts. The physical dissociation method (PDM) had negligible impact, while the effect of the extraction solution was organism dependent. Overall, however, extraction of organisms from wipes using phosphate-buffered saline with 0.04% Tween 80 (PBST) resulted in the highest mean recovery across all three organisms. The results from this study contribute to a better understanding of the factors that influence sampling performance, which is critical to the development of efficient and reliable sampling methodologies relevant to public health and biodefense.

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Osmotic and ionic effects of NaCl on germination, early seedling growth, and ion content of Atriplex halimus (Chenopodiaceae)

Canadian Journal of Botany ◽

10.1139/b02-008 ◽

2002 ◽

Vol 80 (3) ◽

pp. 297-304 ◽

Cited By ~ 91

Author(s):

Mohammed Bajji ◽

Jean-Marie Kinet ◽

Stanley Lutts

Keyword(s):

Calcium Concentration ◽

Deionized Water ◽

Ion Content ◽

Short Term ◽

Atriplex Halimus ◽

Early Seedling Growth ◽

Significant Difference ◽

Early Seedling ◽

Ionic Effects ◽

Higher Doses

The effects of salt and osmotic stresses on the germination processes in seeds of the perennial halophyte species Atriplex halimus L. were compared using iso-osmotic concentrations of NaCl and mannitol. The lowest stress intensity delayed germination, while higher doses of NaCl and mannitol reduced final germination percentages. No significant difference occurred between the effects of these solutes on germination percentages or seedling dry weights. At an external osmotic potential of 0.7 MPa, however, the water content of mannitol-treated seedlings was reduced compared to that of seedlings that developed from NaCl-exposed seeds. The K, Mg, and Pi content decreased in seedlings that developed from mannitol-treated seeds while calcium concentration was strongly reduced in those arising from NaCl-treated seeds. Inhibited seeds were able to germinate at levels similar to those of the control after rinsing in deionized water and imbibition in control conditions. Seedlings produced from NaCl pre-treated seeds had a lower Ca and a higher Na content than control seedlings. The effect of salinity on the germination phase of development is mainly due to its osmotic component, and inhibition of germination is reversible. Both salt and osmotic stresses may have an impact on the mobilization of minerals from the seeds to the young seedling, but this effect does not have any consequence on growth processes analysed on a short-term basis.Key words: Atriplex halimus, halophyte, osmotic stress, recovery of seed germination, salinity.

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In vitro quantitative evaluation of marginal microleakage in class II restorations confected with a glass ionomer cement and two composite resins

Pesquisa Odontológica Brasileira ◽

10.1590/s1517-74912001000400002 ◽

2001 ◽

Vol 15 (4) ◽

pp. 277-282 ◽

Cited By ~ 1

Author(s):

Maria Fernanda Borro BIJELLA ◽

Maria Francisca Thereza Borro BIJELLA ◽

Salete Moura Bonifácio da SILVA

Keyword(s):

Glass Ionomer Cement ◽

Class Ii ◽

Deionized Water ◽

Composite Resins ◽

Glass Ionomer ◽

Dye Penetration ◽

Significant Difference ◽

Distal Direction ◽

Ionomer Cement

This study evaluated, in vitro, marginal microleakage in class II restorations confected with the glass ionomer cement Vitremer and with the composite resins Ariston pHc and P-60. The aims of the study were to assess the effect of thermocycling on those materials and to evaluate two methods utilized in the analysis of dye penetration. Sixty premolars divided in three groups were utilized; the teeth had proximal cavities whose cervical walls were located 1 mm below the cementoenamel junction. Half of the test specimens from each group underwent thermocycling; the other half remained in deionized water, at 37ºC. The specimens were immersed, for 24 hours, in a basic 0.5% fuchsin solution at 37ºC. For the analysis of microleakage, the specimens were sectioned in a mesio-distal direction, and the observation was carried out with the software Imagetools. The results were evaluated through the 2-way ANOVA and through the Tukey’s test. All groups presented marginal microleakage. The smallest values were obtained with Vitremer, followed by those obtained with the composite resins P-60 and Ariston pHc. There was no statistically significant difference caused by thermocycling, and the method of maximum infiltration was the best for detecting the extension of microleakage.

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In Vitro morphological, optical and microbiological evaluation of nanosilver fluoride in the remineralization of deciduous teeth enamel

Nanotechnology Reviews ◽

10.1515/ntrev-2018-0083 ◽

2018 ◽

Vol 7 (6) ◽

pp. 509-520 ◽

Cited By ~ 3

Author(s):

Amitis Vieira Costa e Silva ◽

Joás Araújo Teixeira ◽

Cláudia C.B.O. Mota ◽

Emery Clayton Cabral Correia Lins ◽

Paulo Correia de Melo Júnior ◽

...

Keyword(s):

Dental Enamel ◽

Deionized Water ◽

Deciduous Teeth ◽

Bacterial Suspension ◽

Significant Difference ◽

Ph Cycling ◽

Optical Coherence Tomography Imaging ◽

Caries Lesions ◽

Mixed Linear Regression Model

AbstractBackgroundNanosilver fluoride (NSF) was developed as an alternative in the prevention of dental caries.PurposeThe aim of this study was to test the remineralizing action of NSF on incipient enamel caries and its antimicrobial action on the acid production and adhesion of Streptococcus mutans.MethodsDeciduous enamel fragments were treated with sodium fluoride (NaF), NSF and deionized water. Microhardness, fluorescence spectroscopy and optical coherence tomography imaging were performed on each specimen before chemical caries induction, after caries induction and after 14 days of pH cycling. The treated enamel fragments were also placed into test tubes containing bacterial suspension and saliva. The pH readings and quantification of the adhered microorganisms to the dental enamel were determined. Analysis of variance, Kruskal-Wallis, Mann-Whitney, Tukey and mixed linear regression model were applied.ResultsNSF and NaF were effective in enamel remineralization, with a statistically significant difference (p<0.001) to deionized water, and they had no statistically significant difference between themselves (p>0.005). NSF had greater effectiveness compared to NaF in preventing decreases of pH and adhesion of S. mutans to the enamel surface, with statistically significant (p<0.001) differences.ConclusionNSF may be more effective than conventional fluorides in treating incipient caries lesions due to its remineralization and antibacterial actions.

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Isolation and characterization of bleomycin-resistant clones of CHO cells

Genetics Research ◽

10.1017/s0016672300019509 ◽

1979 ◽

Vol 34 (3) ◽

pp. 269-279 ◽

Cited By ~ 10

Author(s):

Sylvia Brabbs ◽

J. R. Warr

Keyword(s):

Enzyme Activity ◽

Chinese Hamster Ovary Cells ◽

Chinese Hamster ◽

Tween 80 ◽

The Other ◽

Resistant Clone ◽

Ovary Cells ◽

Isolation And Characterization ◽

Significant Difference

SUMMARYFive clones of Chinese hamster ovary cells with increased resistance to bleomycin have been isolated following ethylmethanesulphonate mutagenesis. Resistance was stable in three of the clones, but unstable in the other two. One of the stably resistant clones was cross resistant to unrelated drugs, and in contrast to the parental cells, its response to bleomycin was potentiated by tween 80. These two observations suggested a membrane alteration in the resistant clone. There was no significant difference in bleomycin-inactivating enzyme activity between the parental and resistant clones.

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Evaluation of the efficacy of two methods for direct extraction of DNA from Mycobacterium tuberculosis sputum

The Journal of Infection in Developing Countries ◽

10.3855/jidc.10592 ◽

2018 ◽

Vol 12 (12) ◽

pp. 1067-1072

Author(s):

Victor Ndhlovu ◽

Wilson Mandala ◽

Derek Sloan ◽

Mercy Kamdolozi ◽

Maxine Caws ◽

...

Keyword(s):

Mycobacterium Tuberculosis ◽

Single Molecule ◽

Disease Transmission ◽

Extraction Efficiency ◽

Ease Of Use ◽

Clinical Samples ◽

Direct Extraction ◽

Significant Difference ◽

Ctab Method ◽

Dna Purity

Introduction: Whole genome sequencing (WGS) has shown superiority over other bacterial typing methods and can be used to monitor disease transmission. The long culture period hinders use of WGS as a diagnostic tool for TB. The ideal situation would be to efficiently sequence directly from clinical specimens such as sputum. Attempts to sequence directly from Mtb clinical samples have achieved very low coverage (less than 0.7X). We compared DNA extraction methods for direct extraction from Mycobacterium tuberculosis positive sputum and assessed their suitability for Single Molecule Real Time sequencing. Methodology: We evaluated the extraction efficiency of the PrimeXtract kit and an in-house CTAB method by extracting DNA from Mtb sputum. We evaluated the methods on these parameters: ease of use, efficiency (quantity and purity) and the cost per extraction. Results: The PrimeXtract kit was able to isolate 5.93 µg/mL ± 0.94, (Mean ± SEM) concentration of DNA and a yield of 0.2975 µg ± 0.04723, (Mean ± SEM). Comparatively, the CTAB method isolated 1.88 µg/mL ± 0.38 DNA and a yield of 0.09 µg ± 0.02. Both concentration and yield from the kit were significantly (p = 0.0002) higher than those from CTAB. The PrimeXtract kit had a DNA purity ratio of 1.69 ± 0.09 compared to the CTAB’s 1.73 ± 0.14 and this difference was not statistically different. Conclusion: PrimeXtract kit has a superior extraction efficiency than the CTAB method on Mtb sputum in terms of DNA yield although no significant difference by DNA purity was seen.

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Evolution of Synthetic Fluid from Water Extract from Fermented Ground Maize (WEFGM) as an Alternative to Water-Based Cutting Fluids: Performance Test

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1150.59 ◽

2018 ◽

Vol 1150 ◽

pp. 59-66

Author(s):

Taofeek Ayotunde Yusuf ◽

Chibueze Nnorom ◽

Olusola Femi Olusunmade

Keyword(s):

Performance Test ◽

New Technologies ◽

Temperature Drop ◽

Water Extract ◽

Deionized Water ◽

Additive Concentration ◽

Actual Performance ◽

Two Samples ◽

Significant Difference ◽

Water Based

The use of agricultural wastes and natural materials in new technologies is a novel subject. Consequently, an attempt has been made to formulate a synthetic fluid using an organic water, Water Extract from Fermented Ground Maize (WEFGM) and compare its performance with water-based sample in turning operation using a mild steel as workpiece. Two samples of synthetic fluids were formulated from each of deionized WEFGM, ordinary WEFGM and deionized water as base-fluids at two composition (5 and 10%vol) levels of selected additives. The results of experimental analysis of heat transfer properties of these synthetic fluids exist, hence the need to ascertain the actual performance output. Temperature-Time Gradient (TTG) which is a rate of temperature drop (heat withdrawn) from the work zone was used as evaluation parameters. The result showed that deionized WEFGM is the most efficient of the entire samples at both compositions with an average TTG of 3.61 and 2.16 °C/min at 10 and 5% additive concentration respectively. At lower additive concentration which is more economically advantageous, the performance rating is deionized WEFGM>>WEFGM>>deionized Water. This implies that WEFGM is more effective than water as a base fluid for synthetic fluid in performance as it has been previously so reported in properties. Meanwhile, T-test statistical analysis (using IBM SPSS 23) shows that there is highly significant difference in TTG at each time of application of individual fluid (p<0.05). However, TTG of one fluid sample is not significantly different from the other (p>0.05) implying that the fluids can all work as coolants and relatively have comparable performance output.

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Effect of Imidazoline Inhibitor on the Rehabilitation of Reinforced Concrete with Electromigration Method

Materials ◽

10.3390/ma13020398 ◽

2020 ◽

Vol 13 (2) ◽

pp. 398 ◽

Cited By ~ 2

Author(s):

Chonggen Pan ◽

Jianghong Mao ◽

Weiliang Jin

Keyword(s):

Reinforced Concrete ◽

Extraction Efficiency ◽

Corrosion Potential ◽

Steel Bar ◽

Chloride Migration ◽

Significant Difference ◽

Steel Bars ◽

Novel Method ◽

Electrochemical Chloride Extraction ◽

High Chloride

Steel bars embedded in reinforced concrete are vulnerable to corrosion in high chloride environments. Bidirectional electromigration rehabilitation (BIEM) is a novel method to enhance the durability of reinforced concrete by extracting chloride out of concrete and introducing an inhibitor to the surface of the steel bar under the action of an electric field. During the migration process, a higher ionization capacity of the inhibitor with a symmetrical molecular structure was introduced. A new imidazoline inhibitor was, therefore, employed in this study due to its great ionization capacity. The effect of imidazoline and triethylenetetramine inhibitor on chloride migration, corrosion potential, and strength of concrete were explored. The research results showed that the effect of chloride extraction and electrochemical chloride extraction made no significant difference on the surface of the concrete, where chloride extraction efficiency was more than 70%, and the chloride extraction efficiency was more than 90% around the location of the steel. while a dry-wet cycle test, the potential of concrete increased by about 200 mV by mixing imidazoline inhibitor. The imidazoline inhibitor was found to be effective at facilitating chloride migration and ameliorating corrosion, meanwhile, it had a negligible impact on the concrete’s strength.

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Effect of Nitrate and Ammonium Ions on the Pigment Content (Xanthophylls, Carotenes and Chlorophylls) of Ramalina Capitata

The Lichenologist ◽

10.1006/lich.1995.0012 ◽

1995 ◽

Vol 27 (2) ◽

pp. 155-160

Author(s):

M. A. Sanchez-Hoyos ◽

E. Manrique

Keyword(s):

Water Supply ◽

Chlorophyll A ◽

Nitrate Solution ◽

Deionized Water ◽

Pigment Content ◽

Chlorophyll B ◽

Ammonium Ions ◽

Controlled Conditions ◽

Significant Difference ◽

Β Carotene

AbstractThalli of Ramalina capitata were sprayed with deionized water, 10 mM solutions of KNO3 or NH4Cl, or maintained without any water supply, for 10 days under controlled conditions. The lichens without a water supply showed an increase n antheraxanthin, lutein and β-carotene. The samples treated with deionized water showed a significant increase in violaxathin, antheraxanthin and β-carotene. The lack of a significant difference in zeaxanthin could indicate the absence of de-epoxidation of violaxanthin to zeaxanthin via antheraxanthin. Those samples treated with nitrate solution showed a significant increase in all pigments except for antheraxanthin. In contrast, ammonium treatment did not induce changes compared to water alone, except that antheraxanthin decreased. The lichens treated with nitrate exhibited a significant increase in both chlorophyll a and chlorophyll b, but ammonium affected only chlorophyll b.

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OPTIMIZATION AND QUERCETIN RELEASE TEST OF MORINGA LEAF EXTRACT (MORINGA OLEIFERA) IN GEL-MICROEMULSION PREPARATION

Journal of Islamic Pharmacy ◽

10.18860/jip.v2i2.4508 ◽

2017 ◽

Vol 2 (2) ◽

pp. 34

Author(s):

Weka Sidha Bhagawan ◽

Ria Ramadhani Dwi Atmaja ◽

Sri Nur Atiqah

Keyword(s):

Propylene Glycol ◽

Leaf Extract ◽

Biological Activities ◽

Tween 80 ◽

Flavonoid Compound ◽

Microemulsion System ◽

Release Test ◽

Significant Difference ◽

Gel Preparation ◽

Moringa Leaf Extract

Quercetin is a flavonoid compound of the flavonol group that has various biological activities for health. Moringa leaf is one of the plants rich in quercetin which is about 384.61 mg / 100 g. Quercetin is practically insoluble (4.5 μg / mL). To increase the solubility and release of quercetin microemulsion may be used as Drug Delivery Systems formulated with gels for transdermal use.The aim of this research is to obtain optimum combination formulation of surfactant (tween 80): cosurfactant (propylene glycol) to form optimal microemulsion system, to find out the characteristics of the preparation and to find out the rate of quercetin release of Moringa leaf extract (M. oliefera) in a gel-microemulsion preparation compared with a control gel (without microemulsion) using an HPMC (Hydroxypropyl methylcellulose) gel basis.The result shows that optimal concentration tween 80 comparison : propylene glycol to form optimal microemulsion system up to 30%: 20 % with VCO (virgin coconut oil) oil phase 5%. The characteristics observed including organoleptic, pH, viscosity, and stability are showing optimal condition. The average of quercetin content in gel-microemulsion preparation was 2,22 ± 0,077 ppm and on control gel was 2.37 ± 0.042 ppm. Quercetin release test using Franz diffusion cell using cellophane membrane, saline phosphate buffer pH 7,4 ± 0,05 and temperature 37 ± 0,5 °C for 6 hours. The average quercetin release flux in the gel-microemulsion preparation was 9.436 ± 1.178 (μg/cm 2/min1/2) and the control gel was 5,816 ± 0.485 (μg/cm2/min1/2).Based on these results it can concluded that the microemulsion gel preparation gives significant difference of quercetin flux rate compared with gel preparation. Keywords: Quercetin, Gel-Microemulsion, quercetin release, moringa leaf extract (Moringa oliefera)

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