scholarly journals Molecular marker assisted detection of the mycoparasite Coniothyrium minitans A69 in soil

2000 ◽  
Vol 53 ◽  
pp. 114-117 ◽  
Author(s):  
H.J. Ridgway ◽  
A. Stewart
Keyword(s):  
Detection Methods ◽  
Practical Application ◽  
Coniothyrium Minitans ◽  
Sterile Soil ◽  
Pcr Assay ◽  
Control Activity ◽  
Dna Recovery ◽  
Nonsterile Soil ◽  
Number Of Factors ◽  
Conventional Detection

Coniothyrium minitans A69 has been shown to have biological control activity against the plant pathogen Sclerotinia sclerotiorum and a PCR based assay has been developed to specifically identify this isolate The practical application of this PCR assay for detection of C minitans from soil was assessed Sterile and nonsterile soil was inoculated with spores from C minitans A69 at five different concentrations and DNA recovered using a SDS/Phenol/Chloroform method A number of factors affected DNA recovery and subsequent PCR with a maximum sensitivity of down to 1x102 spores/g soil achieved in sterile soil Detection of C minitans in nonsterile soil was hampered by failure of the fungus to germinate However this method has improved throughput and cost effectiveness compared with conventional detection methods involving quantitative colony recovery

scholarly journals Process Intensification of Dichlorodiphenyltrichloroethane Detection Methods for Determining Trace Concentrations in Soils

2020 ◽  
Vol 1 (1) ◽  
pp. 63-74
Author(s):  
Jinghan Zhao ◽  
Stephen Vanderburgt ◽  
Rafael M. Santos ◽  
Yi Wai Chiang
Keyword(s):  
Operating Time ◽  
Process Intensification ◽  
Soil Samples ◽  
Detection Methods ◽  
Ultrasonic Probe ◽  
Time Consumption ◽  
Trace Concentrations ◽  
Similar Yield ◽  
Conventional Detection

Dichlorodiphenyltrichloroethane (DDT) residue in Ontario soil is expected to be found at trace levels, since it has been banned for over 45 years in Canada. This presents challenges to the efficiency and accuracy of conventional detection methods. This study intensified the conventional DDT detection method, in the characterization of aged soil samples collected from historically-treated sites in Ontario. Recovery, time consumption, and labor intensity were considered for the intensification evaluation. Ultrasonic probe extraction was found to significantly shorten the extraction time, with similar yield compared to ultrasonic water bath extraction and homogenized extraction. Homogenized extraction for 24 h following ultrasonic probe extraction can increase yield over 27%. Rotary evaporator concentration was used, since it can reduce the operating time with comparable recovery. The Florisil clean-up column used in the conventional method was removed from the intensified method, due to its negligible effect and high time consumption. The intensified method may be valuable for further investigation to determine other trace level organochlorine pesticide residues in soil samples.

The Principle of Distinction Between Civilians and Combatants

2014 ◽  
Author(s):  
Nils Melzer
Keyword(s):  
Armed Conflicts ◽  
International Humanitarian Law ◽  
Humanitarian Law ◽  
Practical Application ◽  
Civilian Population ◽  
Number Of Factors ◽  
Armed Actors

This chapter examines the provisions of international humanitarian law (IHL) concerning the distinction between legitimate military targets and persons protected against direct attacks. It explains that the practical application of the principle of distinction in contemporary armed conflicts has become increasingly difficult because of a number of factors. These include the growing asymmetry of military confrontations, the intermingling of armed actors with the civilian population, and the increasing involvement of civilians in the conduct of hostilities.

Rapid real-time PCR assay for detecting Salmonella in raw and ready-to-eat meats

2008 ◽  
Vol 56 (4) ◽  
pp. 451-458 ◽  
Author(s):  
Jitu Patel ◽  
Arvind Bhagwat
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Pathogen Detection ◽  
Molecular Beacon ◽  
False Negative ◽  
Detection Methods ◽  
Time Data ◽  
Pcr Assay ◽  
Serovar Typhimurium ◽  
Meat Samples

A real-time PCR assay was evaluated for the rapid detection (10 h) ofSalmonellain meats using molecular beacon probes available as a commercial kit (iQ-Check, Bio-Rad laboratories). Raw (chicken, pork) and ready-to-eat (RTE) meats were artificially contaminated withSalmonella entericaserovar Typhimurium at the estimated level of 2 to 4 cells per 25 g. After 8 h of pre-enrichment in buffered peptone water, a molecular beacon-based PCR assay was performed to detect contamination in raw and RTE meats. The sensitivity and accuracy of the assay were compared with the conventional USDA microbiological procedure. Comparative evaluation of the USDA procedure with the rapid PCR assay for meat samples (n = 63) revealed 1 false negative pork sample with the PCR assay. All uninoculated controls (n = 34) but one sample were negative by both the 10-h PCR assay and the USDA procedure. Developing rapid pathogen detection methods with shorter pre-enrichment times (8-h) and real-time data monitoring capabilities will benefit the industry in preventing recall of contaminated meats by stopping the contaminated products from being introduced into the marketplace.

Effects of bacterial lignin peroxidase on organic carbon mineralization in soil, using recombinant Streptomyces strains

1991 ◽  
Vol 37 (4) ◽  
pp. 287-294 ◽  
Author(s):  
Zemin Wang ◽  
Don L. Crawford ◽  
Timothy S. Magnuson ◽  
Bruce H. Bleakley ◽  
Greg Hertel
Keyword(s):  
Organic Carbon ◽  
Lignin Peroxidase ◽  
Turnover Rate ◽  
Carbon Mineralization ◽  
Evolution Rate ◽  
Carbon Turnover ◽  
Wild Type ◽  
Sterile Soil ◽  
Short Term ◽  
Nonsterile Soil

To study the effects of bacterial lignin peroxidase ALip-P3 of Streptomyces viridosporus T7A on the rate of organic carbon turnover in soil, purified lignin peroxidase, with and without addition of H2O2, was added to sterile and nonsterile silt loam soil. Recombinant Streptomyces lividans strains expressing plasmid-encoded ALip-P3 were also inoculated into the soil. Carbon mineralization was monitored by measuring the rate of CO2 evolution from the soil. In sterile soil, lignin peroxidase addition altered carbon turnover, by increasing the CO2 evolution rate above the near-zero rate of sterile, uninoculated soil. H2O2, when added alone, had no effect, and its addition in combination with peroxidase gave results similar to peroxidase alone. This effect was also observed upon addition of lignin peroxidase to sterile soil already inoculated with S. viridosporus T7A. The increases in soil CO2 evolution rates were also observed in experiments using nonsterile soil. However, results showed more variation, and the effect was shorter lived as a result of lessened peroxidase stability. Three recombinant S. lividans strains expressing the ALip-P3 gene in plasmid pIJ702.LP were also inoculated into soil. There were no significant differences in CO2 evolution rates for sterile soil inoculated with recombinants as compared with sterile soil inoculated with wild-type S. lividans strains. However, in nonsterile soil, addition of the recombinants caused a significantly greater increase in the CO2 evolution rate as compared with the corresponding wild types or S. viridosporus T7A. The effect was short lived, lasting about 5 days. Both the recombinant and wild-type Streptomyces survived in the soil for at least 30 days, and pIJ702.LP was stable in the recombinants in soil. Plasmid pIJ702.LP was transformed into three mutants of S. viridosporus T7A that lacked lignin peroxidase. Plasmid-expressing transformants regained the ability to produce lignin peroxidase. The results show that addition of lignin peroxidase ALip-P3 to soil transiently enhanced the short-term rate of carbon mineralization in the soil. The enhancement was lignin peroxidase specific, since substitution of horseradish peroxidase for lignin peroxidase in the soil addition studies resulted in no enhancement of CO2 evolution. In addition, pIJ702.LP-expressing S. lividans strains also caused the effect, which was significant only in nonsterile soil. Thus, lignin peroxidase ALip-P3 appears to affect the short-term turnover rate of lignin-derived organic carbon in soil, and normal, low lignin peroxidase concentrations in soil may limit the initial turnover rate of lignified plant residues in soil. This is the first report of a genetically engineered microorganism having a measurable effect on a biogeochemical cycle in soil. Key words: Streptomyces, recombinant, lignin, peroxidase, soil.

The Application of Optical Rotation Principle in Density of Oil Mist Measuring

2009 ◽  
Vol 16-19 ◽  
pp. 980-984 ◽  
Author(s):  
Jian Wen Chen ◽  
L.B. Jia ◽  
Jin Chun Song ◽  
Zhi Wei Zhang ◽  
C.J. Pang
Keyword(s):  
Working Condition ◽  
Optical Rotation ◽  
Measuring Method ◽  
Detection Methods ◽  
Experimental Result ◽  
Lubrication System ◽  
Median Diameter ◽  
Oil Mist ◽  
Conventional Detection

The density of oil mist in this paper is an important factor of oil mist lubrication technology, according to which the effect of lubrication will be known and from which the study on atomization effect will also benefit. In general, the oil mist density of oil mist lubrication system in working condition is 3-12g/ m3 , the median diameter is 1-3 [1], which is difficult to measure with conventional detection methods. The paper takes advantage of optical rotation principle as a measuring method for density of oil mist and achieves a good experimental result.

Qualitative and Quantitative PCR-Based Detection Methods for Authorized Genetically Modified Cotton Events in India

2014 ◽  
Vol 97 (5) ◽  
pp. 1299-1309 ◽  
Author(s):  
Rashmi Chhabra ◽  
Gurinder Jit Randhawa ◽  
Rajesh K Bhoge ◽  
Monika Singh
Keyword(s):  
Genetically Modified ◽  
Cost Effective ◽  
Detection Methods ◽  
Quantitative Detection ◽  
Bt Cotton ◽  
Pcr Assay ◽  
Genetically Modified Cotton ◽  
Detection Assay ◽  
Endogenous Reference ◽  
The Cost

Abstract Qualitative diagnostics for all five commercialized genetically modified (GM) cotton events for insect resistance in India is being reported for the first time in this paper. The cost-effective and robust multiplex PCR (MPCR)-based detection assay, distinguishing the insect resistant transgenic Bt cotton events, viz., MON531, MON15985, Event 1, GFM-cry1A, and MLS-9124, has been developed. This decaplex PCR assay targets nine transgenic elements, viz., sequences of four transgenes, three transgene constructs, and two event-specific sequences along with one endogenous reference gene. The LOD of the qualitative MPCR assay was up to 0.1%. A quantitative detection method for four widely commercially cultivated GM cotton events, namely, MON531, MON15985, Event 1, and GFM-cry1A, covering 99.5% of the total area under GM cultivation in the country, is also reported. A construct-specific real-time PCR assay has been developed for quantification of these GM cotton events with LOQ <0.05% and LOD <0.025%. The developed assays will be of great use to screen for the presence/absence of authorized GM cotton events in unknown samples and to check the authenticity of GM cotton seed samples.

scholarly journals A multi-laboratory comparison of two molecular methods for the detection of toxigenic Clostridium difficile

2016 ◽  
Vol 10 (01) ◽  
pp. 62-67 ◽  
Author(s):  
Diane C Halstead ◽  
Joan Abid ◽  
Lynne Sloan ◽  
Diana Meza ◽  
Daphne Ramsey-Walker ◽  
...  
Keyword(s):  
Clostridium Difficile ◽  
Molecular Characterization ◽  
Regulatory Gene ◽  
Reference Method ◽  
Molecular Methods ◽  
Detection Methods ◽  
Molecular Testing ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Toxigenic Culture

Introduction: Diarrheal disease due to toxigenic Clostridium difficile (CD) accounts for an increased number of hospitalizations and deaths each year. Published guidelines recommend reflex testing of CD antigen-positive samples to molecular testing or testing samples directly by a molecular assay. This multicenter study was designed to compare the accuracy of two different molecular methods targeting different CD genes: Xpert C. difficile Epi RUO RT-PCR assay (XPCR) which targets toxin B (Cepheid, Sunnyvale, CA) and a laboratory-developed PCR (LDPCR) which targets mutations in the tcdC regulatory gene. Methodology: Two molecular methods for toxigenic CD detection, the Xpert C. difficile Epi RUO RT-PCR assay (XPCR) [Cepheid, Sunnyvale, CA] and a laboratory-developed PCR assay (LDPCR) were compared to a consensus gold standard (CGS) or toxigenic culture (TC) as the reference method. A subset of specimens was subjected to additional molecular characterization of toxigenic CD. Results: Both molecular methods were >90% sensitive for CD detection. Discordant results were noted when molecular test results were compared to non-molecular methods. Supplemental molecular characterization illustrated inherent difficulties in comparisons using different molecular methods for CD. Conclusion: Laboratories may consider using multiple CD detection methods or combinations of methods, including molecular detection for rapid and accurate diagnosis of CD, as driven by best practices for the respective healthcare environment. Laboratories must be aware of intrinsic differences when comparing performance characteristics of different molecular assays.

scholarly journals Constructing glucagon biosensors as an alternative to conventional detection methods

2019 ◽  
Vol 33 (S1) ◽  
Author(s):  
Teresa Annmarie Ennis ◽  
Willis K. Samson ◽  
Gina L. C. Yosten
Keyword(s):  
Detection Methods ◽  
Conventional Detection

scholarly journals Evaluation of Diagnostic Performance of BD Max EBP Assay in Patients with Diarrheal Illness.

2021 ◽  
Author(s):  
Ozlem KOYUNCU OZYURT ◽  
Imran SAGLIK ◽  
Betil OZHAK ◽  
Derya MUTLU ◽  
Belkıs LEVENT ◽  
...  
Keyword(s):  
Acute Diarrhea ◽  
Diagnostic Performance ◽  
Detection Methods ◽  
Campylobacter Coli ◽  
Pcr Assay ◽  
Chi Square ◽  
Diarrheal Illness ◽  
Percent Agreement ◽  
Detection And Identification ◽  
Chi Square Test

Abstract Background: Detection of the etiological agents in patients with acute diarrhea is challenging due to a wide variety of pathogens. Detection and identification of the pathogens of acute diarrhea are important for both individual patient care and public health. The aim of this study is to evaluate the diagnostic performance of BD Max Enteric Bacterial Pathogens (EBP) PCR assay in patients with diarrheal illness. Methods: Between 1 January 2014 and 31 May 2015, one thousand two hundred twenty four stool samples from pediatric or adult patients with diarrhea submitted for routine analysis of bacterial stool pathogens were included in the study. We compared the BD Max EBP PCR assay to culture for the detection of Salmonella spp., Shigella spp., Campylobacter jejuni, and Campylobacter coli and an EIA (Enzym Immun Assay) for Shiga toxins 1 and 2. Discordant results were adjudicated by either antigen detection methods or Film array GI (Gastro Intestinal) Panel. Coinfections were excluded. The chi-square test was used for comparisons of PPA and NPA.Results: The PPA (positive percent agreement) values for the BD Max EBP assay was 100% and NPA (negative percent agreement) was between 98.0%-99.7%, when compared with culture and EIA. After discrepant analysis, the PPA values for the BD Max EBP assay was 100% and NPA was between 99.5%-100%. Conclusion: The BD Max EBP assay showed a high correlation rate with conventional and molecular methods for the detection of stool pathogens.

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