Colorimetric Detection of Nucleic Acid Signature of Shiga Toxin Producing Escherichia coli Using Gold Nanoparticles

2010 ◽  
Vol 10 (7) ◽  
pp. 4154-4158 ◽  
Author(s):  
Anurag Jyoti ◽  
Pratibha Pandey ◽  
Surinder Pal Singh ◽  
Swatantra Kumar Jain ◽  
Rishi Shanker
Keyword(s):  
Escherichia Coli ◽  
Gold Nanoparticles ◽  
Nucleic Acid ◽  
Shiga Toxin ◽  
Colorimetric Detection

Colorimetric Nucleic Acid Detection Based on Gold Nanoparticles with Branched DNA

NANO ◽  
2020 ◽  
Vol 15 (08) ◽  
pp. 2050110
Author(s):  
Zhikun Zhang ◽  
Xiaojie Ye ◽  
Qingqing Liu ◽  
Cuixia Hu ◽  
Jimmy Yun ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Nucleic Acid ◽  
Genetic Diseases ◽  
Colorimetric Detection ◽  
Nucleic Acid Detection ◽  
Great Promise ◽  
Dna Nanostructures ◽  
Practical Applications ◽  
Branched Dna ◽  
Target Dna

Nucleic acid detection is becoming increasingly important in the diagnostics of genetic diseases for biological analysis. We herein propose gold nanoparticles as probe for colorimetric detection of nucleic acids with branched DNA nanostructures, which enables a novel and simple colorimetric biosensor. In our system, the target DNA specifically triggered two short-chain ssDNA probes to generate branched DNA nanostructures (Y-shape DNA), which prevent AuNPs from aggregation in aqueous NaCl solution. On the contrary, when the target DNA did not exist, gold nanoparticles were unstable and aggregated easily because there is no anti-aggregation function from Y-shape DNA. Sensor response was found to be proportional to the target DNA concentration from 5 to 100[Formula: see text]nM, with detection limits determined as 5[Formula: see text]nM. The developed platform is for colorimetric nucleic acid detection without enzymes, label and modification holds great promise for practical applications.

scholarly journals Pooled Nucleic Acid Amplification Test for Screening of Stool Specimens for Shiga Toxin-Producing Escherichia coli

2016 ◽  
Vol 54 (11) ◽  
pp. 2711-2715
Author(s):  
Agatha N. Jassem ◽  
Frank Y. Chou ◽  
Cathevine Yang ◽  
Matthew A. Croxen ◽  
Katarina D. M. Pintar ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Nucleic Acid ◽  
Shiga Toxin ◽  
Large Scale ◽  
Nucleic Acid Amplification Test ◽  
Nucleic Acid Amplification ◽  
Accurate Estimation ◽  
Content Type ◽  
Pooling Strategy ◽  
Stool Specimens

Shiga toxin-producingEscherichia coli(STEC)-associated enteric illness is attributed to O157 and non-O157 serotypes; however, traditional culture-based methods underdetect non-O157 STEC. Labor and cost of consumables are major barriers to implementation of the CDC recommendation to test all stools for both O157 and non-O157 serotypes. We evaluated the feasibility of a pooled nucleic acid amplification test (NAAT) as an approach for screening stool specimens for STEC. For retrospective evaluation, 300 stool specimens were used to create pools of 10 samples each. The sensitivity was 83% for the preenrichment pooling strategy and 100% for the postenrichment pooling strategy compared with those for individual NAAT results. The difference in cycle threshold (CT) between individual and pooled NAAT results for specimens was significantly lower and more consistent for postenrichment pooling (stx1mean = 3.90,stx2mean = 4.28) than those for preenrichment pooling (excluding undetected specimens;stx1mean = 9.34,stx2mean = 8.96) (P≤ 0.0013). Cost of consumables and labor time savings of 48 to 81% and 6 to 66%, respectively, were estimated for the testing of 90 specimens by the postenrichment pooled NAAT strategy on the basis of an expected 1 to 2% positivity rate. A 30-day prospective head-to-head clinical trial involving 512 specimens confirmed the sensitivity and labor savings associated with the postenrichment pooled NAAT strategy. The postenrichment pooled NAAT strategy described here is suitable for efficient large-scale surveillance of all STEC serotypes. Comprehensive detection of STEC will result in accurate estimation of STEC burden and, consequently, appropriate public health interventions.

Colorimetric aptasensor for detecting Salmonella spp., Listeria monocytogenes, and Escherichia coli in meat samples

2020 ◽  
Vol 26 (5) ◽  
pp. 430-443 ◽  
Author(s):  
Sudarat Ledlod ◽  
Supatra Areekit ◽  
Somchai Santiwatanakul ◽  
Kosum Chansiri
Keyword(s):  
Escherichia Coli ◽  
Gold Nanoparticles ◽  
Listeria Monocytogenes ◽  
Colorimetric Detection ◽  
Simultaneous Detection ◽  
Dna Aptamer ◽  
Local Market ◽  
Salmonella Spp ◽  
Meat Samples ◽  
Colorimetric Aptasensor

In this study, we successfully developed a simple and rapid method for simultaneous detection of Salmonella spp., Listeria monocytogenes, and Escherichia coli using gold nanoparticles and the aptamer aptasensor. We screened 25 specific DNA aptamer candidates against these pathogens using whole-cell Systematic Evolution of Ligands by EXponential enrichment. Among them, Ap6 was selected due to its low energy minimization values of −12.25 and −27.67 kcal/mol derived from MFold and RNAFold analysis, respectively. The assay presented in this study allowed the visual colorimetric detection of labeled colloidal gold nanoparticles as well as determination of UV absorbance at 625 and 525 nm under optimized conditions. The detection limit of this aptasensor was as less as 105 CFU/ml. A random investigation of 50 meat samples, including ham and chicken sausages, collected from the local market revealed 96% accuracy, 96% specificity, and 100% sensitivity of the assay. The colorimetric aptasensor can accomplish one-step detection without pre-culture, DNA extraction, and amplification. Hence, it is an easy, rapid, specific, and qualitative assay that can be used as a point-of-care testing to directly detect multiplex foodborne pathogens.

Promising Nucleic Acid Lateral Flow Assay Plus PCR for Shiga Toxin–Producing Escherichia coli

2015 ◽  
Vol 78 (8) ◽  
pp. 1560-1568 ◽  
Author(s):  
YOSHITAKA TERAO ◽  
KANA TAKESHITA ◽  
YASUTAKA NISHIYAMA ◽  
NAOKI MORISHITA ◽  
TAKASHI MATSUMOTO ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Detection Limit ◽  
Nucleic Acid ◽  
Real Time ◽  
Shiga Toxin ◽  
Real Time Pcr ◽  
Pcr Assay ◽  
E Coli ◽  
Lower Detection Limit ◽  
Lower Detection

Shiga toxin (Stx)–producing Escherichia coli (STEC) is a frequent cause of foodborne infections, and methods for rapid and reliable detection of STEC are needed. A nucleic acid lateral flow assay (NALFA) plus PCR was evaluated for detecting STEC after enrichment. When cell suspensions of 45 STEC strains, 14 non-STEC strains, and 13 non–E. coli strains were tested with the NALFA plus PCR, all of the STEC strains yielded positive results, and all of the non-STEC and non–E. coli strains yielded negative results. The lower detection limit for the STEC strains ranged from 0.1 to 1 pg of genomic DNA (about 20 to 200 CFU) per test, and the NALFA plus PCR was able to detect Stx1- and Stx2-producing E. coli strains with similar sensitivities. The ability of the NALFA plus PCR to detect STEC in enrichment cultures of radish sprouts, tomato, raw ground beef, and beef liver inoculated with 10-fold serially diluted STEC cultures was comparable to that of a real-time PCR assay (at a level of 100 to 100,000 CFU/ml in enrichment culture). The bacterial inoculation test in raw ground beef revealed that the lower detection limit of the NALFA plus PCR was also comparable to that obtained with a real-time PCR assay that followed the U.S. Department of Agriculture guidelines. Although further evaluation is required, these results suggest that the NALFA plus PCR is a specific and sensitive method for detecting STEC in a food manufacturing plant.

Simultaneous direct detection of Shiga-toxin producing Escherichia coli (STEC) strains by optical biosensing with oligonucleotide-functionalized gold nanoparticles

Nanoscale ◽  
2015 ◽  
Vol 7 (6) ◽  
pp. 2417-2426 ◽  
Author(s):  
Irwin A. Quintela ◽  
Benildo G. de los Reyes ◽  
Chih-Sheng Lin ◽  
Vivian C. H. Wu
Keyword(s):  
Escherichia Coli ◽  
Gold Nanoparticles ◽  
Foodborne Pathogens ◽  
Shiga Toxin ◽  
Direct Detection ◽  
Optical Biosensing ◽  
Functionalized Gold Nanoparticles

We report here a simultaneous and direct detection of foodborne pathogens by an optical biosensing method using oligonucleotide-functionalized gold nanoparticles.

scholarly journals Clinical Evaluation and Cost Analysis of Great Basin Shiga Toxin Direct Molecular Assay for Detection of Shiga Toxin-Producing Escherichia coli in Diarrheal Stool Specimens

2016 ◽  
Vol 55 (2) ◽  
pp. 519-525 ◽  
Author(s):  
Matthew L. Faron ◽  
Nathan A. Ledeboer ◽  
Jessica Connolly ◽  
Paul A. Granato ◽  
Brenda R. Alkins ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Nucleic Acid ◽  
Shiga Toxin ◽  
Nucleic Acid Amplification ◽  
Molecular Assay ◽  
Content Type ◽  
E Coli ◽  
Serotype O ◽  
Stool Specimens ◽  
O 157

ABSTRACTThe Shiga Toxin Direct molecular assay (ST Direct) relies on nucleic acid amplification and solid array-based amplicon detection to identify Shiga toxin-producingEscherichia coli(STEC) in preserved stool specimens. Genes encoding Shiga toxin (stx1andstx2), as well as theE. coliserotype O:157-specific markerrfbE, are simultaneously detected within 2 h. ST Direct was evaluated using 1,084 prospectively collected preserved stool specimens across five clinical centers. An additional 55 retrospectively collected, frozen specimens were included to increase the number of positive specimens evaluated. Results were compared to results from routine culture and an enzyme immunoassay (EIA) specific for the recovery and identification of STEC. ST Direct was found to be 93.2% sensitive and 99.3% specific for detection ofstx1andstx2and 95.7% sensitive and 99.3% specific for detection ofE. coliserotype O:157. All specimens with false-positive results were found to containstx1orstx2or were found to be positive for serotype O:157 when analyzed using alternative molecular methods. All 4 false-negativestx1orstx2results were reported for frozen, retrospectively tested specimens. In all cases, the specimens tested positive forstxby an alternative FDA-cleared nucleic acid amplification test (NAAT) but were negative forstx1andstx2following nucleic acid sequence analysis. Based on these data, culture and EIA-based methods for detection of STEC are only 33% sensitive compared to molecular tests. A retrospective cost analysis demonstrated 59% of the cost of routine stool culture to be attributable to the identification of STEC. Taken together, these data suggest that ST Direct may provide a cost-effective, rapid molecular alternative to routine culture for the identification of STEC in preserved stool specimens.

scholarly journals Application of Alternative Nucleic Acid Extraction Protocols to ProGastro SSCS Assay for Detection of Bacterial Enteric Pathogens

2016 ◽  
Vol 54 (5) ◽  
pp. 1384-1387 ◽  
Author(s):  
Erik Munson ◽  
Maureen Napierala ◽  
Kimber L. Munson ◽  
Dorothy Bilbo ◽  
Michael A. Schulte
Keyword(s):  
Escherichia Coli ◽  
Nucleic Acid ◽  
Shiga Toxin ◽  
Enteric Pathogens ◽  
Acid Extraction ◽  
Automated Extraction ◽  
Nucleic Acid Extraction ◽  
Content Type ◽  
Freeze Thaw ◽  
Processing Times

As an alternative to automated extraction, fecal specimens were processed by investigational lysis/heating (i.e., manual) and by chromatography/centrifugation (i.e., column) methods. ProGastro SSC and Shiga toxin-producingEscherichia coli(i.e., STEC) indeterminate rates for 101 specimens were 1.0% to 3.0% for automated, 11.9% for manual, and 24.8% to 37.6% for column methods. Following freeze-thaw of 247 specimens, indeterminate rates were 1.6% to 2.4% for manual and 0.8 to 5.3% for column methods. Mean processing times for manual and column methods were 30.5 and 69.2 min, respectively. Concordance of investigational methods with automated extraction was ≥98.8%.

Infection of Escherichia coli with bacteriophages

1969 ◽  
Vol 27 ◽  
pp. 370-371
Author(s):  
Manfred E. Bayer
Keyword(s):  
Escherichia Coli ◽  
Nucleic Acid ◽  
Cell Surface ◽  
Virus Type ◽  
Infection Process ◽  
Adsorption Site ◽  
The Other ◽  
Specific Receptors ◽  
Bacterial Receptors

The first step in the infection of a bacterium by a virus consists of a collision between cell and bacteriophage. The presence of virus-specific receptors on the cell surface will trigger a number of events leading eventually to release of the phage nucleic acid. The execution of the various "steps" in the infection process varies from one virus-type to the other, depending on the anatomy of the virus. Small viruses like ØX 174 and MS2 adsorb directly with their capsid to the bacterial receptors, while other phages possess attachment organelles of varying complexity. In bacteriophages T3 (Fig. 1) and T7 the small conical processes of their heads point toward the adsorption site; a welldefined baseplate is attached to the head of P22; heads without baseplates are not infective.

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