Oxygen electrode-based single antibody amperometric biosensor for qualitative detection of E. coli and bacteria in water

2008 ◽  
Vol 43 (5) ◽  
pp. 478-487 ◽  
Author(s):  
Chandra S. Theegala ◽  
Danyelle D. Small ◽  
W. Todd Monroe
Author(s):  
Michele D Tisdale ◽  
David R Tribble ◽  
Indrani Mitra ◽  
Kalyani Telu ◽  
Huai-Ching Kuo ◽  
...  

Abstract Background: We assessed the compliance with self-collection of stool smears on Whatman® FTA® Elute Card (FTA Card) and detection of travelers’ diarrhea (TD) associated pathogens using a quantitative PCR assay (customized TaqMan® array card [TAC]), in a prospective, observational cohort of travelers. Methods: Enrolled travelers documented symptoms on a travel diary and collected an FTA Card during a diarrheal episode, or at the end of travel if they remained asymptomatic. TAC testing was performed on FTA Cards from TD cases and 1:1 matched asymptomatic controls and 1:1 matched loose stool cases that did not meet TD criteria. Odds ratios (OR) were used to determine the association between detected pathogens and TD. Results: 484 of 2456 (19.7%) travelers completed an illness diary and met TD criteria, and 257 (53.1%) collected an FTA Card during the TD episode. FTA Cards were stored for a median of 2 years at room temperature (IQR: 1-4 years) before extraction and testing. The overall TAC detection rate in TD cases was 58.8% (95%CI: 52.5-64.8). Enterotoxigenic E. coli was the most common pathogen in TD cases (26.8%) and 3.5% of samples were positive for norovirus. The odds of detecting TD-associated pathogens in 231 matched cases and asymptomatic controls was 5.4 (95% CI: 3.6-8.1) and 2.0 (95% CI:1.1-3.7) in 121 matched TD and loose stool cases (p < 0.05). Enteroaggregative E coli was the most common pathogen detected in asymptomatic controls and loose stool cases. Detection of diarrheagenic E coli, Shigella/enteroinvasive E coli (EIEC), and Campylobacter spp. was significantly associated with TD. Conclusions: FTA Cards are a useful adjunct to traditional stool collection methods for evaluating the pathogen-specific epidemiology of TD in austere environments. Qualitative detection of pathogens was associated with TD. Measures to improve compliance and quality of FTA Card collection with decreased storage duration may further optimize detection.


1970 ◽  
Vol 44 (2) ◽  
pp. 376-384 ◽  
Author(s):  
Richard W. Hendler ◽  
Amelia H. Burgess ◽  
Raymond Scharff

Fatty acids inhibited the ability of Escherichia coli membrane-envelope fragments to catalyze the oxidation of succinate and nicotinamide adenine dinucleotide, reduced form (NADH) and also inhibited the response of the Clark oxygen electrode to nonenzymatic oxygen uptake. In all cases, unsaturated fatty acids were much more inhibitory than saturated fatty acids. Albumin afforded complete protection from inhibition in the nonenzymatic oxygen-uptake experiments but only partial protection for the respiratory activities of the membrane fragments. The succinoxidase activity was totally inhibited by bovine serum albumin at concentrations that inhibited succinate dehydrogenase only slightly and NADH oxidase not at all. The E. coli acellular preparation showed no dehydrogenase or oxidase activity for any of the fatty acids under a variety of conditions. These conditions included variations of pH, concentration of fatty acids, and the presence or absence of albumin, CoA, ATP, NAD, cysteine, succinate, and carnitine. It thus appears that E. coli grown in the absence of fatty acid can not use fatty acids as an energy source.


2021 ◽  
pp. 123-129
Author(s):  
Ariane Kluczkovski ◽  
◽  
Samir Pinto ◽  
Augusto Kluczkovski-Junior ◽  
Marco Pinto ◽  
...  

Introduction: The hygienic and sanitary conditions of vessels carrying passengers and cargo requires constant diagnosis and monitoring for disease prevention. Objective: The objective of this study was to identify health hazards in food preparation conditions and water potability in mixed vessels in the State of Amazonas-Brazil. Method: 33 vessels were analyzed with qualitative detection analysis of Escherichia coli by chromogenic substrate for water potability and environmental evaluation with questionnaire application. Results: There was microbiological contamination in 13 (39.39%) drinking water samples and 31 (93.93%) sink samples for E. coli. The structural and operational conditions of kitchen handlers mostly did not meet the minimum percentages of safety in food production. Conclusions: This is the first report on the structural and operational conditions of food preparation in mixed vessels in Manaus-AM and we conclude that intervention is necessary with public policies regarding hygienic and sanitary issues involving the supply of water served in vessels for the protection of passenger health and training of food handlers and inspection of environments.


Author(s):  
Rawaa Al-Kayali ◽  
Joud Jalab ◽  
Adawia Kitaz ◽  
Wassim Abdelwahed

Background Acacia cyanophylla is a medicinal plant of the Fabaceae family that is widely distributed in Australia and Asia, also it has many medicinal properties such as antibacterial and antioxidant activity. Thin layer chromatography (TLC) is wildly used in natural product extract analysis as a finger print. Aim and objective: This study is aimed to conducting a qualitative detection of the active compounds in Acacia cyanophylla, Phlomis syriaca and Scolymus hispanicus plants by thin layer chromatography (TLC) method and studying their antibacterial activity. Methods: the qualitative detection of three plants was conducting using thin layer chromatography (TLC) method. Then, aqueous and ethanolic extracts of the aerial parts of the three plants were extracted using an Ultrasonic bath.  The antibacterial activity on E. coli isolates for six extracts was evaluated using minimum inhibitory concentration (MIC) test. The active compounds that may be responsible for the antibacterial effect was isolated by direct bioautograph method. Results: Performing Thin-layer chromatography TLC tests show  that the three plant contain flavonoids, saponin, bitter principles and essential oils, and all extracts showed antibacterial activity on E. coli isolates, but the ethanolic extract of Acacia cyanophylla was the most effective as the MIC values ranged from 0.097to 3.125mg/mL. Bioautography showed that Escherichia coli was inhibited by most of the separated flavonoids on the TLC plates where four inhibiting spots appeared in yellow color with Acacia cyanophylla and five spots with Scolymus hispanicus, while only one spot appeared with Phlomis syriaca. Conclusion: Acacia cyanophylla extract has been considered as the best antibacterial properties among the selected plants due to the presence of flavonoids                    Peer Review History: Received: 19 July 2021; Revised: 7 August; Accepted: 2 September, Available online: 15 September 2021 Academic Editor:  Ahmad Najib, Universitas Muslim Indonesia, Makassar, Indonesia, [email protected] UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency.  Received file:                Reviewer's Comments: Average Peer review marks at initial stage: 6.0/10 Average Peer review marks at publication stage: 7.0/10 Reviewers: Dr. Sangeetha Arullappan, Universiti Tunku Abdul Rahman, Malaysia, [email protected] Taha A.I. El Bassossy, Medicinal and Aromatic Plants Department, Desert Research Center, Cairo, Egypt, [email protected] Similar Articles: EVALUATION OF ANTIBACTERIAL RESISTANCE OF BIOFILM FORMS OF AVIAN SALMONELLA GALLINARUM TO FLUOROQUINOLONES


2019 ◽  
Vol 102 (2) ◽  
pp. 508-524
Author(s):  
Dawn Qian Liu ◽  
Mitsuharu Sato ◽  
Wei Ling Tan ◽  
Grace Pei Wen Khoo ◽  
Kiel Fisher ◽  
...  

Abstract VereBeef™ Detection Kit, incorporating both multiplex PCR and microarray technologies on a lab-on-chip platform, is intended for qualitative detection and differentiation of Escherichia coli O157:H7, E. coli O26, E. coli O45, E. coli O103, E. coli O111, E. coli O121, E. coli O145, Shiga toxin-producing E. coli (STEC) virulence factors (stx1A, stx2A, eae), and Salmonella species in one test using raw beef trim samples. This product underwent extensive evaluations, including inclusivity-exclusivity, method comparison, robustness, lot-to-lot variability, and stability studies. The inclusivity/exclusivity study demonstrated that VereBeef Detection Kit specifically detects and identifies target analytes without occurrence of false-positive and false-negative detection. In the method comparison study, the performance of the VereBeef Detection Kit was compared with U.S. Department of Agriculture Food Safety and Inspection Service Microbiology Laboratory Guidebook’s methods for target organism detection in raw beef trim using E. coli O157:H7 single inoculation and Salmonella and non-O157 STEC dual inoculation. Data demonstrated equivalence in both methods. The robustness study showed that changesin the test parameters do not impact assay performance. Collectively, VereBeef Detection Kit is able to detect target pathogens in raw beef trim with a minimum enrichment time of 8 h for E. coli O157:H7 detection and 10 h for Salmonella and non-O157 STEC detection.


Author(s):  
D. E. Philpott ◽  
A. Takahashi

Two month, eight month and two year old rats were treated with 10 or 20 mg/kg of E. Coli endotoxin I. P. The eight month old rats proved most resistant to the endotoxin. During fixation the aorta, carotid artery, basil arartery of the brain, coronary vessels of the heart, inner surfaces of the heart chambers, heart and skeletal muscle, lung, liver, kidney, spleen, brain, retina, trachae, intestine, salivary gland, adrenal gland and gingiva were treated with ruthenium red or alcian blue to preserve the mucopolysaccharide (MPS) coating. Five, 8 and 24 hrs of endotoxin treatment produced increasingly marked capillary damage, disappearance of the MPS coating, edema, destruction of endothelial cells and damage to the basement membrane in the liver, kidney and lung.


Author(s):  
James A. Lake

The understanding of ribosome structure has advanced considerably in the last several years. Biochemists have characterized the constituent proteins and rRNA's of ribosomes. Complete sequences have been determined for some ribosomal proteins and specific antibodies have been prepared against all E. coli small subunit proteins. In addition, a number of naturally occuring systems of three dimensional ribosome crystals which are suitable for structural studies have been observed in eukaryotes. Although the crystals are, in general, too small for X-ray diffraction, their size is ideal for electron microscopy.


Author(s):  
Manfred E. Bayer

Bacterial viruses adsorb specifically to receptors on the host cell surface. Although the chemical composition of some of the cell wall receptors for bacteriophages of the T-series has been described and the number of receptor sites has been estimated to be 150 to 300 per E. coli cell, the localization of the sites on the bacterial wall has been unknown.When logarithmically growing cells of E. coli are transferred into a medium containing 20% sucrose, the cells plasmolize: the protoplast shrinks and becomes separated from the somewhat rigid cell wall. When these cells are fixed in 8% Formaldehyde, post-fixed in OsO4/uranyl acetate, embedded in Vestopal W, then cut in an ultramicrotome and observed with the electron microscope, the separation of protoplast and wall becomes clearly visible, (Fig. 1, 2). At a number of locations however, the protoplasmic membrane adheres to the wall even under the considerable pull of the shrinking protoplast. Thus numerous connecting bridges are maintained between protoplast and cell wall. Estimations of the total number of such wall/membrane associations yield a number of about 300 per cell.


Author(s):  
John L.Beggs ◽  
John D. Waggener ◽  
Wanda Miller ◽  
Jane Watkins

Studies using mesenteric and ear chamber preparations have shown that interendothelial junctions provide the route for neutrophil emigration during inflammation. The term emigration refers to the passage of white blood cells across the endothelium from the vascular lumen. Although the precise pathway of transendo- thelial emigration in the central nervous system (CNS) has not been resolved, the presence of different physiological and morphological (tight junctions) properties of CNS endothelium may dictate alternate emigration pathways.To study neutrophil emigration in the CNS, we induced meningitis in guinea pigs by intracisternal injection of E. coli bacteria.In this model, leptomeningeal inflammation is well developed by 3 hr. After 3 1/2 hr, animals were sacrificed by arterial perfusion with 3% phosphate buffered glutaraldehyde. Tissues from brain and spinal cord were post-fixed in 1% osmium tetroxide, dehydrated in alcohols and propylene oxide, and embedded in Epon. Thin serial sections were cut with diamond knives and examined in a Philips 300 electron microscope.


Author(s):  
J. P. Petrali ◽  
E. J. Donati ◽  
L. A. Sternberger

Specific contrast is conferred to subcellular antigen by applying purified antibodies, exhaustively labeled with uranium under immunospecific protection, to ultrathin sections. Use of Seligman’s principle of bridging osmium to metal via thiocarbohydrazide (TCH) intensifies specific contrast. Ultrathin sections of osmium-fixed materials were stained on the grid by application of 1) thiosemicarbazide (TSC), 2) unlabeled specific antiserum, 3) uranium-labeled anti-antibody and 4) TCH followed by reosmication. Antigens to be localized consisted of vaccinia antigen in infected HeLa cells, lysozyme in monocytes of patients with monocytic or monomyelocytic leukemia, and fibrinogen in the platelets of these leukemic patients. Control sections were stained with non-specific antiserum (E. coli).In the vaccinia-HeLa system, antigen was localized from 1 to 3 hours following infection, and was confined to degrading virus, the inner walls of numerous organelles, and other structures in cytoplasmic foci. Surrounding architecture and cellular mitochondria were unstained. 8 to 14 hours after infection, antigen was localized on the outer walls of the viral progeny, on cytoplasmic membranes, and free in the cytoplasm. Staining of endoplasmic reticulum was intense and focal early, and weak and diffuse late in infection.


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