scholarly journals Molecular Detection of Viable Bacterial Pathogens in Water by Ratiometric Pre-rRNA Analysis

2009 ◽  
Vol 76 (3) ◽  
pp. 960-962 ◽  
Author(s):  
Gerard A. Cangelosi ◽  
Kris M. Weigel ◽  
Clarita Lefthand-Begay ◽  
John S. Meschke
Keyword(s):  
Environmental Samples ◽  
Molecular Detection ◽  
Dna Detection ◽  
Bacterial Pathogens ◽  
Bacterial Cells ◽  
Viability Test ◽  
Stimulation Of

ABSTRACT Ratiometric pre-rRNA analysis (RPA) detects the replenishment of rRNA precursors that occurs rapidly upon nutritional stimulation of bacterial cells. In contrast to DNA detection by PCR, RPA distinguishes viable from inactivated bacteria. It exhibits promise as a molecular viability test for pathogens in water and other environmental samples.

The effect of exogenous RNA extract on chick embryo fibroblasts in vitro

Development ◽  
1970 ◽  
Vol 23 (2) ◽  
pp. 509-517
Author(s):  
A. Sann ◽  
D. Sharp ◽  
J. McKenzie
Keyword(s):  
Cell Differentiation ◽  
Chick Embryo ◽  
Morphological Changes ◽  
Bacterial Cells ◽  
Baby Hamster Kidney ◽  
Exogenous Rna ◽  
Embryo Fibroblasts ◽  
Stimulation Of ◽  
Rna Extract

It is extremely difficult, if not impossible, to reconcile the conflicting claims of those who have treated different cells and tissues with exogenous RNA. Some authors (e.g. Niu, Cordova & Niu, 1961; Niu, Cordova & Radbill, 1962) maintain that RNA extracts alter the course of cell differentiation to conform in morphological terms to the source of the RNA; in the same vein, Amos, Askonas & Soeiro (1964) have shown that, under certain conditions, RNA from mouse and bacterial cells can stimulate chick embryo fibroblasts to synthesize protein related antigenically to the origin of the RNA. Shepley, Ambrose & Kirby (1965), however, obtained stimulation of growth with permanent morphological changes in baby hamster kidney fibroblasts by the addition of RNA from a variety of sources.

Detection of bacterial pathogens in environmental samples using DNA microarrays

2003 ◽  
Vol 53 (2) ◽  
pp. 235-243 ◽  
Author(s):  
Douglas R. Call ◽  
Monica K. Borucki ◽  
Frank J. Loge
Keyword(s):  
Environmental Samples ◽  
Dna Microarrays ◽  
Bacterial Pathogens

scholarly journals Mode-of-Action of Antimicrobial Peptides: Membrane Disruption vs. Intracellular Mechanisms

2020 ◽  
Vol 2 ◽  
Author(s):  
Aurélie H. Benfield ◽  
Sónia Troeira Henriques
Keyword(s):  
Antimicrobial Peptides ◽  
Physicochemical Properties ◽  
Broad Spectrum ◽  
Mode Of Action ◽  
Bacterial Pathogens ◽  
Model Membranes ◽  
Membrane Disruption ◽  
Attractive Alternative ◽  
Bacterial Cells

Antimicrobial peptides are an attractive alternative to traditional antibiotics, due to their physicochemical properties, activity toward a broad spectrum of bacteria, and mode-of-actions distinct from those used by current antibiotics. In general, antimicrobial peptides kill bacteria by either disrupting their membrane, or by entering inside bacterial cells to interact with intracellular components. Characterization of their mode-of-action is essential to improve their activity, avoid resistance in bacterial pathogens, and accelerate their use as therapeutics. Here we review experimental biophysical tools that can be employed with model membranes and bacterial cells to characterize the mode-of-action of antimicrobial peptides.

scholarly journals Induction of Proinflammatory Cytokines from Human Respiratory Epithelial Cells after Stimulation by NontypeableHaemophilus influenzae

2000 ◽  
Vol 68 (8) ◽  
pp. 4430-4440 ◽  
Author(s):  
Daniel L. Clemans ◽  
Richard J. Bauer ◽  
Julie A. Hanson ◽  
Monte V. Hobbs ◽  
Joseph W. St. Geme ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Proinflammatory Cytokines ◽  
Cytokine Gene Expression ◽  
Bacterial Cells ◽  
Respiratory Epithelial Cells ◽  
Rnase Protection ◽  
Tracheal Epithelial ◽  
Respiratory Epithelial ◽  
Stimulation Of

ABSTRACT Nontypeable Haemophilus influenzae (NTHi) causes repeated respiratory infections in patients with chronic lung diseases. These infections are characterized by a brisk inflammatory response which results in the accumulation of polymorphonucleated cells in the lungs and is dependent on the expression and secretion of proinflammatory cytokines. We hypothesize that multiple NTHi molecules, including lipooligosaccharide (LOS), mediate cellular interactions with respiratory epithelial cells, leading to the production of proinflammatory cytokines. To address this hypothesis, we exposed 9HTEo− human tracheal epithelial cells to NTHi and compared the resulting profiles of cytokine gene expression and secretion using multiprobe RNase protection assays and enzyme-linked immunosorbent assays (ELISA), respectively. Dose-response experiments demonstrated a maximum stimulation of most cytokines tested, using a ratio of 100 NTHi bacterial cells to 1 9HTEo− tracheal epithelial cell. Compared with purified LOS, NTHi bacterial cells stimulated 3.6- and 4.5-fold increases in epithelial cell expression of interleukin-8 (IL-8) and IL-6 genes, respectively. Similar results were seen with epithelial cell macrophage chemotactic protein 1, IL-1α, IL-1β, and tumor necrosis factor alpha expression. Polymyxin B completely inhibited LOS stimulation but only partially reduced NTHi whole cell stimulation. Taken together, these results suggest that multiple bacterial molecules including LOS contribute to the NTHi stimulation of respiratory epithelial cell cytokine production. Moreover, no correlation was seen between NTHi adherence to epithelial cells mediated by hemagglutinating pili, Hia, HMW1, HMW2, and Hap and epithelial cytokine secretion. These data suggest that bacterial molecules beyond previously described NTHi cell surface adhesins and LOS play a role in the induction of proinflammatory cytokines from respiratory epithelial cells.

scholarly journals Molecular detection of marine nematodes from environmental samples: overcoming eukaryotic interference

2006 ◽  
Vol 44 ◽  
pp. 97-103 ◽  
Author(s):  
P Bhadury ◽  
MC Austen ◽  
DT Bilton ◽  
PJD Lambshead ◽  
AD Rogers ◽  
...  
Keyword(s):  
Environmental Samples ◽  
Molecular Detection ◽  
Marine Nematodes

scholarly journals The Mammalian Neuroendocrine Hormone Norepinephrine Supplies Iron for Bacterial Growth in the Presence of Transferrin or Lactoferrin

2000 ◽  
Vol 182 (21) ◽  
pp. 6091-6098 ◽  
Author(s):  
Primrose P. E. Freestone ◽  
Mark Lyte ◽  
Christopher P. Neal ◽  
Anthony F. Maggs ◽  
Richard D. Haigh ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Serum Albumin ◽  
Bacterial Growth ◽  
Bacterial Species ◽  
Bacterial Cells ◽  
Excess Iron ◽  
Iron Supply ◽  
Inactive Metabolite ◽  
Serum Components ◽  
Stimulation Of

ABSTRACT Norepinephrine stimulates the growth of a range of bacterial species in nutritionally poor SAPI minimal salts medium containing 30% serum. Addition of size-fractionated serum components to SAPI medium indicated that transferrin was required for norepinephrine stimulation of growth of Escherichia coli. Since bacteriostasis by serum is primarily due to the iron-withholding capacity of transferrin, we considered the possibility that norepinephrine can overcome this effect by supplying transferrin-bound iron for growth. Incubation with concentrations of norepinephrine that stimulated bacterial growth in serum-SAPI medium resulted in loss of bound iron from iron-saturated transferrin, as indicated by the appearance of monoferric and apo- isoforms upon electrophoresis in denaturing gels. Norepinephrine also caused the loss of iron from lactoferrin. The pharmacologically inactive metabolite norepinephrine 3-O-sulfate, by contrast, did not result in iron loss from transferrin or lactoferrin and did not stimulate bacterial growth in serum-SAPI medium. Norepinephrine formed stable complexes with transferrin, lactoferrin, and serum albumin. Norepinephrine-transferrin and norepinephrine-lactoferrin complexes, but not norepinephrine-apotransferrin or norepinephrine-albumin complexes, stimulated bacterial growth in serum-SAPI medium in the absence of additional norepinephrine. Norepinephrine-stimulated growth in medium containing 55Fe complexed with transferrin or lactoferrin resulted in uptake of radioactivity by bacterial cells. Moreover, norepinephrine-stimulated growth in medium containing [3H]norepinephrine indicated concomitant uptake of norepinephrine. In each case, addition of excess iron did not affect growth but significantly reduced levels of radioactivity (55Fe or 3H) associated with bacterial cells. A role for catecholamine-mediated iron supply in the pathophysiology of infectious diseases is proposed.

scholarly journals Molecular Detection of Northern Leatherside Chub (Lepidomeda copei) DNA in Environmental Samples

2018 ◽  
Vol 78 (1) ◽  
pp. 92 ◽  
Author(s):  
Joseph C. Dysthe ◽  
Kellie J. Carim ◽  
Thomas W. Franklin ◽  
Dave Kikkert ◽  
Michael K. Young ◽  
...  
Keyword(s):  
Environmental Samples ◽  
Molecular Detection ◽  
Leatherside Chub

scholarly journals Advances in the Application of Aptamer Biosensors to the Detection of Aminoglycoside Antibiotics

Antibiotics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 787
Author(s):  
Yunxia Luan ◽  
Nan Wang ◽  
Cheng Li ◽  
Xiaojun Guo ◽  
Anxiang Lu
Keyword(s):  
Environmental Samples ◽  
Molecular Detection ◽  
Electrochemical Sensors ◽  
Detection Method ◽  
Aminoglycoside Antibiotics ◽  
Future Research ◽  
Social Concern ◽  
Food Items ◽  
Detection Technology ◽  
Animal Medicine

Antibiotic abuse is becoming increasingly serious and the potential for harm to human health and the environment has aroused widespread social concern. Aminoglycoside antibiotics (AGs) are broad-spectrum antibiotics that have been widely used in clinical and animal medicine. Consequently, their residues are commonly found in animal-derived food items and the environment. A simple, rapid, and sensitive detection method for on-site screening and detection of AGs is urgently required. In recent years, with the development of molecular detection technology, nucleic acid aptamers have been successfully used as recognition molecules for the identification and detection of AGs in food and the environment. These aptamers have high affinities, selectivities, and specificities, are inexpensive, and can be produced with small batch-to-batch differences. This paper reviews the applications of aptamers for AG detection in colorimetric, fluorescent, chemiluminescent, surface plasmon resonance, and electrochemical sensors for the analysis in food and environmental samples. This study provides useful references for future research.

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