A genetic analysis of in vivo selenate reduction by Salmonella enterica serovar Typhimurium LT2 and Escherichia coli K12

2009 ◽  
Vol 191 (6) ◽  
pp. 519-528 ◽  
Author(s):  
David Guymer ◽  
Julien Maillard ◽  
Frank Sargent
Keyword(s):  
Escherichia Coli ◽  
Genetic Analysis ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Escherichia Coli K12 ◽  
Serovar Typhimurium

Detection of Escherichia coli O157, Salmonella enterica Serovar Typhimurium, and Staphylococcal Enterotoxin B in a Single Sample Using Enzymatic Bio-Nanotransduction

2007 ◽  
Vol 70 (4) ◽  
pp. 841-850 ◽  
Author(s):  
JOSH R. BRANEN ◽  
MARTHA J. HASS ◽  
ERIN R. DOUTHIT ◽  
WUSI C. MAKI ◽  
A. LARRY BRANEN
Keyword(s):  
Escherichia Coli ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Staphylococcal Enterotoxin B ◽  
Escherichia Coli O157 ◽  
Dna Templates ◽  
E Coli ◽  
Serovar Typhimurium ◽  
Biological Recognition ◽  
Enterotoxin B

Enzymatic bio-nanotransduction is a biological detection scheme based on the production of nucleic acid nano-signals (RNA) in response to specific biological recognition events. In this study, we applied an enzymatic bio-nanotransduction system to the detection of important food-related pathogens and a toxin. Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, and staphylococcal enterotoxin B (SEB) were chosen because of the implications of these targets to food safety. Primary antibodies to each of the targets were used to functionalize magnetic beads and produce biological recognition elements (antibodies) conjugated to nano-signal–producing DNA templates. Immunomagnetic capture that was followed by in vitro transcription of DNA templates bound to target molecules produced RNA nano-signals specific for every target in the sample. Discrimination of RNA nano-signals with a standard enzyme-linked oligonucleotide fluorescence assay provided a correlation between nano-signal profiles and target concentrations. The estimated limit of detection was 2.4 × 103 CFU/ml for E. coli O157:H7, 1.9 × 104 CFU/ml for S. enterica serovar Typhimurium, and 0.11 ng/ml for SEB with multianalyte detection in buffer. Low levels of one target were also detected in the presence of interference from high levels of the other targets. Finally, targets were detected in milk, and detection was improved for E. coli O157 by heat treatment of the milk.

scholarly journals Attenuation of Salmonella enterica Serovar Typhimurium by Altering Biological Functions of Murein Lipoprotein and Lipopolysaccharide

2005 ◽  
Vol 73 (12) ◽  
pp. 8433-8436 ◽  
Author(s):  
A. A. Fadl ◽  
J. Sha ◽  
G. R. Klimpel ◽  
J. P. Olano ◽  
C. L. Galindo ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Biological Functions ◽  
Double Knockout ◽  
In Vivo Models ◽  
Background Strain ◽  
Knockout Mutants ◽  
Serovar Typhimurium

ABSTRACT We constructed Salmonella enterica serovar Typhimurium double-knockout mutants in which either the lipoprotein A (lppA) or the lipoprotein B (lppB) gene was deleted from an msbB-negative background strain by marker exchange mutagenesis. These mutants were highly attenuated when tested with in vitro and in vivo models of Salmonella pathogenesis.

Artificial small RNA-mediated growth inhibition in Escherichia coli and Salmonella enterica serovar Typhimurium

2020 ◽  
Vol 521 (3) ◽  
pp. 577-583 ◽  
Author(s):  
Mitsuoki Kawano ◽  
Shota Morohashi ◽  
Kohei Oda ◽  
Masataka Ishikawa ◽  
Shouta Fujita ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Growth Inhibition ◽  
Small Rna ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Serovar Typhimurium

scholarly journals Salmonella enterica Serovar Typhimurium and Escherichia coli Survival in Estuarine Bank Sediments

2018 ◽  
Vol 15 (11) ◽  
pp. 2597 ◽  
Author(s):  
Mahbubul Siddiqee ◽  
Rebekah Henry ◽  
Rebecca Coulthard ◽  
Christelle Schang ◽  
Richard Williamson ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Growth Patterns ◽  
Estuarine Sediments ◽  
Human Pathogens ◽  
Indicator Organisms ◽  
Fecal Indicator ◽  
E Coli ◽  
Serovar Typhimurium

Estuarine bank sediments have the potential to support the survival and growth of fecal indicator organisms, including Escherichia coli. However, survival of fecal pathogens in estuarine sediments is not well researched and therefore remains a significant knowledge gap regarding public health risks in estuaries. In this study, simultaneous survival of Escherichia coli and a fecal pathogen, Salmonella enterica serovar Typhimurium, was studied for 21 days in estuarine bank sediment microcosms. Observed growth patterns for both organisms were comparable under four simulated scenarios; for continuous-desiccation, extended-desiccation, periodic-inundation, and continuous-inundation systems, logarithmic decay coefficients were 1.54/day, 1.51/day, 0.14/day, and 0.20/day, respectively, for E. coli, and 1.72/day, 1.64/day, 0.21/day, and 0.24/day for S. Typhimurium. Re-wetting of continuous-desiccated systems resulted in potential re-growth, suggesting survival under moisture-limited conditions. Key findings from this study include: (i) Bank sediments can potentially support human pathogens (S. Typhimurium), (ii) inundation levels influence the survival of fecal bacteria in estuarine bank sediments, and (iii) comparable survival rates of S. Typhimurium and E. coli implies the latter could be a reliable fecal indicator in urban estuaries. The results from this study will help select suitable monitoring and management strategies for safer recreational activities in urban estuaries.

scholarly journals Rcs and PhoPQ Regulatory Overlap in the Control of Salmonella enterica Virulence

2007 ◽  
Vol 189 (18) ◽  
pp. 6635-6644 ◽  
Author(s):  
Clara B. García-Calderón ◽  
Josep Casadesús ◽  
Francisco Ramos-Morales
Keyword(s):  
Escherichia Coli ◽  
Signal Transduction ◽  
Salmonella Enterica ◽  
In Vivo Studies ◽  
Genetic Screens ◽  
Signal Transduction System ◽  
Constitutive Activation ◽  
Regulatory Systems ◽  
Serovar Typhimurium

ABSTRACT Genetic screens based on the use of MudJ-generated lac fusions permitted the identification of novel genes regulated by the Rcs signal transduction system in Salmonella enterica serovar Typhimurium. Besides genes that are also found in the Escherichia coli genome, our screens identified Salmonella-specific genes regulated by RcsB, including bapA, siiE, srfA, and srfB. Here we show that the srfABC operon is negatively regulated by RcsB and by PhoP. In vivo studies using mutants with constitutive activation of the Rcs and/or PhoPQ system suggested that there is an overlap between these regulatory systems in the control of Salmonella virulence.

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