scholarly journals The use of bacterial luciferase for monitoring the environmental regulation of expression of genes encoding virulence factors in Listeria monocytogenes

1992 ◽  
Vol 138 (12) ◽  
pp. 2619-2627 ◽  
Author(s):  
S. F. Park ◽  
G. S. A. B. Stewart ◽  
R. G. Kroll
Keyword(s):  
Listeria Monocytogenes ◽  
Environmental Regulation ◽  
Virulence Factors ◽  
Bacterial Luciferase ◽  
Regulation Of Expression ◽  
Expression Of Genes ◽  
Genes Encoding

Transcriptome Analysis of Listeria monocytogenes Grown on a Ready-to-Eat Meat Matrix

2011 ◽  
Vol 74 (7) ◽  
pp. 1104-1111 ◽  
Author(s):  
DONGRYEOUL BAE ◽  
MICHAEL R. CROWLEY ◽  
CHINLING WANG
Keyword(s):  
Listeria Monocytogenes ◽  
Virulence Factors ◽  
Microarray Data ◽  
Meat Products ◽  
Phospholipid Metabolism ◽  
Transcriptional Level ◽  
Cellular Processes ◽  
Reverse Transcription Pcr ◽  
Expression Of Genes ◽  
Genes Encoding

The contamination of ready-to-eat (RTE) meat products with Listeria monocytogenes is a major concern for the food industry. For a better understanding of the adaptation and survival ability of L. monocytogenes grown on turkey deli meat, the transcriptome of L. monocytogenes strain F2365 was determined with a microarray. Microarray data were validated with a quantitative real-time reverse transcription PCR assay. Based on the microarray data, 39 and 45 genes from L. monocytogenes were transcriptionally upregulated and down-regulated, respectively. The genes regulated at the transcriptional level were mainly involved in energy metabolism, fatty acid and phospholipid metabolism, biosynthesis of proteins, transport and binding proteins, DNA metabolism, cellular processes, and regulatory functions. No significant change was noted for the expression of genes encoding known virulence factors such as sigB, prfA, inlA, inlB, plcA, plcB, and hly. These results suggest that L. monocytogenes grown on RTE deli meat changes its transcription of proteins involved in its metabolic pathways to obtain an energy source or to adapt to environmental change without increasing the expression of virulence factors. The global transcriptome profiles provide a better understanding of the growth or adaptation of L. monocytogenes in RTE meat products.

scholarly journals NtbHLH1, a JAF13-like bHLH, interacts with NtMYB6 to enhance proanthocyanidin accumulation in Chinese Narcissus

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yuxin Fan ◽  
Jiayu Peng ◽  
Jiacheng Wu ◽  
Ping Zhou ◽  
Ruijie He ◽  
...  
Keyword(s):  
Flavonoid Biosynthesis ◽  
Transcriptional Level ◽  
Flavonoid Pathway ◽  
Regulation Of Expression ◽  
Over Expression ◽  
Expression Of Genes ◽  
Genes Encoding ◽  
Regulatory Complex ◽  
Positive Regulators ◽  
R2r3 Myb

Abstract Background Flavonoid biosynthesis in plants is primarily regulated at the transcriptional level by transcription factors modulating the expression of genes encoding enzymes in the flavonoid pathway. One of the most studied transcription factor complexes involved in this regulation consists of a MYB, bHLH and WD40. However, in Chinese Narcissus (Narcissus tazetta L. var. chinensis), a popular monocot bulb flower, the regulatory mechanism of flavonoid biosynthesis remains unclear. Results In this work, genes related to the regulatory complex, NtbHLH1 and a R2R3-MYB NtMYB6, were cloned from Chinese Narcissus. Phylogenetic analysis indicated that NtbHLH1 belongs to the JAF13 clade of bHLH IIIf subgroup, while NtMYB6 was highly homologous to positive regulators of proanthocyanidin biosynthesis. Both NtbHLH1 and NtMYB6 have highest expression levels in basal plates of Narcissus, where there is an accumulation of proanthocyanidin. Ectopic over expression of NtbHLH1 in tobacco resulted in an increase in anthocyanin accumulation in flowers, and an up-regulation of expression of the endogenous tobacco bHLH AN1 and flavonoid biosynthesis genes. In contrast, the expression level of LAR gene was significantly increased in NtMYB6-transgenic tobacco. Dual luciferase assays showed that co-infiltration of NtbHLH1 and NtMYB6 significantly activated the promoter of Chinese Narcissus DFR gene. Furthermore, a yeast two-hybrid assay confirmed that NtbHLH1 interacts with NtMYB6. Conclusions Our results suggest that NtbHLH1 may function as a regulatory partner by interacting directly with NtMYB6 to enhance proanthocyanidin accumulation in Chinese Narcissus.

Peptidergic Regulation of Expression of Genes Encoding Antioxidant and Anti-Inflammatory Proteins

2012 ◽  
Vol 152 (5) ◽  
pp. 615-618 ◽  
Author(s):  
V. Kh. Khavinson ◽  
N. S. Lin’kova ◽  
A. V. Dudkov ◽  
V. O. Polyakova ◽  
I. M. Kvetnoi
Keyword(s):  
Regulation Of Expression ◽  
Expression Of Genes ◽  
Genes Encoding ◽  
Inflammatory Proteins ◽  
Anti Inflammatory

scholarly journals Effect of Acid Adaptation on the Fate of Listeria monocytogenes in THP-1 Human Macrophages Activated by Gamma Interferon

2002 ◽  
Vol 70 (8) ◽  
pp. 4369-4378 ◽  
Author(s):  
Maria Pia Conte ◽  
Gloria Petrone ◽  
Assunta Maria Di Biase ◽  
Catia Longhi ◽  
Michela Penta ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Cell Invasion ◽  
Acid Resistance ◽  
Intracellular Survival ◽  
Low Ph ◽  
Gamma Interferon ◽  
Acid Adaptation ◽  
Human Macrophages ◽  
Expression Of Genes ◽  
Genes Encoding

ABSTRACT In Listeria monocytogenes the acid tolerance response (ATR) takes place through a programmed molecular response which ensures cell survival under unfavorable conditions. Much evidence links ATR with virulence, but the molecular determinants involved in the reactivity to low pHs and the behavior of acid-exposed bacteria within host cells are still poorly understood. We have investigated the effect of acid adaptation on the fate of L. monocytogenes in human macrophages. Expression of genes encoding determinants for cell invasion and intracellular survival was tested for acid-exposed bacteria, and invasive behavior in the human myelomonocytic cell line THP-1 activated with gamma interferon was assessed. Functional approaches demonstrated that preexposure to an acidic pH enhances the survival of L. monocytogenes in activated human macrophages and that this effect is associated with an altered pattern of expression of genes involved in acid resistance and cell invasion. Significantly decreased transcription of the plcA gene, encoding a phospholipase C involved in vacuolar escape and cell-to-cell spread, was observed in acid-adapted bacteria. This effect was due to a reduction in the quantity of the bicistronic plcA-prfA transcript, concomitant with an increase in the level(s) of the monocistronic prfA mRNA(s). The transcriptional shift from distal to proximal prfA promoters resulted in equal levels of the prfA transcript (and, as a consequence, of the inlA, hly, and actA transcripts) under neutral and acidic conditions. In contrast, the sodC and gad genes, encoding a cytoplasmic superoxide dismutase and the glutamate-based acid resistance system, respectively, were positively regulated at a low pH. Morphological approaches confirmed the increased intracellular survival and growth of acid-adapted L. monocytogenes cells both in vacuoles and in the cytoplasm of interferon gamma-activated THP-1 macrophages. Our data indicate that preexposure to a low pH has a positive impact on subsequent challenge of L. monocytogenes with macrophagic cells.

scholarly journals σB Activation under Environmental and Energy Stress Conditions in Listeria monocytogenes

2006 ◽  
Vol 72 (8) ◽  
pp. 5197-5203 ◽  
Author(s):  
Soraya Chaturongakul ◽  
Kathryn J. Boor
Keyword(s):  
Listeria Monocytogenes ◽  
Cumene Hydroperoxide ◽  
Stress Conditions ◽  
Wild Type ◽  
Regulation Of Expression ◽  
Transcript Levels ◽  
Energy Stress ◽  
Expression Studies ◽  
Genes Encoding ◽  
Gene Expression Studies

ABSTRACT To measure σB activation in Listeria monocytogenes under environmental or energy stress conditions, quantitative reverse transcriptase PCR (TaqMan) was used to determine the levels of transcripts for the σB-dependent opuCA and clpC genes in strains having null mutations in genes encoding regulator of sigma B proteins (rsbT and rsbV) and sigma B (sigB) and in the L. monocytogenes wild-type 10403S strain under different stress conditions. The ΔsigB, ΔrsbT, and ΔrsbV strains previously exhibited increased hemolytic activities compared to the hemolytic activity of the wild-type strain; therefore, transcript levels for hly were also determined. RsbT, RsbV, and σB were all required for opuCA expression during growth under carbon-limiting conditions or following exposure to pH 4.5, salt, ethanol, or the protonophore carbonyl cyanide m-chlorophenylhydrazone (CCCP). Expression of clpC was RsbT, RsbV, and σB dependent in the presence of CCCP but not under the other conditions. hly expression was not RsbT, RsbV, or σB dependent in the presence of either CCCP or salt. opuCA transcript levels did not increase in the presence of rapidly lethal stresses (i.e., pH 2.5 or 13 mM cumene hydroperoxide) despite the enhanced survival of the wild type compared with the survival of the mutant strains under these conditions. These findings highlight the importance of complementing phenotypic characterizations with gene expression studies to identify direct and indirect effects of null mutations in regulatory genes, such as sigB. Overall, our data show that while σB activation occurs through a single pathway under both environmental and energy stress conditions, regulation of expression of some stress response and virulence genes in the σB regulon (e.g., clpC) appears to require networks involving multiple transcriptional regulators.

scholarly journals Chlorogenic Acid Protects against Advanced Alcoholic Steatohepatitis in Rats via Modulation of Redox Homeostasis, Inflammation, and Lipogenesis

Nutrients ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 4155
Author(s):  
Vyacheslav Buko ◽  
Ilya Zavodnik ◽  
Grażyna Budryn ◽  
Małgorzata Zakłos-Szyda ◽  
Elena Belonovskaya ◽  
...  
Keyword(s):  
Chlorogenic Acid ◽  
High Fat Diet ◽  
Redox Homeostasis ◽  
Therapeutic Effects ◽  
High Fat ◽  
Regulation Of Expression ◽  
Alcoholic Steatohepatitis ◽  
Expression Of Genes ◽  
Genes Encoding ◽  
Liver Triglycerides

The aim of this study was to evaluate the therapeutic effects of chlorogenic acid (CGA) in rats with advanced alcoholic steatohepatitis. The rats were fed on a high-fat diet and gavaged with ethanol (4 g/kg) for 8 weeks. The livers of ethanol-treated rats showed steatosis; necrosis and mononuclear infiltration; and significant upregulation of the mRNA expression of the prooxidant (Cyp2e1, iNos), lipogenic (Srebp1, Acc), proinflammatory (Tlr4, Nf-κb, TnfA, Il-1B, and Il-6), and profibrogenic (TgfB, Col1, VegfA) genes. Simultaneously, a downregulation of level of Sod and Nrf2 was observed, which was accompanied by increased serum transaminase, TnfA, and serum and liver triglycerides levels. CGA administration (40 and 80 mg/kg, 8 weeks) to ethanol-fed group reduced the liver expression levels of Cyp2e1 and iNos, whereas it markedly enhanced the expression of Sod, Nrf2, and Ho-1. CGA at both doses downregulated the expressions of lipogenic, proinflammatory, and profibrogenic genes, while the expression of Tlr4 was lowered only after the higher dose of CGA. The higher dose of CGA efficiently prevented the progression of alcohol-induced steatosis and reduced inflammation through regulation of the expression of genes encoding the proteins involved in the Tlr4/Nf-κB signaling pathway and fibrosis. The study revealed hepatoprotective and anti-inflammatory effects of CGA through the regulation of expression of genes encoding Cyp2e1/Nrf2 involved in oxidative stress modulation. These results demonstrate CGA as a therapeutic candidate for the prevention and treatment of alcoholic steatohepatitis.

scholarly journals O-Acetylserine and the Regulation of Expression of Genes Encoding Components for Sulfate Uptake and Assimilation in Potato

2005 ◽  
Vol 138 (1) ◽  
pp. 433-440 ◽  
Author(s):  
Laura Hopkins ◽  
Saroj Parmar ◽  
Anna Błaszczyk ◽  
Holger Hesse ◽  
Rainer Hoefgen ◽  
...  
Keyword(s):  
Sulfate Uptake ◽  
Regulation Of Expression ◽  
Expression Of Genes ◽  
Genes Encoding

scholarly journals Tools, Strains, and Strategies To Effectively Conduct Anaerobic and Aerobic Transcriptional Reporter Screens and Assays in Staphylococcus aureus

2021 ◽  
Vol 87 (21) ◽  
Author(s):  
Erin E. Price ◽  
Paulami Rudra ◽  
Javiera Norambuena ◽  
Franklin Román-Rodríguez ◽  
Jeffrey M. Boyd
Keyword(s):  
Infectious Disease ◽  
Staphylococcus Aureus ◽  
Virulence Factors ◽  
Human Pathogen ◽  
Content Type ◽  
Transcriptional Reporter ◽  
Expression Of Genes ◽  
Genes Encoding ◽  
Host Tissues

Staphylococcus aureus is a human pathogen and a leading cause of infectious disease-related illness and death worldwide. For S. aureus to successfully colonize and invade host tissues, it must tightly control the expression of genes encoding virulence factors.

scholarly journals Enterococcal PrgU Provides Additional Regulation of Pheromone-Inducible Conjugative Plasmids

mSphere ◽  
2021 ◽  
Author(s):  
Lena Lassinantti ◽  
Martha I. Camacho ◽  
Rebecca J. B. Erickson ◽  
Julia L. E. Willett ◽  
Nicholas R. De Lay ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Secretion Systems ◽  
Gram Positive ◽  
Regulation Of Expression ◽  
Conjugative Plasmids ◽  
Gram Positive Bacteria ◽  
Genes Encoding ◽  
Surface Adhesins

Bacteria utilize type 4 secretion systems (T4SS) to efficiently transfer DNA between donor and recipient cells, thereby spreading genes encoding antibiotic resistance as well as various virulence factors. Regulation of expression of the T4SS proteins and surface adhesins in Gram-positive bacteria is crucial, as some of these are highly toxic to the cell.

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