scholarly journals Investigating Transcriptomic Induction of Resistance and/or Virulence in Listeria monocytogenes Cells Surviving Sublethal Antimicrobial Exposure

Foods ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2382
Author(s):  
Eleni-Anna Kokkoni ◽  
Nikolaos Andritsos ◽  
Christina Sakarikou ◽  
Sofia Michailidou ◽  
Anagnostis Argiriou ◽  
...  
Keyword(s):  
Stress Response ◽  
Benzalkonium Chloride ◽  
Sublethal Concentration ◽  
Mitigation Strategies ◽  
Stress Physiology ◽  
Clinical Settings ◽  
Master Regulators ◽  
Sublethal Stress ◽  
Induction Of Resistance

The potential transcriptomic induction of resistance and/or virulence in two L. monocytogenes strains belonging to the most frequent listeriosis-associated serovars (i.e., 1/2a and 4b), following their sublethal antimicrobial exposure, was studied through qPCR determination of the relative expression of 10 selected related genes (i.e., groEL, hly, iap, inlA, inlB, lisK, mdrD, mdrL, prfA, and sigB). To induce sublethal stress, three common antimicrobials (i.e., benzalkonium chloride, thymol, and ampicillin) were individually applied for 2 h at 37 °C against stationary phase cells of each strain, each at a sublethal concentration. In general, the expression of most of the studied genes remained either stable or was significantly downregulated following the antimicrobial exposure, with some strain-specific differences to be yet recorded. Thymol provoked downregulation of most of the studied genes, significantly limiting the expression of 6/10 and 4/10 genes in the strains of ser. 1/2a and ser. 4b, respectively, including those coding for the master regulators of stress response and virulence (SigB and PrfA, respectively), in both strains. At the same time, the two genes coding for the invasion internalin proteins (InlA and InlB), with crucial role in the onset of L. monocytogenes pathogenesis, were both importantly upregulated in ser. 4b strain. The results obtained increase our knowledge of the stress physiology of L. monocytogenes under certain sublethal antimicrobial conditions that could be encountered within the food chain and in clinical settings, and may assist in better and more effective mitigation strategies.

scholarly journals MicroRNAs Are Involved in Regulating Plant Development and Stress Response through Fine-Tuning of TIR1/AFB-Dependent Auxin Signaling

2022 ◽  
Vol 23 (1) ◽  
pp. 510
Author(s):  
Pan Luo ◽  
Dongwei Di ◽  
Lei Wu ◽  
Jiangwei Yang ◽  
Yufang Lu ◽  
...  
Keyword(s):  
Stress Response ◽  
Fine Tuning ◽  
Auxin Signaling ◽  
In Planta ◽  
Auxin Response ◽  
Signal Molecule ◽  
Master Regulators ◽  
Non Coding Rna ◽  
Complex Regulation ◽  
Indole 3 Acetic Acid

Auxin, primarily indole-3-acetic acid (IAA), is a versatile signal molecule that regulates many aspects of plant growth, development, and stress response. Recently, microRNAs (miRNAs), a type of short non-coding RNA, have emerged as master regulators of the auxin response pathways by affecting auxin homeostasis and perception in plants. The combination of these miRNAs and the autoregulation of the auxin signaling pathways, as well as the interaction with other hormones, creates a regulatory network that controls the level of auxin perception and signal transduction to maintain signaling homeostasis. In this review, we will detail the miRNAs involved in auxin signaling to illustrate its in planta complex regulation.

A Practical Technique for Tympanocentesis for Culturing Aerobic and Anaerobic Bacteria

PEDIATRICS ◽  
1980 ◽  
Vol 65 (3) ◽  
pp. 626-627
Author(s):  
Itzhak Brook
Keyword(s):  
Middle Ear ◽  
Negative Pressure ◽  
Anaerobic Bacteria ◽  
Acute Otitis Media ◽  
Clinical Settings ◽  
Middle Ear Fluid ◽  
Simplified Method ◽  
Medical Indications ◽  
Aerobic And Anaerobic

Tympanocentesis is a method frequently used to aspirate middle ear fluid from infected ears. There are some medical indications to perform tympanocentesis in certain clinical settings.1 This procedure could be beneficial in some patients in which determination of the etiology of the acute otitis media and relieving the pain and acute symptoms is of importance. The instrument frequently used by otolaryngologists is the Senturia ear specimen collector (Storz Instrument Company, St Louis) which operates by controlled suctioning using an external negative pressure. A simplified method for performing myringotomy and tumpanocentesis2 that avoids the use of complicated equipment and prevents contamination of the specimen is presented here.

scholarly journals Determination of Benzalkonium Chloride Partition in Micelle Solutions Using Ultrafiltration Method

2009 ◽  
Vol 10 (4) ◽  
Author(s):  
Jun Liu ◽  
Guang Wei Lu ◽  
Miguel Sandoval ◽  
Yangzhen Ciringh ◽  
Gang Xue ◽  
...  
Keyword(s):  
Benzalkonium Chloride

scholarly journals Cyclosporin A but not FK506 activates the integrated stress response in human cells

2020 ◽  
Vol 295 (44) ◽  
pp. 15134-15143
Author(s):  
Anthony O. Fedele ◽  
Valérie Carraro ◽  
Jianling Xie ◽  
Julien Averous ◽  
Christopher G. Proud
Keyword(s):  
Stress Response ◽  
Cyclosporin A ◽  
Nutrient Deficiency ◽  
Initiation Factor ◽  
Clinical Settings ◽  
Nuclear Factor ◽  
Integrated Stress Response ◽  
Activated T Cells ◽  
Translational Machinery ◽  
Acute Reaction

Cyclosporin A (CsA) and tacrolimus (FK506) are valuable immunosuppressants for a range of clinical settings, including (but not limited to) organ transplantation and the treatment of autoimmune diseases. They function by inhibiting the activity of the Ca2+/calmodulin-dependent phosphatase calcineurin toward nuclear factor of activated T-cells (NF-AT) in T-lymphocytes. However, use of CsA is associated with more serious side effects and worse clinical outcomes than FK506. Here we show that CsA, but not FK506, causes activation of the integrated stress response (ISR), an event which is normally an acute reaction to various types of intracellular insults, such as nutrient deficiency or endoplasmic reticulum stress. These effects of CsA involve at least two of the stress-activated protein kinases (GCN2 and PERK) that act on the translational machinery to slow down protein synthesis via phosphorylation of the eukaryotic initiation factor (eIF) 2α and thereby induce the ISR. These actions of CsA likely contribute to the adverse effects associated with its clinical application.

scholarly journals Primary Investigation into the Occurrence of Hydroxymethylfurfural (HMF) in a Range of Smoked Products

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Laura-Artemis Bouzalakou-Butel ◽  
Pantelis Provatidis ◽  
Keith Sturrock ◽  
Alberto Fiore
Keyword(s):  
Thermal Processing ◽  
Elevated Temperatures ◽  
Food Products ◽  
Mitigation Strategies ◽  
Processed Meat ◽  
Thermal Processes ◽  
Preparation Process ◽  
Product Categories ◽  
Smoke Generation

5-Hydroxymethylfurfural (HMF) is produced in foods through many different pathways. Recently, studies have revealed its potential mutagenic and carcinogenic properties. Determination of HMF was originally used as an indicator of both the extent of thermal processing a food had undergone and food quality. It has been identified in a variety of food products such as bread, breakfast cereals, fruit juices, milk, and honey. In addition to the thermal processes that lead to the formation of HMF during thermal treatment, food smoking also creates conditions that result in the formation of HMF. This can take place within the food due to the elevated temperatures associated with hot smoking or by the proximity of the products of the pyrolysis of the wood matrix that is used for smoking (cold smoking). This may lead to further contamination of the product by HMF over and above that associated with the rest of the preparation process. Until now, there have been no studies examining the relation between the smoking procedure and HMF contamination in smoked food. This study is a primary investigation measuring HMF levels in three categories of smoked food products, cheese, processed meat, and fish, using HPLC-UV. The amount of HMF found in all three product categories supports our hypothesis that HMF levels are due to both internal pathways during processing and external contamination from the smoke generation matrix (wood) employed. The results ranged from 1 ppb (metsovone traditional Greek smoked cheese) to 4 ppm (hot-smoked ready-to-eat mackerel). Subsequently for smoked cheese products, a correlation was found between HMF and phenolic compounds generated by the smoking procedures and identified by SPME-GCMS. It was observed that cheese samples that had higher concentrations of HMF were also found to have higher concentrations of syringol and cresols. It is important therefore to understand the smoking procedure’s effect on HMF formation. This will aid in the development of mitigation strategies to reduce HMF formation while retaining the flavour of the smoked products.

scholarly journals Increasing Temperature and Relative Humidity Accelerates Inactivation of SARS-CoV-2 on Surfaces

mSphere ◽  
2020 ◽  
Vol 5 (4) ◽  
Author(s):  
Jennifer Biryukov ◽  
Jeremy A. Boydston ◽  
Rebecca A. Dunning ◽  
John J. Yeager ◽  
Stewart Wood ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Culture Media ◽  
Mitigation Strategies ◽  
Accurate Estimation ◽  
Clinical Settings ◽  
Indoor Environments ◽  
Type Stainless Steel ◽  
Contact Transmission ◽  
The Stability ◽  
Increasing Temperature

ABSTRACT Coronavirus disease 2019 (COVID-19) was first identified in China in late 2019 and is caused by newly identified severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Previous studies had reported the stability of SARS-CoV-2 in cell culture media and deposited onto surfaces under a limited set of environmental conditions. Here, we broadly investigated the effects of relative humidity, temperature, and droplet size on the stability of SARS-CoV-2 in a simulated clinically relevant matrix dried on nonporous surfaces. The results show that SARS-CoV-2 decayed more rapidly when either humidity or temperature was increased but that droplet volume (1 to 50 μl) and surface type (stainless steel, plastic, or nitrile glove) did not significantly impact decay rate. At room temperature (24°C), virus half-life ranged from 6.3 to 18.6 h depending on the relative humidity but was reduced to 1.0 to 8.9 h when the temperature was increased to 35°C. These findings suggest that a potential for fomite transmission may persist for hours to days in indoor environments and have implications for assessment of the risk posed by surface contamination in indoor environments. IMPORTANCE Mitigating the transmission of SARS-CoV-2 in clinical settings and public spaces is critically important to reduce the number of COVID-19 cases while effective vaccines and therapeutics are under development. SARS-CoV-2 transmission is thought to primarily occur through direct person-to-person transfer of infectious respiratory droplets or through aerosol-generating medical procedures. However, contact with contaminated surfaces may also play a significant role. In this context, understanding the factors contributing to SARS-CoV-2 persistence on surfaces will enable a more accurate estimation of the risk of contact transmission and inform mitigation strategies. To this end, we have developed a simple mathematical model that can be used to estimate virus decay on nonporous surfaces under a range of conditions and which may be utilized operationally to identify indoor environments in which the virus is most persistent.

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