scholarly journals Coordination of cohabiting phage elements supports bacteria–phage cooperation

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Tal Argov ◽  
Shai Ran Sapir ◽  
Anna Pasechnek ◽  
Gil Azulay ◽  
Olga Stadnyuk ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Bacterial Pathogens ◽  
Molecular Switch ◽  
Complex Environments ◽  
Phage Tail ◽  
Bacterial Lysis ◽  
Viral Particles ◽  
Response To Stress ◽  
Insight Into

AbstractBacterial pathogens often carry multiple prophages and other phage-derived elements within their genome, some of which can produce viral particles in response to stress. Listeria monocytogenes 10403S harbors two phage elements in its chromosome, both of which can trigger bacterial lysis under stress: an active prophage (ϕ10403S) that promotes the virulence of its host and can produce infective virions, and a locus encoding phage tail-like bacteriocins. Here, we show that the two phage elements are co-regulated, with the bacteriocin locus controlling the induction of the prophage and thus its activity as a virulence-associated molecular switch. More specifically, a metalloprotease encoded in the bacteriocin locus is upregulated in response to stress and acts as an anti-repressor for CI-like repressors encoded in each phage element. Our results provide molecular insight into the phenomenon of polylysogeny and its intricate adaptation to complex environments.

New insight into the molecular switch mechanism of human Rho family proteins: shifting a paradigm

2013 ◽  
Vol 394 (1) ◽  
pp. 89-95 ◽  
Author(s):  
Mamta Jaiswal ◽  
Eyad Kalawy Fansa ◽  
Radovan Dvorsky ◽  
Mohammad Reza Ahmadian
Keyword(s):  
Quantitative Analysis ◽  
Bound State ◽  
Molecular Switch ◽  
Nucleotide Exchange ◽  
Gtp Binding ◽  
Switch Mechanism ◽  
Rho Family ◽  
Rho Family Proteins ◽  
Insight Into ◽  
Made In

Abstract Major advances have been made in understanding the structure, function and regulation of the small GTP-binding proteins of the Rho family and their involvement in multiple cellular process and disorders. However, intrinsic nucleotide exchange and hydrolysis reactions, which are known to be fundamental to Rho family proteins, have been partially investigated in the case of RhoA, Rac1 and Cdc42, but for others not at all. Here we present a comprehensive and quantitative analysis of the molecular switch functions of 15 members of the Rho family that enabled us to propose an active GTP-bound state for the rather uncharacterized isoforms RhoD and Rif under equilibrium and quiescent conditions.

scholarly journals Anticoagulants and the Hemostatic System: A Primer for Occupational Stress Researchers

2021 ◽  
Vol 18 (20) ◽  
pp. 10626
Author(s):  
Eamonn Arble ◽  
Bengt B. Arnetz
Keyword(s):  
Occupational Stress ◽  
Blood Clotting ◽  
Biological Process ◽  
Occupational Functioning ◽  
System A ◽  
Hemostatic System ◽  
Response To Stress ◽  
Occupational Strain ◽  
Potential Methods ◽  
Insight Into

Anticoagulation, the body’s mechanism to prevent blood clotting, is an internal biomarker of an individual’s response to stress. Research has indicated that understanding the causes, processes, and consequences of anticoagulation can provide important insight into the experience of individuals facing emotional and occupational strain. Unfortunately, despite their importance, the mechanisms and implications of anticoagulation are unfamiliar to many researchers and practitioners working with trauma-exposed professionals. This paper provides an accessible primer on the topic of anticoagulation, including an overview of the biological process, the research connecting these processes with emotional and occupational functioning, as well as some potential methods for assessment.

scholarly journals A global perspective of antibiotic-resistant Listeria monocytogenes prevalence in assorted ready to eat foods: A systematic review

2021 ◽  
pp. 2219-2229
Author(s):  
Prudence Mpundu ◽  
Allan Rabson Mbewe ◽  
John Bwalya Muma ◽  
Wizaso Mwasinga ◽  
Nawa Mukumbuta ◽  
...  
Keyword(s):  
Systematic Review ◽  
Antibiotic Resistance ◽  
Listeria Monocytogenes ◽  
Meta Analysis ◽  
Global Perspective ◽  
Valuable Insight ◽  
Resistance Profile ◽  
Antibiotic Resistance Profile ◽  
Pooled Prevalence ◽  
Insight Into

Background and Aim: Listeria monocytogenes in ready-to-eat (RTE) foods remains consistently under-reported globally. Nevertheless, several independent studies conducted to investigate have elucidated the prevalence and antibiotic resistance profiles of L. monocytogenes in RTE-associated foods and their antibiotic resistance profiles. Given the rapid increase in consumption of RTE foods of both animal and plant origin, it is imperative to know the prevalence deductive data focusing on how much of L. monocytogenes is present in RTE foods, which is critical for food safety managers and retailers to assess the possible risk posed to end-users. In addition, valuable insight and another angle to the depth of the problem, we conducted a systematic review and meta-analysis to synthesize available data regarding the prevalence of L. monocytogenes in RTE foods and antibiotic resistance profiles. Materials and Methods: We conducted a meta-analysis study of L. monocytogenes and antibiotic resistance to clinically relevant antibiotics to determine the extent of L. monocytogenes contamination in RTE foods and antibiotic resistance profiles. The primary search terms, also known as keywords used, were restricted to peer-reviewed and review articles, and databases, including Google Scholars, Science-Direct, and Scopus, were searched. The inclusion of articles meeting eligibility criteria published between 2010 and 2020 after title, abstract, and full article screening. Data analysis was performed at multiple stages using quantitative meta-analysis reviews. Results: L. monocytogenes pooled proportion/prevalence was highest in chicken products determined at (22%) followed by various but uncategorized RTE foods at 21%. Regarding antibiotic resistance, profiling's highest pooled prevalence resistance was observed in penicillin at 80% resistance, followed by cephalosporin at 47%. Conclusion: Within its limitations, this study has attempted to provide insight into the pooled proportion/prevalence of L. monocytogenes in RTE foods and the antibiotic resistance profile at the global level. Determining the proportion/ prevalence of L. monocytogenes in RTE foods across the globe and antibiotic resistance profile is essential for providing quality food and reducing public health problems due to unsuccessful treatment of foodborne illness. This study provides insight into the pooled prevalence of L. monocytogenes in RTE foods and the antibiotic resistance profile. The results of this study partly endeavored to help appropriate authorities strengthen their preventive measures on specific RTE foods that are most likely to be contaminated with L. monocytogenes and antibiotic resistance profiles.

scholarly journals The CBL–CIPK Pathway in Plant Response to Stress Signals

2020 ◽  
Vol 21 (16) ◽  
pp. 5668
Author(s):  
Xiao Ma ◽  
Quan-Hui Li ◽  
Ya-Nan Yu ◽  
Yi-Ming Qiao ◽  
Saeed ul Haq ◽  
...  
Keyword(s):  
Functional Characterization ◽  
Future Research ◽  
Complex Environments ◽  
Yield Improvement ◽  
Interacting Protein ◽  
Secondary Messenger ◽  
Calcineurin B ◽  
Response To Stress ◽  
Stress Signals

Plants need to cope with multitudes of stimuli throughout their lifecycles in their complex environments. Calcium acts as a ubiquitous secondary messenger in response to numerous stresses and developmental processes in plants. The major Ca2+ sensors, calcineurin B-like proteins (CBLs), interact with CBL-interacting protein kinases (CIPKs) to form a CBL–CIPK signaling network, which functions as a key component in the regulation of multiple stimuli or signals in plants. In this review, we describe the conserved structure of CBLs and CIPKs, characterize the features of classification and localization, draw conclusions about the currently known mechanisms, with a focus on novel findings in response to multiple stresses, and summarize the physiological functions of the CBL–CIPK network. Moreover, based on the gradually clarified mechanisms of the CBL–CIPK complex, we discuss the present limitations and potential prospects for future research. These aspects may provide a deeper understanding and functional characterization of the CBL–CIPK pathway and other signaling pathways under different stresses, which could promote crop yield improvement via biotechnological intervention.

scholarly journals Makes caterpillars floppy-like effector-containing MARTX toxins require host ADP-ribosylation factor (ARF) proteins for systemic pathogenicity

2019 ◽  
Vol 116 (36) ◽  
pp. 18031-18040 ◽  
Author(s):  
Youngjin Lee ◽  
Byoung Sik Kim ◽  
Sanghyeon Choi ◽  
Eun-Young Lee ◽  
Shinhye Park ◽  
...  
Keyword(s):  
Cysteine Protease ◽  
Bacterial Pathogens ◽  
Target Cells ◽  
Effector Domains ◽  
Adp Ribosylation ◽  
Switching Mechanism ◽  
Subcellular Compartments ◽  
Adp Ribosylation Factor ◽  
Insight Into

Upon invading target cells, multifunctional autoprocessing repeats-in-toxin (MARTX) toxins secreted by bacterial pathogens release their disease-related modularly structured effector domains. However, it is unclear how a diverse repertoire of effector domains within these toxins are processed and activated. Here, we report that Makes caterpillars floppy-like effector (MCF)-containing MARTX toxins require ubiquitous ADP-ribosylation factor (ARF) proteins for processing and activation of intermediate effector modules, which localize in different subcellular compartments following limited processing of holo effector modules by the internal cysteine protease. Effector domains structured tandemly with MCF in intermediate modules become disengaged and fully activated by MCF, which aggressively interacts with ARF proteins present at the same location as intermediate modules and is converted allosterically into a catalytically competent protease. MCF-mediated effector processing leads ultimately to severe virulence in mice via an MCF-mediated ARF switching mechanism across subcellular compartments. This work provides insight into how bacteria take advantage of host systems to induce systemic pathogenicity.

Efficacy of Sodium Hypochlorite and Peroxyacetic Acid To Reduce Murine Norovirus 1, B40-8, Listeria monocytogenes, and Escherichia coli O157:H7 on Shredded Iceberg Lettuce and in Residual Wash Water

2009 ◽  
Vol 72 (5) ◽  
pp. 1047-1054 ◽  
Author(s):  
LEEN BAERT ◽  
ISABELLE VANDEKINDEREN ◽  
FRANK DEVLIEGHERE ◽  
ELS VAN COILLIE ◽  
JOHAN DEBEVERE ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Sodium Hypochlorite ◽  
Tap Water ◽  
Bacterial Pathogens ◽  
Wash Water ◽  
Escherichia Coli O157 ◽  
Murine Norovirus ◽  
Peroxyacetic Acid ◽  
Iceberg Lettuce

The efficiency of sodium hypochlorite (NaOCl) and peroxyacetic acid (PAA) to reduce murine norovirus 1 (MNV-1), a surrogate for human norovirus, and Bacteroides fragilis HSP40–infecting phage B40-8 on shredded iceberg lettuce was investigated. The levels of removal of viruses MNV-1 and B40-8 were compared with the reductions observed for bacterial pathogens Listeria monocytogenes and Escherichia coli O157:H7. Two inoculation levels, one with a high organic load and the other containing a 10-fold lower number of pathogens and organic matter, showed that the effectiveness of NaOClwas greatly influenced by the presence of organic material, which was not observed for PAA. Moreover, the present study showed that 200 mg/liter NaOCl or 250 mg/liter PAA is needed to obtain an additional reduction of 1 log (compared with tap water) of MNV-1 on shredded iceberg lettuce, whereas only 250 mg/liter PAA achieved this for bacterial pathogens. None of the treatments resulted in a supplementary 1-log PFU/g reduction of B40-8 compared with tap water. B40-8 could therefore be useful as an indicator of decontamination processes of shredded iceberg lettuce based on NaOCl or PAA. Neither MNV-1, B40-8, nor bacterial pathogens could be detected in residual wash water after shredded iceberg lettuce was treated with NaOCl and PAA, whereas considerable numbers of all these microorganisms were found in residual wash water consisting solely of tap water. This study illustrates the usefulness of PAA and NaOCl in preventing cross-contamination during the washing process rather than in causing a reduction of the number of pathogens present on lettuce.

scholarly journals Exploring Predatory Nematode Chemotaxis Using Low-Cost and Easy-to-Use Microfluidics

2017 ◽  
Vol 79 (9) ◽  
pp. 753-762 ◽  
Author(s):  
Matthew D. Stilwell ◽  
Julia F. Nepper ◽  
Elizabeth D. Clawson ◽  
Val Blair ◽  
Travis Tangen ◽  
...  
Keyword(s):  
Low Cost ◽  
Complex Environments ◽  
Soil Composition ◽  
Ecological Studies ◽  
Teachers And Students ◽  
Nematode Chemotaxis ◽  
Microbial Symbiosis ◽  
Quantitative Changes ◽  
K 12 ◽  
Insight Into

Symbiosis is a fascinating and diverse phenomenon. The study of symbiosis is important to understanding ecology, as it helps us understand relationships between organisms and provides insight into co-evolution, mutualism, adaptation, and survival. Ecological studies are challenging to implement in K-12 classrooms because they often require multiple organisms (often very different in size) and complex environments that are difficult to replicate accurately (e.g., soil composition, temperature, pH, and humidity). These factors can make it difficult to study quantitative changes in ecosystems. We developed an inexpensive, quantitative experiment for classrooms that can be used to explore important aspects of microbial symbiosis, pathogenesis, and ecology, and that helps support more investigations in this area of education. The experiment is low-cost, designed for K-12 teachers and students, uses common materials, and teaches students about the exciting relationships among bacteria, worms, and insects.

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