The ultrafine fibers were produced using a polymeric blend of soy protein isolate (SPI), polyethylene oxide (PEO), and zein at a ratio of 1:1:1 (v/v/v) by electrospinning. The ginger essential oil ...(GEO) was encapsulated in the ultrafine fibers and the morphology, Fourier-Transform Infrared Spectroscopy (FTIR) analysis, thermal properties and relative crystallinity were evaluated. The antimicrobial activity of ginger essential oil was evaluated against five bacteria (Listeria monocytogenes, Staphylococcus aureus, Escherichia coli 0157:H7, Salmonella typhimurium, and Pseudomonas aeruginosa). Based on the preliminary tests, the concentration of GEO selected to add in the polymer solution was 12% (v/v; GEO/polymer solution). The fiber produced with 12% (v/v) GEO was used for antimicrobial analysis and in situ application (in fresh Minas cheese) against L. monocytogenes by micro-atmosphere. The ultrafine fibers produced, regardless the concentration of the essential oil, presented homogeneous morphology with cylindrical shape without the presence of beads. The application of the active fibers containing 12% GEO showed high potential to be applied in food packaging to reduce microbial contamination.
•The proteins ultrafine fibers were effective for encapsulation of GEO.•The antimicrobial activity of ginger essential oil (GEO) was effective.•Fibers containing 12% GEO eliminated the growth of L. monocytogenes.•Fibers with GEO reduced L. monocytogenes growth in fresh Minas cheese.
Bacteria switch only intermittently to motile planktonic lifestyles under favorable conditions. Under chronic nutrient deprivation, however, bacteria orchestrate a switch to stationary phase, ...conserving energy by altering metabolism and stopping motility. About two-thirds of bacteria use flagella to swim, but how bacteria deactivate this large molecular machine remains unclear. Here, we describe the previously unreported ejection of polar motors by γ-proteobacteria. We show that these bacteria eject their flagella at the base of the flagellar hook when nutrients are depleted, leaving a relic of a former flagellar motor in the outer membrane. Subtomogram averages of the full motor and relic reveal that this is an active process, as a plug protein appears in the relic, likely to prevent leakage across their outer membrane; furthermore, we show that ejection is triggered only under nutritional depletion and is independent of the filament as a possible mechanosensor. We show that filament ejection is a widespread phenomenon demonstrated by the appearance of relic structures in diverse γ-proteobacteria including Plesiomonas shigelloides, Vibrio cholerae, Vibrio fischeri, Shewanella putrefaciens, and Pseudomonas aeruginosa. While the molecular details remain to be determined, our results demonstrate a novel mechanism for bacteria to halt costly motility when nutrients become scarce.
The development of novel therapies to control diseases caused by antibiotic-resistant pathogens is one of the major challenges we are currently facing. Many important plant, animal, and human ...pathogens regulate virulence by quorum sensing, bacterial cell-to-cell communication with small signal molecules. Consequently, a significant research effort is being undertaken to identify and use quorum-sensing-interfering agents in order to control diseases caused by these pathogens. In this review, an overview of our current knowledge of quorum-sensing systems of Gram-negative model pathogens is presented as well as the link with virulence of these pathogens, and recent advances and challenges in the development of quorum-sensing-interfering therapies are discussed.
Research over the past decades has shown that bacteria communicate with each other with small signal molecules in a process that has been termed quorum sensing, and the list of bacterial quorum-sensing molecules is still growing.
The virulence of many bacterial pathogens of plants, animals, and humans is controlled by quorum sensing, and quorum-sensing-interference is one of the most intensively studied strategies for controlling disease caused by antibiotic-resistant bacteria.
Various quorum-sensing-interfering agents have been described in recent years, including natural and synthetic compounds, enzymes, and antibodies, and these agents have been proven to attenuate bacterial disease in animal and plant models.
This article reviews the roles that laterally transferred genes (LTG) play in the virulence of bacterial pathogens. The features of LTG that allow them to be recognized in bacterial genomes are ...described, and the mechanisms by which LTG are transferred between and within bacteria are reviewed. Genes on plasmids, integrative and conjugative elements, prophages, and pathogenicity islands are highlighted. Virulence genes that are frequently laterally transferred include genes for bacterial adherence to host cells, type 3 secretion systems, toxins, iron acquisition, and antimicrobial resistance. The specific roles of LTG in pathogenesis are illustrated by specific reference to Escherichia coli, Salmonella, pyogenic streptococci, and Clostridium perfringens.
Viruses can infect all cell-based organisms, from bacteria to humans, animals, and plants. They are responsible for numerous cases of hospitalization, many deaths, and widespread crop destruction, ...all of which result in an enormous medical, economical, and biological burden. Each of the currently used decontamination methods has important drawbacks. Cold plasma (CP) has entered this field as a novel, efficient, and clean solution for virus inactivation. We present recent developments in this promising field of CP-mediated virus inactivation, and describe the applications and mechanisms of the inactivation. This is particularly relevant because viral pandemics, such as COVID-19, highlight the need for alternative virus inactivation methods to replace, complement, or upgrade existing procedures.
Pathogenic viruses are becoming an increasing burden for health, agriculture, and the global economy. Classic disinfection methods have several drawbacks, and innovative solutions for virus inactivation are urgently needed.CP can be used as an environmentally friendly tool for virus inactivation. It can inactivate different human, animal, and plant viruses in various matrices.When using CP for virus inactivation it is important to set the correct parameters and to choose treatment durations that allow particles to interact with the contaminated material.Reactive oxygen and/or nitrogen species have been shown to be responsible for virus inactivation through effects on capsid proteins and/or nucleic acids. The development of more accurate methods will provide information on which plasma particles are crucial in each experiment, and how exactly they affect viruses.
Abstract
Standardized definitions for MDR are currently not available in veterinary medicine despite numerous reports indicating that antimicrobial resistance may be increasing among clinically ...significant bacteria in livestock and companion animals. As such, assessments of MDR presented in veterinary scientific reports are inconsistent. Herein, we apply previously standardized definitions for MDR, XDR and pandrug resistance (PDR) used in human medicine to animal pathogens and veterinary antimicrobial agents in which MDR is defined as an isolate that is not susceptible to at least one agent in at least three antimicrobial classes, XDR is defined as an isolate that is not susceptible to at least one agent in all but one or two available classes and PDR is defined as an isolate that is not susceptible to all agents in all available classes. These definitions may be applied to antimicrobial agents used to treat bovine respiratory disease (BRD) caused by Mannheimia haemolytica, Pasteurella multocida and Histophilus somni and swine respiratory disease (SRD) caused by Actinobacillus pleuropneumoniae, P. multocida and Streptococcus suis, as well as antimicrobial agents used to treat canine skin and soft tissue infections (SSTIs) caused by Staphylococcus and Streptococcus species. Application of these definitions in veterinary medicine should be considered static, whereas the classification of a particular resistance phenotype as MDR, XDR or PDR could change over time as more veterinary-specific clinical breakpoints or antimicrobial classes and/or agents become available in the future.
The role of cell polarity regulators in the development of cancer has long been an enigma. Despite displaying characteristics of tumour suppressors, the core regulators of polarity are rarely mutated ...in tumours and there are few data from animal models to suggest that they directly contribute to cancer susceptibility, thus questioning their relevance to human carcinogenesis. However, a body of data from human tumour viruses is now providing compelling evidence of a central role for the perturbation of cell polarity in the development of cancer.
Seasonality of Respiratory Viral Infections Moriyama, Miyu; Hugentobler, Walter J; Iwasaki, Akiko
Annual review of virology,
09/2020, Letnik:
7, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The seasonal cycle of respiratory viral diseases has been widely recognized for thousands of years, as annual epidemics of the common cold and influenza disease hit the human population like ...clockwork in the winter season in temperate regions. Moreover, epidemics caused by viruses such as severe acute respiratory syndrome coronavirus (SARS-CoV) and the newly emerging SARS-CoV-2 occur during the winter months. The mechanisms underlying the seasonal nature of respiratory viral infections have been examined and debated for many years. The two major contributing factors are the changes in environmental parameters and human behavior. Studies have revealed the effect of temperature and humidity on respiratory virus stability and transmission rates. More recent research highlights the importance of the environmental factors, especially temperature and humidity, in modulating host intrinsic, innate, and adaptive immune responses to viral infections in the respiratory tract. Here we review evidence of how outdoor and indoor climates are linked to the seasonality of viral respiratory infections. We further discuss determinants of host response in the seasonality of respiratory viruses by highlighting recent studies in the field.
Microbial pathogens possess a diversity of weapons that disrupt host homeostasis and immune defenses, thus resulting in the establishment of infection. The best-characterized system mediating ...bacterial protein delivery into target eukaryotic cells is the type III secretion system (T3SS) expressed by Gram-negative bacteria, including the human enteric pathogens Shigella, Salmonella, Yersinia, and enteropathogenic/enterohemorragic Escherichia coli (EPEC/EHEC). The emerging global view is that these T3SS-bearing pathogens share similarities in their ability to target key cellular pathways such as the cell cytoskeleton, trafficking, cell death/survival, and the NF-κB and MAPK signaling pathways. In particular, multiple host proteins are targeted in a given pathway, and different T3SS effectors from various pathogens share functional similarities.
Convergent targeting strategies are shared by Shigella, Salmonella, Yersinia, and EPEC/EHEC to hijack host responses.
An impressive diversity of interactions takes place between the T3SS effectors and their cellular targets belonging to key cellular pathways.
Modulation of host responses occurs during the entire course of infection, with T3SS effectors acting sequentially and displaying antagonistic effects on a given cellular pathway.
One given effector may ensure a diversity of action towards different cell types while infection proceeds.
Both innate and adaptive immune responses are modulated by T3SS effectors.
The food-borne trematodiases are an important group of neglected tropical diseases (NTDs). Over 40 million people are infected with food-borne trematodes and 750 million (>10% of the world's ...population) are at risk of these NTDs. Here, we review the life cycles, epidemiology, clinical manifestations, pathology and pathogenesis, diagnosis, treatment, and prevention and control of the major food-borne trematodiases in Southeast Asia. We focus particularly on opisthorchiasis caused by Opisthorchis viverrini and clonorchiasis caused by Clonorchis sinensis, which people contract by ingestion of metacercariae in flesh of raw or undercooked freshwater fishes, on fascioliasis caused by Fasciola species, where infection arises from ingestion of metacercariae on water plants such as watercress, and on Paragonimus species, the lung flukes, which use freshwater crabs and other crustaceans as intermediate hosts. We also include information on the intestinal flukes Fasciolopsis buski, the echinostomes and the so-called 'minute intestinal flukes' of the family Heterophyidae. Ecological information, placing emphasis on reservoir hosts, intermediate snail hosts and secondary hosts where applicable, is also reviewed and research needs are highlighted.
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