Topic Review
Virulence Factor of Legionella
Pathogenic species of Legionella can infect human alveolar macrophages through Legionella-containing aerosols to cause a disease called Legionellosis, which has two forms: a flu-like Pontiac fever and severe pneumonia named Legionnaires’ disease (LD). Legionella is an opportunistic pathogen that frequently presents in aquatic environments as a biofilm or protozoa parasite. Long-term interaction and extensive co-evolution with various genera of amoebae render Legionellae pathogenic to infect humans and also generate virulence differentiation and heterogeneity.
  • 506
  • 13 Jan 2023
Topic Review
Virology of Phages and Phage-Resistance in Therapy
Bacteriophages, also known simply as phages, are prokaryotic viruses that exclusively infect and kill bacteria. Phage therapy has been overshadowed in the past by the widespread use of antibiotics in Western countries. However, it has been revitalized as a powerful approach due to the increasing prevalence of antimicrobial-resistant bacteria. Although bacterial resistance to phages has been reported in clinical cases, studies on the fitness trade-offs between phage and antibiotic resistance have revealed new avenues in the field of phage therapy.
  • 182
  • 15 Nov 2023
Topic Review
Viral Infections and Thymus
The thymus gland is a primary lymphoid organ for T-cell development. T-cells are one of the white blood cells that play a critical role in adaptive immune response. Various viral infections can result in the disturbance of thymic functions.
  • 1.4K
  • 17 Jun 2021
Topic Review
Viral Enteritis in Cattle
Livestock products supply about 13 percent of energy and 28 percent of protein in diets consumed worldwide. Diarrhea is a leading cause of sickness and death of beef and dairy calves in their first month of life and also affecting adult cattle, resulting in large economic losses and a negative impact on animal welfare. Despite the usual multifactorial origin, viruses are generally involved, being among the most important causes of diarrhea. There are several viruses that have been confirmed as etiological agents (i.e., rotavirus and coronavirus), and some viruses that are not yet confirmed as etiological agents. 
  • 620
  • 03 Sep 2021
Topic Review
Viable but Non-Culturable Listeria monocytogenes
The detection, enumeration, and virulence potential of viable but non-culturable (VBNC) pathogens continues to be a topic of discussion. While there is a lack of definitive evidence that VBNC Listeria monocytogenes (Lm) pose a public health risk, recent studies suggest that Lm in its VBNC state remains virulent. VBNC bacteria cannot be enumerated by traditional plating methods, so the results from routine Lm testing may not demonstrate a sample’s true hazard to public health. We suggest that supplementing routine Lm testing methods with methods designed to enumerate VBNC cells may more accurately represent the true level of risk.
  • 445
  • 13 Feb 2021
Topic Review
Verrucomicrobia
Verrucomicrobia is a phylum of Gram-negative bacteria that contains only a few described species. The species identified have been isolated from fresh water, marine and soil environments and human faeces. A number of as-yet uncultivated species have been identified in association with eukaryotic hosts including extrusive explosive ectosymbionts of protists and endosymbionts of nematodes residing in their gametes. Verrucomicrobia are abundant within the environment, though relatively inactive. This phylum is considered to have two sister phyla: Chlamydiae and Lentisphaerae within the PVC group. The Verrucomicrobia phylum can be distinguished from neighbouring phyla within the PVC group by the presence of several conserved signature indels (CSIs). These CSIs represent unique, synapomorphic characteristics that suggest common ancestry within Verrucomicrobia and an independent lineage amidst other bacteria. CSIs have also been found that are shared by Verrucomicrobia and Chlamydiae exclusively of all other bacteria. These CSIs provide evidence that Chlamydiae is the closest relative to Verrucomicrobia, and that they are more closely related to one another than to the Planctomycetales. Verrucomicrobia might belong in the clade Planctobacteria in the larger clade Gracilicutes. In 2008, the whole genome of Methylacidiphilum infernorum (2.3 Mbp) was published. On the single circular chromosome, 2473 predicted proteins were found, 731 of which had no detectable homologs. These analyses also revealed many possible homologies with Proteobacteria.
  • 902
  • 21 Oct 2022
Topic Review
Venom-Derived Peptides
Peptides are potential therapeutic alternatives against global diseases, such as antimicrobial-resistant infections and cancer. Venoms are a rich source of bioactive peptides that have evolved over time to act on specific targets of the prey. Peptides are one of the main components responsible for the biological activity and toxicity of venoms. South American organisms such as scorpions, snakes, and spiders are important producers of a myriad of peptides with different biological activities.
  • 355
  • 21 Feb 2023
Topic Review
Varidnaviria
Varidnaviria is a realm of viruses that includes all DNA viruses that encode major capsid proteins that contain a vertical jelly roll fold. The major capsid proteins (MCP) form into pseudohexameric subunits of the viral capsid, which stores the viral deoxyribonucleic acid (DNA), and are perpendicular, or vertical, to the surface of the capsid. Apart from this, viruses in the realm also share many other characteristics, such as minor capsid proteins (mCP) with the vertical jelly roll fold, an ATPase that packages viral DNA into the capsid, and a DNA polymerase that replicates the viral genome. Varidnaviria was established in 2019 based on the shared characteristics of the viruses in the realm. There are two groups of viruses in Varidnaviria: viruses that have a double vertical jelly roll (DJR) folds in the MCP, assigned to the kingdom Bamfordvirae, and viruses that have a single vertical jelly roll (SJR) fold in the MCP, assigned to the kingdom Helvetiavirae. The DJR-MCP lineage is thought to be descended from the SJR-MCP lineage via a gene fusion event, and the SJR-MCP shows a close relation to nucleoplasmins, pointing to a possible origin of the realm's jelly roll fold MCP. Most identified eukaryotic DNA viruses belong to Varidnaviria. Marine viruses in the realm are highly abundant worldwide and are important in marine ecology. Many animal viruses in the realm are associated with disease, including adenoviruses, poxviruses, and the African swine fever virus. Poxviruses have been prominent in the history of medicine, especially smallpox, caused by Variola virus, which was the target of the first vaccine and which later became the first disease eradicated. The realm also notably includes giant viruses that are physically larger and contain a much larger number of genes than typical viruses.
  • 634
  • 20 Oct 2022
Topic Review
Varicella-Zoster Virus Prevalence among Pregnant Women
Varicella-zoster virus (VZV) is a human-specific α-herpes virus responsible for chickenpox and herpes zoster. VZV is a virus with a lipid-rich envelope acquired from cellular membranes, where viral glycoproteins are inserted. Inside the envelope, a tegument layer formed by regulatory proteins surrounds an icosahedral nucleocapsid core containing the linear double-stranded DNA genome.
  • 288
  • 10 Mar 2023
Topic Review
Variants of SARS-CoV-2
The immune response elicited by the current COVID-19 vaccinations declines with time, especially among the immunocompromised population. Furthermore, the emergence of novel SARS-CoV-2 variants, particularly the Omicron variant, has raised serious concerns about the efficacy of currently available vaccines in protecting the most vulnerable people.
  • 446
  • 19 Apr 2023
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