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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.
  • 2.3K
  • 21 Oct 2022
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.
  • 2.3K
  • 17 Jun 2021
Topic Review
Klebsiella pneumoniae
Klebsiella pneumoniae is an opportunistic pathogen that causes nosocomial and community-acquired infections. The spread of resistant strains of K. pneumoniae represents a growing threat to human health, due to the exhaustion of effective treatments. K. pneumoniae releases outer membrane vesicles (OMVs). OMVs are a vehicle for the transport of virulence factors to host cells, causing cell injury. Previous studies have shown changes of gene expression in human bronchial epithelial cells after treatment with K. pneumoniae OMVs. These variations in gene expression could be regulated through microRNAs (miRNAs), which participate in several biological mechanisms. Thereafter, miRNA expression profiles in human bronchial epithelial cells were evaluated during infection with standard and clinical K. pneumoniae strains. Microarray analysis and RT-qPCR identified the dysregulation of miR-223, hsa-miR-21, hsa-miR-25 and hsa-let-7g miRNA sequences. Target gene prediction revealed the essential role of these miRNAs in the regulation of host immune responses involving NF-ĸB (miR-223), TLR4 (hsa-miR-21), cytokine (hsa-miR-25) and IL-6 (hsa-let-7g miRNA) signalling pathways. The current study provides the first large scale expression profile of miRNAs from lung cells and predicted gene targets, following exposure to K. pneumoniae OMVs. Our results suggest the importance of OMVs in the inflammatory response.
  • 2.3K
  • 29 Dec 2020
Topic Review
Cold-Tolerant Microbes
Cold adapted microorganisms represent a large fraction of biomass on earth due to the dominance of low temperature environments. Himalaya is one of the most important low temperature environments on Earth because it possess environmental similarities to Polar Regions. The extreme cold environments of Himalaya are mainly dependent on the tiny life forms because of climatic restrictions to higher plants and animals. These cold loving microbes are known to possess several structural and functional adaptations in order to perform various life processes under the stressful low temperature environments. Their biological activities maintain the nutrient flux in environment and contribute in the global biogeochemical cycles. The culture dependent and culture independent studies revealed their diversity in community structure and functional potential. Apart from the ecological importance, these microorganisms have been recognized as a source of cold active enzymes and novel bioactive compounds. These products have several applications in biotechnological industries. 
  • 2.3K
  • 27 Oct 2020
Topic Review
Zearalenone
Zearalenone (ZEN), a mycotoxin categorized as a xenoestrogen poses structural similarity wif natural estrogens that enables its binding to the estrogen receptors leading to hormonal misbalance and numerous reproductive diseases. 
  • 2.2K
  • 20 Feb 2021
Topic Review
Fusarium graminearum Pigments and Compounds
Fusarium graminearum (teleomorph: Gibberella zeae) is a pathogen of maize, wheat, rice, and barley responsible for the disease known as Fusarium head blight (FHB) and mycotoxin contamination. Several studies have explored in depth the biochemistry and genetics of the pigments present in Fusarium graminearum. Still, there is a need to discuss their relationship with the mold’s observable surface color pattern variation throughout its lifecycle. 
  • 2.2K
  • 07 Jul 2021
Topic Review
Bottle Conditioning
Bottle conditioning refers to a method of adding fermenting wort or yeast suspension in sugar solution into beer in its final package. Additionally denoted as bottle refermentation, this technique has been originally developed to assure beer carbonation, and has further significance related to formation of distinctive sensory attributes and enhancement of sensory stability, which are the phenomena associated with ongoing yeast metabolic activities in the final package.
  • 2.2K
  • 23 Sep 2020
Topic Review
Lactic Acid Bacteria in Fermented Foods and Beverages
Traditional fermented foods are inherent to the human diet and represent an important part of the culture of each country. The fermentation process has been traditionally used as a method of food preservation. It allows modifying the technological, sensory, and nutritional attributes of raw ingredients. Latin America has a vast history with these products, but they are not always known worldwide. One of the most used microorganisms in fermented foods is lactic acid bacteria. A bibliography analysis of the general aspects of fermented products from this region was carried out, focusing on the foods and beverages (with and without alcohol), their representation in native communities, nutritional value and effect on health, as well as the risk of their consumption. It is concluded that traditional fermented products of Latin America are usually prepared with specific ingredients of the region (such as cassava and corn), and that the lactic acid bacteria present in these foods are not always identifiable due to the inherent variability of artisanal production. The bacteria observed include Lacticaseibacillus, Lactiplantibacillus, Lactobacillus, Limosilactobacillus, Leuconostoc, Streptococcus, and Weisella, among others.
  • 2.2K
  • 10 Apr 2023
Topic Review
Human Microbiota
The human microbiota is the aggregate of microorganisms that resides on or within any of a number of human tissues and biofluids, including the skin, mammary glands, placenta, seminal fluid, uterus, ovarian follicles, lung, saliva, oral mucosa, conjunctiva, biliary and gastrointestinal tracts. They include bacteria, archaea, fungi, protists and viruses. Though micro-animals can also live on the human body, they are typically excluded from this definition. The human microbiome refers specifically to the collective genomes of resident microorganisms. Humans are colonized by many microorganisms; the traditional estimate is that the average human body is inhabited by ten times as many non-human cells as human cells, but more recent estimates have lowered that ratio to 3:1 or even to approximately the same number. Some microorganisms that colonize humans are commensal, meaning they co-exist without harming humans; others have a mutualistic relationship with their human hosts.:700 Conversely, some non-pathogenic microorganisms can harm human hosts via the metabolites they produce, like trimethylamine, which the human body converts to trimethylamine N-oxide via FMO3-mediated oxidation. Certain microorganisms perform tasks that are known to be useful to the human host but the role of most of them is not well understood. Those that are expected to be present, and that under normal circumstances do not cause disease, are sometimes deemed normal flora or normal microbiota. The Human Microbiome Project took on the project of sequencing the genome of the human microbiota, focusing particularly on the microbiota that normally inhabit the skin, mouth, nose, digestive tract, and vagina. It reached a milestone in 2012 when it published its initial results.
  • 2.2K
  • 27 Oct 2022
Topic Review
Genus Ochrobactrum
Ochrobactrum spp. are found in a wide range of environments including soils and water. They are non-enteric, Gram-negative organisms that are closely related to the genus Brucella. Several species of this genus have now been characterised and implicated as opportunistic pathogens in multiple outbreaks. This entry gives a brief overview of the Genus Ochrobactrum.
  • 2.2K
  • 27 Nov 2020
Topic Review
Biological Nitrogen Fixation
In agroecosystems, nitrogen is one of the major nutrients limiting plant growth. To meet the increased nitrogen demand in agriculture, synthetic fertilizers have been used extensively in the latter part of the twentieth century, which have led to environmental challenges such as nitrate pollution. Biological nitrogen fixation (BNF) in plants is an essential mechanism for sustainable agricultural production and healthy ecosystem functioning. BNF by legumes and associative, endosymbiotic, and endophytic nitrogen fixation in non-legumes play major roles in reducing the use of synthetic nitrogen fertilizer in agriculture, increased plant nutrient content, and soil health reclamation. 
  • 2.2K
  • 24 Nov 2021
Topic Review
Staphylococcus Aureus and Septic Arthritis
Staphylococcus aureus (S. aureus) infections are a major healthcare challenge and new treatment alternatives are needed. S. aureus septic arthritis, a debilitating joint disease, causes permanent joint dysfunction in almost 50% of the patients. S. aureus bacteremia is associated with higher mortalities than bacteremia caused by most other microbes and can develop to severe sepsis and death. The key to new therapies is understanding the interplay between bacterial virulence factors and host immune response, which decides the disease outcome. S. aureus produces numerous virulence factors that facilitate bacterial dissemination, invasion into joint cavity, and cause septic arthritis. Monocytes, activated by several components of S. aureus such as lipoproteins, are responsible for bone destructions. In S. aureus sepsis, cytokine storm induced by S. aureus components leads to the hyperinflammatory status, DIC, multiple organ failure, and later death. 
  • 2.2K
  • 10 May 2021
Topic Review
Campylobacter Upsaliensis
Campylobacter upsaliensis is a gram negative bacteria in the Campylobacter genus. C. upsaliensis is found worldwide, and is a common cause of Campylobacteriosis in humans, as well as gastroenteritis in dogs. Human infections are primarily associated with raw or undercooked meat and contaminated water sources, however there is some zoonotic risk associated with the spread from dogs. C. upsaliensis primarily affects the gastrointestinal tract as it damages gastrointestinal epithelial cells. There are many methods for detecting C.upsaliensis including PCR and ELISA, however there is no current gold standard in detection techniques. Infection is typically self limiting, however there is antimicrobial therapy available.
  • 2.2K
  • 30 Sep 2022
Topic Review
Medical Devices Associated Nosocomial Infections
Healthcare-associated infections (HAIs) are caused by nosocomial pathogens. HAIs have an immense impact not only on developing countries but also on highly developed parts of world. They are predominantly device-associated infections that are caused by the planktonic form of microorganisms as well as those organized in biofilms. This review elucidates the impact of HAIs, focusing on device-associated infections such as central line-associated bloodstream infection including catheter infection, catheter-associated urinary tract infection, ventilator-associated pneumonia, and surgical site infections associated with their peculiar microorganisms along with conventional and novel therapies.
  • 2.2K
  • 29 Mar 2022
Topic Review
Applications of Adaptive Laboratory Evolution in Biotechnology
Changes in biological properties over several generations, induced by controlling short-term evolutionary processes in the laboratory through selective pressure, and whole-genome re-sequencing, help determine the genetic basis of microorganism's adaptive laboratory evolution (ALE). Due to the versatility of this technique and the imminent urgency for alternatives to petroleum-based strategies, ALE has been actively conducted for several yeasts, primarily using the conventional species Saccharomyces cerevisiae, but also non-conventional yeasts. As a hot topic at the moment since genetically modified organisms are a debatable subject and a global consensus on their employment has not yet been attained, a panoply of new studies employing ALE approaches have emerged and many different applications have been exploited in this context. For the first time, relevant studies showing the ALE of non-conventional yeast species towards their biotechnological improvement, cataloging them according to the aim of the study, and comparing them considering the species used, the outcome of the experiment, and the employed methodology. The applicability of ALE as a powerful tool to enhance species features and improve their performance in biotechnology, with emphasis on the non-conventional yeast species are lighted, as an alternative or in combination with genome editing approaches.
  • 2.2K
  • 13 Feb 2023
Topic Review
Feline Panleukopenia
Feline panleukopenia virus (FPLV) is a species of parvovirus that can infect all wild and domestic members of the felid (cat) family worldwide. It is a highly contagious, severe infection that causes gastrointestinal, immune system, and nervous system disease. ("Panleukopenia" means a decrease in the number of white blood cells.) It has been thought to be single variant of Carnivore protoparvovirus (CPV 1); however, it has been confirmed that a feline panleukopenia illness can be caused by CPV 2a, 2b, and 2c. FPLV is commonly referred to as: It is sometimes confusingly referred to as "cat plague" and "feline distemper". In addition to members of the felid family, it can also affect some members of related families (e.g. raccoon, mink).
  • 2.2K
  • 23 Nov 2022
Topic Review
The Role of Commensal and other Non-Pathogenic Bacteria
Not only pathogenic bacteria are reservoirs of antibiotic resistance and virulence genes. Opportunistic pathogenic bacteria, commensal bacteria, and mutualistic bacteria (here named non-pathogenic for simplification) may also carry resistance and virulence genes. However, contrary to pathogenic strains, which are the target of the immune system, non-pathogenic bacteria can colonize hosts for prolonged periods because hosts do not need to be rid of them. Thus, the basic reproductive number of a non-pathogenic bacterial strain, a measure of the strain’s fitness and denoted as R0, is likely to be much higher than one. That is, the expected number of colonized hosts by a single colonized host in a population not yet colonized by that strain is higher than one, which implies that this strain can spread exponentially among hosts. This spread has peculiar consequences for the spread of virulence and resistance genes. For example, computer models that simulate the spread of these genes have shown that their diversities should correlate positively throughout microbiomes. Bioinformatics analysis with real data corroborates this expectation.
  • 2.1K
  • 07 Feb 2023
Topic Review
West Timorese Farmers in Land Management
Facing the marginal land conditions of West Timor, adaptation efforts by farmers related to food production and planting activities have led to various local knowledge and practices, including the existence of agricultural commodities that are derived from natural selection, which have been ongoing for quite some time. 
  • 2.1K
  • 02 Jun 2022
Topic Review
Food Safety Culture in Nigeria
Food safety culture describes a collection of learned and shared attitudes, values and beliefs that form the foundation of the hygienic behaviors used within a particular food handling environment. Sharman et al. defines food safety culture as a long-term paradigm in a food handling organization deeply rooted in beliefs, behaviors and assumptions which impact the food safety performance within the organization.
  • 2.1K
  • 22 Aug 2021
Topic Review
Clostridium Difficile Infection
Clostridium difficile infection (CDI or C-dif) is a symptomatic infection due to the spore-forming bacterium, Clostridium difficile. Symptoms include watery diarrhea, fever, nausea, and abdominal pain. It makes up about 20% of cases of antibiotic-associated diarrhea. Complications may include pseudomembranous colitis, toxic megacolon, perforation of the colon, and sepsis. Clostridium difficile infection is spread by bacterial spores found within feces. Surfaces may become contaminated with the spores with further spread occurring via the hands of healthcare workers. Risk factors for infection include antibiotic or proton pump inhibitors use, hospitalization, other health problems, and older age. Diagnosis is by stool culture or testing for the bacteria's DNA or toxins. If a person tests positive but has no symptoms, the condition is known as C. difficile colonization rather than an infection. Prevention is by hand washing, terminal room cleaning in hospital, and limiting antibiotic use. Discontinuation of antibiotics may result in resolution of symptoms within three days in about 20% of those infected. Often the antibiotics metronidazole, vancomycin or fidaxomicin will cure the infection. Retesting after treatment, as long as the symptoms have resolved, is not recommended, as the person may remain colonized. Recurrences have been reported in up to 25% of people. Some tentative evidence indicates fecal microbiota transplantation and probiotics may decrease the risk of recurrence. C. difficile infections occur in all areas of the world. About 453,000 cases occurred in the United States in 2011, resulting in 29,000 deaths. Rates of disease globally have increased between 2001 and 2016. Women are more often affected than men. The bacterium was discovered in 1935 and found to be disease-causing in 1978. In the United States, health–care associated infections increase the cost of care by US$1.5 billion each year.
  • 2.1K
  • 07 Nov 2022
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