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Topic Review
Cyanobacteria and Microalgae Antibacterial Peptides
Cyanobacteria and microalgae are oxygen-producing photosynthetic unicellular organisms encompassing a great diversity of species, which are able to grow under all types of extreme environments and exposed to a wide variety of predators and microbial pathogens. The antibacterial compounds described for these organisms include organic compounds such as  alkaloids, fatty acids, indoles, macrolides, phenols, pigments and terpenes, among others, but the peptides have an special pharmacological appeal, due to their broad chemical space, achieved by their dual biosynthetic alternatives in cyanobacteria, the ribosomal synthesis, or a polypeptide assembly through the non-ribosomal peptide synthases. This diversity ensures a broad range of biological properties with a large pharmacological potential.   
  • 1.9K
  • 14 Jan 2021
Topic Review
Bacteremia
Bacteremia (also bacteraemia) is the presence of bacteria in the blood. Blood is normally a sterile environment, so the detection of bacteria in the blood (most commonly accomplished by blood cultures) is always abnormal. It is distinct from sepsis, which is the host response to the bacteria. Bacteria can enter the bloodstream as a severe complication of infections (like pneumonia or meningitis), during surgery (especially when involving mucous membranes such as the gastrointestinal tract), or due to catheters and other foreign bodies entering the arteries or veins (including during intravenous drug abuse). Transient bacteremia can result after dental procedures or brushing of teeth. Bacteremia can have several important health consequences. The immune response to the bacteria can cause sepsis and septic shock, which has a high mortality rate. Bacteria can also spread via the blood to other parts of the body (which is called hematogenous spread), causing infections away from the original site of infection, such as endocarditis or osteomyelitis. Treatment for bacteremia is with antibiotics, and prevention with antibiotic prophylaxis can be given in high risk situations.
  • 1.9K
  • 10 Oct 2022
Topic Review
Mangrove Streptomycetes with Anticancer Activity
Worldwide cancer incidence and mortality have always been a concern to the community. The cancer mortality rate has generally declined over the years; however, there is still an increased mortality rate in poorer countries that receives considerable attention from healthcare professionals. This suggested the importance of the prompt detection, effective treatment, and prevention strategies. The genus Streptomyces has been documented as a prolific producer of biologically active secondary metabolites. Streptomycetes from mangrove environments attract researchers’ attention due to their ability to synthesize diverse, interesting bioactive metabolites. The present entry highlights research on mangrove-derived streptomycetes and the production of anticancer-related compounds from these microorganisms. Research studies conducted between 2008 and 2019, specifically mentioning the isolation of streptomycetes from mangrove areas and described the successful purification of compound(s) or generation of crude extracts with cytotoxic activity against human cancer cell lines, were compiled in this entry. It is anticipated that there will be an increase in prospects for mangrove-derived streptomycetes as one of the natural resources for the isolation of chemotherapeutic agents. 
  • 1.9K
  • 09 Dec 2020
Topic Review
The Gene Elongation Mechanism
Gene elongation is a molecular mechanism consisting of an in-tandem duplication of a gene and divergence and fusion of the two copies, resulting in a gene constituted by two divergent paralogous modules. Several examples of genes with internal sequence repetitions are reported in literature; thus, gene elongation might have shaped the structures of many genes during the first steps of molecular and cellular evolution.  
  • 1.9K
  • 28 Oct 2020
Topic Review
Promising Lead Compounds for Resistant-Tuberculosis
According to WHO report, globally about 10 million active tuberculosis cases, resulting in about 1.6 million deaths, further aggravated by drug-resistant tuberculosis and/or comorbidities. Incomplete therapeutic regimen, meager dosing, and the capability of the latent and/or active state tubercular bacilli to abide and do survive against contemporary first-line and second-line antitubercular drugs escalate the prevalence of drug-resistant tuberculosis. To explore and identify the most potential antitubercular drug candidate among various reported compounds, here we focused to highlight the promising lead derivatives of isoniazid, coumarin, griselimycin, and antimicrobial peptides. The aim of the present review is to fascinate significant lead compounds in the development of potential clinical drug candidates that might be more precise and effective against drug-resistant tuberculosis, the world research looking for a long time.
  • 1.9K
  • 10 Dec 2020
Topic Review
Tetrahydrofuran Biodegradation
Tetrahydrofuran (THF) is widely used as a precursor for polymer syntheses and a versatile solvent in industries. THF is an environmental hazard and carcinogenic to humans. We characterized the THF degradation potential of a number of THF-degrading bacteria reported before and a new isolated filamentous fungus Pseudallescheria boydii ZM01. Two different microbial THF degradation pathways have been proposed here. In addition, The initial key metabolic intermediate 2-hydroxytetrahydrofuran was detected and identified by gas chromatography (GC) analyses for the first time during the THF degradation process.
  • 1.9K
  • 10 Nov 2020
Topic Review
Distribution of Sulfate-Reducing Bacteria in the Environment
Sulfate-reducing bacteria (SRB) are a heterogeneous group of anaerobic microorganisms that play an important role in producing hydrogen sulfide not only in the natural environment, but also in the gastrointestinal tract and oral cavity of animals and humans.
  • 1.9K
  • 25 Oct 2021
Topic Review
Yellow Rice Wine Production Research
Yellow rice wine is a traditional fermented beverage in China. The microorganisms in the brewing process play a crucial role in shaping the composition and quality of the wine through their regulation of microbial growth, fermentation metabolites, metabolic balance, and ethanol production. Yellow rice wine not only has culinary value but also possesses potential medicinal value. This is attributed to the presence of polyphenolic compounds, antioxidants, and other natural products that can provide antioxidant and other probiotic effects. The fermentation process of yellow rice wine offers potential nutritional supplementation and improved digestion. While traditional brewing techniques have long been employed, modern biotechnology helps enhance the quality and stability of the wine by selecting suitable microbial strains, optimizing fermentation conditions, and precisely controlling the fermentation process. The collection of diverse fermentation microbes and the construction of specifically designed microbiota for yellow rice wine production could expedite the production of high-quality yellow rice wine. The ultimate goal is to enhance the nutritional value, conditioning function, and overall consumption experience of yellow rice wine. 
  • 1.9K
  • 11 Jan 2024
Topic Review
Probiotics
Probiotics and prebiotics are microbiota-management instruments for improving human health once they may be beneficial for maintaining a healthy community of gut microbiota and bowel function. Probiotic’s main target is the gut, via the gastrointestinal tract, although direct application to other body zones such as the vaginal tract, the oral cavity, and skin have been studied.
  • 1.9K
  • 16 Dec 2020
Topic Review
Aeromonas
It is well known that correct identification of recovered Aeromonas strains at the genus and species level is a complex process.  Biochemical or phenotypic identification tests and specially those included in miniaturized and/or semi-automatic commercial identification systems (API, Vitek, BBLCrystal, MicroScan etc) produce confusion with the Vibrio genus and an erroneous overestimation of the species Aeromonas hydrophila. Correct identification requires the use of molecular techniques, like the detection of the gene that encode for the GCAT (glycerophospholopid-cholesterol acyltransferase) that can discriminate the genus or the analysis of the sequences of housekeeping genes (gyrB, rpoD, etc) to correctly identifying the species. The latter genes are necessary because the 16S rRNA gene does not show enough resolution to discriminate closely related species (i.e. A. salmonicida from A. bestiarum). In fact many new species were discovered thanks to the use of gyrB and rpoD genes for identification, and the construction of a multilocus phylogenetic analysis with the concatenated sequences of five housekeeping genes was used as a tool in their descriptions. The progress in the techniques used to obtain bacteria genomes had an spectacular impact on the genus Aeromonas  because the genome of the type strain of the different species are available at the GenBank. Tools developed for bacterial identification based on the comparison of genomes like the in silico DNA-DNA hybridization (isDDH) and the Average Nucleotide Identity (ANI) provides objective criteria to define if two genomes belong or not to the same species. This review aims to guide microbiologists in the correct identification of the Aeromonas spp.
  • 1.9K
  • 23 Oct 2020
Topic Review
Attenuated Vaccine
An attenuated vaccine (or a live attenuated vaccine, LAV) is a vaccine created by reducing the virulence of a pathogen, but still keeping it viable (or "live"). Attenuation takes an infectious agent and alters it so that it becomes harmless or less virulent. These vaccines contrast to those produced by "killing" the virus (inactivated vaccine). Attenuated vaccines stimulate a strong and effective immune response that is long-lasting. In comparison to inactivated vaccines, attenuated vaccines produce a stronger and more durable immune response with a quick immunity onset. Attenuated vaccines function by encouraging the body to create antibodies and memory immune cells in response to the specific pathogen which the vaccine protects against. Common examples of live attenuated vaccines are measles, mumps, rubella, yellow fever, and some influenza vaccines.
  • 1.9K
  • 01 Dec 2022
Topic Review
Secondary Metabolites of Endophytic Fungi
Plant–microbe interactions range from symbiotic to pathogenic; in the symbiotic relationship, microbes are called ‘endophytes’. Endophytes are conventionally known as microbes existing in all plant endospheric tissues (roots, shoots, fruits, leaves, flowers, seeds, etc.) without causing harmful consequences to the host plant. These microorganisms are usually more abundant in roots and they can be transferred horizontally and vertically. Particularly, endophytic fungi constitute an extremely large community, reaching up to three million species worldwide. These eukaryotic organisms are known to harbor a large variety of secondary metabolites valuable to mankind, plants and the environment. They constitute an excellent substitute for exploring whole plants, thereby gaining time, facilitating the process of isolation and protecting the ecosystem. The scientific community has approved the excellent roles of the fungal bioactive compounds in several vital fields including medicine, pharmacy, agriculture, industry and bioremediation.
  • 1.8K
  • 23 Jan 2022
Topic Review
Leishmaniases
The control of leishmaniases, a complex parasitic disease caused by the protozoan parasite Leishmania, requires continuous innovation at the therapeutic and vaccine levels. Thus, the classical drugs are toxic and generate drug resistance. These limitations are also the consequence of a non adapted biodistribution of the active principles. Chitosan is a biocompatible polymer administrable via different routes and possessing numerous qualities to be used in the antileishmanial strategies.
  • 1.8K
  • 27 Oct 2020
Topic Review
Anaerobic Phototrophic Sulfur Bacteria
Phototrophic purple and green sulfur bacteria have been known for a long time. These microorganisms are characterized by using reduced sulfur (S) compounds as electron donors in the process of anoxygenic photosynthesis and are classified into different families based on their morphology, physiological and biochemical characteristics. Representatives of the largest family, the Chromatiaceae—members of which may be observed in nature as a light red coloration of the anaerobic layer of water—were first described in the second half of the 19th century. In contrast, the less numerous Chlorobiaceae family—also referred to as green sulfur bacteria—were isolated later in the second half of the 20th century.
  • 1.8K
  • 24 Jun 2021
Topic Review
Histamine: A Bacterial Signal Molecule
Histamine is a key signal molecule in humans, with multiple functions, such as being a neurotransmitter or modulator of immune responses. More recent studies have shown that bacteria have evolved different mechanisms to sense histamine or histamine metabolites. Histamine sensing in the human pathogen Pseudomonas aeruginosa was found to trigger chemoattraction to histamine and to regulate the expression of many virulence-related genes.
  • 1.8K
  • 17 Jun 2021
Topic Review
Bacteriologist (Professional)
A bacteriologist is a professional trained in bacteriology, a subdivision of microbiology. The duties of a bacteriologist include prevention, diagnosis and prognosis of diseases, as well as health care, and they may carry out various functions such as epidemiological surveillance, quality auditing with biotechnology development, basic research, management and teaching related to the career, scientist management, laboratory coordination and blood banks.
  • 1.8K
  • 03 Nov 2022
Topic Review
Cellular Communication
Cellular communication is an umbrella term used in biology and more in depth in biophysics, biochemistry and biosemiotics to identify different types of communication methods between living cellulites. Some of the methods include cell signaling among others. This process allows millions of cells to communicate and work together to perform important bodily processes that are necessary for survival. Both multicellular and unicellular organisms heavily rely on cell-cell communication.
  • 1.8K
  • 24 Oct 2022
Topic Review
Meningococcal Disease
Meningococcal disease describes infections caused by the bacterium Neisseria meningitidis (also termed meningococcus). It has a high mortality rate if untreated but is vaccine-preventable. While best known as a cause of meningitis, it can also result in sepsis, which is an even more damaging and dangerous condition. Meningitis and meningococcemia are major causes of illness, death, and disability in both developed and under-developed countries. There are approximately 2,600 cases of bacterial meningitis per year in the United States, and on average 333,000 cases in developing countries. The case fatality rate ranges between 10 and 20 percent. The incidence of endemic meningococcal disease during the last 13 years ranges from 1 to 5 per 100,000 in developed countries, and from 10 to 25 per 100,000 in developing countries. During epidemics the incidence of meningococcal disease approaches 100 per 100,000. Meningococcal vaccines have sharply reduced the incidence of the disease in developed countries. The disease's pathogenesis is not fully understood. Neisseria meningitidis colonises a substantial proportion of the general population harmlessly, but in a very small percentage of individuals it can invade the bloodstream, affecting the entire body, most notably limbs and brain, causing serious illness. Over the past few years, experts have made an intensive effort to understand specific aspects of meningococcal biology and host interactions; however, the development of improved treatments and effective vaccines is expected to depend on novel efforts by workers in many different fields. While meningococcal disease is not as contagious as the common cold (which is spread through casual contact), it can be transmitted through saliva and occasionally through close, prolonged general contact with an infected person.
  • 1.8K
  • 10 Oct 2022
Topic Review
Anthranilic Acid and Beyond
Anthranilic acid, a kynurenine metabolite produced by host and microbe alike, is a bioactive compound with potential systemic neurological effects. Though in the past much research has focused on the kynurenine pathway at large, the role of anthranilic acid in the gut–brain axis is emerging as an important piece of the puzzle. Anthranilic acid is a direct metabolic product of kynurenine digestion in humans and microbes and represents an alternate branch to two other immediate products (i.e., 3-hydroxykynurenine and kynurenic acid). Kynurenine is hydrolyzed to anthranilic acid and L-alanine with the help of kynureninase. With the transfer of an amino group, kynurenine becomes the alternate product kynurenic acid, and the addition of an oxygen by kynurenine-3-monoxygenase turns kynurenine into 3-hydroxykynurenine. Anthranilic acid, through non-specific hydroxylation, becomes 3-hydroxyanthranilic acid, which is the precursor for quinolinic acid, picolinic acid, and the terminal product NAD+. The ratio of anthranilic acid to the downstream 3-hydroxyanthranilic acid has been suggested as one potential biomarker for both neurological and physiological disorders. 
  • 1.8K
  • 07 Aug 2023
Topic Review
Fungal Light Responses
Organisms have developed different features to capture or sense sunlight. Vertebrates have evolved specialized organs (eyes) which contain a variety of photosensor cells that help them to see the light to aid orientation. Opsins are major photoreceptors found in the vertebrate eye. Fungi, with more than five million estimated members, represent an important clade of living organisms which have important functions for the sustainability of life on our planet. Light signalling regulates a range of developmental and metabolic processes including asexual sporulation, sexual fruit body formation, pigment and carotenoid production and even production of secondary metabolites. Fungi have adopted three groups of photoreceptors: (I) blue light receptors, White Collars, vivid, cryptochromes, blue F proteins and DNA photolyases, (II) red light sensors, phytochromes and (III) green light sensors and microbial rhodopsins.
  • 1.8K
  • 15 Jun 2023
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