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Diversity of Endophytes and Biotechnological Potential
Published in Luzia Valentina Modolo, Mary Ann Foglio, Brazilian Medicinal Plants, 2019
Daiani Cristina Savi, Chirlei Glienke
The search for interesting biological activity from microorganisms has been the basis for the development of several biotechnological applications, mainly in the pharmaceutical and agricultural industries (Vitorino and Bessa, 2017). The most promising compounds in the clinic for treatment of bacterial infections were isolated from microorganisms, such as penicillin isolated from Penicillium digitatum (Laich et al., 2002); vancomycin produced by Streptomyces orientalis (Levine, 2006); streptomycin isolated from Streptomyces griseus and erythromycin produced by Saccharopolyspora erythraea (Donadio et al., 1996), among several others. Besides the high exploration of microorganisms for active compounds in the past, studies have shown that unknown species and genetically different strains are still abundant in nature, and natural products remain the most promising source for new compounds (Monciardini et al., 2014).
The Effects of Synthetic Phosphonates on Living Systems
Published in Richard L. Hilderbrand, The Role of Phosphonates in Living Systems, 2018
The phosphonate antibiotics are primarily of natural occurrence. These antibiotics are produced by various strains of the Streptomycetes and are discussed in Chapter 2, Section II. A. However, there are several compounds of synthetic origin with potential use as antibiotics. L-alanyl-L-l-aminoethylphosphonic acid (alafosfalin) interferes with cell wall synthesis.113,114 This effect apparently occurs following transport of the peptide and intracellular cleavage by peptidase and is the result of the inhibition of alanine racemase in susceptible organisms.115
Streptomycin
Published in M. Lindsay Grayson, Sara E. Cosgrove, Suzanne M. Crowe, M. Lindsay Grayson, William Hope, James S. McCarthy, John Mills, Johan W. Mouton, David L. Paterson, Kucers’ The Use of Antibiotics, 2017
Streptomycin is a natural product of the soil actinomycete Streptomyces griseus (Schatz et al., 2005). It is a member of the aminoglycoside class of antibiotics that typically consist of two or more amino-sugars covalently linked to a central aminocyclitol. However, streptomycin differs from most other medically available aminoglycosides in that the aminocyclitol is peripherally rather than centrally located and is a streptidine rather than deoxystreptamine. Aminoglycosides are inhibitors of bacterial protein synthesis, but their action is bactericidal, unlike most other antibiotics that act in this way. Streptomycin is active against Gram-negative aerobic bacilli, some medically important mycobacteria (particularly Mycobacterium tuberculosis), enterococci when combined with a cell wall–active agent, streptococci, and staphylococci (Chambers, 2006).
Actinomycetoma by Actinomadura madurae. Clinical and therapeutic characteristics of 18 cases with two treatment modalities
Published in Journal of Dermatological Treatment, 2022
Alexandro Bonifaz, Andrés Tirado-Sánchez, Denisse Vázquez-González, Leonel Fierro-Arias, Javier Araiza, Gloria M. González
The diagnosis of actinomycetomas due to A. madurae is confirmed with the observation of grains on direct examination, or histopathologically, requiring confirmation by culture (13–15). Actinomycetoma is susceptible to several chemotherapeutic agents, however, the response is variable and related to several factors such as extent and duration of the disease, bone involvement, and the treatment used. Moreover, the low-rates of treatment response are also due to the severe fibrosis, with inadequate access to the lesion and the low sensitivity of the microorganism to different antibiotics (10,12). Treatment regimen includes at least two medications for extended periods. One of the most widely used schemes for A. madurae includes sulfamethoxazole-trimethoprim (TMP/SMX) + DDS, with variable results (16). Maghoub (17) added streptomycin to the management of actinomycetomas due to Actinomadura sp. and Streptomyces sp, with improvement the efficacy in both cases (18). In recent years, Negroni et al. (19), showed good results with the use of TMP/SMX + ciprofloxacin in actinomycetoma, although currently studies with this scheme are scarce.
Maculosin, a non-toxic antioxidant compound isolated from Streptomyces sp. KTM18
Published in Pharmaceutical Biology, 2021
Babita Paudel, Rukusha Maharjan, Prajwal Rajbhandari, Niraj Aryal, Saefuddin Aziz, Keshab Bhattarai, Bikash Baral, Rajani Malla, Hari Datta Bhattarai
Streptomyces are Gram-positive bacteria that are found in various environmental conditions and have a filamentous mycelium similar to fungi. Phylogenetically, Streptomyces is a part of Actinobacteria, with high GC-rich (70%) content. Most of them are ubiquitous and highly versatile soil-dwelling saprophytes known to produce diverse secondary metabolites, many of which are well-known antibiotics (Omura et al. 2001; Khan et al. 2011). Antioxidant activities of 30 strains of rare Actinomycetes were reported (Mohammadipanah and Momenilandi 2018) without characterizing the active molecules. Similarly, the broth extract of Streptomyces carpaticus displayed a significant DPPH free radical scavenging activity (IC50, 84.5 µg/mL) (Subramanian et al. 2017); however, the active molecule was not characterized. Thus, besides antibiotics, Streptomyces could be a promising source of antioxidant compounds.
Auto-reactivity against gut bacterial peptides in patients with late-onset diabetes
Published in Autoimmunity, 2020
Mohammad Sajid, Krishna Biswas, Harpreet Singh, Sapna Negi
Gut microbes can come in contact with the immune system due to damage in the gut barrier and modulate host immunity, thereby can generate auto-immunity. This auto-immunity may give rise to metabolic disorders. In addition, impairment of the gut barrier was displayed in autoimmune diseases like T2D and coeliac disease [31,32]. The diabetic individuals showed increased intestinal permeability which is linked with the pathogenesis of diabetes [33,34]. In addition, aging or gut microbiota composition can induce gut leakage resulting in the transport of exogenous antigens and thereby damaging pancreatic β–cells [35]. For instance, the administration of bafilomycin-A1 from Streptomyces sp. diminishes glucose tolerance, decreases islet size, and reduces relative β-cell mass [36]. Further, gut barrier permeability enables increased transport of lipopolysaccharide (LPS) to the host which can destroy β–cells of pancreatic islets and provoke insulin resistance [37,38].