Streptomyces
Streptomyces is the largest genus of Actinobacteria, Gram-positive bacteria.[1] Streptomyces is often found in soil and is very much similar to fungi by its shape. They form long thin threads called hyphae that can differentiate into a chain of spores for reproduction.[2] Almost all of the bioactive compounds produced by Streptomyces are made while the hyphae are forming from the substrate mycelium.[3]
| Streptomyces | |
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| S. griseus - a species of Streptomyces genus | |
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| Genus: | Streptomyces Waksman & Henrici 1943
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Use in medicine and science
Streptomyces are medically important, as they produce antifungals, antiparasitic drugs, antivirals, antitumorals, anti-hypertensives, immunosuppressants and antibiotics.[4][5] Different species of streptomyces are used to produce different antibiotics. Over 500 species of Streptomyces bacteria have been described.[6] For example, widely studied S. griseus was the first to be used in production of an antibiotic streptomycin, while S. avermitilis as a source of avermictin.[7] Another well-studied species, S coelicolor, is widely used in genetic studies due to its relative ease of handling and distinct morphological stages.[8] Overall, Streptomyces produce over two-thirds of the clinically useful antibiotics of natural origin, such as tetracycline, neomycin and chloramphenicol.[9][10]
Antibiotic mechanism
Antibiotics target essential proteins for pathogens’ growth and survival, inhibiting essential functions. For example, streptomycin, which is made from S. griseus, irreversibly binds to bacterial genetic material and causes errors in the production of new proteins, which leads to cell death.[11] It can be used for treating severe infections, such as tuberculosis and plague.[12] Another example is avermectin, made from S. avermitili. It causes invertebrate paralysis (inability to make and pass nerve impulses), which is used as a drug and pesticide against parasitic worms and insects. Avermectin enhances glutamate (neurotransmitter) at the glutamate-gated chloride channels that mammals don’t possess. It causes the excess of chloride ions inside the cell (hyperpolarisation), so the action potential cannot be further induced, ultimately leading to paralysis.[13]
Antibiotic resistance
Genetic changes in bacteria might result in antibiotic resistance. They might be acquired through spontaneous mutations (vertical gene transfer) or through other bacteria passing their genes (horizontal gene transfer). Self-medications or improper medication use can result in the emergence of resistant bacteria. It is difficult to obtain new antibiotics, that is why researchers seek to improve existing ones,[14] as well as working to discover new drugs.
Streptomyces Media
The chemical structures of Saptomycin D and E
References
- ↑ Kämpfer P.. The prokaryotes: a handbook on the biology of bacteria (2006). Berlin: Springer. p. 538–604. ISBN 0-387-25493-5.
- ↑ de Lima Procópio, Rudi Emerson. Antibiotics produced by Streptomyces (in en). The Brazilian Journal of Infectious Diseases 16 (5) (2012-09-01). p. 466–471. doi:10.1016/j.bjid.2012.08.014.
- ↑ Chater, Keith F. et al 2010. The complex extracellular biology of Streptomyces. FEMS Microbiology Reviews 34 (2): 171–98. [1]
- ↑ Ōmura, Satoshi. Genome sequence of an industrial microorganism Streptomyces avermitilis : Deducing the ability of producing secondary metabolites (in en). Proceedings of the National Academy of Sciences 98 (21) (2001-10-09). p. 12215–12220. doi:10.1073/pnas.211433198.
- ↑ Watve M.G.. How many antibiotics are produced by the genus Streptomyces?. Arch. Microbiol. 176 (5) (2001). p. 386–90. doi:10.1007/s002030100345.
- ↑ Euzéby J.P.. Genus Streptomyces. List of prokaryotic names with standing in nomenclature (2008). Retrieved 2008-09-28.
- ↑ Ohnishi, Yasuo. Genome Sequence of the Streptomycin-Producing Microorganism Streptomyces griseus IFO 13350 (in en). Journal of Bacteriology 190 (11) (June 2008). p. 4050–4060. doi:10.1128/JB.00204-08.
- ↑ Bentley, S. D.. Complete genome sequence of the model actinomycete Streptomyces coelicolor A3(2) (in en). Nature 417 (6885) (May 2002). p. 141–147. doi:10.1038/417141a.
- ↑ Watve, Milind G.. How many antibiotics are produced by the genus Streptomyces? (in en). Archives of Microbiology 176 (5) (2001-11-01). p. 386–390. doi:10.1007/s002030100345.
- ↑ Kieser T.. Practical Streptomyces genetics (2000). Norwich, England: John Innes Foundation. ISBN 0-7084-0623-8.
- ↑ PubChem. Streptomycin (in en). pubchem.ncbi.nlm.nih.gov. Retrieved 2022-07-24.
- ↑ Streptomycin Monograph for Professionals (in en). Drugs.com. Retrieved 2022-07-24.
- ↑ Bloomquist, Jeffrey R.. Toxicology, mode of action and target site-mediated resistance to insecticides acting on chloride channels (in en). Comparative Biochemistry and Physiology Part C: Pharmacology, Toxicology and Endocrinology 106 (2) (1993-10-01). p. 301–314. doi:10.1016/0742-8413(93)90138-B.
- ↑ Fischbach, Michael A.. Antibiotics for Emerging Pathogens (in en). Science 325 (5944) (2009-08-28). p. 1089–1093. doi:10.1126/science.1176667.