Why cells need antibiotics streptomycinafter cryopresevation thawing?5 answersCells may require antibiotics like streptomycin after cryopreservation thawing to control bacterial contamination and maintain cell quality. Antibiotics play a crucial role in reducing bacterial loads in semen samples, ensuring sperm quality is preserved during the freezing and thawing process. Studies have shown that the addition of antibiotics, such as streptomycin, can effectively control bacterial growth in semen samples, leading to improved post-thaw viability and in vivo fertility of spermatozoa. Antibiotics like streptomycin, when used in combination with other antibiotics, have been found to be both effective in controlling bacterial contamination and safe for sperm quality in frozen semen samples. Therefore, the inclusion of antibiotics like streptomycin post-cryopreservation thawing is essential for maintaining the integrity and quality of cells by preventing bacterial infections.
What is the molecular mechanism of action of streptomycin?4 answersThe molecular mechanism of action of streptomycin involves multiple pathways. Streptomycin induces mitochondrial-dependent ferroptosis in non-adherent tumor initiating cells (TIC) from colon and breast cancer cell lines, leading to alterations in mitochondrial morphology and function. In bacterial cells, streptomycin has been shown to alter the activity of the mechanosensitive ion channel MscL, causing potassium efflux and potentially facilitating cell entry. Additionally, streptomycin's entry into bacterial cells may involve interaction with MscL, modifying its conformation to allow passage of dihydrostreptomycin into the cell. These findings highlight the diverse effects of streptomycin on both cancer cells and bacteria, shedding light on its intricate mechanisms of action.
What are the mechanisms by which Streptomyces produces melanin?5 answersStreptomyces produces melanin through various mechanisms. One mechanism involves the use of L-tyrosine as a precursor for melanin biosynthesis, which is activated by the transcriptional regulator AdpA. This activation leads to the production of tyrosinases and tyrosine peroxygenases, such as MelC2, MelD2, MelE, and LmbB2, which are involved in the conversion of L-tyrosine to melanin. Additionally, the production of melanin in Streptomyces can be visualized during conjugation, where a conjugative plasmid carrying the melC operon encoding an extracellular tyrosinase is transferred to a recipient strain, resulting in the synthesis of tyrosinase and subsequent melanin formation. These mechanisms highlight the role of L-tyrosine metabolism and the regulation of melanin biosynthetic genes in Streptomyces for melanin production.
How strB?5 answersThe strB gene has been identified in multiple studies. It has been found to be associated with streptomycin resistance in Escherichia coli strains, where it is located downstream of the strA gene. The strB gene encodes a hydrolase enzyme that can catalytically degrade pesticides containing an ester bond, such as deltamethrin and lambda-cyhalothrin. In Erwinia amylovora, the strA-strB gene pair is responsible for high-level streptomycin resistance, with strA encoding aminoglycoside-3"-phosphotransferase and strB encoding aminoglycoside-6-phosphotransferase. The hydrolase gene strB can also be used for removing pesticide residues in agricultural products and for constructing transgenic crops to produce pollution-free green agricultural products. Overall, the strB gene plays a crucial role in antibiotic resistance and pesticide degradation, offering potential applications in agriculture and environmental remediation.
What is the role of streptomycin in the treatment of MRSA?4 answersStreptomycin does not have a specific role in the treatment of MRSA infections according to the abstracts provided. The abstracts focus on the role of daptomycin as an alternative therapy for MRSA infections, highlighting its effectiveness and safety in treating skin and soft tissue infections (SSTIs). Daptomycin is also indicated for the treatment of S. aureus, including MRSA, in bacteremia, endocarditis, and complicated skin and skin structure infections. The limitations of vancomycin, the backbone antibiotic for MRSA infections, are discussed, and daptomycin is suggested as a viable alternative. Streptomycin is mentioned in one of the abstracts, but it focuses on its effectiveness in vitro against bacteria resistant to other antibiotics and its low toxicity in animal and clinical studies, without specifically mentioning MRSA. Therefore, streptomycin does not appear to have a significant role in the treatment of MRSA infections based on the provided abstracts.
Why streptomycin Cannot be given orally for treatment of tuberculosis?10 answers