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[Characterization of multiple changes of antibiotic resistance characters in Streptomyces coelicolor A3(2)]
Abstract:
Among mutants of Streptomyces coelicolor A3(2) studied which were sensitive to chloramphenicol (Cmls), strains sensitive to a number of antibiotics (ristomycin, tetracycline, polymyxin, lincomycin) amount of 46%. Antibiotic-sensitive mutants are capable to form different classes of resistant revertants with frequency varying from 10(-2) to 10(-6) in independent strains. Ristomycin-sensitive clones (Rims) have been found to occur with high frequency in Cmls strains and Cmlr revertants. Mutations mediating the Rims phenotype are mapped in a locus linked to the gene for resistance to chloramphenicol. The results obtained are discussed, in accordance with the notion about possible role of cml mutation in induction of secondary mutational changes in the genome of S. coelicolor A3(2).
Insights
Mutations conferring chloramphenicol sensitivity (Cmls) in Streptomyces coelicolor A3(2) can induce secondary mutations, leading to increased sensitivity to other antibiotics like ristomycin. This suggests a role for chloramphenicol resistance genes in genome instability.
Area of Science:
- Microbiology
- Genetics
- Molecular Biology
Context:
- Streptomyces coelicolor A3(2) is a model organism for studying antibiotic production and genetic manipulation.
- Antibiotic resistance and sensitivity are crucial factors in microbial evolution and drug development.
- Understanding the genetic basis of mutational changes is key to controlling microbial populations.
Purpose:
- To investigate the genetic consequences of chloramphenicol sensitivity mutations in Streptomyces coelicolor A3(2).
- To characterize the frequency and nature of secondary mutations arising in chloramphenicol-sensitive strains.
- To explore the potential link between chloramphenicol resistance genes and genome instability.
Summary:
- A significant proportion (46%) of chloramphenicol-sensitive (Cmls) mutants of Streptomyces coelicolor A3(2) also exhibited sensitivity to multiple other antibiotics.
- Ristomycin-sensitive (Rims) clones emerged at high frequency in Cmls strains and chloramphenicol-resistant (Cmlr) revertants.
- Mutations conferring the Rims phenotype were mapped to a locus genetically linked to the chloramphenicol resistance gene, suggesting a pleiotropic effect of the initial mutation.
Impact:
- The findings suggest that mutations affecting chloramphenicol resistance may play a role in inducing broader genetic instability within the Streptomyces coelicolor genome.
- This research provides insights into the mechanisms underlying spontaneous mutations and antibiotic resistance development in bacteria.
- Understanding these genetic pathways could inform strategies for manipulating microbial genomes and developing novel antimicrobial agents.