Streptothricin

A class of antibiotics produced by certain actinomycetes

Streptothricin is a class of antibiotics that are produced by certain species of actinomycetes, particularly those belonging to the genus Streptomyces. These antibiotics are known for their broad-spectrum activity against a variety of bacteria, including both Gram-positive and Gram-negative organisms.

Structure and Chemistry

Structure of Streptothricin F

Streptothricins are characterized by their unique chemical structure, which includes a beta-lysine moiety linked to a sugar component. The structure of streptothricin F, one of the most studied members of this class, is depicted in the adjacent image. The presence of the beta-lysine moiety is crucial for the antibiotic activity of streptothricins.

Mechanism of Action

Streptothricins exert their antibacterial effects by inhibiting protein synthesis in susceptible bacteria. They achieve this by binding to the bacterial ribosome, thereby interfering with the translation process. This action ultimately leads to the cessation of bacterial growth and cell death.

Production

Streptothricins are naturally produced by certain species of the genus Streptomyces, which are filamentous bacteria found in soil. These organisms are known for their ability to produce a wide range of secondary metabolites, including many clinically important antibiotics.

Clinical Use

Although streptothricins have potent antibacterial properties, their clinical use has been limited due to concerns about toxicity. In particular, streptothricins have been associated with nephrotoxicity, which has restricted their use in human medicine. However, they have been used in veterinary medicine and as research tools in microbiology.

Resistance

Bacterial resistance to streptothricins can occur through various mechanisms, including the modification of the antibiotic target site, enzymatic inactivation, and efflux pumps. The development of resistance is a significant concern in the use of any antibiotic, and streptothricins are no exception.

Related Pages

• Antibiotic
• Streptomyces
• Protein synthesis inhibitor
• Bacterial resistance