Definition

Noun: 1. An antibiotic substance: Tyrothricin is a mixture of antibiotic compounds produced by the bacterium Bacillus brevis. It is primarily effective against Gram-positive bacteria.

Usage

Tyrothricin is used as a topical antimicrobial agent. It is applied directly to the skin or mucous membranes to treat localized infections. - It is not used systemically (taken internally or injected) due to its potential toxicity to human cells.

Examples

• The doctor prescribed a topical ointment containing tyrothricin for the bacterial skin infection.
• Tyrothricin is often found in certain throat lozenges and topical creams.
• Due to its narrow spectrum, tyrothricin is only effective against specific types of bacteria.

Advanced Usage

• Historical Context: Tyrothricin, discovered in the 1930s, was one of the first antibiotic substances to be studied in detail. Its discovery helped pave the way for the development of other antibiotics.
• Gram-positive specific: The term "Gram-positive" refers to a classification of bacteria based on a laboratory staining method. Tyrothricin's mechanism of action disrupts the cell membranes of these specific bacteria.

Variants and Related Words

• Gramicidin (noun): One of the two main antibiotic components found within the tyrothricin mixture. The other is tyrocidine.
• Tyrocidine (noun): The other primary antibiotic component of the tyrothricin complex.

Synonyms

• Topical antibiotic: A general term for antibiotics applied to the body's surface.
• Antimicrobial agent: A broader term for any substance that kills or inhibits microorganisms.

Notes

• While tyrothricin itself is a defined mixture, the term is sometimes used more generally in historical or scientific contexts to refer to this early class of polypeptide antibiotics.
• Its use in modern medicine has declined with the advent of broader-spectrum and less toxic antibiotics.

Noun

1. a mixture of antibiotics applied locally to infections caused by Gram-positive bacteria