Bacitracin is a mixture of various related polypeptide antibiotic compounds derived from the bacterium, Bacillus subtilis. Bacitracin inhibits cell wall and peptidoglycan synthesis in Gram-positive bacteria.

Bacitracin is comprised of numerous related compounds and impurities including bacitracins A, B1, B2, B3, F, C1, C2, C3, E, H1, H2, H3, I1, I2, and I3. Standard grade bacitracin is a mixture of these fractions. Bacitracin A has been found to have the most antibacterial activity. Bacitracins B1 and B2 together have a similar antibacterial potency (approx. 90% of bacitracin A). Other bacitracin fractions including bacitracin F and bacitracin Xa have not been studied extensively; however, they appear to have negligible antibacterial activity.

For all TOKU-E bacitracin fractions/components and products, click here.

CAS Number

1405-87-4

Molecular Formula

C₆₆H₁₀₃N₁₇O₁₆S

Molecular Weight

1422.69

Mechanism of Action

Bacitracin prevents phosphorylation of bactoprenol; a transport protein which carries peptidoglycan components outside the cell membrane. Without the active phosphorylated bactoprenol, peptidoglycan synthesis cannot be complete and the cell lyses. Two mechanisms of bacitracin resistance are understood. One mechanism relies on a protein called a BcrABC transporter which pumps bacitracin out after it has entered the cell. Another mechanism relies on another protein called BacA which provides the active phosphorylated bactoprenol from a different synthetic pathway.

Storage Conditions

2-8 °C

Tariff Code

2941.90.5000

Spectrum

Bacitracin inhibits cell wall synthesis in Gram positive bacteria including Streptococcus pyogenes and Staphylococcus aureus. Representative MIC values include:

• Staphylococcus aureus 2µg/mL - >32 µg/mL
• Streptococcus agalactiae >16 µg/mL (Group B)
• For a complete list of bacitracin MIC values, click here.

Specifications: