Antibiotic Susceptibility Tests are conducted in microbiological laboratories to study the effect of an antibiotic on the growth of a microbe. The most common method to study antibiotic susceptibility includes the Kirby-Bauer Method. In this method, small discs saturated with antibiotic is placed on the plate containing the bacteria. A zone of inhibition of growth around the disc is observed to study the susceptibility of the microbe to the antibiotic. Polymyxin-B-PB-300 units is a product manufactured by Micromaster. This drug is administered against gram-negative bacterial infections. The drug is naturally acquired from Bacillus subtilis. The drug acts by binding to the plasma membrane of the bacterial cell and creating structural alterations. The drug binds to the negative side of the cell membrane, which is composed of lipopolysaccharides. The alterations in the cell membrane structure caused makes it more permeable to extracellular water. The resulting water intake by the cell causes cell death. The drug also binds to bacterial endotoxins to deactivate them. Hence, in biological research, Polymyxin B is also added to reagents to remove any possible endotoxin contamination. The organisms susceptible to the activity of the drug include, Haemolphilus influenzae, Pseudomonas aeruginosa.

Specifications:

Product name: Polymyxin-B-PB-300 units

Brand: Micromaster

Molecular formula: C56H100N16O17S

Molecular mass: 1301.56 g/mol