Polymyxin B2 sulfate is one of several polypeptide components that comprises the antibiotic polymyxin B sulfate. The unique fatty acid moiety found in polymyxin B2 is 6-methylheptanoic acid (6-MHA). Results from in vitro studies have shown marginal differences in MIC data when comparing the fractions.
Kassamali, et al. used polymyxin B1, polymyxin B2, polymyxin B3, and polymyxin B1-I to test for synergistic and antagonistic effects against various Gram-negative organisms.
Read more here: "Microbiological Assessment of Polymyxin B Components Tested Alone and In Combination"
Lim et al. used polymyxin B1, B2, B3, and B1-I from TOKU-E to study the stability of each compound in saline, dextrose, and saline/dextrose infusion solutions. "Physicochemical stability study of polymyxin B in various infusion solutions for administration to critically Ill patients."
| Mechanism of Action | Polymyxin B targets and alters permeability lipopolysaccharide (LPS) of gram negative bacteria leading to lysing of the cell. Polymyxin B only needs to interact with LPS, it is not required to enter the cell. |
| Spectrum | Polymyxin B sulfate targets the outer membrane of gram negative bacteria especially Pseudomonas aeruginosa. |
| Microbiology Applications | Polymyxin B sulfate is commonly used in clinical in vitro microbiological antimicrobial susceptibility tests (panels, discs, and MIC strips) against gram negative microbial isolates. Medical microbiologists use AST results to recommend antibiotic treatment options for infected patients. Representative MIC values include:
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| Plant Biology Applications | Polymyxin B sulfate was successfully tested to counteract phytopathogenic gram-negative bacterial growth including different strains of Pseudomonas viridiflava and Erwinia carotovora. Polymixin B sulfate was shown to reduce bacterial growth of different strains of Pseudomonas viridiflava at low concentrations, (0.08 µg/ml) and Erwinia carotovora growth at slightly higher concentrations (0.25 µg/ml) (Selim et al. 2005). |
| Molecular Formula | C55H96N16O13 · xH2SO4 (lot specific) |
| References | Newton, B. A. "The Properties and Mode of Action of the Polymyxins." Bacteriology Reviews (n.d.): 14-27. www.ncbi.gov. Web. 21 Aug. 2012. Selim S., Negrel J., Govaerts C., Gianinazzi S. and Tuinen van D., 2005, Isolation and Partial Characterization of Antagonistic Peptides Produced by Paenibacillus sp. Strain B2 Isolated from the Sorghum Mycorrhizosphere. Applied and Environmental Microbiology, Nov. 2005, p. 6501–6507 Zavascki, Alexandre Prehn et al. "Polymyxin B for the Treatment of Multidrug-resistant Pathogens: A Critical Review." Journal of Antimicrobial Chemotherapy 60 (2007): 1206-215.Oxfordjournals. Web. 15 Jan. 2013. Li, Jian et al. "Development and Validation of a Reversed-phase High-performance Liquid Chromatography Assay for Polymyxin B in Human Plasma." Journal of Antimicrobial Chemotherapy (2009): n. pag. Oxfordjournals. Web. 15 Jan. 2013. Tam, Vincent H, et al. "In Vitro Potency of Various Polymyxin B Components." In Vitro Potency of Various Polymyxin B Components 55.9 (2011): 4490-491. Asm.org. Web. 15 Jan. 2013. Orwa, J. A., et al "Isolation and Structural Characterization of Polymyxin B Components." Isolation and Structural Characterization of Polymyxin B Components 912.2 (2001): 369-73. Sciencedirect. Web. 15 Jan. 2013. MJ Mueller, W Brodschelm. "Signaling in the elicitation process is mediated through the octadecanoid pathway leading to jasmonic acid". Proc. Natl. Acad. Sci. USA Vol. 90, pp. 7490-7494, August 1993. |
| MIC | P. aeruginosa (ATCC 27853)| 2 |1666| A. baumannii (ATCC BAA 747)|1|1666| K. pneumoniae ATCC 13883|2|1666| P. aeruginosa (9019)|2|1666| A. baumannii (1261)|2|1666| K. pneumoniae (VM9)|2|1666| |
