Sisomicin (bactoCeaze, ensamycin, and initially antibiotic 6640 and rickamicin), is an

aminoglycoside Aminoglycoside is a medicinal and bacteriologic category of traditional Gram-negative antibacterial medications that inhibit protein synthesis and contain as a portion of the molecule an amino-modified glycoside (sugar). The term can also refer ...

antibiotic An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of ...

, isolated from the fermentation broth of '' Micromonospora inositola''. It is a newer broad-spectrum aminoglycoside most structurally related to

gentamicin Gentamicin is an antibiotic used to treat several types of bacterial infections. This may include bone infections, endocarditis, pelvic inflammatory disease, meningitis, pneumonia, urinary tract infections, and sepsis among others. It is not e ...

. Sisomicin is the most predictably active aminoglycoside against

Gram-positive bacteria In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. Gram-positive bact ...

. Like most other aminoglycosides, sisomicin is bactericidal for sensitive clinical isolates. The minimum bactericidal concentrations (MBC) have been found to be equivalent or very close to the minimum inhibitory concentrations (MIC). Like other aminoglycosides, most clinical isolates of ''

Pseudomonas aeruginosa ''Pseudomonas aeruginosa'' is a common encapsulated, gram-negative, aerobic–facultatively anaerobic, rod-shaped bacterium that can cause disease in plants and animals, including humans. A species of considerable medical importance, ''P. aerugi ...

'' remain susceptible to sisomicin. Resistance to sisomicin may be enzymatically or non-enzymatically mediated. Sisomicin is inactivated by the same enzymes as

, but it is active against many organisms that resist gentamicin by non-enzymatic mechanisms. Some studies show that sisomicin has been effective in the treatment of infections that either had failed to respond to other drugs or were due to microorganisms resistant ''in vitro'' to other aminoglycosides.

References

{{AminoglycosideAntiBiotics Aminoglycoside antibiotics Micromonosporaceae