Pristinamycin is a mixture of two components that have a synergistic antibacterial action. Pristinamycin IIA is a macrolide, and results in pristinamycin's having a similar spectrum of action to erythromycin. Pristinamycin IA (streptogramin B) is a depsipeptide.[1] PI and PII are coproduced by S. pristinaespiralis in a ratio of 30:70. Each compound binds to the bacterial 50 S ribosomal subunit and inhibits the elongation process of the protein synthesis, thereby exhibiting only a moderate bacteriostatic activity. However, the combination of both substances acts synergistically and leads to a potent bactericidal activity that can reach up to 100 times that of the separate components.
The pristinamycin biosynthetic gene cluster is the largest antibiotic supercluster known so far, with a size of ~210 kb, wherein the PI and PII biosynthetic genes are not clustered individually but are scattered across the complete sequence region.[2] Furthermore, this biosynthetic gene region is interrupted by a cryptic type II PKS gene cluster.
Clinical use
Despite the macrolide component, it is effective against erythromycin-resistant staphylococci and streptococci.[3][4] It is active against methicillin-resistant Staphylococcus aureus (MRSA). Its usefulness for severe infections, however, may be limited by the lack of an intravenous formulation owing to its poor solubility.[5] Nevertheless, it is sometimes used as an alternative to rifampicin+fusidic acid or linezolid for the treatment of MRSA.
The lack of an intravenous formulation led to the development of the pristinamycin-derivative quinupristin/dalfopristin (i.e., Synercid), which may be administered intravenously for more severe MRSA infections.
↑ Weber P (December 2001). "[Streptococcus pneumoniae: lack of emergence of pristinamycin resistance]". Pathologie-Biologie. 49 (10): 840–845. doi:10.1016/S0369-8114(01)00255-3. PMID11776696.
↑ Leclercq R, Soussy CJ, Weber P, Moniot-Ville N, Dib C (September 2003). "[In vitro activity of the pristinamycin against the isolated staphylococci in the french hospitals in 1999-2000]". Pathologie-Biologie. 51 (7): 400–404. doi:10.1016/S0369-8114(03)00054-3. PMID12948760.
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Methicillin-resistant Staphylococcus aureus (MRSA) is a group of gram-positive bacteria that are genetically distinct from other strains of Staphylococcus aureus. MRSA is responsible for several difficult-to-treat infections in humans. It caused more than 100,000 deaths worldwide attributable to antimicrobial resistance in 2019.
Methicillin (USAN), also known as meticillin (INN), is a narrow-spectrum β-lactam antibiotic of the penicillin class.
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Quinupristin/dalfopristin, or quinupristin-dalfopristin, is a combination of two antibiotics used to treat infections by staphylococci and by vancomycin-resistant Enterococcus faecium.
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Streptogramins are a class of antibiotics.
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A staphylococcal infection or staph infection is an infection caused by members of the Staphylococcus genus of bacteria.
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