Macrolides


Also found in: Dictionary, Medical.
Related to Macrolides: clindamycin, Fluoroquinolones

Macrolides

 

an extensive group of antibiotics that contain a polymerous lactone cycle.

All known macrolides are isolated from soil fungi of the genus Streptomyces. They are divided into two subgroups, according to their structure and physiological effect. The first subgroup (more than 30 antibiotics) includes lactones whose carbon skeleton consists of a fatty polyoxyacid that is saturated or that contains one or two double bonds with one or two hydroxyl groups bonded to the carbohydrate residues. The compounds of the subgroup (for example, pikromycin, methymycin, narbomycin, oleandomycin, erythromycin, lancamycin, magnamycin, carbomycin B, macrocin, and leukomycin A) are colorless crystals that are readily soluble in polar organic solvents, have weakly basic properties, and are active against most gram-positive and some gram-negative bacteria (brucellae), rickettsiae, and, sometimes, cocci. Their mode of action consists in the suppression of protein synthesis in the cells of the microorganisms.

The second subgroup (about 30 antibiotics) consists of lactones whose carbon skeleton contains, in addition to hydroxyl groups, from four to seven conjugated double bonds. In most of the macrolides of this type (also called polyene antibiotics), one or two hydroxyl groups are bonded to amino sugar residues. The compounds of this group (Filipin, nystatin, amphotericin B, pimaricin, lagosin, and fungichromin, for example) are yellow crystals that decompose in light. They are active against fungi and yeasts but are only weakly bacteriostatic. Their mode of action consists in disruption of the functions of the cytoplasmic membranes, owing to the formation of molecular complexes with sterols in the membranes. The biosynthesis of macrolides by their producer-fungi follows the pattern of the biosynthesis of fatty acids.

REFERENCES

Khimiia antibiotikov, 3rd ed., vol. 1. Moscow, 1961.
Sazykin, Iu. O. Antibiotiki kak ingibitory biokhimicheskikh protsessov. Moscow, 1968.
Mekhanizm deistviia antibiotikov. Moscow, 1969. (Collection of articles; translated from English.)
Biogenesis of Antibiotic Substances. Prague, 1965.

E. P. SEREBRIAKOV

References in periodicals archive ?
Solithromycin is the first fluoroketolide belonging to the macrolide class and is the first macrolide since azithromycin with the potential for both IV and oral administration.
We report an outbreak of shigellosis in and around Paris, France, in which azithromycin failure was related to emergence of plasmid-mediated resistance to macrolides.
Macrolides and doxycycline are generally preferred for uncomplicated CAP in outpatients to preserve the effectiveness of fluoroquinolones.
With reported resistance rates as high as 40 percent to standard-of-care macrolide antibiotics in the U.
Pneumococcal resistance to macrolides, lincosamides, ketolides, and streptogramin B agents: molecular mechanisms and resistance phenotype.
In this case-control study of 444 adults with bacteremic pneumococcal pneumonia, we found that exposure to macrolides in the 6 months preceding infection, a history of influenza vaccination in the 12 months preceding infection, and Hispanic ethnicity were all independently associated with an increased probability of an erythromycin-resistant infection.
Penicillins were prescribed most often (34%), followed by macrolides (22%), cephalosporins (14%), fluoroquinolones (13%), and sulfonamides (4%).
In the meeting, the FDA guided that, to assess the approvability for Restanza to treat CABP, the Company should establish a SPA using a superiority clinical trial design comparing Restanza to a marketed macrolide antibiotic in two clinical trials.
Although our study has confirmed MRMP in 6 geographically diverse US states, macrolides should remain the drugs of choice in children with M.
Fluoroquinolones, but not cephalosporins, showed a significantly increased risk of dysglycemia relative to macrolides, the reference drug category.
It also points to the possibility that the effect of macrolides in reducing COPD exacerbations may not be the direct effect against the bacteria.