Comparison of the Activity of Ionophores with Other Antibacterial Agents Against Anaerobes

Abstract

Representative polyethers of each group in Westley's classification and related ionophore antibiotics were examined for in vitro activity against 25 anaerobic strains. Lasalocid (X-537A) and nigericin were found to have activity comparable in potency to some leading antianaerobe antibiotics, newer cephalosporins and nitroimidazoles, with a different spectrum as revealed by a spectral comparison. A strict relationship between their antianaerobe activity and either their structural features or cation transporting properties was not apparent.

Antimicrobial Growth Promoters Used in Animal Feed: Effects of Less Well Known Antibiotics on Gram-Positive Bacteria

“…The reason for this incomplete cross-resistance remains unclear. Acquired resistance to ionophores has not yet been reported either for clostridia (33,34,72,79,82,129,228) or for other anaerobic bacteria (228).…”

“…It transports Na ϩ more efficiently than K ϩ (48,108). Lasalocid is a divalent ionophore antibiotic (228). Although it transports bivalent ions such as Ca 2ϩ and Mg 2ϩ very well (176), it is also an efficient K ϩ carrier (48).…”

“…Examples of channel-forming quasi-ionophores include gramicidin and the polyene antibiotics, the best-known representatives of which are the antimycotic agents nystatin and amphotericin B. These antibiotics have a different mechanism of transmembrane transport: they open up ion conduction channels (177,228). The ionophore antibiotics are active against parasites, including coccidia (Eimeria) and Plasmodium (25,103,104,191), as well as against gram-positive organisms and mycoplasmas.…”

“…They are not used therapeutically in humans. In animals the ionophores are used mainly for growth promotion and as "coccidiostats," in the prevention of coccidiosis (39,51,72,81,201,228). Monensin, lasalocid, salinomycin, narasin, and maduramycin are used in Europe.…”

Cytotoxicity of Monensic Acid and its Biometal(II) Complexes Against Anaerobic Bacterial StrainClostridium PerfringensSpp.

“…and Staphylococcus spp. in the concentration range from 0.25 μg/mL to 16 μg/mL (12). These compounds are usually applied in the form of the corresponding sodium complexes, which possess strong antimicrobial efficacy, but many studies have revealed that their biological activity is sensitive to the local cation(ii) environment both in in vivo and in vitro experiments (1,2,3,4,5).…”