In vitro activities of antibiotics against Plasmodium falciparum are inhibited by iron.
The in vitro activities of cyclines (tetracycline, doxycycline, minocycline, oxytetracycline, and rolitetracycline), macrolides (erythromycin, spiramycin, roxithromycin, and lincomycin), quinolones (norfloxacin and ofloxacin), rifampin, thiamphenicol, tobramycin, metronidazole, vancomycin, phosphomycin, and cephalosporins (cephalexin, cefaclor, cefamandole, cefuroxime, ceftriazone, cefotaxime, and cefoxitin) were evaluated on Plasmodium falciparum clones, using an isotopic, micro-drug susceptibility test. Only tetracyclines, macrolides, quinolones, and rifampin demonstrated in vitro activity against P. falciparum, which increased after a prolonged exposure (96 or 144 h). In the presence of iron (FeCl(3)), only the activities of tetracyclines and norfloxacin were decreased. Their in vitro activity against intraerythrocytic stages of multidrug-resistant P. falciparum and their efficacy in vivo favor the use of antibiotics as antimalarial drugs. However, due to their slow antimalarial action and to the fact that they act better after prolonged contact, they probably need to be administered in conjunction with a rapidly acting antimalarial drug, such as a short course of chloroquine or quinine.
Pradines
B
B
Unité de Parasitologie, Institut de Médecine Tropicale du Service de Santé des Armées, Le Pharo, 13998 Marseille, France. bruno.pradines@free.fr
Rogier
C
C
Fusai
T
T
Mosnier
J
J
Daries
W
W
Barret
E
E
Parzy
D
D
D000818:Animals; D000900:Anti-Bacterial Agents / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D000962:Antimalarials / Q000494:pharmacology; D002478:Cells, Cultured; D002712:Chlorides; D002738:Chloroquine / Q000494:pharmacology; D018432:Drug Resistance, Multiple; D005290:Ferric Compounds / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D010963:Plasmodium falciparum / Q000187:drug effects*
D000900:Anti-Bacterial Agents; D000962:Antimalarials; D002712:Chlorides; D005290:Ferric Compounds; D002738:Chloroquine; C024555:ferric chloride