[Concentrations preventing resistance mutations against fluoroquinolones].
AS A PRECAUTION: The new fluoroquinolones are clearly active on both Gram negative and Gram positive bacteria and on intracellular and strictly anaerobic bacteria, with excellent pharmacological properties. Nevertheless, there is a risk of resistant mutants appearing due to selective pressure, that would rapidly delete their activity. CONCENTRATIONS AVOIDING MUTATIONS: Among the definitions envisaged for the concept of a concentration that would prevent mutations or "mutation preventing concentration" (MPC), the most frequently retained is the concentration at which no mutant appears in the presence of a high inoculum. VALUES OF CONCENTRATIONS PREVENTING MUTATIONS: These have been established for Gram negative bacilli, for staphylococci methicillinsusceptible and for pneumococci. The MPC values are not correlated with those of the minimum inhibitory concentration (MIC), they are related to the bactericidal potential of fluoroquinolones.


CONCLUSIONS
Despite their limits, the MPC are of major interest for the prevention of mutants, which are always dangerous, since their underlying resistance mechanism is eventually unknown.
Dubreuil
Luc
L
Laboratoire de Microbiologie, Faculté de pharmacie, 3, rue du Pr Laguesse, BP 83, 59006 Lille. ldubreuil@phare.univ-lille2.fr
D000890:Anti-Infective Agents / Q000008:administration & dosage* / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004351:Drug Resistance / Q000235:genetics*; D024841:Fluoroquinolones; D006090:Gram-Negative Bacteria / Q000235:genetics* / Q000472:pathogenicity; D006094:Gram-Positive Bacteria / Q000235:genetics* / Q000472:pathogenicity; D006801:Humans; D012307:Risk Factors
D000890:Anti-Infective Agents; D024841:Fluoroquinolones