paradoxic effect

par·a·dox·ic ef·fect

(par'ă-dok'sik e-fekt')
As related to minimal bactericidal concentration testing, decreased bactericidal activity of an antimicrobial agent at higher concentrations, as demonstrated by growth of more colonies on subcultures at higher concentrations than at lower concentrations.
References in periodicals archive ?
Paradoxic effect of multiple mild coagulation factor deficiencies on the prothrombin time and activated partial thromboplastin time.