Non-canonical mechanisms of antibiotic resistance.

Although the current in vitro methods used for detection and analysis of the phenotypes of antibiotic resistance in the laboratory are well established, other resistance mechanisms of resistance exist which may escape detection using the standard approach. The present article reviews some of these mechanisms which are grouped under the term 'non-canonical mechanisms' of antibiotic resistance. Such mechanisms include gene dosage, heterologous induction or selection, populational resistance and synergism between mechanisms of low resistance. The role of these mechanisms in the failure of therapy is discussed.