Probable mechanisms of drug resistance in Candida species. (1) Drugs are pumped out by efflux pump. (2) Drug targets such as enzymes are overproduced and drugs cannot inhibit the enzymatic reactions. (3) Due to mutations, the structures of enzymes or other proteins are altered and drugs cannot bind to it. (4) Crucial enzymatic function that is inhibited by drug can be bypassed. (5) Drugs may be degraded and are used as carbon source. (6) Drugs may be modified by enzymes and become nontoxic. (7) Drugs are degraded and become nonfunctional. (8) Extracelluar enzyme may degrade the drugs outside the fungal cell and make them inactive. (9) Altered membrane may inhibit the entry of drugs into cell and drugs cannot function.
