01700nas a2200289   4500000000100000008004100001260001300042653004200055653003300097653003100130653001100161653001200172653002400184653002400208653002500232653003100257653003700288653001500325653001700340100001000357700001000367245004100377300001000418490000700428520096100435022001401396       1994                            d  c1994 Mar10aAIDS-Related Opportunistic Infections10aDNA-Directed RNA Polymerases10aDrug Resistance, Microbial10aHumans10aleprosy10aMolecular Structure10aMycobacterium avium10aMycobacterium leprae10aMycobacterium tuberculosis10aReverse Transcriptase Inhibitors10aRifamycins10aTuberculosis1 aLal R1 aLal S00aRecent trends in rifamycin research.  a211-60 v163 a<p>Rifamycin is a clinically useful macrolide antibiotic produced by the gram positive bacterium Amycolatopsis mediterranei. This antibiotic is primarily used against Mycobacterium tuberculosis and Mycobacterium leprae, causative agents of tuberculosis and leprosy, respectively. In these bacteria, rifamycin treatment specifically inhibits the initiation of RNA synthesis by binding to beta-subunit of RNA polymerase. Apart from its activity against the bacteria, rifamycin has also been reported to inhibit reverse transcriptase (RT) of certain RNA viruses. Recently, rifamycin derivatives have been discovered that are effective against Mycobacterium avium, which is associated with the AIDS complex. Consequently, the importance of and demand for rifamycin has increased tremendously, the world over. In this article, recent trends in rifamycin research and accessibility of recombinant DNA techniques to increase rifamycin production are reviewed.</p>  a0265-9247