A NOVEL approach to the treatment of tuberculosis (TB) has been investigated by a team of molecular geneticists in the United Kingdom, following the direction of a new gene in mycobacteria, one type of which causes the disease.The presence of the gene opens up opportunities for the use of azole drugs which are already available for ht etreatment of fungal infections.
These treatments such as in Canestan and Diflucan are central to antifungal treatments of patinets suffering infections such as Canadida albicans but also increasingly in internal fungal infections.New azole drugs are being developed against fungi as the incidence of infection has increased dramatically in recent years.The potential value of these drugs against mycobacteria had not received attention because were not thought to contain this drug target which is associated with the sterol bio-synthesis pathway.
Laboratory tests have already shown that some of these drugs work on various mycobacteria, including the BCG strain that is used for inoculations and Mycobacterium Smegmatis, generally an opportunistic pathogen.The equivalent of the target of the drugs in fungi has been detected in several mycobacterial pathogens including that causing TB and the protein in the BCG strain is identical to that in M. Tuberculosis causing TB.
These results suggest that the drugs are also likely ot be active against the strains that cause infection.Further tests will confirm which of the family of azole drugs could be candidates for fast-tracking the drug discovery programme.Professor Steven Kelley, of the Institute of Biological Sciences at University of Wales Aberystwyth, said:"The sterol biosynthesis pathways are commonly found in fungi, animals and plants but this was the first that this gene had been found in bacteria. We now see the gene in several of the databases containing the genetic blueprints of different mycobacteria.
"It gives us the prospect of using existing anti-fungal compounds where there is knowledge about toxicological safety or at least provides strong leads for drug development - means that these drugs could be suitable to combat TB many years before an entirely new type of drug can be discovered. Thes ecompounds should be considered urgently," added Professor Kelly.