02815nas a2200397   4500000000100000008004100001260004300042653002500085653001200110653002700122653001100149653002300160653002800183653002300211653001000234653000900244653002400253653003200277653002400309653002900333653003100362653001300393653001900406653001400425100002200439700002600461700002500487700001900512700002200531700002100553245014700574300001100721490000700732520166400739022001402403       2012                            d  c2012 OctbSpringer-Verlag TokyoaTokyo10aAnalysis of Variance10aAnimals10aDisease Models, Animal10aFemale10aHistocytochemistry10aIndicators and Reagents10aLeprostatic Agents10aLiver10aMice10aMice, Inbred BALB C10aMicrobial Sensitivity Tests10aMicrobial Viability10aMycobacterium Infections10aMycobacterium lepraemurium10aOxazines10aPlant Extracts10aXanthenes1 aMendoza-Aguilar M1 aAlmaguer-Villagrán L1 aJiménez-Arellanes A1 aArce-Paredes P1 aCid-Gutiérrez JL1 aRojas-Espinosa O00aThe use of the microplate alamar blue assay (MABA) to assess the susceptibility of Mycobacterium lepraemurium to anti-leprosy and other drugs.  a652-610 v183 a<p>Although murine leprosy is no longer a common illness, our understanding of the biology of this disease is incomplete. One particular example of this concerns the etiologic agent Mycobacterium lepraemurium (MLM). MLM is a fastidious microorganism that is difficult to grow in axenic media; in a way, this has hampered attempts to thoroughly study its physiological and metabolic characteristics. MLM is an obligate intracellular bacillus that invades macrophages and replicates profusely with a generation time that oscillates between 0.5 and 11 days. In the present study, we have successfully maintained MLM alive for more than 12 days in vitro, providing us with an opportunity to study its susceptibility to several anti-leprosy agents and other drugs. To achieve this, we used a fluorescence reduction assay of alamar blue (a resazurin) in a microplate format (microplate-alamar-blue-assay; MABA), which is a highly sensitive, practical, and inexpensive method for assaying cell viability. We found that MLM was highly susceptible to clofazimine and rifampicin and was less susceptible to streptomycin, thiacetazone, kanamycin, dapsone, and ethionamide, in that order. MLM was not susceptible to four plant triterpenoids (oleanolic acid, neolignan-c, sitosterol, and ursolic acid) for which bactericidal activity has been reported in M. tuberculosis. Because the MABA has high sensitivity, it can be used to monitor the activity of microorganisms that are difficult to cultivate (such as M. lepraemurium), in response to various drugs, thus offering a method to complement the study of murine leprosy, about which many questions remain unanswered.</p>  a1437-7780