Ultraviolet (UV) light is recognized as a potent sterilizing aid, but its relative effectiveness against Mycobacterium leprae has not been shown. We examined the influence of UV on the growth and metabolic activity of M. leprae harvested fresh from foot pads of nude mice. Temporary static suspensions were exposed to timed intervals of UV radiation generated from a fixed source to constitute dosages ranging from 0-12.64 x 10(4) erg/cm2. The metabolic activity of the bacilli was indexed by the oxidation of 14C-palmitate in BACTEC 12-B vials. The long-term effects of irradiation on cell division and growth were assessed by inoculation of BALB/c mouse foot pads. The metabolic activity in BACTEC showed an immediate dose-response-related decline to a maximum of 50% of the control activity after exposure to 6.3 x 10(4) erg/cm2. Mouse foot pad studies showed a similar dose-response pattern. Effective-dose determinations based on metabolic or foot pad data were similar. UV doses of 3.52 x 10(4) erg/cm2 resulted in an average 50% killing, and 7.73 x 10(4) erg/cm2 killed 84% of the M. leprae exposed. This UV sensitivity is similar to that reported for M. tuberculosis. UV sterilization and disinfection practices suitable for M. tuberculosis are likely to be equally effective for M. leprae.
BT - International journal of leprosy and other mycobacterial diseases : official organ of the International Leprosy Association C1 - http://www.ncbi.nlm.nih.gov/pubmed/10834064?dopt=Abstract DA - 2000 Mar IS - 1 J2 - Int. J. Lepr. Other Mycobact. Dis. LA - eng N2 -Ultraviolet (UV) light is recognized as a potent sterilizing aid, but its relative effectiveness against Mycobacterium leprae has not been shown. We examined the influence of UV on the growth and metabolic activity of M. leprae harvested fresh from foot pads of nude mice. Temporary static suspensions were exposed to timed intervals of UV radiation generated from a fixed source to constitute dosages ranging from 0-12.64 x 10(4) erg/cm2. The metabolic activity of the bacilli was indexed by the oxidation of 14C-palmitate in BACTEC 12-B vials. The long-term effects of irradiation on cell division and growth were assessed by inoculation of BALB/c mouse foot pads. The metabolic activity in BACTEC showed an immediate dose-response-related decline to a maximum of 50% of the control activity after exposure to 6.3 x 10(4) erg/cm2. Mouse foot pad studies showed a similar dose-response pattern. Effective-dose determinations based on metabolic or foot pad data were similar. UV doses of 3.52 x 10(4) erg/cm2 resulted in an average 50% killing, and 7.73 x 10(4) erg/cm2 killed 84% of the M. leprae exposed. This UV sensitivity is similar to that reported for M. tuberculosis. UV sterilization and disinfection practices suitable for M. tuberculosis are likely to be equally effective for M. leprae.
PY - 2000 SP - 11 EP - 7 T2 - International journal of leprosy and other mycobacterial diseases : official organ of the International Leprosy Association TI - The effect of ultraviolet light radiation on Mycobacterium leprae. UR - http://ila.ilsl.br/pdfs/v68n1a03.pdf VL - 68 SN - 0148-916X ER -