Efecto micobactericida del ácido hipocloroso en tres especies ambientales potencialmente patógenas y en Mycobacterium tuberculosis / Mycobactericidal effect of hypochlorous acid in three potentially pathogenic environmental species and in Mycobacterium tuberculosis

Objetivo. Evaluar el efecto micobactericida del ácido hipocloroso siguiendo las normas internacionales de desarrollo de nuevos desinfectantes. Materiales y métodos. Se evaluó la efectividad del ácido hipocloroso en Mycobacterium chelonae, M. fortuitum, M. intracellulare y M. tuberculosis en diferentes concentraciones en cuatro intervalos de tiempo, a 225 ppm, 450 ppm, 750 ppm y 1.500 ppm, durante 5, 10, 15 y 20 minutos. Las pruebas desarrolladas fueron: exposición directa al desinfectante en condiciones limpias, exposición con interferencia (condiciones sucias), exposición en superficies en condiciones limpias y prueba de corrosión del desinfectante. Resultados. Todas las concentraciones evaluadas del ácido hipocloroso en condiciones limpias, es decir, en exposición directa y en superficies, resultaron ser efectivas durante todos los intervalos de tiempo, mientras que para la prueba con interferencia, fue necesario aumentar el tiempo, la concentración o ambos para tener, al menos, un 99,9 % de efectividad del desinfectante sobre la concentración bacteriana usada; estos resultados probablemente dependieron de la reducción de la concentración del ácido hipocloroso, causada por la interferencia con albúmina y de la resistencia intrínseca de cada especie micobacteriana. Conclusiones. El ácido hipocloroso es 100 % efectivo en todos los intervalos de tiempo y a todas las concentraciones evaluadas en condiciones limpias, y demostró ser efectivo después de lavados que arrastren con la mayoría de materia orgánica en una superficie, debido a que, en condiciones sucias, sólo es efectivo con las concentraciones más altas (900 y 1.500 ppm) y en tiempos mayores de 15 minutos.

Objective: to evaluate the mycobactericidal effect of hypochlorous acid according to the international standards for the development of new disinfectants. Materials and methods: the effectiveness of hypochlorous acid in M. chelonae, M. fortuitum, M. intracellulare and M. tuberculosis was evaluated at different disinfectant concentrations in 4 time intervals, at 225 ppm, 450 ppm, 750 ppm and 1500 ppm for 5, 10, 15 and 20 minutes. The main tests Results: all concentrations of hypochlorous acid tested in clean conditions, i.e. in direct exposure and in surfaces, were found to be effective at all the time intervals, while for the test with interference it was necessary to increase the time and/or concentration of the disinfectant for it to be at least 99.9% effective in the bacterial concentration used; these results were likely due to the reduction of acid concentration caused by the albumin used as interference and the intrinsic resistance of each mycobacterial species. Conclusions: hypochlorous acid is 100% effective in clean conditions at all the time intervals and in all the concentrations tested, proving to be effective after performing washes that drag away most organic matter on a surface, as in contaminated conditions its effectiveness is reduced to just higher disinfectant concentrations (900 and 1500 ppm) and times longer than 15 minutes.

Influence of Three High-level Disinfectants Sterilization on Cauterization of Dental Instruments / 中华医院感染学杂志

OBJECTIVE To evaluate the influence of three high-level chemical disinfectants for sterilization on cauterization of dental instruments.METHODS The measuring methods for disinfectants on cauterization of metal instruments,and usage indications for disinfectants followed Technical Standard for Disinfection published in 2002 by the Ministry of Health.Fourteen kinds of small instruments(grouped by 4 different metal materials) were analyzed on receipt and after sterilization by three high-level disinfectants(2% glutaraldehyde,chlorine dioxide, and symclosene),using cauterization rate.RESULTS Three high-level disinfectants had different cauterization rates,the cauterization rate was affected by concentration of disinfectant,sterilizing time,and morphology of instruments.The cauterization of chlorine dioxide was the strongest,followed by symclosene(trichloroisocyanuric acid),and then 2% glutaraldehyde.CONCLUSIONS In clinical sterilization,different materials of small instruments need proper disinfectants,concentration and sterilizing time for decreasing their cauterization.