ABSTRACT
Objetivos : Determinar si la formación de cordones ocurre en la microcolonias de M. kansasii. Material y métodos : Se sembraron en medio solido 7H11, cuatro especies de micobacterias patógenas de alta prevalencia Mycobacterium kansasii, Mycobacterium abscessus, Mycobacterium tuberculosis y Mycobacterium neonarum y se evaluaron hasta por 21 días, realizando complementariamente las coloraciones Ziehl-Neelsen para cada una de ellas. Para observar la presencia de la formación de cordones en las microcolonias, se utilizó microscopia de fase invertida. Resultados : En todas las especies se observó a nivel de las microcolonias la formación de cordones, además se identificó la formación de cordones en etapa temprana por la coloración Zhiel-Nelsen en Mycobacterium kansasii, Mycobacterium abscessus, y Mycobacterium tuberculosis. Conclusiones : Mycobacterium kansasii es capaz de desarrollar cordones a nivel microscópico, por lo que la premisa basada en la formación de cordones por M. tuberculosis como un patrón diferencial de las demás micobacterias deben ser tomadas con cautela.
SUMMARY Objectives : Determine if cord formation occurs in microcolonies of M. kansasii. Methods : 4 highly prevalent pathogenic mycobacterial species Mycobacterium kansasii, Mycobacterium abscessus, Mycobacterium tuberculosis and Mycobacterium neonarum were sown in 7H11 solid medium and observed for up to 21 days, additionally Ziehl-Neelsen staining was performed for each of them. Additionally, Ziehl-Neelsen staining was performed for each of them, observing the presence of cord formation in the microcolonies and determining their relationship with virulence and specific species Results : In all the species cultivated in solid medium 7H11, the formation of cords was observed at the level of the microcolones, in addition, the formation of cords in an early stage was identified by the Zhiel-Nelsen staining in Mycobacterium kansasii, Mycobacterium abscessus, and Mycobacterium tuberculosis. Conclusions : Mycobacterium kansasii is capable of developing beads at the microscopic level as was observed in microcoloneas, so the premise based on beads by microscopy specific for the M. tuberculosis species as a differential pattern from the other mycobacteria by forming beads in cultures must be taken with caution so as not to generate a misdiagnosis since there are other species that are capable of forming a similar pattern as has been observed in Mycobacterium kansasii.
ABSTRACT
RESUMEN Con el objetivo de identificar diferencias morfológicas en colonias de diferentes especies de micobacterias mediante microscopía de fase invertida, se sembraron en medio sólido 7H11, nueve especies de micobacterias patógenas de alta prevalencia y se observaron hasta por 21 días. Adicionalmente se realizaron coloraciones Ziehl-Neelsen (ZN) para cada una de ellas. No se identificó variaciones morfológicas entre las especies cultivadas, sin embargo, se observó que todas fueron capaces de formar cordones en su etapa temprana de crecimiento, siendo corroborado por coloración ZN en Mycobacterium tuberculosis. Asimismo, se determinó ciertas características microbiológicas como tiempo mínimo y la temperatura de crecimiento, y características bacilares basadas en la tinción ZN para cada especie estudiada. Estos hallazgos son importantes para la identificación del agente etiológico y podrían servir de base para estudios posteriores sobre la identificación de las biomoléculas involucradas en la agregación celular de cada micobacteria.
ABSTRACT With the aim of identifying morphological differences in colonies of different species of mycobacteria by means of inverted phase microscopy, nine species of high-prevalence pathogenic mycobacteria were seeded in 7H11 solid medium and were observed for up to 21 days. Additionally, Ziehl-Neelsen (ZN) stains were carried out for each one of them. No morphological variations were identified among the species grown on solid medium; however, it was identified that all are able to form cords in solid medium in an early stage of growth, being corroborated by the Ziehl-Neelsen stain in Mycobacterium tuberculosis. so techniques based on detecting M. tuberculosis depending on the identification of the cords should be taken with caution so as not to generate a bad diagnosis, so microbiological characteristics could also be established as a minimum time to detect growth, temperature of growth and bacillary characteristics based on the Ziehl-Neelsen stain for each species studied.