[Isolation of environmental mycobacteria from soils of Córdoba city Argentina].

The interest for the research on enviromental mycobacteria has risen over the last decades, in part, due to a significant incidence rate rise. Reports from all over the world address the soil as the major source for human contamination. In Argentina two documents report the prevalence of atypical mycobacteriosis at Córdoba (1997), and the isolation of enviromental mycobacteria from soils of the Province of La Pampa (1999) respectively. The aim of our study was to confirm the presence of enviromental mycobacteria in soil of the city of Córdoba. The map of the city was divided in 9 regions according to avenues and major streets distribution. A total of 120 soil samples were recollected with spatula from a 10 x 10 cm square up to 1 cm deep. Samples were kept at 4 degrees C no more than 7 days. Soil samples were homogenized with destilled water in a 1:1 proportion, and decontaminated according to Petroff's method. The cultures were made in Lowestein-Jehnsen media and incubated at 37 degrees C controlling development every 7 days for 2 months. An acid-fast-bacilli smear was made from colonies obtained. Twenty three cultures (19%) were discarded due to contamination. Twenty cultures (17%) developed acid fast bacilli (AFB). Colonies obtained were sent to the Mycobacteria Service of the Instituto Nacional de Enfermedades Infecciosas Dr. Carlos G. Malbrán, in the city of Buenos Aires, for identification. A single isolation was identified as Mycobacterium triviale. A positive correlation was observed between the frequency of positive AFB isolation and the number of samples taken from park areas. The presence of enviromental mycobacteria in soils of Córdoba was confirmed. Results suggest higher odds of isolation in parklands and soils where animals live. Extensive works are needed to asset the features that allow and contribute the proliferation of mycobacteria in soils.