Tipificación de micobacterias a partir de cepas inactivadas mediante análisis de patrones de restricción (PRA)

Abstract

Conventionally used tools and techniques have been developed to ensure that symptomatic, positive patients are promptly enrolled in anti-tuberculosis medical treatment. Consequently, cases involving diseases caused by non-tuberculous mycobacteria (NTM) are often managed or treated incorrectly. To address this, the Restriction Analysis (PRA) method for mycobacterial identification was implemented, aiming to improve diagnostic accuracy and ensure appropriate medical treatment for patients. Sixty random samples from the strain bank at the National Institute of Public Health Research (INSPI) in Guayaquil were analyzed using both phenotypic-based testing (PBT) and the PRA method. The PRA method relies on the cleavage of the *hsp65* gene using the restriction enzymes BstEII and HaeIII, which produces fragments of varying sizes; these fragments are then compared against reference patterns available on the website http://app.chuv.ch/prasite/index.html to determine the specific species. PBT identified 4 species and 2 complexes, while PRA identified 7 species and 1 complex. A comparison of the results revealed one sample that could not be identified by PRA and one discordant result. These findings are supported by the patients' clinical histories, underscoring the need for clear and comprehensive data management in studies of this nature. In conclusion, PRA is a rapid, accessible, and suitable method for the identification of NTM. It is recommended that efforts toward the molecular study of mycobacteria be expanded at the national level.