RESUMO
Molecular techniques have revolutionized tuberculosis (TB) diagnosis by offering a faster and more sensitive approach, detecting Mycobacterium tuberculosis (Mtb) DNA directly from samples. Single-tube nested PCR (STNPCR) combines two PCR reactions with separate oligonucleotide sets in a single tube. Moreover, colorimetric methods in PCR products have been studied for pathogen detection. Thus, this study aimed to establish a novel system based on colorimetric STNPCR for Mtb detection using microtiter plates with IS6110-amplified fragments. The results showed a general colorimetric STNPCR detection limit of 1 pg/µl. Its general sensitivity and specificity were 76.62 and 60.53%, respectively, with kappa index agreement of 0.166.
A total of 318 biological samples (urine, plasma, peripheral blood mononuclear cells, pleural fluid and sputum) from pulmonary/extrapulmonary TB and non-TB patients were used in this study. The colorimetric STNPCR assay using IS6110 as the target gene was developed and optimized for Mtb detection based on similar validated systems. Cut-off values based on receiver operator characteristic curve analysis were defined to determine the sensitivity and specificity for each sample type. The technique's performance was assessed according to kappa index calculations and interpretation.
Assuntos
Colorimetria , DNA Bacteriano , Mycobacterium tuberculosis , Reação em Cadeia da Polimerase , Tuberculose , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/isolamento & purificação , Colorimetria/métodos , Reação em Cadeia da Polimerase/métodos , Humanos , Tuberculose/diagnóstico , Tuberculose/microbiologia , DNA Bacteriano/genética , DNA Bacteriano/análise , Sensibilidade e Especificidade , Limite de DetecçãoRESUMO
Mycobacterium wolinskyi is a rapidly growing mycobacterium, first described in 1999 as a member of the group Mycobacterium smegmatis (Mycobacterium smegmatis, Mycobacterium wolinskyi and Mycobacterium goodii). Only 19 case reports all over the world have been described on literature, none of them in Brazil. On this report, it is described one case of infection after a mammoplasty procedure performed in a private health service in the county of Recife, Pernambuco, Brazil, in 2009. The mycobacteria specie was identified using biochemical tests and sequencing the specific gene rpoB. To treat the infection by Mycobacterium wolinskyi it was necessary to combine antibiotics for a long period of time associated with surgical procedures of the breast abscesses.