PCR could be a method of choice for identification of both pulmonary and extra-pulmonary tuberculosis

Abstract

BackgroundNucleic acid amplification assays including PCR have revolutionized the detection of Mycobacterium tuberculosis (MTB). Tuberculosis spread to almost every organ of the body and is characterized on the basis of localization of infection. Therefore, different types of body fluids and tissues can be used for the detection of MTB.From 2004 to 2010 total 766 different types of smear negative samples from patients, clinically suspected for tuberculosis were received and investigated at Division of Molecular Diagnostics, University of the Punjab Lahore for the diagnosis of tuberculosis. Mycobacterial DNA was extracted followed by PCR amplification.FindingsA total of 356 (46.5%) samples were found positive by PCR for MTB. These included; serum (4.8%), blood (36.3%), urine (46.6%), cerebro spinal fluid (CSF) (42.1%), ascetic fluid (67.6%), pleural fluid (52%), pericardial fluid (30%), pus (38.6%), bone marrow (60%), sputum (38.8%) and bronchoalveolar lavage (BAL) (70%). Over all there was no significant difference in males and females neither in different age groups for the identification of MTB.ConclusionWe conclude that PCR is a useful and sensitive tool for the early diagnosis of MTB in variety of clinical samples.

PCR as a Diagnostic Tool for Extra-Pulmonary Tuberculosis

“…In the present study, PCR could detect M. tuberculosis in 11% of the tested cases. The reported positivity rates of PCR in the tested nonrespiratory samples ranged from 8.6-63% [11][12][13][14][15]. Among the laboratory confirmed cases in the present study, PCR detected the maximum number of cases i.e.…”

Microbiological diagnosis of spinal tuberculosis

“…When low numbers of bacilli are present, PCR assay has more sensitivity than conventional methods [24]. PCR can become a reliable technique for rapid identification of TB [30].…”

“…In Pakistan, Amin et al [30] analysed 766 samples with suspected TB and found a total of 356 (46.5%) positive by the PCR method. They noted that the efficiency of the PCR depends on the sample, with values of 70% in respiratory samples such as bronco alveolar lavage and 4.8% in serum.…”

Xpert MTB/RIF® como herramienta diagnóstica en una cohorte de niños menores de 15 años con sospecha clínica de tuberculosis pulmonar en un hospital de alta complejidad de Medellín

“…Debido a que los métodos utilizados de forma tradicional no permiten detectar micobacterias de manera rápida y debido a la necesidad de iniciar tratamiento de forma precoz para evitar mayor progresión de la enfermedad y tener una más rápida recuperación, se han desarrollado técnicas moleculares que permiten obtener resultados en tiempo corto, con alta especificidad y mejorando la sensibilidad 12,13 .…”