Comparative Study of a Real-Time PCR Assay Targeting senX3-regX3 versus Other Molecular Strategies Commonly Used in the Diagnosis of TuberculosisReportar como inadecuado




Comparative Study of a Real-Time PCR Assay Targeting senX3-regX3 versus Other Molecular Strategies Commonly Used in the Diagnosis of Tuberculosis - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Background

Nucleic acid amplification tests are increasingly used for the rapid diagnosis of tuberculosis. We undertook a comparative study of the efficiency and diagnostic yield of a real-time PCR senX3-regX3 based assay versus the classical IS6110 target and the new commercial methods.

Methods

This single-blind prospective comparative study included 145 consecutive samples: 76 from patients with culture-confirmed tuberculosis 86.8% pulmonary and 13.2% extrapulmonary tuberculosis: 48.7% smear-positive and 51.3% smear-negative and 69 control samples 24 from patients diagnosed with non-tuberculous mycobacteria infections and 45 from patients with suspected tuberculosis which was eventually ruled out. All samples were tested by two CE-marked assays Xpert®MTB-RIF and AnyplexTM plus MTB-NTM and two in-house assays targeting senX3-regX3 and the IS6110 gene.

Results

The detection limit ranged from 1.00E+01 fg for Anyplex, senX3-regX3 and IS6110 to 1.00E+04 fg for Xpert. All three Xpert, senX3-regX3 and IS6110 assays detected all 37 smear-positive cases. Conversely, Anyplex was positive in 34 91.9% smear-positive cases. In patients with smear-negative tuberculosis, differences were observed between the assays; Xpert detected 22 56.41% of the 39 smear-negative samples, Anyplex 24 61.53%, senX3-regX3 28 71.79% and IS6110 35 89.74%. Xpert and senX3-regX3 were negative in all control samples; however, the false positive rate was 8.7% and 13% for Anyplex and IS6110, respectively. The overall sensitivity was 77.6%, 85.7%, 77.3% and 94.7% and the specificity was 100%, 100%, 90.8% and 87.0% for the Xpert, senX3-regX3, Anyplex and IS6110 assays, respectively.

Conclusion

Real-time PCR assays targeting IS6110 lack the desired specificity. The Xpert MTB-RIF and in-house senX3-regX3 assays are both sensitive and specific for the detection of MTBC in both pulmonary and extrapulmonary samples. Therefore, the real time PCR senX3-regX3 based assay could be a useful and complementary tool in the diagnosis of tuberculosis.



Autor: Rocio Sanjuan-Jimenez , Inmaculada Toro-Peinado, Pilar Bermudez, Juan D. Colmenero, Pilar Morata

Fuente: http://plos.srce.hr/



DESCARGAR PDF




Documentos relacionados