Estudo comparativo entre um sistema de sonda genética e métodos clássicos na identificação das micobactérias

Coelho, Andréa Gobetti Vieira; Zamarioli, Liliana Aparecida; Reis, Clemira M. P. V.; Nascimento, Ana Carolina Chiou; Rodrigues, Juliana dos Santos

doi:10.1590/s1806-37132008001100006

Cited by 4 publications

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References 5 publications

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“…The identification of M. tuberculosis infections in 63.6 % (35/55) of samples is consistent with other studies that found a higher prevalence of MTB; 67 % [ 26 ], 57.5 % [ 27 ], 78.6 % [ 28 ] and 77 % [ 29 ]. Despite the higher occurrence of MTB, it has been shown elsewhere that the MTB frequency is declining over the years, while the NTM frequency is significantly increased, with prevalence ranging from 9.1 % in 2003 to 31.9 % in 2009 [ 28 ].…”

Section: Discussionsupporting

confidence: 91%

Diagnosis of mycobacterial infections based on acid-fast bacilli test and bacterial growth time and implications on treatment and disease outcome

et al. 2016

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BackgroundThe establishment of therapeutic regimens for mycobacteriosis depends on the accurate identification of Mycobacterium species, and misdiagnosis can result in inappropriate treatment and increased mortality of patients. Differential diagnosis among Mycobacterium species has been made by conventional phenotypic and biochemical tests after a long culture period. Specialized molecular diagnostics of mycobacteria allows rapid detection and species identification; however, such tests are not available in public health programs. Our aim was to demonstrate the clinical implications of erroneous diagnosis by performing molecular genotyping of mycobacterial infections in patients that were diagnosed based on symptoms, culture and bacilloscopy.MethodsCulture samples of mycobacterial infections from 55 patients clinically diagnosed as tuberculosis in 2013 and 2014, based on conventional methods, were identified by PCR -RFLP and results are discussed.ResultsWe have confirmed 35 (63.6 %) positive samples as M. tuberculosis, but 18 (32.7 %) were identified as non-tuberculous mycobacteria (M. avium type 1, M. avium type 2, M. kansasii type 1 type 1, M. mucogenicum, M. chelonae, M. terrae type 3, and 1 unknown RFLP pattern) and two were negative. Regarding clinical diagnosis, 61.8 % (34/55) was classified as pulmonary tuberculosis. It is important to emphasize that 36.4 % (20/55) of samples were misdiagnosed by conventional methods, and 11 (61.1 %) of the HIV positive patients (18/55) were NTM-coinfected.ConclusionThe identification of species in mycobacterial infections is essential for correct diagnosis and choice of treatment regimen, and misdiagnosis by conventional tools can lead to chronic disease, increased resistance and death.Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-016-1474-6) contains supplementary material, which is available to authorized users.

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Section: Discussionsupporting

confidence: 91%

Diagnosis of mycobacterial infections based on acid-fast bacilli test and bacterial growth time and implications on treatment and disease outcome

et al. 2016

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Tuberculosis in cancer patients: Role of newer techniques in relation to conventional diagnostic methods

El-Mahallawy

Eissa

Rafeh

et al. 2010

Journal of Advanced Research

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The highly infectious nature of tuberculosis (TB) urges the need to increase the efficiency and rapidity of lab methods. The coexistence of TB and cancer was investigated using Mycobacterium tuberculosis direct test (MTD) and the mycobacteria growth indicator tube (MGIT), besides the conventional lab procedures. All assays were performed on 101 patients clinically suspected of having a mycobacterial infection. Over a period of 4 years, TB was confirmed in 32 patients with malignancy by applying the gold standard of considering patients with positive culture on Lowenstein-Jensen or MGIT or having any two or more positive tests as confirmed mycobacterial infection. Among the confirmed cases, the underlying malignant conditions were hematologic malignancies, bronchogenic carcinoma, and other solid tumors, in 14, 12, and 6 of the patients; respectively. TB developed during cancer chemotherapy in 18 cases (56%), and was discovered synchronously with malignancy in 14 (44%) patients. The ZN stain revealed acid-fast bacilli in 15 (47%) cases. The LJ culture was positive in 20 (63%) cases and MGIT was positive in 18 (56%) cases. Although the MTD test was positive in 18 (56%) of the confirmed TB cases; i.e., it was negative in 14 cases positive by other tests. There was a moderate agreement between results of LJ and MGIT, Kappa 0.396 and ZN and MGIT, Kappa 0.436. There was a weak agreement between results of LJ and MTD, ZN and MTD, Kappa 0.227 and 0.209; respectively; whereas, no agreement was calculated between MGIT and MTD Kappa 0.029. The calculation of the combined sensitivity of any two tests was 94%. TB is a major pathogen in patients with malignant diseases if clinically suspected. Little overlap between different technologies used necessitates the utilization of combination of tests together with consideration of key clinical characteristics to improve the diagnostic accuracy of TB.

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Usefulness of the mycobacterium tuberculosis direct assay in early diagnosis of extrapulmonary TB

Zhang

Fang

Guo

et al. 2014

ARCH BIOL SCI BELGRA

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The aim of this study was to evaluate the in situ detection of living mycobacterium TB rRNA by the mycobacterium TB direct assay (MTD) and its clinical significance in the early diagnosis of extrapulmonary TB. Eighty-six patients were recruited from the Shanghai Public Health Clinical Center from June to November in 2010, having been diagnosed with extrapulmonary TB, including tuberculous peritonitis (n=22), lymphatic TB (n=21), tuberculous meningitis (n=15), HIV-associated TB (n=13), nephroTB (n=9), spinal TB (n=2), cutaneous TB (n=13), parotid TB (n=1), chest wall TB (n=1), intestinal TB (n=1). One hundred and five extrapulmonary specimens, including CSF, puncture fluid, drainage, pleural fluid, urine, secretion, ascites, lymphatic tissue and marrow were collected from the patients. The samples were examined using acid-fast stain, solid culture, liquid culture and MTD in parallel. In MTD, the target segments of MTB rRNA in either cultures or clinical specimens were amplified prior to being qualitatively detected with the hybridization protection assay (HPA). The sensitivities of MTD and acid-fast staining in liquid and solid cultures were 48.6%, 41.9%, 20.0% and 14.3%, respectively. MTD sensitivity was higher than that of the others and its specificity was 100%. We concluded that MTD rRNA detection is an effective, rapid, convenient, sensitive and reliable method for the early diagnosis of extrapulmonary TB.

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Estudo comparativo entre um sistema de sonda genética e métodos clássicos na identificação das micobactérias

Cited by 4 publications

References 5 publications

Diagnosis of mycobacterial infections based on acid-fast bacilli test and bacterial growth time and implications on treatment and disease outcome

Diagnosis of mycobacterial infections based on acid-fast bacilli test and bacterial growth time and implications on treatment and disease outcome

Tuberculosis in cancer patients: Role of newer techniques in relation to conventional diagnostic methods

Usefulness of the mycobacterium tuberculosis direct assay in early diagnosis of extrapulmonary TB

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