rpoB gene high-resolution melt curve analysis: a rapid approach for diagnosis and screening of drug resistance in tuberculous meningitis

Gupta

et al. 2017

Eye

PurposeTimely diagnosis of intraocular tuberculosis (IOTB) along with detection of drug resistance can save many eyes from visual impairment. With the growing incidence of IOTB and rising drug resistance, a reliable diagnostic platform for simultaneous detection of the agent and mutated gene is urgently needed. The MTBDRplus assay was evaluated directly on vitreous fluid samples for the same.Patients and methodsIn a prospective study, The MTBDRplus assay was performed on 127 vitreous fluid samples (77 'study group' comprising cases of presumed ocular tuberculosis and 50 'control group' cases of disease controls (n=25) and non-uveitic controls (n=25)). All samples positive by MTBDRplus assay were subjected to gene sequencing to confirm the mutations for rifampicin and isoniazid resistance.ResultsThe MTBDRplus assay produced a sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 36.36%, 100%, 100%, and 50.50%, respectively, for the detection of IOTB. Among the 28 cases from study group that were positive by MTBDRplus assay, rifampicin resistance was reported in six and isoniazid resistance in two cases. On sequencing of rpoB and katG gene, one case of false rifampicin-resistant by MTBDRplus was found. The other resistant isolates showed concordant mutations between MTBDRplus assay and sequencing.ConclusionThe MTBDRplus assay is an effective tool for the rapid diagnosis of IOTB along with detection of drug resistance, thereby improving the outcome in IOTB.

Section: Discussionsupporting

confidence: 91%

MTBDRplus for the rapid diagnosis of ocular tuberculosis and screening of drug resistance

Gupta

et al. 2017

Eye

Ann Clin Microbiol Antimicrob

“…In our study, two out of five MDR-TBM cases exhibited resistance to EMB, and the other two to both EMB and SM. In general, rifampicin resistance is considered to be a good marker to detect MDR-TB [ 22 , 23 ]. This was consistent with our finding, in that all patients with resistance to RIF are MDR-TBM cases.…”

Section: Discussionmentioning

confidence: 99%

Antituberculosis drug resistance patterns in adults with tuberculous meningitis: results of haydarpasa-iv study

Şenbayrak

Özkütük

Erdem

et al. 2015

BackgroundTuberculous meningitis (TBM) caused by Mycobacterium tuberculosis resistant to antituberculosis drugs is an increasingly common clinical problem. This study aimed to evaluate drug resistance profiles of TBM isolates in adult patients in nine European countries involving 32 centers to provide insight into the empiric treatment of TBM.MethodsMycobacterium tuberculosis was cultured from the cerebrospinal fluid (CSF) of 142 patients and was tested for susceptibility to first-line antituberculosis drugs, streptomycin (SM), isoniazid (INH), rifampicin (RIF) and ethambutol (EMB).ResultsTwenty of 142 isolates (14.1 %) were resistant to at least one antituberculosis drug, and five (3.5 %) were resistant to at least INH and RIF, [multidrug resistant (MDR)]. The resistance rate was 12, 4.9, 4.2 and 3.5 % for INH, SM, EMB and RIF, respectively. The monoresistance rate was 6.3, 1.4 and 0.7 % for INH, SM and EMB respectively. There was no monoresistance to RIF. The mortality rate was 23.8 % in fully susceptible cases while it was 33.3 % for those exhibiting monoresistance to INH, and 40 % in cases with MDR-TBM. In compared to patients without resistance to any first-line drug, the relative risk of death for INH-monoresistance and MDR-TBM was 1.60 (95 % CI, 0.38–6.82) and 2.14 (95 % CI, 0:34–13:42), respectively.ConclusionINH-resistance and MDR rates seemed not to be worrisome in our study. However, considering their adverse effects on treatment, rapid detection of resistance to at least INH and RIF would be most beneficial for designing anti-TB therapy. Still, empiric TBM treatment should be started immediately without waiting the drug susceptibility testing.

“…Limited studies are available on evaluation of HRM on EPTB samples. To the best of our knowledge, other than two studies (one on tuberculous meningitis 13 and other on EPTB samples containing <20 OATB samples 6 ), no study has yet evaluated HRM for detection of drug resistance in substantial number of OATB cases. The current study was therefore planned to evaluate potential of rpoB and katG HRM in detecting RifR and InhR, respectively, on a large cohort of OATB.…”

Section: Introductionmentioning

confidence: 99%

“…12 Limited studies are available on evaluation of HRM on EPTB samples. To the best of our knowledge, other than two studies (one on tuberculous meningitis 13 and other on EPTB samples containing <20 OATB samples 6 ), no study has yet evaluated HRM for detection of drug resistance in substantial number of OATB cases.…”

Section: Introductionmentioning

confidence: 99%

Diagnosing osteo‐articular tuberculosis and multidrug resistance using real‐time polymerase chain reaction and high‐resolution melt‐curve analysis

Journal Orthopaedic Research

et al. 2022

Self Cite

The study evaluated real-time quantitative polymerase chain reaction (qPCR) and high-resolution melt-curve analysis (HRM) for simultaneous diagnosis of osteoarticular tuberculosis (OATB) and drug resistance. Two hundred and fifty synovial fluid and pus specimens (20 confirmed OATB by culture, 130 suspected OATB, and 100 controls) processed in the Department of Medical Microbiology, PGIMER were subjected to qPCR using rpoB, MPB64, and IS6110 genes. All OATB positive specimens were subjected to HRM for detecting resistance to rifampicin and isoniazid. qPCR detected 129/150 OATB cases with a sensitivity of 86% (95% for confirmed and 84.6% for suspected OATB cases) and specificity of 100%. rpoB and MPB64 genes had higher sensitivity than IS6110 (86% vs. 74.6%). HRM reported eight multidrug resistant (MDR), two mono-rifampicin, and five mono-isoniazid resistant cases, all were concordant with gene sequencing. qPCR followed by HRM analysis offer a simple, accurate, and rapid platform for simultaneous detection of OATB and MDR.