The thiourea isoxyl (thiocarlide; 4,4′-diisoamyloxydiphenylthiourea) is known to be an effective anti-tuberculosis drug, active against a range of multidrug-resistant strains Mycobacterium tuberculosis and has been used clinically. Little was its mode action. We now demonstrate that results in dose-dependent decrease the synthesis oleic and, consequently, tuberculostearic acid M. with complete inhibition at 3 μg/ml. Synthesis mycolic also affected. anti-bacterial effect partially reversed by...

A number of nucleic acid amplification assays (NAAs) have been employed to detect tubercle bacilli in clinical specimens for tuberculosis (TB) diagnosis. Among these, loop-mediated isothermal (LAMP) is an NAA possessing superior reaction characteristics. In the present study, a set six specific primers targeting Mycobacterium 16S rRNA gene with high sensitivity was selected and LAMP system (MTB-LAMP) developed. Using this system, total 200 sputum samples from Nepalese patients were...

Isoxyl (ISO), a thiourea (thiocarlide; 4, 4'-diisoamyloxythiocarbanilide), demonstrated potent activity against Mycobacterium tuberculosis H37Rv (MIC, 2.5 micrograms/ml), bovis BCG 0.5 microgram/ml), avium 2.0 and aurum A+ resulting in complete inhibition of mycobacteria grown on solid media. Importantly, panel clinical isolates M. from different geographical areas with various drug resistance patterns were all sensitive to ISO the range 1 10 microgram/ml. In murine macrophage model,...

An RNA-based assay is an additional molecular tool for leprosy diagnosis and determination of the viability bacilli. To simplify RNA detection, a one-step reverse transcriptase PCR (RT-PCR) was established evaluated. DNA could be isolated simultaneously. With use Mycobacterium leprae-specific primers targeting 171-bp fragment M. leprae 16S gene, RT-PCR resulted in detection both slit skin smears biopsy specimens. enhance positive signal, digoxigenin-labeled developed, successfully detected...

Diagnosis of leprosy is usually based on clinical features and skin smear results including the number lesions. Mycobacterium leprae not cultivable bacterial enumeration by microscopic examination required for classification, choice in choosing monitoring chemotherapy regimens, diagnosis relapse. However, detection quantification using standard microscopy yields limited specificity sensitivity. We describe an extremely sensitive specific assay M. biopsy specimens. Primers that amplified a...

Abstract Background and objective Limited data exist for the performance of Q uanti FERON ‐ TB Gold I n‐tube T est ( QFT‐IT ) in comparison to tuberculin skin test TST detecting latent tuberculosis LTB patients with human immunodeficiency virus HIV infection from )‐endemic A sia‐ P acific countries. Methods cohort study hai ‐infected without history or treatment was conducted M arch 2012 through 2013. Each patient underwent simultaneous . Results Among 150 enrolled subjects, median age 40...

Recently about 500 new cases of leprosy have been reported each year in Thailand. In addition to a steady rate case detection, Thailand is Southeast Asia where endemic neighbouring countries; therefore, strain differentiation could be useful tracing origins and routes infection, general surveillance. To identify suitable markers for M. leprae strains different global geographic regions determine the applicability systematic genotyping method transmission, variable nucleotide tandem repeats...

Detecting latent tuberculosis infection (LTBI) is important, especially in high-risk populations including healthcare workers (HCWs). QuantiFERON-TB Gold Plus (QFT-Plus) a new version of the interferon-gamma release assays (IGRAs) to replace In-tube (QFT-GIT). However, data on use QFT-Plus for LTBI detection high TB-burden countries are limited. This study was conducted TB-endemic setting Thailand. HCWs were enrolled and underwent both tests during annual health screening. The testing...

Definitive diagnosis of tuberculosis (TB) by conventional culture, followed bacterial identification based on biochemical tests is time-consuming and tedious. Simple loop-mediated isothermal amplification (LAMP) specific for Mycobacterium complex, targeting the M. 16S ribosomal RNA gene, termed TB-LAMP, was evaluated as an alternative rapid culture confirmation. TB-LAMP assessed its ability to detect complex in BACTEC MGIT 960-positive cultures. Of 103 cultures evaluated, 100 were identified...

Simple, low-cost and effective diagnostic tests for tuberculosis (TB) are needed especially in TB-high burden settings. The present study evaluated the performance of an in-house loop-mediated isothermal amplification (LAMP) diagnosing TB by comparing it to Xpert MTB/RIF, microscopy culture. In Thailand, a total 204 excess sputum samples volume after processing cultures were used Mycobacterium (MTB) detection MTB/RIF LAMP. Based on culture results as gold standard, overall sensitivity LAMP...

Introduction: COVID-19, an emerging infectious disease caused by SARS-CoV-2, continues to be a global public health threat. The development of colorimetric reverse transcription loop-mediated isothermal amplification (RT-LAMP) can extend the availability simple, reliable molecular tests for rapid detection COVID-19. Methodology: RT-LAMP assay was developed using new primer set targeting portion SARS-CoV-2 orf8. method validated at 63 ºC 60 minutes with naked-eye visualization color change....

The diagnosis of tuberculosis (TB) in endemic countries is challenging due to high caseloads and limited resources. A simple cost-effective diagnostic test for the rapid detection Mycobacterium (M. tuberculosis) clinical specimens crucially needed. We evaluated performance an in-house assay based on loop-mediated isothermal amplification (LAMP) targeting M. 16S ribosomal RNA (rRNA) gene TB Thailand. total 252 sputum samples from suspected cases pulmonary were analyzed. sensitivity LAMP was...

Introduction Latent tuberculosis infection (LTBI) is an enormous reservoir for (TB), and healthcare workers (HCWs) are at high risk TB infection. QuantiFERON-TB Gold Plus (QFT-Plus) alternative to the tuberculin skin test LTBI detection, but data on its application detected by QFT-Plus in burden countries limited. This study aimed determine prevalence of factors, investigate results Thai HCWs. Methods A cross-sectional analytical was conducted among HCWs a secondary care hospital Health...

Interferon-gamma (IFN-γ) release assays have improved latent tuberculosis (TB) detection and been considered promising for the diagnosis of TB disease. However, efficacy data is limited in high burden countries. The aim this study was to determine diagnostic potential QuantiFERON-TB Gold In-Tube (QFT-GIT) test active an endemic setting TB. A cross-sectional conducted a group 102 Thai patients with clinical symptoms chest x-ray findings suggesting pulmonary 112 healthy adults. Testing carried...

To improve the quality of diagnosing pulmonary tuberculosis (TB), WHO recommends use rapid molecular testing as an alternative to conventional microscopic methods. Loop-mediated isothermal amplification assay (LAMP test) is a practical and cost-effective nucleic technique. We evaluated pragmatic accuracy in-house LAMP for diagnosis TB in remote health care setting where advanced test not available.A prospective diagnostic study was conducted. Patients with clinical symptoms suggestive were...

Based on the discovery of three single nucleotide polymorphisms (SNPs) in Mycobacterium leprae, it has been previously reported that there are four major SNP types associated with different geographic regions around world. Another typing system for global differentiation M. leprae is analysis variable number short tandem repeats within rpoT gene. To expand distribution classified by and gene polymorphisms, we studied 85 clinical isolates from Thai patients compared findings those Asian...

A cross-sectional study was conducted on the performance of tuberculin skin test (TST) and QuantiFERON(®)-TB Gold In-Tube (QFT-IT) for detecting latent tuberculosis infection among Thai healthcare workers (HCWs). Each HCW underwent both TST QFT-IT during annual health screening. Among 260 HCWs enrolled, median age 30 years (range 19-60 years), 92% were women, 64% nurses nurse assistants, 78% Bacillus Calmette Guérin vaccinated, 37% had previously taken TST. Correlation between reaction size...

Multidrug-resistant TB (MDR-TB) outbreaks have occurred in the Thamaka district, Kanchanaburi province Thailand.Seventy-two isolates, which included 7% mono-, 30.6% MDR and extensively drug-resistant (XDR-TB), were genotyped by spoligotyping, mycobacterial interspersed repetitive unit-variable-number tandem repeat (MIRU-VNTR) single nucleotide polymorphism genotyping, their drug resistance was analysed.The spoligotyping results showed that Beijing spoligo-international type (SIT)1...

Loop-mediated isothermal amplification (LAMP) was assessed for rapid identification of Mycobacterium tuberculosis complex (MTC) in comparison with an immunochromatographic test (ICT) using SD Bioline Ag MPT64 Rapid®. One hundred and fifty-one MGIT cultures positive acid-fast bacilli were tested MTC. DNA extracted from a small portion culture samples by heat lysis subjected to LAMP analysis. Of these, 144 5 negative both tests. that ICT but confirmed have mutation the mpt64 gene. The...

Screening for latent tuberculosis infection (LTBI) is important to identify healthcare workers (HCWs) benefiting from preventive therapy. Interferon-gamma release assays (IGRAs) are sensitive and specific tests LTBI diagnosis. However, in settings where IGRAs not available, clinical risk assessment may be used as an alternative diagnose LTBI. A cross-sectional study was conducted among HCWs of a tertiary-care university hospital Thailand. All underwent T-SPOT®.TB test (T-SPOT) risks....

Loop-mediated isothermal amplification (LAMP) is a simple and efficient nucleic acid method for the rapid diagnosis of infectious diseases. This study assessed performance an in-house LAMP tuberculosis (TB) at remote reference laboratory in endemic setting Thailand. As part routine service, 1,882 sputum samples were processed mycobacterial culture Lowenstein-Jensen MGIT media. The DNA was extracted from remaining decontaminated after procedure real-time polymerase chain reaction (PCR)...

Optimal testing strategies for diagnosing latent tuberculosis infection and the administration of isoniazid preventive therapy (IPT) remain uncertain among human immunodeficiency virus (HIV)-infected patients. A 4-year prospective study was conducted Thai HIV-infected patients who underwent simultaneous tuberculin skin test (TST) QuantiFERON-TB Gold In-Tube Test (QFT-IT) at care entry. Based on baseline results, were categorized into following 4 groups: i) QFT-IT-positive, TST-reactive; ii)...

A simple, rapid, and low-cost identification method is required in tuberculosis high-burden countries. We report the applicability of in-house loop-mediated isothermal amplification (LAMP) targeting 16S ribosomal RNA for rapid Mycobacterium complex grown on Lowenstein–Jensen media. Eighty acid-fast staining-positive clinical isolates were selected used to evaluate LAMP assay comparison with polymerase chain reaction conventional culture-based tests. The identified 60 M. from 80 using simple...