scholarly journals Nanoparticle-Based Biosensing of Tuberculosis, an Affordable and Practical Alternative to Current Methods

Biosensors ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 1 ◽  
Author(s):  
Nirajan Bhusal ◽  
Sunaina Shrestha ◽  
Nisha Pote ◽  
Evangelyn Alocilja

Access to community-based point-of-care, low-cost, and sensitive tuberculosis (TB) diagnostics remains an unmet need. Objective: The objective of this study was to combine principles in nanotechnology, TB biology, glycochemistry, and engineering, for the development of a nanoparticle-based colorimetric biosensing assay (NCBA) to quickly and inexpensively detect acid-fast bacilli (AFB) in sputum samples. Methods: In NCBA, the isolation of AFB from sputum samples was accomplished through glycan-coated magnetic nanoparticles (GMNP) interacting with AFB and then using a simple magnet to separate the GMNP-AFB complex. Acid-fastness and cording properties of mycobacteria were utilized to provide visually observable red-stained clumps of bacteria that were surrounded by brown nanoparticles under a light microscope on prepared smears. The NCBA technique was compared against sputum smear microscopy (SSM) and Xpert MTB/RIF in 500 samples from patients that were suspected to have TB. Results: Statistical analysis showed that NCBA had sensitivity and specificity performances in perfect agreement with Xpert MTB/RIF as gold standard for all 500 samples. SSM had a sensitivity of 40% for the same samples. Conclusion: NCBA technique yielded full agreement in terms of sensitivity and specificity with the Xpert MTB/RIF in 500 samples. The method is completed in 10–20 min through a simple process at an estimated cost of $0.10 per test. Implementation of NCBA in rural communities would help to increase case finding and case notification, and would support programs against drug-resistance. Its use at the first point-of-contact by patients in the healthcare system would facilitate quick treatment in a single clinical encounter, thus supporting the global “End TB Strategy” by 2035.

Biosensors ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 29
Author(s):  
Cristina Gordillo-Marroquín ◽  
Héctor J. Sánchez-Pérez ◽  
Anaximandro Gómez-Velasco ◽  
Miguel Martín ◽  
Karina Guillén-Navarro ◽  
...  

Despite its reduced sensitivity, sputum smear microscopy (SSM) remains the main diagnostic test for detecting tuberculosis in many parts of the world. A new diagnostic technique, the magnetic nanoparticle-based colorimetric biosensing assay (NCBA) was optimized by evaluating different concentrations of glycan-functionalized magnetic nanoparticles (GMNP) and Tween 80 to improve the acid-fast bacilli (AFB) count. Comparative analysis was performed on 225 sputum smears: 30 with SSM, 107 with NCBA at different GMNP concentrations, and 88 with NCBA-Tween 80 at various concentrations and incubation times. AFB quantification was performed by adding the total number of AFB in all fields per smear and classified according to standard guidelines (scanty, 1+, 2+ and 3+). Smears by NCBA with low GMNP concentrations (≤1.5 mg/mL) showed higher AFB quantification compared to SSM. Cell enrichment of sputum samples by combining NCBA-GMNP, incubated with Tween 80 (5%) for three minutes, improved capture efficiency and increased AFB detection up to 445% over SSM. NCBA with Tween 80 offers the opportunity to improve TB diagnostics, mainly in paucibacillary cases. As this method provides biosafety with a simple and inexpensive methodology that obtains results in a short time, it might be considered as a point-of-care TB diagnostic method in regions where resources are limited.


2018 ◽  
Vol 56 (12) ◽  
Author(s):  
George B. Sigal ◽  
Abraham Pinter ◽  
Todd L. Lowary ◽  
Masanori Kawasaki ◽  
Andra Li ◽  
...  

ABSTRACTThe only currently commercialized point-of-care assay for tuberculosis (TB) that measures lipoarabinomannan (LAM) in urine (Alere LF-LAM) has insufficient sensitivity. We evaluated the potential of 100 novel monoclonal antibody pairs targeting a variety of LAM epitopes on a sensitive electrochemiluminescence platform to improve the diagnostic accuracy. In the screening, many antibody pairs showed high reactivity to purified LAM but performed poorly at detecting urinary LAM in clinical samples, suggesting differences in antigen structure and immunoreactivity of the different LAM sources. The 12 best antibody pairs from the screening were tested in a retrospective case-control study with urine samples from 75 adults with presumptive TB. The best antibody pair reached femtomolar analytical sensitivity for LAM detection and an overall clinical sensitivity of 93% (confidence interval [CI], 80% to 97%) and specificity of 97% (CI, 85% to 100%). Importantly, in HIV-negative subjects positive for TB by sputum smear microscopy, the test achieved a sensitivity of 80% (CI, 55% to 93%). This compares to an overall sensitivity of 33% (CI, 20% to 48%) of the Alere LF-LAM and a sensitivity of 13% (CI, 4% to 38%) in HIV-negative subjects in the same sample set. The capture antibody targets a unique 5-methylthio-d-xylofuranose (MTX)-dependent epitope in LAM that is specific to theMycobacterium tuberculosiscomplex and shows no cross-reactivity with fast-growing mycobacteria or other bacteria. The present study provides evidence that improved assay methods and reagents lead to increased diagnostic accuracy. The results of this work have informed the development of a sensitive and specific novel LAM point-of-care assay with the aim to meet the WHO's performance target for TB diagnosis.


Author(s):  
Sri Kartika Sari ◽  
Aryati Aryati

In Indonesia, the diagnosis of pulmonary tuberculosis relies primarily on an identification of acid-fast bacilli on sputum smears. However, microscopic device has several limitations. The sensitivity of microscopic examination is variable. The quality of smear microscopic results is heavily depend on the workload, and the skill of the technician’s reading the slide. TB antigen rapid test device (TB Ag) is fast, easy and does not either need skillness of the operator. The kit detects specific secreted antigen M.tuberculosis coded by: RD (Region of Difference) 1, RD2 and RD3. These RD1−3 were found deleted from BCG (Bacille Calmette-Guerine) vaccine strain. In the present study, the diagnostic value of TB Ag was assessed. Sputum samples were examined from 59 suspected tuberculosis patients and 22 non tuberculosis patients. The samples of the suspected tuberculosis patients were collected as three consecutive sputum specimens (spot, morning, spot). The total 199 specimens were examined by sputum smear microscopy and TB Ag. M.tuberculosis culture by using Lowenstein Jensen media, which was used as a gold standard. The sensitivity and specificity of microscopic sputum smear were 83.8% (95% CI: 70.0–89.4) and 96.3% (95% CI: 89.8–98.7), respectively. While, the sensitivity and specificity of TB Ag were 72.6% (95% CI: 63.9–79.9) and 90.9% (95% CI: 72.2–97.5), respectively. The concordance between microscopic sputum smear and TB Ag was 70.8%. TB Ag can be considered as a new diagnostic tool for the diagnosis of pulmonary tuberculosis, especially at the health services where there is no expert technician available for microscopic sputum smear examination.


Diagnostics ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 222 ◽  
Author(s):  
Ruben Kenny Briceno ◽  
Shane Ryan Sergent ◽  
Santiago Moises Benites ◽  
Evangelyn C. Alocilja

Tuberculosis (TB) is the leading cause of death globally, surpassing HIV. Furthermore, multidrug-resistant and extensively drug-resistant TB have become global public health threats. Care of TB patients starts with quality, accessible, and affordable diagnosis. The study presents a novel technique called nanoparticle-based colorimetric biosensing assay (NCBA) based on the principles of magnetically activated cell enrichment. A total of 1108 sputum samples were subjected to sputum smear microscopy (SSM), NCBA, and standard culture. SSM and NCBA were completed in 20 min; culture was completed in 8 weeks. Results show that NCBA has matching sensitivity of 100.0% and specificity of 99.7% compared to the gold standard culture method at a cost of $0.50/test based on Peruvian conditions. Sputum smear microscopy has 63.87% sensitivity compared to culture. NCBA has the potential of being used in local health clinics as it only requires a microscope that is widely available in many rural areas. Because NCBA could detect low levels of bacterial load comparable to culture, it could be used for rapid and early TB-onset detection. The gain in time is critical as TB is airborne and highly infectious, minimizing contact exposure. Early detection could lead to early treatment, while the patient’s immune system is still high. The low cost makes NCBA affordable and accessible to those who need them the most.


2017 ◽  
Vol 29 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Jeffrey Holden ◽  
Joshua Goheen ◽  
Mary Jett-Goheen ◽  
Mathilda Barnes ◽  
Yu-Hsiang Hsieh ◽  
...  

Many health agencies now recommend routine HIV and syphilis testing for pregnant women and most-at-risk populations such as men who have sex with men. With the increased availability of highly sensitive, low cost rapid point-of-care tests, the ability to meet those recommendations has increased, granting wider access to quick and accurate diagnoses. Using blood specimens collected from a Baltimore City Health Department (BCHD) sexually transmitted infection clinic, we evaluated the SD Bioline HIV/Syphilis Duo, a rapid test that simultaneously detects antibodies to HIV and syphilis and has the potential to further benefit clinics and patients by reducing costs, testing complexity, and patient wait times. SD DUO HIV sensitivity and specificity, when compared to BCHD results, were 91.7 and 99.5%, respectively. SD DUO syphilis sensitivity and specificity, when compared to rapid plasma reagin, were 85.7 and 96.8%, respectively, and 69.7 and 99.7%, respectively, when compared to Treponema pallidum particle agglutination (TPPA). SD DUO syphilis sensitivity and specificity, when compared to a traditional screening algorithm, improved to 92.3 and 100%, respectively, and improved to 72.9 and 99.7%, respectively, when compared to a reverse screening algorithm. The HIV component of the SD DUO performed moderately well. However, results for the SD DUO syphilis component, when compared to TPPA, support the need for further testing and assessment.


2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Jason Arthur ◽  
Zachary Lewis ◽  
Brian Russ ◽  
Melissa P. Plumley ◽  
Anjali Patel ◽  
...  

Purpose: This retrospective study compares point-of-care ocular ultrasound to MRI in order to establish preliminary data for and identify challenges to a multicenter study into the utility of ocular ultrasound for diagnosing optic neuritis. Methods: Our ultrasound archive was queried to identify subjects suspected of having optic neuritis who underwent ocular ultrasound and MRI of the brain or orbit. Blinded ultrasounds were reviewed by ultrasound faculty. The presence of optic disc elevation, optic nerve, or sheath dilation, and overall impression were recorded and compared to MRI results. Sensitivity and specificity of each ultrasound finding and the overall impression, as well as agreement between the raters, were calculated. Results: Sensitivity and specificity of ultrasound for MRI confirmed optic neuritis was 100 % (95 % CI 54.1-100) and 58.3 % (95 % CI 27.7-84.8). Optic nerve sheath diameter had nearly perfect agreement (κ = 0.8828), however agreement on optic disc elevation (κ = 0.5641), nerve diameter (κ = 0.2174), and overall agreement (κ = 0.1818) were moderate, fair, and poor, respectively. Conclusions: This preliminary study estimates test characteristics of ocular ultrasound for the diagnosis of optic neuritis for the purposes of power analysis and to identify potential pitfalls in preparation for a larger prospective investigation.


2019 ◽  
Vol 71 (5) ◽  
pp. 1161-1167 ◽  
Author(s):  
Maunank Shah ◽  
Sonia Paradis ◽  
Joshua Betz ◽  
Natalie Beylis ◽  
Renu Bharadwaj ◽  
...  

Abstract Background Tuberculosis (TB) control is hindered by absence of rapid tests to identify Mycobacterium tuberculosis (MTB) and detect isoniazid (INH) and rifampin (RIF) resistance. We evaluated the accuracy of the BD MAX multidrug-resistant (MDR)-TB assay (BD MAX) in South Africa, Uganda, India, and Peru. Methods Outpatient adults with signs/symptoms of pulmonary TB were prospectively enrolled. Sputum smear microscopy and BD MAX were performed on a single raw sputum, which was then processed for culture and phenotypic drug susceptibility testing (DST), BD MAX, and Xpert MTB/RIF (Xpert). Results 1053 participants with presumptive TB were enrolled (47% female; 32% with human immunodeficiency virus). In patients with confirmed TB, BD MAX sensitivity was 93% (262/282 [95% CI, 89–95%]); specificity was 97% (593/610 [96–98%]) among participants with negative cultures on raw sputa. BD MAX sensitivity was 100% (175/175 [98–100%]) for smear-positive samples (fluorescence microscopy), and 81% (87/107 [73–88%]) in smear-negative samples. Among participants with both BD MAX and Xpert, sensitivity was 91% (249/274 [87–94%]) for BD MAX and 90% (246/274 [86–93%]) for Xpert on processed sputa. Sensitivity and specificity for RIF resistance compared with phenotypic DST were 90% (9/10 [60–98%]) and 95% (211/222 [91–97%]), respectively. Sensitivity and specificity for detection of INH resistance were 82% (22/27 [63–92%]) and 100% (205/205 [98–100%]), respectively. Conclusions The BD MAX MDR-TB assay had high sensitivity and specificity for detection of MTB and RIF and INH drug resistance and may be an important tool for rapid detection of TB and MDR-TB globally.


PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0251236
Author(s):  
Jacob Bigio ◽  
Mikashmi Kohli ◽  
Joel Shyam Klinton ◽  
Emily MacLean ◽  
Genevieve Gore ◽  
...  

The advent of affordable, portable ultrasound devices has led to increasing interest in the use of point-of-care ultrasound (POCUS) for the detection of pulmonary TB (PTB). We undertook a systematic review of the diagnostic accuracy of POCUS for PTB. Five databases were searched for articles published between January 2010 and June 2020. Risk of bias was assessed using QUADAS-2. Data on sensitivity and specificity of individual lung ultrasound findings were collected, with variable reference standards including PCR and sputum smear microscopy. Six of 3,919 reviewed articles were included: five in adults and one in children, with a total sample size of 564. Studies had high risk of bias in many domains. In adults, subpleural nodule and lung consolidation were the lung ultrasound findings with the highest sensitivities, ranging from 72.5% to 100.0% and 46.7% to 80.4%, respectively. Only one study reported specificity data. Variability in sensitivity may be due to variable reference standards or may imply operator dependence. There is insufficient evidence to judge the diagnostic accuracy of POCUS for PTB. There is also no consensus on the optimal protocols for acquiring and analysing POCUS images for PTB. New studies which minimise potential sources of bias are required to further assess the diagnostic accuracy of POCUS for PTB.


2019 ◽  
Vol 26 (11) ◽  
pp. 1946-1959 ◽  
Author(s):  
Le Minh Tu Phan ◽  
Lemma Teshome Tufa ◽  
Hwa-Jung Kim ◽  
Jaebeom Lee ◽  
Tae Jung Park

Background:Tuberculosis (TB), one of the leading causes of death worldwide, is difficult to diagnose based only on signs and symptoms. Methods for TB detection are continuously being researched to design novel effective clinical tools for the diagnosis of TB.Objective:This article reviews the methods to diagnose TB at the latent and active stages and to recognize prospective TB diagnostic methods based on nanomaterials.Methods:The current methods for TB diagnosis were reviewed by evaluating their advantages and disadvantages. Furthermore, the trends in TB detection using nanomaterials were discussed regarding their performance capacity for clinical diagnostic applications.Results:Current methods such as microscopy, culture, and tuberculin skin test are still being employed to diagnose TB, however, a highly sensitive point of care tool without false results is still needed. The utilization of nanomaterials to detect the specific TB biomarkers with high sensitivity and specificity can provide a possible strategy to rapidly diagnose TB. Although it is challenging for nanodiagnostic platforms to be assessed in clinical trials, active TB diagnosis using nanomaterials is highly expected to achieve clinical significance for regular application. In addition, aspects and future directions in developing the high-efficiency tools to diagnose active TB using advanced nanomaterials are expounded.Conclusion:This review suggests that nanomaterials have high potential as rapid, costeffective tools to enhance the diagnostic sensitivity and specificity for the accurate diagnosis, treatment, and prevention of TB. Hence, portable nanobiosensors can be alternative effective tests to be exploited globally after clinical trial execution.


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