scholarly journals Tween 80 Improves the Acid-Fast Bacilli Quantification in the Magnetic Nanoparticle-Based Colorimetric Biosensing Assay (NCBA)

Biosensors ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 29
Author(s):  
Cristina Gordillo-Marroquín ◽  
Héctor J. Sánchez-Pérez ◽  
Anaximandro Gómez-Velasco ◽  
Miguel Martín ◽  
Karina Guillén-Navarro ◽  
...  
Keyword(s):  
Magnetic Nanoparticle ◽  
Point Of Care ◽  
Diagnostic Technique ◽  
Tween 80 ◽  
Sputum Smear ◽  
Smear Microscopy ◽  
Acid Fast Bacilli ◽  
Tb Diagnostics ◽  
Short Time ◽  
Colorimetric Biosensing

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.

scholarly journals Magnetic Nanoparticle-Based Biosensing Assay Quantitatively Enhances Acid-Fast Bacilli Count in Paucibacillary Pulmonary Tuberculosis

Biosensors ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 128 ◽  
Author(s):  
Cristina Gordillo-Marroquín ◽  
Anaximandro Gómez-Velasco ◽  
Héctor Sánchez-Pérez ◽  
Kasey Pryg ◽  
John Shinners ◽  
...  
Keyword(s):  
Pulmonary Tuberculosis ◽  
Magnetic Nanoparticle ◽  
Sputum Sample ◽  
Sputum Smear ◽  
Smear Microscopy ◽  
Tb Control ◽  
Control Programs ◽  
Acid Fast Bacilli ◽  
Functionalized Magnetic Nanoparticles ◽  
Colorimetric Biosensing

A new method using a magnetic nanoparticle-based colorimetric biosensing assay (NCBA) was compared with sputum smear microscopy (SSM) for the detection of pulmonary tuberculosis (PTB) in sputum samples. Studies were made to compare the NCBA against SSM using sputum samples collected from PTB patients prior to receiving treatment. Experiments were also conducted to determine the appropriate concentration of glycan-functionalized magnetic nanoparticles (GMNP) used in the NCBA and to evaluate the optimal digestion/decontamination solution to increase the extraction, concentration and detection of acid-fast bacilli (AFB). The optimized NCBA consisted of a 1:1 mixture of 0.4% NaOH and 4% N-acetyl-L-cysteine (NALC) to homogenize the sputum sample. Additionally, 10 mg/mL of GMNP was added to isolate and concentrate the AFB. All TB positive sputum samples were identified with an increased AFB count of 47% compared to SSM, demonstrating GMNP’s ability to extract and concentrate AFB. Results showed that NCBA increased AFB count compared to SSM, improving the grade from “1+” (in SSM) to “2+”. Extending the finding to paucibacillary cases, there is the likelihood of a “scant” grade to become “1+”. The assay uses a simple magnet and only costs $0.10/test. NCBA has great potential application in TB control programs.

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
Keyword(s):  
Rural Communities ◽  
Sensitivity And Specificity ◽  
Point Of Care ◽  
Low Cost ◽  
Unmet Need ◽  
Clinical Encounter ◽  
Sputum Smear ◽  
Smear Microscopy ◽  
Perfect Agreement ◽  
Tb Diagnostics

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.

scholarly journals A Novel Sensitive Immunoassay Targeting the 5-Methylthio-D-Xylofuranose–Lipoarabinomannan Epitope Meets the WHO's Performance Target for Tuberculosis Diagnosis

2018 ◽  
Vol 56 (12) ◽  
Author(s):  
George B. Sigal ◽  
Abraham Pinter ◽  
Todd L. Lowary ◽  
Masanori Kawasaki ◽  
Andra Li ◽  
...  
Keyword(s):  
Diagnostic Accuracy ◽  
Point Of Care ◽  
Clinical Samples ◽  
Sputum Smear ◽  
Smear Microscopy ◽  
Analytical Sensitivity ◽  
Retrospective Case ◽  
Hiv Negative ◽  
Point Of Care Assay ◽  
Performance Target

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.

scholarly journals EVALUATION OF MODIFIED CYTOSPIN SLIDE MICROSCOPY FOR DETECTION OF ACID FAST BACILLI IN BRONCHOALVEOLAR LAVAGE FLUID FOR DIAGNOSIS OF PULMONARY TUBERCULOSIS

2021 ◽  
Vol 71 (3) ◽  
pp. 920-23
Author(s):  
Anam Imtiaz ◽  
Aamer Ikram ◽  
Gohar Zaman ◽  
Luqman Satti ◽  
Fatima Sana
Keyword(s):  
Positive Predictive Value ◽  
Bronchoalveolar Lavage ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Armed Forces ◽  
Sputum Smear ◽  
Smear Microscopy ◽  
Becton Dickinson ◽  
Acid Fast Bacilli ◽  
Sensitivity Specificity

Objective: To evaluate the cytospin slide microscopy method for detection of acid fast bacilli (AFB) in bronchoalveolar lavage (BAL) fluid comparing it with concentrated smear microscopy. Study Design: Cross-sectional validation study. Place and Duration of Study: Department of Microbiology, Armed Forces Institute of Pathology (AFIP), Rawalpindi, from Dec 2016 to Sep 2018. Methodology: BAL specimens from suspected tuberculosis patients who were sputum smear negative, submitted to AFIP for diagnosis were included in the study. Smears for microscopy were prepared with the modified cytospin method as well as the standard concentrated technique. The prepared smears from both methods were stained with Ziehl–Neelsen (ZN) staining method and examined under 100 × oil immersion lens. TB culture performed on BACTEC MGIT 960 automated culture system (Becton Dickinson, USA) was taken as gold standard for TB diagnosis. The two methods were compared in terms of sensitivity, specificity, positive predictive value and negative predictive value. Results: Out of the 130 samples tested, 62 (47.7%) were positive on culture using MGIT 960 system. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of the modified cytospin method for pulmonary TB diagnosis was found to be 68.3%, 100%, 100%, 77% and 84.6%, respectively. Conclusion: The sensitivity of the modified cytopsin smear method was significantly higher than that of the concentrated method. The study concludes that this is a simpler and more accurate method for BAL fluid microscopy.

scholarly journals Improved Diagnosis of Pulmonary Tuberculosis using Bleach (Sodium hypochlorite) Concentration Technique at Tertiary Care Hospital

2021 ◽  
Vol 1 (2) ◽  
pp. 15-22
Author(s):  
Saroj Kumar Thakur ◽  
Vishvesh Prakashchandra Bansal ◽  
Jyotsna Mishra ◽  
M.P. Bansal ◽  
Iswari Sapkota ◽  
...  
Keyword(s):  
Pulmonary Tuberculosis ◽  
Sodium Hypochlorite ◽  
Direct Method ◽  
Tertiary Care ◽  
Sputum Smear ◽  
Smear Microscopy ◽  
Care Hospital ◽  
Case Detection ◽  
Acid Fast Bacilli ◽  
Concentration Method

Introduction: In the Revised National Tuberculosis Control Program (RNTCP), microscopic examination of sputum for acid-fast bacilli (AFB) is currently the backbone for the diagnosis of pulmonary tuberculosis. Studies have shown liquefaction and concentration of sputum by 5% sodium hypochlorite is useful in providing increased sensitivity and safety for the handling of specimens. Objective: To assess the utility of the 5% Sodium hypochlorite concentration method in increasing the sensitivity of smear microscopy for detection of AFB for diagnosis of pulmonary tuberculosis. Methods: The study included a total of 1000 sputum samples from 500 patients with suspected pulmonary tuberculosis. Direct smears were prepared from the sputum samples as per RNTCP guidelines. The remaining sputum was used for bleach concentration and smears prepared from the concentrated material. Both smears were stained by Ziehl-Neelsen staining and screened for acid-fast bacilli and graded according to the RNTCP guidelines. Results: A total of 158 samples (15.8%) from 89 patients were positive by a routine direct method whereas by concentration method 236 samples (23.6%) from 143 patients were found positive diagnosing additional 54 patients. The gain in sputum smear positivity of 7.8% over the routine method is highly significant (p=0.0000, χ2= 270) with a 10.8% increase in case detection. Conclusions: Improvement in the sensitivity of smears microscopy will be useful in case detection of tuberculosis especially in resource-poor countries. The increased positivity of microscopy by bleach method indicates that would prove useful if included in the RNTCP to improve case detection. Keywords: Concentration; smear positivity; sodium hypochlorite; tuberculosis.

scholarly journals HUMAN IMMUNO DEFICIENCY VIRUS AND TUBERCULOSIS COINFECTION AMONG PATIENTS ATTENDING HOLLEY MEMORIAL HOSPITAL OCHADAMU, OFU LOCAL GOVERNMENT AREA, KOGI STATE

2017 ◽  
Vol 5 (8) ◽  
pp. 55-62
Author(s):  
Abraham ◽  
Nwobodo ◽  
Ngwu ◽  
Onwuatuegwu ◽  
Nwaogwugwu ◽  
...  
Keyword(s):  
Clinical Symptoms ◽  
Demographic Data ◽  
Memorial Hospital ◽  
Full Blood Count ◽  
Sputum Smear ◽  
Smear Microscopy ◽  
Hiv Status ◽  
Human Immuno Deficiency Virus ◽  
Acid Fast Bacilli ◽  
Resource Limited

Tuberculosis and human Immuno-deficiency virus co-epidemics remain a major public health challenge particularly in resource limited settings. This study determined the prevalence of HIV co-infection among TB patients and the risk factors among patients attending Holly memorial Hospital Ochadamu, Ofu L.G.A., Kogi State, Nigeria. Two hundred (200) patients participated in the research, out of which one hundred and seventy three (173) were already confirmed to be HIV positive. Sputum samples were collected by experts into sample bottles aseptically for Acid fast Bacilli test for Mycobacterium tuberculosis; while blood samples were collected by trained nurses from the same candidates by venepuncture into anticoagulated bottles for HIV screening to re- confirm their status. Questionnaires were also administered to obtain some important demographic data. Sputum smear microscopy was carried out to test for Acid Fast Bacilli. Rapid haemagglutination assay was carried out to re-confirm the HIV status of the patients. Results showed that Twenty seven (27) patients signifying 13.5 % were TB/HIV co-infected. There was significant (p<0.05) relationship between TB and HIV status of the patients and clinical symptoms (dry cough, cough with sputum, weight loss and fever). There is need to study Immuno-haematological indices (CD4 count, Full Blood Count and ESR) routinely to monitor TB and HIV patients on regular basis in order to reduce morbidity and mortality associated with the diseases.

scholarly journals Decentralization of Acid Fast Bacilli(AFB) External Quality Assurance Using Blind Rechecking for Sputum Smear Microscopy in Ethiopia

PLoS ONE ◽  
2016 ◽  
Vol 11 (3) ◽  
pp. e0151366 ◽  
Author(s):  
Muluken Melese ◽  
Degu Jerene ◽  
Genetu Alem ◽  
Jemal Seid ◽  
Feleke Belachew ◽  
...  
Keyword(s):  
Quality Assurance ◽  
External Quality Assurance ◽  
Sputum Smear ◽  
Smear Microscopy ◽  
Sputum Smear Microscopy ◽  
External Quality ◽  
Acid Fast Bacilli

scholarly journals Molecular Epidemiology of Mycobacterium tuberculosis strains isolated from pulmonary tuberculosis patients in south Ethiopia

2021 ◽  
Vol 15 (09) ◽  
pp. 1299-1307
Author(s):  
Yared Merid ◽  
Elena Hailu ◽  
Getnet Habtamu ◽  
Melaku Tilahun ◽  
Markos Abebe ◽  
...  
Keyword(s):  
Susceptibility Testing ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
Southern Ethiopia ◽  
Sputum Smear ◽  
Smear Microscopy ◽  
Drug Resistant ◽  
Newly Diagnosed ◽  
Cross Sectional ◽  
Acid Fast Bacilli

Introduction: Understanding the epidemiology of tuberculosis is limited by lack of genotyping data. We sought to characterize the drug susceptibility testing patterns and genetic diversity of M. tuberculosis isolates in southern Ethiopia. Methodology: A cross-sectional study was conducted among newly diagnosed sputum smear positive patients with tuberculosis visiting nine health facilities in southern Ethiopia from June 2015 to May 2016. Three consecutive sputum samples (spot-morning-spot) per patient were examined using acid-fast bacilli smear microscopy with all smear positive specimens having acid-fast bacilli cultures performed. M. tuberculosis isolates had drug susceptibility testing performed using indirect proportion method and were genotyped with RD9 deletion analysis and spoligotyping. Mapping of strain was made using geographic information system. Results: Among 250 newly diagnosed patients with tuberculosis, 4% were HIV co-infected. All 230 isolates tested were M. tuberculosis strains belonging to three lineages: Euro-American, 187 (81%), East-African-Indian, 31 (14%), and Lineage 7 (Ethiopian lineage), 8 (4%); categorized into 63 different spoligotype patterns, of which 85% fell into 28 clusters. M. tuberculosis strains were clustered by geographic localities. The dominant spoligotypes were SIT149 (21%) and SIT53 (19%). Drug susceptibility testing found that 14% of isolates tested were resistant to > 1 first line anti- tuberculosis drugs and 11% to INH. SIT 149 was dominant among drug resistant isolates. Conclusions: The study revealed several clusters and drug resistant strains of M. tuberculosis in the study area, suggesting recent transmission including of drug resistant tuberculosis. Wider monitoring of drug susceptibility testing and geospatial analysis of transmission trends is required to control tuberculosis in southern Ethiopia.

scholarly journals Diagnostic accuracy of point-of-care ultrasound for pulmonary tuberculosis: A systematic review

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0251236
Author(s):  
Jacob Bigio ◽  
Mikashmi Kohli ◽  
Joel Shyam Klinton ◽  
Emily MacLean ◽  
Genevieve Gore ◽  
...  
Keyword(s):  
Systematic Review ◽  
Diagnostic Accuracy ◽  
Lung Ultrasound ◽  
Point Of Care ◽  
Risk Of Bias ◽  
Reference Standards ◽  
Sputum Smear ◽  
Smear Microscopy ◽  
Point Of Care Ultrasound ◽  
Ultrasound Findings

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.

Sign in / Sign up

Export Citation Format

Share Document