scholarly journals Species Typing of Nontuberculous Mycobacteria by Use of Deoxyribozyme Sensors

2019 ◽  
Vol 65 (2) ◽  
pp. 333-341 ◽  
Author(s):  
Hillary N Wood ◽  
Ashelyn E Sidders ◽  
Lauren E Brumsey ◽  
Evgeny S Morozkin ◽  
Yulia V Gerasimova ◽  
...  
Keyword(s):  
Nontuberculous Mycobacteria ◽  
Point Of Care ◽  
Pcr Amplification ◽  
Rapid Identification ◽  
Mycobacterium Abscessus ◽  
Mycobacterium Fortuitum ◽  
Target Sequence ◽  
Proof Of Concept ◽  
Catalytic Core ◽  
Point Of Care Diagnostics

Abstract BACKGROUND Nontuberculous mycobacteria (NTM) species are a rising threat, especially to patients living with pulmonary comorbidities. Current point-of-care diagnostics fail to adequately identify and differentiate NTM species from Mycobacterium tuberculosis (Mtb). Definitive culture- and molecular-based testing can take weeks to months and requires sending samples out to specialized diagnostic laboratories. METHODS In this proof-of-concept study, we developed an assay based on PCR amplification of 16S ribosomal RNA (rRNA) rrs genes by using universal mycobacterial primers and interrogation of the amplified fragments with a panel of binary deoxyribozyme (BiDz) sensors to enable species-level identification of NTM (BiDz-NTMST). Each BiDz sensor consists of 2 subunits of an RNA-cleaving deoxyribozyme, which form an active deoxyribozyme catalytic core only in the presence of the complimentary target sequence. The target-activated BiDz catalyzes cleavage of a reporter substrate, thus triggering either fluorescent or colorimetric (visually observed) signal depending on the substrate used. The panel included BiDz sensors for differentiation of 6 clinically relevant NTM species (Mycobacterium abscessus, Mycobacterium avium, Mycobacterium intracellulare, Mycobacterium fortuitum, Mycobacterium kansasii, and Mycobacterium gordonae) and Mtb. RESULTS Using the fluorescent BiDz-NTMST assay, we successfully identified the species of 38 clinical isolates. In addition, a subset of strains was tested with visual BiDz sensors, providing proof-of-concept for species typing of NTM by the naked eye. CONCLUSIONS The BiDz-NTMST assay is a novel platform for rapid identification of NTM species. This method is highly specific and significantly faster than current tools and is easily adaptable for onsite diagnostic laboratories in hospitals or clinical laboratories.

scholarly journals Profile of Nontuberculous Mycobacteria in Patients Suspected of Tuberculosis and Drug-Resistant Tuberculosis

2020 ◽  
Vol 12 (03) ◽  
pp. 203-211
Author(s):  
Megha Sharma ◽  
Bharti Malhotra ◽  
Jitendra Tiwari ◽  
Shipra Bhargava
Keyword(s):  
Nontuberculous Mycobacteria ◽  
Multidrug Resistant ◽  
Mycobacterium Abscessus ◽  
Mycobacterium Fortuitum ◽  
Drug Resistant ◽  
Culture Methods ◽  
Mycobacterium Chelonae ◽  
Drug Resistant Tuberculosis ◽  
Indicator Tube ◽  
Resistant Tuberculosis

Abstract Objective Infections due to nontuberculous mycobacteria (NTM) is increasing globally and may present as drug-resistant tuberculosis (DRTB). In India, data on NTM prevalence and species diversity is limited. Present study was conducted to detect the prevalence and profile of NTM among patients suspected of DRTB using paraffin slide culture (PSC)and mycobacteria growth indicator tube (MGIT) culture methods for isolation of NTM. Material and Method A total of 2,938 samples suspected of TB/DRTB were cultured on PSC and MGIT960. Species identification of mycobacterial isolate was done by sequencing of 16s ribosomal RNA gene. Result Among 2938 samples, 35 (1.19%) were found positive for NTM by PSC and 9 (0.30%) were found positive by MGIT. The diversity of NTM species was high (13 species). Out of 35 NTM isolates by PSC, maximum 34.29% (12) isolates were found to be Mycobacterium fortuitum, followed by 11.43% (4) Mycobacterium abscessus and Mycobacterium chelonae, and 42.85% (15) were other species viz. 8.57% (3) were Mycobacterium intracellulare and Mycobacterium kansasii, 5.71% (2) were Mycobacterium peregrinum, and 2.85% (1) were Mycobacterium flavescens, Mycobacterium farcinogenes, Mycobacterium moriokanese, Mycobacterium wolinskyi, Mycobacterium simiae, Mycobacterium goodii, and Mycobacterium terrae each. Coinfection of Mycobacterium tuberculosis(MTB) and NTM was found in 60% (21) samples. Conclusion Prevalence of NTM was low among multidrug resistant tuberculosis/TB suspected patients, similar to other studies done in India. PSC was found better than MGIT for the isolation of NTM, though poor separation of NTM and MTB on subculture may have led to false negativity in cases of coinfection. About 13 species were isolated; M. fortuitum was the most common of all. Since coinfection of NTM and TB can also occur, samples of patients suspected of NTM should be cultured on PSC even if positive for MTB.

scholarly journals Point-of-service, quantitative analysis of ascorbic acid in aqueous humor for evaluating anterior globe integrity

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Manas R. Gartia ◽  
Santosh K. Misra ◽  
Mao Ye ◽  
Aaron Schwartz-Duval ◽  
Lisa Plucinski ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Aqueous Humor ◽  
Colorimetric Assay ◽  
Point Of Care ◽  
High Impact ◽  
Clinical Samples ◽  
Proof Of Concept ◽  
Point Of Care Diagnostics ◽  
Concentration Levels ◽  
Point Of Service

Abstract Limited training, high cost and low equipment mobility leads to inaccuracies in decision making and is concerning with serious ocular injuries such as suspected ruptured globe or post-operative infections. Here, we present a novel point-of-service (POS) quantitative ascorbic acid (AA) assay with use of the OcuCheck Biosensor. The present work describes the development and clinical testing of the paper-based biosensor that measures the changes in electrical resistance of the enzyme-plated interdigitated electrodes to quantify the level of AA present in ocular fluid. We have demonstrated the proof-of-concept of the biosensor testing 16 clinical samples collected from aqueous humor of patients undergoing therapeutic anterior chamber paracentesis. Comparing with gold standard colorimetric assay for AA concentration, OcuCheck showed accuracy of >80%, sensitivity of >88% and specificity of >71%. At present, there are no FDA-approved POS tests that can directly measures AA concentration levels in ocular fluid. We envisage that the device can be realized as a handheld, battery powered instrument that will have high impact on glaucoma care and point-of-care diagnostics of penetrating ocular globe injuries.

scholarly journals The Changing Pattern of Nontuberculous Mycobacterial Disease

2003 ◽  
Vol 14 (5) ◽  
pp. 281-286 ◽  
Author(s):  
Joseph O Falkinham
Keyword(s):  
Pulmonary Disease ◽  
Nontuberculous Mycobacteria ◽  
Mycobacterial Infection ◽  
Mycobacterium Abscessus ◽  
Mycobacterium Fortuitum ◽  
Older Individuals ◽  
Mycobacterial Disease ◽  
Cervical Lymphadenitis ◽  
Source Of Infection ◽  
Increased Risk

Nontuberculous mycobacteria are human opportunistic pathogens whose source of infection is the environment. These include both slow-growing (eg,Mycobacterium kansasii and Mycobacterium avium) and rapid-growing (eg,Mycobacterium abscessusandMycobacterium fortuitum) species. Transmission is through ingestion or inhalation of water, particulate matter or aerosols, or through trauma. The historic presentation of pulmonary disease in older individuals with predisposing lung conditions and in children has been changing. Pulmonary disease in elderly individuals who lack the classic predisposing lung conditions is increasing. Pulmonary disease and hypersensitivity pneumonitis have been linked with occupational or home exposures to nontuberculous mycobacteria. There has been a shift fromMycobacterium scrofulaceumtoM aviumin children with cervical lymphadenitis. Further, individuals who are immunosuppressed due to therapy or HIV-infection are at a greatly increased risk for nontuberculous mycobacterial infection. The changing pattern of nontuberculous mycobacterial disease is due in part to the ability of these pathogens to survive and proliferate in habitats that they share with humans, such as drinking water. The advent of an aging population and an increase in the proportion of immunosuppressed individuals suggest that the prevalence of nontuberculous mycobacterial disease will increase.

scholarly journals In Vitro Activity of Bedaquiline against Nontuberculous Mycobacteria in China

2017 ◽  
Vol 61 (5) ◽  
Author(s):  
Yu Pang ◽  
Huiwen Zheng ◽  
Yaoju Tan ◽  
Yuanyuan Song ◽  
Yanlin Zhao
Keyword(s):  
Molecular Mechanisms ◽  
Nontuberculous Mycobacteria ◽  
Mycobacterium Abscessus ◽  
Dilution Method ◽  
Mycobacterium Fortuitum ◽  
Nucleotide Substitutions ◽  
Content Type ◽  
Prevalent Species ◽  
Broth Dilution

ABSTRACT The main goal of our study was to evaluate the in vitro bedaquiline susceptibility of six prevalent species of pathogenic nontuberculous mycobacteria (NTM) in China. In addition, we investigated the potential molecular mechanisms contributing to bedaquiline resistance in the different NTM species. Among slowly growing mycobacteria (SGM), bedaquiline exhibited the highest activity against Mycobacterium avium; the MIC50 and MIC90 values were 0.03 and 16 mg/liter, respectively. Among rapidly growing mycobacteria (RGM), Mycobacterium abscessus subsp. abscessus (M. abscessus) and Mycobacterium abscessus subsp. massiliense (M. massiliense) seemed more susceptible to bedaquiline than Mycobacterium fortuitum, with MIC50 and MIC90 values of 0.13 and >16 mg/liter, respectively, for both species. On the basis of bimodal distributions of bedaquiline MICs, we proposed the following epidemiological cutoff (ECOFF) values: 1.0 mg/liter for SGM and 2.0 mg/liter for RGM. Among M. avium, Mycobacterium intracellulare, Mycobacterium kansasii, M. abscessus, M. massiliense, and M. fortuitum isolates, 14 (29.8%), 41 (27.2%), 33 (39.3%), 44 (20.2%), 42 (25.8%), and 7 (31.8%), respectively, were resistant to bedaquiline. No significant differences in the proportions of bedaquiline resistance among these species were observed (P > 0.05). Genetic mutations were observed in 74 isolates (10.8%), with all nucleotide substitutions being synonymous. In conclusion, our data demonstrate that bedaquiline shows moderate in vitro activity against NTM species. Using the proposed ECOFF values, we could distinguish between bedaquiline-resistant and -susceptible strains with the broth dilution method. In addition, no nonsynonymous mutations in the atpE gene that conferred bedaquiline resistance in all six NTM species were identified.

scholarly journals COVID-19 Point-of-Care Diagnostics: Present and Future

ACS Nano ◽  
2021 ◽  
Author(s):  
Enrique Valera ◽  
Aaron Jankelow ◽  
Jongwon Lim ◽  
Victoria Kindratenko ◽  
Anurup Ganguli ◽  
...  
Keyword(s):  
Point Of Care ◽  
Point Of Care Diagnostics

scholarly journals 145 Point of care lung ultrasound in patient triage: integration of ultrasound into a streaming pathway for COVID-19

2020 ◽  
Vol 37 (12) ◽  
pp. 839.1-839
Author(s):  
Dominic Craver ◽  
Aminah Ahmad ◽  
Anna Colclough
Keyword(s):  
Point Of Care ◽  
District General Hospital ◽  
Training Programme ◽  
Service Evaluation ◽  
University Hospital ◽  
Junior Doctors ◽  
Point Of Care Ultrasound ◽  
Face To Face ◽  
Point Of Care Diagnostics ◽  
Audit Data

Aims/Objectives/BackgroundRapid risk stratification of patients is vital for Emergency Department (ED) streaming during the COVID-19 pandemic. Ideally, patients should be split into red (suspected/confirmed COVID-19) and green (non COVID-19) zones in order to minimise the risk of patient-to-patient and patient-to-staff transmission. A robust yet rapid streaming system combining clinician impression with point-of-care diagnostics is therefore necessary.Point of care ultrasound (POCUS) findings in COVID-19 have been shown to correlate well with computed tomography (CT) findings, and it therefore has value as a front-door diagnostic tool. At University Hospital Lewisham (a district general hospital in south London), we recognised the value of early POCUS and its potential for use in patient streaming.Methods/DesignWe developed a training programme, ‘POCUS for COVID’ and subsequently integrated POCUS into streaming of our ED patients. The training involved Zoom lectures, a face to face practical, a 10 scan sign off process followed by a final triggered assessment. Patient outcomes were reviewed in conjunction with their scan reports.Results/ConclusionsCurrently, we have 21 ED junior doctors performing ultrasound scans independently, and all patients presenting to our department are scanned either in triage or in the ambulance. A combination of clinical judgement and scan findings are used to stream the patient to an appropriate area.Service evaluation with analysis of audit data has found our streaming to be 94% sensitive and 79% specific as an indicator of COVID 19. Further analysis is ongoing.Here we present both the structure of our training programme and our integrated streaming pathway along with preliminary analysis results.

scholarly journals Point of Care Diagnostics in the Age of COVID-19

Diagnostics ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 9
Author(s):  
Meysam Rezaei ◽  
Sajad Razavi Bazaz ◽  
Sareh Zhand ◽  
Nima Sayyadi ◽  
Dayong Jin ◽  
...  
Keyword(s):  
Point Of Care ◽  
Diagnostic Methods ◽  
Global Public Health ◽  
Current Standard ◽  
Healthcare Facilities ◽  
Major Threat ◽  
Point Of Care Diagnostics ◽  
Recent Outbreak ◽  
Control Virus ◽  
Biosafety Level

The recent outbreak of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its associated serious respiratory disease, coronavirus disease 2019 (COVID-19), poses a major threat to global public health. Owing to the lack of vaccine and effective treatments, many countries have been overwhelmed with an exponential spread of the virus and surge in the number of confirmed COVID-19 cases. Current standard diagnostic methods are inadequate for widespread testing as they suffer from prolonged turn-around times (>12 h) and mostly rely on high-biosafety-level laboratories and well-trained technicians. Point-of-care (POC) tests have the potential to vastly improve healthcare in several ways, ranging from enabling earlier detection and easier monitoring of disease to reaching remote populations. In recent years, the field of POC diagnostics has improved markedly with the advent of micro- and nanotechnologies. Due to the COVID-19 pandemic, POC technologies have been rapidly innovated to address key limitations faced in existing standard diagnostic methods. This review summarizes and compares the latest available POC immunoassay, nucleic acid-based and clustered regularly interspaced short palindromic repeats- (CRISPR)-mediated tests for SARS-CoV-2 detection that we anticipate aiding healthcare facilities to control virus infection and prevent subsequent spread.

scholarly journals Pocket MUSE: an affordable, versatile and high-performance fluorescence microscope using a smartphone

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yehe Liu ◽  
Andrew M. Rollins ◽  
Richard M. Levenson ◽  
Farzad Fereidouni ◽  
Michael W. Jenkins
Keyword(s):  
High Performance ◽  
Point Of Care ◽  
Low Cost ◽  
Consumer Electronics ◽  
Practical Implementation ◽  
The Novel ◽  
Point Of Care Diagnostics ◽  
Optical Module ◽  
Optical Configuration ◽  
User Friendly

AbstractSmartphone microscopes can be useful tools for a broad range of imaging applications. This manuscript demonstrates the first practical implementation of Microscopy with Ultraviolet Surface Excitation (MUSE) in a compact smartphone microscope called Pocket MUSE, resulting in a remarkably effective design. Fabricated with parts from consumer electronics that are readily available at low cost, the small optical module attaches directly over the rear lens in a smartphone. It enables high-quality multichannel fluorescence microscopy with submicron resolution over a 10× equivalent field of view. In addition to the novel optical configuration, Pocket MUSE is compatible with a series of simple, portable, and user-friendly sample preparation strategies that can be directly implemented for various microscopy applications for point-of-care diagnostics, at-home health monitoring, plant biology, STEM education, environmental studies, etc.

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