scholarly journals Detection of live mycobacteria with a solvatochromic trehalose probe for point-of-care tuberculosis diagnosis

2017 ◽  
Author(s):  
M. Kamariza ◽  
P. Shieh ◽  
F. P. Rodriguez-Rivera ◽  
C. S. Ealand ◽  
B. Chu ◽  
...  

Abstract:Tuberculosis (TB) is the leading cause of death from an infectious bacterial disease. Poor diagnostic tools to detect active disease plague TB control programs and affect patient care. Accurate detection of live Mycobacterium tuberculosis (Mtb), the causative agent of TB, will improve TB diagnosis and patient treatment. We report that live mycobacteria can be specifically detected with a fluorogenic trehalose analog. We designed a 4-N,N-dimethylamino-1,8- naphthalimide-trehalose (DMN-Tre) conjugate that undergoes >700-fold fluorescence increase when transitioned from aqueous to hydrophobic environments. This enhancement occurs upon metabolic conversion of DMN-Tre to trehalose monomycolate and incorporation into the outer membrane. DMN-Tre labeling enabled the rapid, no-wash visualization of mycobacterial and corynebacterial species without nonspecific labeling of Gram-positive or –negative bacteria. DMN-Tre labeling was selective for live mycobacteria and was reduced by treatment with TB drugs. Lastly, DMN-Tre labeled Mtb in TB-positive sputum samples suggesting this operationally simple method may be deployable for TB diagnosis.

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0261084
Author(s):  
Abyot Meaza ◽  
Ephrem Tesfaye ◽  
Zemedu Mohamed ◽  
Betselot Zerihun ◽  
Getachew Seid ◽  
...  

Background Rapid and sensitive Tuberculosis (TB) diagnosis closer to patients is a key global TB control priority. Truenat assays (MTB, MTB Plus, and MTB-RIF Dx) are new TB molecular diagnostic tools for the detection of TB and Rifampicin (RIF)-resistance from sputum samples. The diagnostic accuracy of the assays is needed prior to implementation in clinical use in Ethiopia. This study aimed to determine the sensitivity and specificity of Truenat assays; and aimed to compare the assays to the Xpert MTB/RIF assay. Methods A prospective evaluation study was conducted among 200 presumptive TB patients in microscopy centers in Addis Ababa, Ethiopia from May 2019 to December 2020. Culture (Solid and Liquid methods) and phenotypic (liquid method) drug susceptibility testing (DST) were used as a reference standard. Results Of 200 adult participants, culture confirmed TB cases were 25 (12.5%), and only one isolate was resistant to RIF by phenotypic DST. The sensitivity of Truenat MTB was 88.0% [95% CI 70.1, 95.8], while 91.7 [95% CI 74.2, 97.7] for Truenat MTB Plus at the microscopy centers. The specificity of Truenat MTB was 97.2% [95% CI 93.1, 98.9], while for Truenat MTB Plus was 97.2% [95% CI 93.0, 99.0]. The sensitivity of Truenat MTB was 90.5% while for MTB Plus, 100% compared to the Xpert MTB/RIF assay. Conclusion Truenat assays were found to have high diagnostic accuracy. The assays have the potential to be used as a point of care (POC) TB diagnostic tests.


Diagnostics ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1239
Author(s):  
Thomas E. Serena ◽  
Philip G. Bowler ◽  
Gregory S. Schultz ◽  
Anna D’souza ◽  
Monique Y. Rennie

Early awareness and management of bacterial burden and biofilm is essential to wound healing. Semi-quantitative analysis of swab or biopsy samples is a relatively simple method for measuring wound microbial load. The accuracy of semi-quantitative culture analysis was compared to ‘gold standard’ quantitative culture analysis using 428 tissue biopsies from 350 chronic wounds. Semi-quantitative results, obtained by serial dilution of biopsy homogenates streaked onto culture plates divided into 4 quadrants representing occasional, light, moderate, and heavy growth, were compared to total bacterial load quantified as colony-forming units per gram (CFU/g). Light growth, typically considered an insignificant finding, averaged a clinically significant 2.5 × 105 CFU/g (SE = 6.3 × 104 CFU/g). Occasional growth (range: 102–106 CFU/g) and light growth (103–107 CFU/g) corresponded to quantitative values that spanned a 5-log range; moderate and heavy growth corresponded to a range of 4-log and 6-log, respectively, with a high degree of overlap in range of CFU/g per category. Since tissue biopsy and quantitative culture cannot be widely practiced and semi-quantitative analysis is unreliable, other clinically relevant approaches are required to determine wound bioburden and guide best management practices. Fluorescence imaging is a point-of-care technology that offers great potential in this field.


The Analyst ◽  
2021 ◽  
Author(s):  
Yu Ning ◽  
Fan Lu ◽  
Yucheng Liu ◽  
Sisi Yang ◽  
Fubing Wang ◽  
...  

Cholesterol is an essential compound for human health, and high or low concentration of cholesterol is closely related to various diseases. Thus, developing a simple method for POCT of cholesterol...


2020 ◽  
Vol 58 (9) ◽  
Author(s):  
Katharina Ziegler ◽  
Anca Rath ◽  
Christoph Schoerner ◽  
Renate Meyer ◽  
Thomas Bertsch ◽  
...  

ABSTRACT Diagnosis of Lyme neuroborreliosis (LNB) is challenging, as long as Borrelia-specific intrathecal antibodies are not yet detectable. The chemokine CXCL13 is elevated in the cerebrospinal fluid (CSF) of LNB patients. Here, we compared the performances of the Euroimmun CXCL13 enzyme-linked immunosorbent assay (CXCL13 ELISA) and the ReaScan CXCL13 lateral flow immunoassay (CXCL13 LFA), a rapid point-of-care test, to support the diagnosis of LNB. In a dual-center case-control study, CSF samples from 90 patients (34 with definite LNB, 10 with possible LNB, and 46 with other central nervous system [CNS] diseases [non-LNB group]) were analyzed with the CXCL13 ELISA and the CXCL13 LFA. Classification of patients followed the European Federation of Neurological Societies (EFNS) guidelines on LNB. The CXCL13 ELISA detected elevated CXCL13 levels in all patients with definite LNB (median, 1,409 pg/ml) compared to the non-LNB controls (median, 20.7 pg/ml; P < 0.0001), with a sensitivity of 100% and a specificity of 84.8% (cutoff value, 78.6 pg/ml; area under the receiver operating characteristic [ROC] curve, 0.93). Similarly, the CXCL13 LFA yielded elevated CXCL13 levels in 31 patients with definite LNB (median arbitrary value, 223.5) compared to the non-LNB control patients (median arbitrary value, 0; P < 0.0001) and had a sensitivity and specificity of 91.2% and 93.5%, respectively (cutoff arbitrary value, 22.5; area under the ROC curve, 0.94). The correlation between the CXCL13 levels obtained by ELISA and LFA was strong (Spearman correlation coefficient r = 0.89; P < 0.0001). The CXCL13 ELISA and the CXCL13 LFA are comparable diagnostic tools for the detection of CXCL13 in the CSF of patients with definite LNB. The advantage of the CXCL13 LFA is the shorter time to result.


2022 ◽  
Author(s):  
Sharmili Roy ◽  
FAREEHA ARSHAD ◽  
Shimaa Eissa ◽  
Mohammadali Safavieh ◽  
Sanaa G. Alattas ◽  
...  

The rapid development of accurate and quick diagnostic tools for infectious diseases has made a massive impact in global health. POC devices for pathogen detection have primarily contributed to clinical...


2021 ◽  
Vol 8 ◽  
Author(s):  
Pablo Rodríguez-Hernández ◽  
Vicente Rodríguez-Estévez ◽  
Lourdes Arce ◽  
Jaime Gómez-Laguna

Volatile organic compounds (VOCs) are small molecular mass metabolites which compose the volatilome, whose analysis has been widely employed in different areas. This innovative approach has emerged in research as a diagnostic alternative to different diseases in human and veterinary medicine, which still present constraints regarding analytical and diagnostic sensitivity. Such is the case of the infection by mycobacteria responsible for tuberculosis and paratuberculosis in livestock. Although eradication and control programs have been partly managed with success in many countries worldwide, the often low sensitivity of the current diagnostic techniques against Mycobacterium bovis (as well as other mycobacteria from Mycobacterium tuberculosis complex) and Mycobacterium avium subsp. paratuberculosis together with other hurdles such as low mycobacteria loads in samples, a tedious process of microbiological culture, inhibition by many variables, or intermittent shedding of the mycobacteria highlight the importance of evaluating new techniques that open different options and complement the diagnostic paradigm. In this sense, volatilome analysis stands as a potential option because it fulfills part of the mycobacterial diagnosis requirements. The aim of the present review is to compile the information related to the diagnosis of tuberculosis and paratuberculosis in livestock through the analysis of VOCs by using different biological matrices. The analytical techniques used for the evaluation of VOCs are discussed focusing on the advantages and drawbacks offered compared with the routine diagnostic tools. In addition, the differences described in the literature among in vivo and in vitro assays, natural and experimental infections, and the use of specific VOCs (targeted analysis) and complete VOC pattern (non-targeted analysis) are highlighted. This review emphasizes how this methodology could be useful in the problematic diagnosis of tuberculosis and paratuberculosis in livestock and poses challenges to be addressed in future research.


Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1464
Author(s):  
Florina Silvia Iliescu ◽  
Ana Maria Ionescu ◽  
Larisa Gogianu ◽  
Monica Simion ◽  
Violeta Dediu ◽  
...  

The deleterious effects of the coronavirus disease 2019 (COVID-19) pandemic urged the development of diagnostic tools to manage the spread of disease. Currently, the “gold standard” involves the use of quantitative real-time polymerase chain reaction (qRT-PCR) for SARS-CoV-2 detection. Even though it is sensitive, specific and applicable for large batches of samples, qRT-PCR is labour-intensive, time-consuming, requires trained personnel and is not available in remote settings. This review summarizes and compares the available strategies for COVID-19: serological testing, Point-of-Care Testing, nanotechnology-based approaches and biosensors. Last but not least, we address the advantages and limitations of these methods as well as perspectives in COVID-19 diagnostics. The effort is constantly focused on understanding the quickly changing landscape of available diagnostic testing of COVID-19 at the clinical levels and introducing reliable and rapid screening point of care testing. The last approach is key to aid the clinical decision-making process for infection control, enhancing an appropriate treatment strategy and prompt isolation of asymptomatic/mild cases. As a viable alternative, Point-of-Care Testing (POCT) is typically low-cost and user-friendly, hence harbouring tremendous potential for rapid COVID-19 diagnosis.


2018 ◽  
Vol 58 (2) ◽  
Author(s):  
Juozas Vidmantis Vaitkus ◽  
Darius Varanius ◽  
Ignas Čiplys ◽  
Vilmantas Gėgžna ◽  
Gunaras Terbetas ◽  
...  

The level of degeneration (LOD) in the human intervertebral disc (IVD) could determine the choice of patient treatment strategy, thus there is a need for methods applicable at a point of care that enable quick medical decisions. In this paper, infrared light absorption, FT-Raman scattering and fluorescence spectroscopy were used to analyse the same specimens from different groups of IVD samples. Samples from the lumbar part of spine of 37 patients (mean age 48.2 years old) were included in the study. The gender distribution was 27 women and 10 men. The distribution by LOD in the Pfirrmann scale was as follows: grade 3 (40.5%), grade 4 (48.6%) and grade 5 (10.8%) were evaluated in our samples. Spectroscopic signals were measured and analysed. Features such as medical condition (LOD), patient’s age and gender were taken into account. All three methods of spectroscopy revealed age-dependent spectroscopic features related to LOD. For the first time a promissing possibility was found to recognize the LOD by fluorescence spectra in human IVD material taking gender and age into account. The findings create a background for the design of equipment and the design of experiment of more advanced clinical trials. FT-IR absorption and FT-Raman scattering spectra demonstrated the age dependences of a few components. The Raman peak at 2707 cm–1 seems promising for recognition of lumbar IVD LOD, but a higher number of specimens is necessary.


2021 ◽  
Vol 17 ◽  
Author(s):  
Rajasekhar Chokkareddy ◽  
Suvardhan Kanchi ◽  
Inamuddin

Background: While significant strides have been made to avoid mortality during the treatment of chronic diseases, it is still one of the biggest health-care challenges that have a profound effect on humanity. The development of specific, sensitive, accurate, quick, low-cost, and easy-to-use diagnostic tools is therefore still in urgent demand. Nanodiagnostics is defined as the application of nanotechnology to medical diagnostics that can offer many unique opportunities for more successful and efficient diagnosis and treatment for infectious diseases. Methods: In this review we provide an overview of infectious disease using nanodiagnostics platforms based on nanoparticles, nanodevices for point-of-care (POC) applications. Results: Current state-of-the-art and most promising nanodiagnostics POC technologies, including miniaturized diagnostic tools, nanorobotics and drug delivery systems have been fully examined for the diagnosis of diseases. It also addresses the drawbacks, problems and potential developments of nanodiagnostics in POC applications for chronic diseases. Conclusions: While progress is gaining momentum in this field and many researchers have dedicated their time in developing new smart nanodevices for POC applications for various chronic diseases, the ultimate aim of achieving longterm, reliable and continuous patient monitoring has not yet been achieved. Moreover, the applicability of the manufactured nanodevices to rural patients for on-site diagnosis, cost, and usability are the crucial aspects that require more research, improvements, and potential testing stations. Therefore, more research is needed to develop the demonstrated smart nanodevices and upgrade their applicability to hospitals away from the laboratories.


2020 ◽  
Vol 148 ◽  
pp. 111835 ◽  
Author(s):  
Fabio Lisi ◽  
Joshua R. Peterson ◽  
J. Justin Gooding

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