Recent technological advancements in tuberculosis diagnostics - A review

Microfluidic platform for the enzymatic pretreatment of human serum for the detection of the tuberculosis biomarker mannose-capped lipoarabinomannan

Tuberculosis (TB) represents a major public health threat, with millions of new cases reported worldwide each year. A major hurdle to curtailing the spread of this disease is the need for low-cost, point-of-care (PoC) diagnostics. Mannose-capped lipoarabinomannan, a significant component of the Mycobacterium tuberculosis bacillus, has been heavily studied as a biomarker for TB, but with little success due to its complexation with endogenous components of body fluids in a manner that sterically interferes with its detection by ELISA and other immunoassays. Recent work by our group and others has shown that complexation can be disrupted with protein-denaturing protocols. By way of followup, we recently described an enzymatic digestion (Proteinase K) sample pretreatment that enables quantitative recovery of ManLAM spiked into healthy human control serum. Herein, we report on the transfer of our benchtop sample pretreatment methodology to an automated microfluidic platform. We show that this platform can be configured to: (1) carry out the pretreatment process with very little user interaction and, (2) yield recoveries for ManLAm spiked into control serum which are statistically indistinguishable from those achieved by the benchtop process. Plans to integrate this device with a portable sample reader as a possible basis for a PoC TB diagnostic system and analyze patient samples are briefly discussed.

Early detection of tuberculosis: a systematic review

Tuberculosis remains a significant global health challenge. Tuberculosis affects millions of individuals worldwide. Early detection of tuberculosis plays a relevant role in the management of treatment of tuberculosis. This systematic review will analyze the findings of several published studies on the topic of the early detection of tuberculosis. This systematic review highlights their methodologies and limitations as well as their contributions to our understanding of this pressing issue. Early detection of tuberculosis can be achieved through tuberculosis screening for contacts. Comprehensive health education for household contacts can be used as early detection. The in-house deep learning models can be used in the X-ray used for automatic detection of tuberculosis. Interferon gamma release assay, routine passive and active case detection, portable X-ray and nucleic acid amplification testing, and highly sensitive enzyme-linked immunosorbent assay tests play critical roles in improving tuberculosis detection.

Lipoarabinomannan-based tuberculosis diagnosis using a fiber cavity ring down biosensor

Despite existing for millennia, tuberculosis (TB) remains a persistent global health challenge. A significant obstacle in controlling TB spread is the need for a rapid, portable, sensitive, and accurate diagnostic test. Currently, sputum culture stands as a benchmark test for TB diagnosis. Although highly reliable, it necessitates advanced laboratory facilities and involves considerable testing time. In this context, we present a rapid, portable, and cost-effective optical fiber sensor designed to measure lipoarabinomannan (LAM), a TB biomarker found in patients' urine samples. Our sensing approach is based on the applications of phase shift-cavity ringdown spectroscopy (PS-CRDS) to an optical fiber cavity created by two fiber Bragg gratings. A tapered fiber is spliced inside the optical cavity to serve as the sensing head. We functionalize the tapered fiber surface with anti-LAM antigen CS-35 through a unique chemistry, creating a strong affinity for LAM molecules. We measure the phase difference between the cavity transmission and the reference modulating signal at the cavity output. The measured phase is directly proportional to the injected LAM concentrations in aqueous solutions over the sensing head. Our demonstrated sensor provides a detection limit of 10 pg/mL and a sensitivity of 0.026°/pg/mL. This sensor holds promise for numerous applications in the healthcare sector, particularly in low-resource settings.

Microfluidic systems for infectious disease diagnostics

Microorganisms, encompassing both uni- and multicellular entities, exhibit remarkable diversity as omnipresent life forms in nature. They play a pivotal role by supplying essential components for sustaining biological processes across diverse ecosystems, including higher host organisms. The complex interactions within the human gut microbiota are crucial for metabolic functions, immune responses, and biochemical signalling, particularly through the gut-brain axis. Viruses also play important roles in biological processes, for example by increasing genetic diversity through horizontal gene transfer when replicating inside living cells. On the other hand, infection of the human body by microbiological agents may lead to severe physiological disorders and diseases. Infectious diseases pose a significant burden on global healthcare systems, characterized by substantial variations in the epidemiological landscape. Fast spreading antibiotic resistance or uncontrolled outbreaks of communicable diseases are major challenges at present. Furthermore, delivering field-proven point-of-care diagnostic tools to the most severely affected populations in low-resource settings is particularly important and challenging. New paradigms and technological approaches enabling rapid and informed disease management need to be implemented. In this respect, infectious disease diagnostics taking advantage of microfluidic systems combined with integrated biosensor-based pathogen detection offers a host of innovative and promising solutions. In this review, we aim to outline recent activities and progress in the development of microfluidic diagnostic tools. Our literature research mainly covers the last 5 years. We will follow a classification scheme based on the human body systems primarily involved at the clinical level or on specific pathogen transmission modes. Important diseases, such as tuberculosis and malaria, will be addressed more extensively.

An insight to the recent advancements in detection of Mycobacterium tuberculosis using biosensors: A systematic review

Since ancient times, Tuberculosis (TB) has been a severe invasive illness that has been prevalent for thousands of years and is also known as "consumption" or phthisis. TB is the most common chronic lung bacterial illness in the world, killing over 2 million people each year, caused by Mycobacterium tuberculosis (MTB). As per the reports of WHO, in spite of technology advancements, the average rate of decline in global TB infections from 2000-2018 was only 1.6% per year, and the worldwide reduction in TB deaths was only 11%. In addition, COVID-19 pandemic has reversed years of global progress in tackling TB with fewer diagnosed cases. The majority of undiagnosed patients of TB are found in low- and middle-income countries where the GeneXpert MTB/RIF assay and sputum smear microscopy have been approved by the WHO as reference procedures for quickly detecting TB. Biosensors, like other cutting-edge technologies, have piqued researchers' interest since they offer a quick and accurate way to identify MTB. Modern integrated technologies allow for the rapid, low-cost, and highly precise detection of analytes in extremely little amounts of sample by biosensors. Here in this review, we outlined the severity of tuberculosis (TB) and the most recent developments in the biosensors sector, as well as their various kinds and benefits for TB detection. The review also emphasizes how widespread TB is and how it needs accurate diagnosis and effective treatment.

An insight into biosensing platforms used for the diagnosis of various lung diseases: A review

Many of the infectious diseases are ubiquitous in nature and pose a threat to global and public health. The original cause for such type of serious maladies can be summarized as the scarcity of appropriate analysis and treatment methods. Pulmonary diseases are considered one of the life-threatening lung diseases that affect millions of people globally. It consists of several types, namely, asthma, lung cancer, tuberculosis, chronic obstructive pulmonary disease, and several respiratory-related infections. This is due to the limited access to well-equipped healthcare facilities for early disease diagnosis. This needs the availability of processes and technologies that can help to stop this harmful disease-diagnosing practice. Various approaches for diagnosing various lung diseases have been developed over time, namely, autopsy, chest X-rays, low-dose CT scans, and so forth. The need of the hour is to develop a rapid, simple, portable, and low-cost method for the diagnosis of pulmonary diseases. So nowadays, biosensors have been becoming one of the highest priority research areas as a potentially useful tool for the early diagnosis and detection of many pulmonary lung diseases. In this review article, various types of biosensors and their applications in the diagnosis of lung-related disorders are expansively explained.

Ultrasensitive biosensing platform for Mycobacterium tuberculosis detection based on functionalized graphene devices

Tuberculosis (TB) has high morbidity as a chronic infectious disease transmitted mainly through the respiratory tract. However, the conventional diagnosis methods for TB are time-consuming and require specialists, making the diagnosis of TB with point-of-care (POC) detection difficult. Here, we developed a graphene-based field-effect transistor (GFET) biosensor for detecting the MPT64 protein of Mycobacterium tuberculosis with high sensitivity as a POC detection platform for TB. For effective conjugation of antibodies, the graphene channels of the GFET were functionalized by immobilizing 1,5-diaminonaphthalene (1,5-DAN) and glutaraldehyde linker molecules onto the graphene surface. The successful immobilization of linker molecules with spatial uniformity on the graphene surface and subsequent antibody conjugation were confirmed by Raman spectroscopy and X-ray photoelectron spectroscopy. The GFET functionalized with MPT64 antibodies showed MPT64 detection with a detection limit of 1 fg/mL in real-time, indicating that the GFET biosensor is highly sensitive. Compared to rapid detection tests (RDT) and enzyme-linked immunosorbent assays, the GFET biosensor platform developed in this study showed much higher sensitivity but much smaller dynamic range. Due to its high sensitivity, the GFET biosensor platform can bridge the gap between time-consuming molecular diagnostics and low-sensitivity RDT, potentially aiding in early detection or management of relapses in infectious diseases.

Diagnostic performance of microRNA-29a in active pulmonary tuberculosis: a systematic review and meta-analysis

BACKGROUND

In recent years, more and more studies have shown that microRNA-29a (miRNA-29a) can be used as a potential biomarker for active tuberculosis, but the results of these studies are not consistent.

OBJECTIVE

To comprehensively evaluate the value of miRNA-29a in the diagnosis of active tuberculosis by meta-analysis.

METHODS

The databases of CNKI, WanFang, PubMed, The Cochrane Library, Web of Science and EMBASE were searched for relevant studies. Studies were screened strictly according to inclusion and exclusion criteria. QUADAS-2 scale was used to evaluate the quality of the included studies. Data were extracted and analyzed by Meta-DiSc 1.4 and Stata 16.0 software.

RESULTS

13 articles were included, including a total of 1598 subjects, including 872 active tuberculosis patients and 726 controls. The combined sensitivity and specificity of miRNA-29a in the diagnosis of active tuberculosis were 78 % and 76 %, respectively, and the area under the overall summary receiver operating characteristic curve was 0.8564.

CONCLUSION

miRNA-29a can be used as a biomarker for the diagnosis of active tuberculosis.

Engineered Biosensors for Diagnosing Multidrug Resistance in Microbial and Malignant Cells

To curtail pathogens or tumors, antimicrobial or antineoplastic drugs have been developed. These drugs target microbial/cancer growth and survival, thereby improving the host's health. In attempts to evade the detrimental effects of such drugs, these cells have evolved several mechanisms over time. Some variants of the cells have developed resistances against multiple drugs or antimicrobial agents. Such microorganisms or cancer cells are said to exhibit multidrug resistance (MDR). The drug resistance status of a cell can be determined by analyzing several genotypic and phenotypic changes, which are brought about by significant physiological and biochemical alterations. Owing to their resilient nature, treatment and management of MDR cases in clinics is arduous and requires a meticulous approach. Currently, techniques such as plating and culturing, biopsy, gene sequencing, and magnetic resonance imaging are prevalent in clinical practices for determining drug resistance status. However, the major drawbacks of using these methods lie in their time-consuming nature and the problem of translating them into point-of-care or mass-detection tools. To overcome the shortcomings of conventional techniques, biosensors with a low detection limit have been engineered to provide quick and reliable results conveniently. These devices are highly versatile in terms of analyte range and quantities that can be detected to report drug resistance in a given sample. A brief introduction to MDR, along with a detailed insight into recent biosensor design trends and use for identifying multidrug-resistant microorganisms and tumors, is presented in this review.

A rapid, accurate, and low-cost method for detecting Mycobacterium tuberculosis and its drug-resistant genes in pulmonary tuberculosis: Applications of MassARRAY DNA mass spectrometry

Introduction

Mycobacterium tuberculosis (MTB) identification and drug resistance diagnosis are very important for treatment of drug-resistant tuberculosis (DR-TB). Therefore, high throughput, accurate and low-cost molecular detection techniques are urgently needed. This study aimed to evaluate the clinical application value of MassARRAY in tuberculosis diagnosis and drug resistance screening.

Methods

The limit of detection (LOD) and clinical application value of MassARRAY were evaluated using reference strains and clinical isolates. MTB in bronchoalveolar lavage fluid (BALF) and sputum samples were detected using MassARRAY, quantitative real-time polymerase chain reaction (qPCR) and MGIT960 liquid culture (culture). Using culture as the standard, the efficacy of MassARRAY and qPCR for the detection of TB was analyzed. Mutation of drug resistance genes in MTB clinical isolates was tested using MassARRAY, high-resolution melting curve (HRM), and Sanger sequencing. Using sequencing as the standard, the efficacy of MassARRAY, and HRM for the detection of each drug resistance site of MTB was analyzed. Simultaneously, the mutation of drug resistance genes by the MassARRAY method was compared with the results of drug susceptibility testing (DST), and the genotype-phenotype relationship was analyzed. The ability of MassARRAY to discriminate mixed infections was detected using mixtures of standard strains (M. tuberculosis H37Rv) and drug-resistant clinical isolates and mixtures of wild-type and mutant plasmids.

Results

In MassARRAY, 20 related gene mutations could be detected by two PCR systems. All genes could be accurately detected when the bacterial load was 10⁴ CFU/mL. When the load of wild-type and drug-resistant MTB mixture was 10⁵ CFU/mL (respectively reached 10⁴ CFU/mL), variants and wild-type genes could be detected simultaneously. The sensitivity of MassARRAY (96.9%) for identification was higher than that of qPCR (87.5%) (p < 0.001). The sensitivity and specificity of MassARRAY for all drug resistance gene mutations were 100.0%, with higher accuracy and consistency than HRM (sensitivity = 89.3% and specificity = 96.9%, p = 0.001). Analyzing the relationship between MassARRAY genotype and DST phenotype, the accuracy of katG_315, rpoB_531, rpsL_43, rpsL_88, and rrs_513 sites was 100.0%, and embB_306 and rpoB_526 were inconsistent with the DST results when the base changes were different.

Discussion

MassARRAY can obtain base mutation information and identify heteroresistance infections simultaneously when the mutant proportion was at least 5-25%. It has good application prospects in the diagnosis of DR-TB with high throughput, accurate and low-cost.

Current progress of functional nanobiosensors for potential tuberculosis diagnosis: The novel way for TB control?

Tuberculosis (TB), induced by the foxy Mycobacterium tuberculosis (Mtb), is still one of the top killers worldwide among infectious diseases. Although several antibiotics have been developed to significantly relieve the tuberculosis epidemics worldwide, there are still several important scientific challenges for tuberculosis. As one of the most critical issues for tuberculosis control, the accurate and timely diagnosis of tuberculosis is critical for the following therapy of tuberculosis and thus responsible for the effective control of drug-resistant tuberculosis. Current tuberculosis diagnostic methods in clinic are still facing the difficulties that they can't provide the rapid diagnostic results with high sensitivity and accuracy, which therefore requires the development of more effective novel diagnostic strategies. In recent decades, nanomaterials have been proved to show promising potentials for novel nanobiosensor construction based on their outstanding physical, chemical and biological properties. Taking these promising advantages, nanomaterial-based biosensors show the potential to allow the rapid, sensitive and accurate tuberculosis diagnosis. Here, aiming to increase the development of more effective tuberculosis diagnostic strategy, we summarized the current progress of nanobiosensors for potential tuberculosis diagnosis application. We discussed the different kind diagnostic targets for tuberculosis diagnosis based on nanobiosensors, ranging from the detection of bacterial components from M. tuberculosis, such as DNA and proteins, to the host immunological responses, such as specific cytokine production, and to the direct whole cell detection of M. tuberculosis. We believe that this review would enhance our understandings of nanobiosensors for potential tuberculosis diagnosis, and further promote the future research on nanobiosensor-based tuberculosis diagnosis to benefit the more effective control of tuberculosis epidemic.

Designable microfluidic ladder networks from backstepping microflow analysis for mass production of monodisperse microdroplets

Controllable mass production of monodisperse droplets plays a key role in numerous fields ranging from scientific research to industrial application. Microfluidic ladder networks show great potential in mass production of monodisperse droplets, but their design with uniform microflow distribution remains challenging due to the lack of a rational design strategy. Here an effective design strategy based on backstepping microflow analysis (BMA) is proposed for the rational development of microfluidic ladder networks for mass production of controllable monodisperse microdroplets. The performance of our BMA rule for rational microfluidic ladder network design is demonstrated by using an existing analogism-derived rule that is widely used for the design of microfluidic ladder networks as the control group. The microfluidic ladder network designed by the BMA rule shows a more uniform flow distribution in each branch microchannel than that designed by the existing rule, as confirmed by single-phase flow simulation. Meanwhile, the microfluidic ladder network designed by the BMA rule allows mass production of droplets with higher size monodispersity in a wider window of flow rates and mass production of polymeric microspheres from such highly monodisperse droplet templates. The proposed BMA rule provides new insights into the microflow distribution behaviors in microfluidic ladder networks based on backstepping microflow analysis and provides a rational guideline for the efficient development of microfluidic ladder networks with uniform flow distribution for mass production of highly monodisperse droplets. Moreover, the BMA method provides a general analysis strategy for microfluidic networks with parallel multiple microchannels for rational scale-up.

Biosensors for the detection of Mycobacterium tuberculosis: a comprehensive overview

Tuberculosis (TB) infection is one of the leading causes of death in the world. According to WHO reports 2019, the average rate of decrease in global TB incidences was only 1.6% per year from 2000 to 2018, besides that the global decline in TB deaths was just 11%. Therefore, the dire need for early detection of the pathogen for the successful diagnosis of TB seems justified. Mycobacterium tuberculosis secretory proteins have gained more attention as TB biomarkers, for the early diagnosis and treatment of TB. Here in this review, we elaborate on the recent advancements made in the field of piezoelectric, magnetic, optical, and electrochemical biosensors, in addition to listing their merits and setbacks. Additionally, this review also discusses the construction of biosensors through modern integrated technologies, such as combinations of analytical chemistry, molecular biology, and nanotechnology. Integrated technologies enhance the detection for perceiving highly selective, specific, and sensitive signals to detect M. tuberculosis. Furthermore, this review highlights the recent challenges and scope of improvement in numerous biosensors developed for rapid, specific, selective, and sensitive detection of tuberculosis to reduce the TB burden and successful treatment.

Portable immunosensor directly and rapidly detects Mycobacterium tuberculosis in sputum

Tuberculosis (TB) remains a public health problem that cannot be ignored. The portable and efficient detection of Mycobacterium tuberculosis (MTB) is important for the effective control of this disease. However, current detection techniques do not meet the requirements for MTB detection in the actual environment and often require cumbersome detection steps that are time consuming and inflexible. In this study, a portable immunosensor to detect MTB in sputum was prepared and then subjected to interface characterizations, such as scanning electron microscopy, hydrophilic angle test, and fluorescence characterization. The source and gate voltage of the device were optimized and tested using a non-contact photoresponse. The results showed that the sensitivity of the sensor to luminance increases with the decrease in source voltage. The gate voltage can substantially improve the response of the immunosensor to the normalized current of protein and amplify the signal at least 1.6 times. The optimal voltage detection conditions of source voltage (0.3 V) and gate voltage (0.1 V) were also determined. Several common proteins present in simulated saliva were used for anti-interference tests, and the sensor exhibited good specificity. Finally, the dilution gradient of an actual TB sputum sample was optimized. In the absence of preconditioning, a double-blind experiment was used to distinguish between the sputum from patients with TB and healthy individuals to shorten the TB detection time to a few minutes. Compared with the hospital's conventional detection method using cultures, the proposed method can complete the detection in a shorter time. This study provides a new strategy for the portable diagnosis of TB.

Rapid detection of airborne protein from Mycobacterium tuberculosis using a biosensor detection system

The developed biosensor detection system can complete the detection of air samples by collecting exhaled breath condensate, greatly reducing the time to diagnose tuberculosis.

Detection of Mycobacterium Tuberculosis IS6110 gene fragment by fluorescent biosensor based on FRET between two-dimensional metal-organic framework and quantum dots-labeled DNA probe

Herein, a universal fluorescent biosensor was developed for detecting Mycobacterium Tuberculosis (MTB) specific insertion sequence IS6110 gene fragment based on Förster resonance energy transfer (FRET) strategy. CdTe quantum dots (QDs), with excellent luminous performance, were used to label single-stranded DNA (ssDNA) as fluorescence donor (QDs-DNA), in which the ssDNA was complementary to the IS6110 gene fragment. A new type of two-dimensional metal-organic framework (Cu-TCPP) was served as an acceptor. The Cu-TCPP exhibited a higher affinity towards ssDNA than double-stranded DNA (dsDNA). In the absence of targets, the fluorescence of QDs-DNA was quenched - due to the π-π stacking interactions between Cu-TCPP and ssDNA. Otherwise, QDs-DNA hybridized with the target to form a double helix and the fluorescence maintained in a target-concentration dependent manner. Excess QDs-DNA would be quenched and produced negligible background signal. The fluorescent sensor possessed a linear range from 0.05 nM to 1.0 nM with a low detection limit of 35 pM. Furthermore, we successfully applied this biosensing system to detect clinical sputum samples. This method displayed high sensitivity, specificity and great potentials in the early diagnosis of Tuberculosis.

Recent advances in the detection of interferon-gamma as a TB biomarker

Tuberculosis (TB) is one of the main infectious diseases worldwide and accounts for many deaths. It is caused by Mycobacterium tuberculosis usually affecting the lungs of patients. Early diagnosis and treatment are essential to control the TB epidemic. Interferon-gamma (IFN-γ) is a cytokine that plays a part in the body’s immune response when fighting infection. Current conventional antibody-based TB sensing techniques which are commonly used include enzyme-linked immunosorbent assay (ELISA) and interferon-gamma release assays (IGRAs). However, these methods have major drawbacks, such as being time-consuming, low sensitivity, and inability to distinguish between the different stages of the TB disease. Several electrochemical biosensor systems have been reported for the detection of interferon-gamma with high sensitivity and selectivity. Microfluidic techniques coupled with multiplex analysis in regular format and as lab-on-chip platforms have also been reported for the detection of IFN-γ. This article is a review of the techniques for detection of interferon-gamma as a TB disease biomarker. The objective is to provide a concise assessment of the available IFN-γ detection techniques (including conventional assays, biosensors, microfluidics, and multiplex analysis) and their ability to distinguish the different stages of the TB disease.

Detection of Mycobacterium tuberculosis in clinical sputum by a unique gene in MTB strains called Conserved protein TB18.5 (TB18.5)

A rapid and accurate diagnosis increases the treatment effect and decreases the mortality of tuberculosis (TB) patients. The purpose of this study was to establish an accurate, unique, and rapid molecular diagnostic technique to screen Mycobacterium tuberculosis (MTB) from clinical sputum. A unique gene in MTB strains called conserved protein TB18.5 (TB18.5) was selected by bioinformatics analysis. Two pairs of primers were designed to amplify TB18.5 using the nested polymerase chain reaction (PCR) or quantitative real‐time PCR. Nine pathogens and the MTB strain were used to determine the specificity of the TB18.5 gene. The sensitivity assay was performed after optimizing the PCR conditions. The correct fragment was amplified when a 10 copy number template was used. A total of 232 sputum samples were collected from TB patients (from 2019 to 2020) to evaluate the accuracy of the molecular method in this study. MTB was first detected using the BACTEC MGIT‐960 culture test and the Gene Xpert MTB/RIF assay. Totals of 195 (84.05%), 182 (78.45%), and 162 (69.83%) sputum samples were determined to be infected with MTB using nested PCR, the Gene Xpert MTB/RIF assay, and the BACTEC MGIT‐960 culture test, respectively. In summary, a rapid, unique, and sensitive molecular method was established to diagnose TB infection in clinical sputum samples.

Rapid and Sensitive Detection of Mycobacterium tuberculosis by an Enhanced Nanobiosensor

Tuberculosis (TB) mostly spreads from person to person through Mycobacterium tuberculosis (MTB). However, the majority of conventional detection methods for MTB cannot satisfy the requirements for actual TB detection. As one of the most promising powerful platforms, a silicon nanowire field-effect transistor (SiNW-FET) biosensor shows good prospect in TB detection. In this study, an enhanced SiNW-FET biosensor was developed for the rapid and sensitive detection of MTB. The surface functional parameters of the biosensor were explored and optimized. The SiNW-FET biosensor has good sensitivity with a detection limit of 0.01 fg/mL toward protein. The current change value shows a linear upward trend with the increase in protein concentration in the range of 1 fg/mL to 100 μg/mL. One whole test cycle can be accomplished within only 30 s. More importantly, a good distinction was realized in the sputum without pretreatment between normal people and TB patients, which greatly shortened the TB detection time (only 2-5 min, considering the dilution of sputum). Compared with other methods, the SiNW-FET biosensor can detect MTB with a remarkably broad dynamic linear range in a shorter time.

Neoteric advancements in TB diagnostics and its future frame

Tuberculosis (TB) is one of the major infectious disease that causes threat to human health and leads to death in most of the cases. Mycobacterium tuberculosis is the causative agent that can affect both pulmonary and extra pulmonary regions of the body. This infection can be presented either as an active or latent form in the patients. Although this disease has been declared curable and preventable by WHO, it still holds its position as a global emergency. Over the past decade many hurdles such as low immunity, co-infections like HIV, autoimmune disorders, poverty, malnutrition and emerging trends in drug resistance patterns are hindering the eradication of this infection. However, many programmes have been launched by WHO with involvement of governments at various level to put a full stop over the disease. Under the Revised National Tuberculosis Control Programme (RNTCP) which was recently renamed as National Tuberculosis Elimination Programme (NTEP), the major focus is on eliminating tuberculosis by the year 2025. The main aim of the programme is to identify feasible quality testing, evaluate through NIKSHYA poshak yozana, restrict through BCG vaccination and assemble with public awareness to eradicate MTB. Numerous novel diagnostic techniques and molecular tools have been developed to elucidate and differentiate report of various suspected and active tuberculosis patients. However, improvements are still required to cut short the duration of the overall process ranging from screening of patients to their successful treatment.

MPT64 assays for the rapid detection of Mycobacterium tuberculosis

Background

Tuberculosis (TB) is a serious infectious disease caused by Mycobacterium tuberculosis (MTB). An estimated 1.7 billion people worldwide are infected with Mycobacterium tuberculosis (LTBI) during the incubation period without any obvious symptoms. Because of MTB’s high infection and mortality rates, there is an urgent need to develop a fast, portable, and sensitive diagnostic technology for its detection.

Methods

We included research from PubMed, Cochrane Library, Web of Science, and Embase and extracted the data. MetaDisc and STATA were used to build forest plots, Deek’s funnel plot, Fagan plot, and bivariate boxplot for analysis.

Results

Forty-six articles were analyzed, the results of which are as follows: sensitivity and specificity were 0.92 (0.91–0.93) and 0.95 (0.94–0.95) respectively. The NLR and PLR were 0.04 (95% CI 0.03–0.07) and 25.32 (95% CI 12.38–51.78) respectively. DOR was 639.60 (243.04–1683.18). The area under the SROC curve (AUC) was 0.99.

Conclusions

MPT64 exhibits good diagnostic efficiency for MTB. There is no obvious heterogeneity between the three commercial kits.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06022-w.

Advances in airborne microorganisms detection using biosensors: A critical review

Humanity has been facing the threat of a variety of infectious diseases. Airborne microorganisms can cause airborne infectious diseases, which spread rapidly and extensively, causing huge losses to human society on a global scale. In recent years, the detection technology for airborne microorganisms has developed rapidly; it can be roughly divided into biochemical, immune, and molecular technologies. However, these technologies still have some shortcomings; they are time-consuming and have low sensitivity and poor stability. Most of them need to be used in the ideal environment of a laboratory, which limits their applications. A biosensor is a device that converts biological signals into detectable signals. As an interdisciplinary field, biosensors have successfully introduced a variety of technologies for bio-detection. Given their fast analysis speed, high sensitivity, good portability, strong specificity, and low cost, biosensors have been widely used in environmental monitoring, medical research, food and agricultural safety, military medicine and other fields. In recent years, the performance of biosensors has greatly improved, becoming a promising technology for airborne microorganism detection. This review introduces the detection principle of biosensors from the three aspects of component identification, energy conversion principle, and signal amplification. It also summarizes its research and application in airborne microorganism detection. The new progress and future development trend of the biosensor detection of airborne microorganisms are analyzed.

Point-of-care detection of tuberculosis using magnetoresistive biosensing chip

In this paper, a highly sensitive and specific technique based on the principle of giant magnetoresistance (GMR) has been proposed for the early stage Tuberculosis (TB) diagnostics. This GMR biosensing assay employs monoclonal antibodies against M. tuberculosis specific ESAT-6 antigen with the use of magnetic nanoparticles (MNPs) as labels. MNPs bind to the GMR sensor in presence of ESAT-6 and the binding is proportional to the ESAT-6 protein concentration leading to the change in overall resistance of GMR sensor. GMR biosensor simulation showed that ESAT-6 concentration can be detected in the range of pg/mL in comparison to the other transduction techniques available for ESAT-6 detection and further, the signal strength increased with the increase in the concentration. This work has shown that the GMR biosensing strategy is pertinent for the TB detection at the primitive phases when compared with other magnetic techniques used for TB diagnostics.

Carbon nanotube-based thin-film resistive sensor for point-of-care screening of tuberculosis

For point-of-care diagnosis of tuberculosis (TB), current TB diagnostic approaches need to be further improved for achieving an accurate diagnosis that is rapid and low-cost. This paper presents an immuno-resistive sensor on a plastic film for inexpensive, simple TB screening. The sensor is composed of single-walled carbon nanotubes (SWCNTs) functionalized with polyclonal antibodies raised against the MPT64 surface antigen from Mycobacterium tuberculosis (MTB). The target analyte of either MTB or MPT64 is spiked in tongue swab and sputum samples. Under optimized conditions, targets are directly detected from tongue swab samples by resistive measurement. Target analytes spiked into human sputa are enriched with a magnetic bead protocol followed by resistive detection. This highly sensitive film sensor will facilitate rapid TB screening with the added benefits of a small form factor, simple operation, low power requirement, and low cost.

Lateral Flow Genochromatographic Strip for Naked-Eye Detection of Mycobacterium Tuberculosis PCR Products with Gold Nanoparticles as a Reporter

Background

Mycobacterium tuberculosis (MTB) is a pathogen causing tuberculosis (TB) in human, and TB can cause enormous social and economic disruptions. Lateral flow test strips (LFTSs) are inexpensive, portable, disposable, rapid, and easy-to-use analytical tools.

Objective

LFTSs were prepared for the detection of MTB. LFTSs were fabricated using a new specific probe for MTB H37Rv, based on IS6110 sequence gene, and tailed with poly deoxyadenine (dA).

Material and Methods

In this experimental study, to create test and control zones, streptavidin (STP) and a 150-mer dA were dotted on a nitrocellolose membrane. Gold nanoparticles (GNPs) were conjugated with poly deoxythymidine sequence and placed on the conjugate pad. The composition of immersion buffers for sample pad and conjugate pad, running solution, solutions of GNPs-S-dT150 and STP were introduced. DNA genome of MTB and Mycobacterium bovis in clinical samples was amplified with PCR, and then detected by the LFTSs. During the assay, samples were firstly hybridized in two steps and then placed on a conjugate pad in a manner that positive and negative samples provided two and one red lines, respectively, on the detection pad.

Results

After PCR reaction with biotinylated primer, hybridization process with specific MTB probe-dA70-100 toke 10 min, and running process on the strip was performed within 5 min.

Conclusion

We showed that LFTS can discriminate a particular bacteria strain from others. The LFTSs can be redesigned for detection of other pathogenic genomes.

Circular RNA hsa_circ_0001380 in peripheral blood as a potential diagnostic biomarker for active pulmonary tuberculosis

Numerous studies have suggested that circular RNAs (circRNAs), a type of non-coding RNA lacking 5′-caps and 3′-poly(A) tails, are involved in the biological processes of various human diseases. However, little is known about their functions and diagnostic value in active pulmonary tuberculosis (APTB). The aim of the present study was to examine whether hsa_circ_0001380 is able to serve as a diagnostic biomarker for patients with APTB. The expression level of hsa_circ_0001380 was detected in the peripheral blood of 32 patients with APTB and 31 healthy volunteers by reverse transcription-quantitative PCR. The functional prediction of hsa_circ_0001380 was performed in silico. RNase R was used to detect the stability of hsa_circ_0001380. Finally, the diagnostic value of hsa_circ_0001380 was evaluated by receiver operating characteristic (ROC) curve analysis. The results showed that hsa_circ_0001380 was significantly downregulated in the peripheral blood of patients with APTB. In addition, hsa_circ_0001380 was found to be resistant to RNase R treatment. Moreover, four N6-adenosine methylation modification sites and two potential microRNA binding sites were predicted in silico. Importantly, the area under the ROC curve was 0.9502, which suggested that hsa_circ_0001380 may act as a diagnostic biomarker for APTB. Taken together, the results indicated that circRNA hsa_circ_0001380 was downregulated in the peripheral blood of patients with APTB, and could serve as a diagnostic biomarker.

DNA markers and nano-biosensing approaches for tuberculosis diagnosis

According to WHO 2018 report, 10 million people developed tuberculosis and 1.3 million died from it making it 1 of 10 deadliest diseases worldwide. Tuberculosis is caused by infection with the bacillus Mycobacterium tuberculosis (Mtb). WHO recommends using a specific diagnostic kit Xpert MTB/RIF developed by Cepheid (California, United States). An alarming number of new cases (ca. 558,000) of rifampicin-resistant tuberculosis was diagnosticated in 2017. In recent years, new diagnosis tools targeting the Mtb DNA biomarkers have emerged using a plethora of nanomaterials capable of delivering new technological approaches for the rapid diagnostics of TB and rifampicin-resistant TB (RR-TB). In this chapter, we summarized the state-of-the-art of the current available DNA biomarkers and the potential applications for the development of new diagnosis nanotechnology-based devices. The latter use carbonaceous nanomaterials (graphene and carbon nanotubes), noble metals (silver and gold), semi-conducting (metal oxides, magnetic beads, and quantum dots) in order to reveal and/or to amplify the signal after the recognition of target DNA biomarker. The readout techniques such as colorimetry, fluorescence, surface plasmon resonance, and electrochemical methods were also reviewed. Future is bright for point-of-care diagnostics with a sample-in answer-out approach that hampers user-error through miniaturization of biochip technology to the nanoscale range, which will enable their use by nonspecialized personnel.

Crosstalk between Vaginal Microbiome and Female Health: A review

Microbiota plays a fundamental role in the overall development and defences of human beings. The majority of indigenous microbiota exists in a mutually beneficial relationship with their hosts, while few of these are opportunistic pathogens that can lead to life-threatening diseases and chronic infections. These microbial communities constitute the primary defence against infections induced by non-indigenous invasive organisms. Female vaginal ecosystem thought to have been shaped over the years by co-evolutionary processes occurring between the particular microbial partners and the human host. Vaginal secretions contain numerous microorganisms and the host provides them nutrients for their growth and development. Disruptions in vaginal association with the microbiomes lead to the change in the vaginal environment, which enhanced the risk of acquiring diseases including sexually transmitted infections, bacterial vaginosis, fungal infections, preterm birth etc. The focus of this review is on the detailed analysis of vaginal microbiome interplay and its overall impact on female health. The mutualistic relationship between the vagina and residing microbial species has been well described. Finally, the recent advancements in the detection of microbiome interactions with the vaginal environment have been presented.

Trends in Diagnosis for Active Tuberculosis Using Nanomaterials

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.

Plasma indoleamine 2,3-dioxygenase activity as a potential biomarker for early diagnosis of multidrug-resistant tuberculosis in tuberculosis patients

Purpose: Multidrug-resistant tuberculosis (MDR-TB) remains a challenge of global TB control, with difficulty in early detection of drug-sensitive tuberculosis (DS-TB). We investigate the diagnostic significance of IDO as a potential biomarker to discriminate MDR patients among the TB patients.

Patients and methods: Plasma indoleamine 2,3-dioxygenase (IDO) was measured by the ratio of kynurenine (Kyn) to tryptophan (Trp) concentrations, using high performance liquid chromatography-mass spectrometry (LC-MS/MS). Chest computed tomography (CT) imaging signs from TB patients were collected and analyzed in 18 DS-TB patients, 16 MDR-TB patients, 6 lung cancer (LC) patients, and 11 healthy individuals. Lung imaging signs from TB patients were collected and analyzed.

Results: We found that plasma IDO activity was significantly higher in the MDR-TB patients than in the DS-TB patients (p=0.012) and in the LC patients (p=0.003). We evaluated the diagnostic significance of plasma IDO activity in discriminating the MDR-TB group from the DS-TB group using a receiver operating characteristic (ROC) curve. With a cutoff level of 46.58 uM/mM, the diagnostic sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for IDO activity were 87.50%, 72.22%, 73.68%, and 86.67%, respectively. Plasma IDO activity was higher in cavity cases than in non-cavity cases (p=0.042), proving a positive correlation between lung cavity number and cavity size (p<0.05, separately) among all the TB patients studied.

Conclusion: Our findings confirmed that plasma IDO activity might have an auxiliary diagnosis value for early discrimination of MDR-TB patients from DS-TB patients. Among the TB patients with cavitary lung lesions, higher plasma IDO activity can indicate a higher risk of MDR-TB.

The construction of Mycobacterium tuberculosis 16S rDNA MSPQC sensor based on Exonuclease III-assisted cyclic signal amplification

Tuberculosis caused by Mycobacterium tuberculosis (M. tuberculosis) remains one of the most serious infectious diseases all over the world. The key to reduce the spread and mortality rate of tuberculosis is to develop faster and more sensitive approaches for detection of M. tuberculosis. However, current detection methods can not meet the requirements of rapid clinical M. tuberculosis detection in terms of detection time. Herein, a new 16S rDNA multichannel series piezoelectric quartz crystal (MSPQC) sensor based on Exonuclease III (Exo III)-aided target recycling has been developed for rapid detection of M. tuberculosis. The specific 16S rDNA fragment of M. tuberculosis was used as biomarker, DNA capture probes complementary to the biomarker were designed and modified on the surface of AuNPs. The Exo III which could recognise hybrid duplexes and selectively digest DNA capture probe was used to assist digestion cycle by digesting DNA capture probe and releasing the intact target fragment. After all DNA probes loading on the surface of AuNPs were removed, the surface of AuNPs was exposed and conductive connection was formed between the nanogap network electrode by self-catalytic growth of exposed AuNPs in the glucose and HAuCl₄ solution. This resulted in sensitive response of M. tuberculosis sensor and M. tuberculosis was detected by recording this response. The limit of detection (LOD) of the method was 20 CFU/mL and the detection time was less than 3 h. It was expected to be widely used in detection methods of M. tuberculosis.

Liquid biopsy of circulating tumor DNA and biosensor applications

Circulating tumor DNA (ctDNA) as a class of liquid biopsy is a type of gene fragment that contains tumor-specific gene changes in body fluids such as human peripheral blood. More and more evidences show that ctDNA is an excellent tumor biomarker for diagnosis, prognosis, tumor heterogeneity and so on. ctDNA is a tumor code in the blood. Liquid biopsy of ctDNA is firstly summarized. Compared with the traditional detection technologies of ctDNA, the biosensor is an excellent choice for the detection of ctDNA because of its portability, sensitivity, specificity and ease of use. This review mainly evaluates various biosensors applied to the detection of ctDNA. We discuss the most commonly used bioreceptors to specifically identify and bind ctDNA, including complementary DNA (cDNA), peptide nucleic acid (PNA) and anti-5 MethylCytosines, and the biotransducers which convert biological signals to analysable signs. The review also discusses signal amplification strategies in biosensors to detect ctDNA.

DNA markers for tuberculosis diagnosis

Tuberculosis (TB), caused by Mycobacterium tuberculosis complex (MTBC), is an infectious disease with more than 10.4 million cases and 1.7 million deaths reported worldwide in 2016. The classical methods for detection and differentiation of mycobacteria are: acid-fast microscopy (Ziehl-Neelsen staining), culture, and biochemical methods. However, the microbial phenotypic characterization is time-consuming and laborious. Thus, fast, easy, and sensitive nucleic acid amplification tests (NAATs) have been developed based on specific DNA markers, which are commercially available for TB diagnosis. Despite these developments, the disease remains uncontrollable. The identification and differentiation among MTBC members with the use of NAATs remains challenging due, among other factors, to the high degree of homology within the members and mutations, which hinders the identification of specific target sequences in the genome with potential impact in the diagnosis and treatment outcomes. In silico methods provide predictive identification of many new target genes/fragments/regions that can specifically be used to identify species/strains, which have not been fully explored. This review focused on DNA markers useful for MTBC detection, species identification and antibiotic resistance determination. The use of DNA targets with new technological approaches will help to develop NAATs applicable to all levels of the health system, mainly in low resource areas, which urgently need customized methods to their specific conditions.