‘Off–on’ switchable fluorescent probe for prompt and cost-efficient detection of bacteria

2019 ◽  
Vol 43 (33) ◽  
pp. 13094-13102
Author(s):  
Giorgia Giovannini ◽  
Vladimir Gubala ◽  
Andrew J. Hall

The rapid and straightforward detection of bacteria in food and human samples is becoming important, particularly in view of the development of point-of-care devices and lab-on-a-chip tools for prevention and treatment of bacterial infections.

Author(s):  
Marion Ritzi-Lehnert ◽  
Jan Claussen ◽  
Eva Schaeffer ◽  
Ole Wiborg ◽  
Isabell Wick ◽  
...  

Early diagnosis followed by personalised efficient therapy of infectious diseases (e.g. respiratory diseases, meningitis, sepsis) can lead to considerable reduction of costs in health care. Point-of-care testing (POCT) can provide early detection since this kind of decentralised analysis can be done by unskilled personnel at any time. Other advantages of automated miniaturised Lab-on-a-Chip systems (LoC) are reduction of time and reagents, elimination of cross-contamination and enhanced reproducibility due to enhanced process control. Such Lab-on-a-Chip systems will establish themselves on market only when sensitivity and specificity meet clinical requirements. An integrated cost-efficient lab-on-a-chip system is presented which allows performing all diagnostic process steps for pathogen analysis of respiratory viruses from nasopharyngeal samples. The microfluidic disposable chip comprises structures for lysis of nasopharyngeal swab samples, preparation of total nucleic acids using magnetic silica beads, reverse transcription followed by QIAplex PCR technology and labelling of the nucleic acids by hybridisation with LiquiChip Beads and streptavidin-R-phycoerythrin. Labelled target sequences are transferred for analysis into a QIAGEN LiquiChip 200 workstation. The core of the instrument is a construction based on rotating heating bars allowing for fast cycling. All chemicals needed for performing of 24 analyses are either stored freeze-dried on the single-use disposable microfluidic chip (processing cartridge) or as liquids in a separate reagent cartridge. After introducing the sample into the lysis chamber of the microfluidic chip and inserting the chip into the device all steps are done automatically. To realise these steps, fluidic control in terms of light barriers and turning valves are integrated into the injection moulded disposable chip. This includes metering structures as well as magnetic stir bars for mixing. The functionality was proven by direct comparison of samples processed manually vs. automatically using the “ResPlex Panel II” for detection of respiratory viruses from nasopharyngeal samples. The efficiency of the automated LoC system yields at about 30–60% as compared to the manually performed reference experiments. Comparing the performance of the instrument with commercially available kits and nucleic acid preparation devices showed slightly weaker but clearly positive final signal intensities obtained from the prototype device even without protocol optimization.


2017 ◽  
Author(s):  
Caitlin S. DeJong ◽  
David I. Wang ◽  
Aleksandr Polyakov ◽  
Anita Rogacs ◽  
Steven J. Simske ◽  
...  

Through the direct detection of bacterial volatile organic compounds (VOCs), via surface enhanced Raman spectroscopy (SERS), we report here a reconfigurable assay for the identification and monitoring of bacteria. We demonstrate differentiation between highly clinically relevant organisms: <i>Escherichia coli</i>, <i>Enterobacter cloacae</i>, and <i>Serratia marcescens</i>. This is the first differentiation of bacteria via SERS of bacterial VOC signatures. The assay also detected as few as 10 CFU/ml of <i>E. coli</i> in under 12 hrs, and detected <i>E. coli</i> from whole human blood and human urine in 16 hrs at clinically relevant concentrations of 10<sup>3</sup> CFU/ml and 10<sup>4</sup> CFU/ml, respectively. In addition, the recent emergence of portable Raman spectrometers uniquely allows SERS to bring VOC detection to point-of-care settings for diagnosing bacterial infections.


2020 ◽  
Vol 8 (6) ◽  
pp. 437-451
Author(s):  
Malkiet Kaur ◽  
Gayatri Devi ◽  
Manju Nagpal ◽  
Manjinder Singh ◽  
Gitika A. Dhingra ◽  
...  

Background: Coronavirus has become a life-threatening disease and it is caused by severe acute respiratory syndrome (SARS). This new strain of coronavirus is not completely understood and to date, there is no treatment for coronavirus. Traditional ayurvedic medicines, mainly essential oils and Chinese herbs, have always played a vital role in the prevention and treatment of several epidemics and pandemics. In the meantime, guidelines of the ministry of AYUSH (Ayurveda, yoga, unani, siddha and homoepathy) include a traditional medicinal treatment for flu and fever and also recommended to boost immunity to prevent the spread of coronavirus. It is not possible to find which essential oil will offer the best level of protection. However, it is likely to assume that some essential oils are likely to offer a measurable level of defense in the same way they do with many other known viruses. Methods: Literature relevant to various essential oils having antiviral activity has been collected and compiled. Various nanocarriers of essential oils have also been stated. The database was collected using various search engines such as J-Gate, Google Scholar, Sci-Hub, PubMed, ScienceDirect, etc. Results: Essential oils contain active constituents such as phenolic compounds, terpenoids, alkaloids, phenyl propanoids, etc., which are responsible for their biological properties such as antiviral, antibacterial, antimicrobial, antioxidant activities and many more. However, the use of essential oils has always been limited due to poor solubility, solvent toxicity, volatility and low solubility. Many nanotechnology based carriers especially, liposomes, dendrimers, nanoparticles, nanoemulsion and microemulsion, etc. have been evidenced to overcome limitations associated with essential oils. Conclusion: Several essential oils possess potent antiviral activity and are characterized by fewer side effects and are safe for human use. The nanocarrier systems of these oils have proved the potential to treat viral and bacterial infections. Lay Summary: Current COVID-19 era demands traditional treatment for immunity boost up as support therapy. Traditional ayurvedic medicines, mainly essential oils and Chinese herbs, have always played a vital role in the prevention and treatment of several epidemics and pandemics. Therefore, authors have summarized various essential oils having antiviral activity in current manuscript. Various nanocarriers of essential oils have been reported. Essential oils contain active constituents such as phenolic compounds, terpenoids, alkaloids, phenyl propanoids, etc., which are responsible for their biological properties such as antiviral, antibacterial, antimicrobial, antioxidant activity. However, the use of essential oils has always been limited due to poor solubility, solvent toxicity, volatility and low solubility. Many nanotechnology based carriers especially, liposomes, dendrimers, nanoparticles, nanoemulsion and microemulsion, etc. have been evidenced to overcome limitations associated with essential oils. The nanocarrier systems of these oils have proved the potential to treat viral and bacterial infections.


Author(s):  
Daniel Berman

How can we prevent the rise of resistance to antibiotics? In this video, Daniel Berman,  Nesta Challenges, discusses the global threat of AMR and how prizes like the Longitude Prize can foster the development of rapid diagnostic tests for bacterial infections, helping to contribute towards reducing the global threat of drug resistant bacteria. Daniel outlines how accelerating the development of rapid point-of-care tests will ensure that bacterial infections are treated with the most appropriate antibiotic, at the right time and in the right healthcare setting.


2021 ◽  
Vol 22 (1) ◽  
pp. 456
Author(s):  
Simone Rentschler ◽  
Lars Kaiser ◽  
Hans-Peter Deigner

Precise and rapid identification and characterization of pathogens and antimicrobial resistance patterns are critical for the adequate treatment of infections, which represent an increasing problem in intensive care medicine. The current situation remains far from satisfactory in terms of turnaround times and overall efficacy. Application of an ineffective antimicrobial agent or the unnecessary use of broad-spectrum antibiotics worsens the patient prognosis and further accelerates the generation of resistant mutants. Here, we provide an overview that includes an evaluation and comparison of existing tools used to diagnose bacterial infections, together with a consideration of the underlying molecular principles and technologies. Special emphasis is placed on emerging developments that may lead to significant improvements in point of care detection and diagnosis of multi-resistant pathogens, and new directions that may be used to guide antibiotic therapy.


2021 ◽  
pp. 72-75
Author(s):  
Y. S. Galimova ◽  

The article is devoted to the formation and systematic development of the Bashkir Research Trachomatous Institute-the oldest eye research institution of the country , which led the work on the elimination of trachoma in the republic. The Trachomatous Institute became the coordinator of these activities: field examination work, study of the etiology of the disease, its prevention and treatment, surgical care, training of medical and junior staff, etc. The founder and first director of the Institute V.P. Odintsov was able to organize the work of the team at the appropriate level, so that the task set for the institution was completed - trachoma was eliminated. Key words: Bashkir Research Trachomatous Institute, trachoma, V.P. Odintsov, eye departments, trachomatous point of care, trachomatous dispensary.


Author(s):  
Paul C. Adamson ◽  
Jeffrey D. Klausner

Chlamydia trachomatis and Neisseria gonorrhoeae are two of the most often reported bacterial infections in the United States. The rectum and oropharynx are important anatomic sites of infection and can contribute to ongoing transmission. Nucleic acid amplification tests (NAATs) are the mainstays for the detection of C. trachomatis and N. gonorrhoeae infections owing to their high sensitivity and specificity. Several NAATs have been evaluated for testing in rectal and pharyngeal infections. A few assays recently received clearance by the Food and Drug Administration, including one point-of-care test. Those assays can be used for testing in symptomatic individuals, as well as for asymptomatic screening in certain patient populations. Routine screening for C. trachomatis in pharyngeal specimens is not recommended by the Centers for Disease Control and Prevention, though is often performed due to the use of multiplex assays. While expanding the types of settings for screening and using self-collected rectal and pharyngeal specimens can help to increase access and uptake of testing, additional research is needed to determine the potential benefits and costs associated with increased screening for rectal and pharyngeal C. trachomatis and N. gonorrhoeae infections on a population level.


2015 ◽  
Vol 22 (9) ◽  
pp. 1025-1032 ◽  
Author(s):  
Per Venge ◽  
Lena Douhan-Håkansson ◽  
Daniel Garwicz ◽  
Christer Peterson ◽  
Shengyuan Xu ◽  
...  

ABSTRACTThe distinction between causes of acute infections is a major clinical challenge. Current biomarkers, however, are not sufficiently accurate. Human neutrophil lipocalin (HNL) concentrations in serum or whole blood activated by formyl-methionine-leucine-phenylalanine (fMLP) were shown to distinguish acute infections of bacterial or viral cause with high accuracy. The aim was therefore to compare the clinical performance of HNL with currently used biomarkers. Seven hundred twenty-five subjects (144 healthy controls and 581 patients with signs and symptoms of acute infections) were included in the study. C-reactive protein (CRP), the expression of CD64 on neutrophils, procalcitonin (PCT), and blood neutrophil counts were measured by established techniques, and HNL concentrations were measured in whole-blood samples after activation with fMLP. All tested biomarkers were elevated in bacterial as opposed to viral infections (P< 0.001). CRP, PCT, and CD64 expression in neutrophils was elevated in viral infections compared to healthy controls (P< 0.001). In the distinction between healthy controls and patients with bacterial infections, the areas under the receiver operating characteristic (ROC) curves were >0.85 for all biomarkers, whereas for the distinction between bacterial and viral infections, only HNL concentration in fMLP-activated whole blood showed an area under the ROC curve (AUROC) of >0.90 and superior clinical performance. The clinical performance of HNL in fMLP-activated whole blood was superior to current biomarkers and similar to previous results of HNL in serum. The procedure can be adopted for point-of-care testing with response times of <15 min.


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