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Langmuir : the ACS Journal of Surfaces... Oct 2023Water and food contamination has become the major contributor to infections and deaths. However, rapid and sensitive bacterial detection still remains an unmet demand...
Water and food contamination has become the major contributor to infections and deaths. However, rapid and sensitive bacterial detection still remains an unmet demand that has attracted widespread attention. Often water and food samples are sent out for laboratory testing to detect the presence of contamination, which is time-consuming and laborious. Herein, we have developed a highly ensitive, enable, ffordable, and obust (STAR) paper-based colorimetric dipstick sensor based on the principle of Prussian blue (PB) synthesis as an indicator of bacterial contamination. In the presence of bacteria, it leads to the formation of PB, a dye that acts as a colorimetric indicator. The intensity of the PB is the direct measure of the degree of contamination. The fabrication of the STAR dipstick sensor involves a simple and cost-effective process. The STAR dipstick sensor is ultrasensitive and can detect up to 10 CFU/mL of bacteria within minutes of contact with the test sample. The STAR dipstick sensor is fabricated using biodegradable components, which is speculated to facilitate quick and environmentally friendly degradation after each use. The sensor has been validated for its properties and capabilities at different pH to detect both Gram-positive and Gram-negative bacterial strains in real-time samples. The stability and degradation were also monitored. Comprehensively, the proposed STAR dipstick sensor can serve as a point-of-care device to detect bacterial contamination in a swift and sensitive manner.
PubMed: 37750674
DOI: 10.1021/acs.langmuir.3c01451 -
Journal of Veterinary Diagnostic... Sep 2023Standard visual urine dipstick analysis (UDA) is performed routinely in veterinary medicine; results can be influenced by both the operator and the method. We evaluated...
Standard visual urine dipstick analysis (UDA) is performed routinely in veterinary medicine; results can be influenced by both the operator and the method. We evaluated the agreement of results for canine and feline urine samples analyzed using a 10-patch dipstick (Multistix10SG; Siemens), both visually under double-anonymized conditions by students and a laboratory technician, and with an automated device (AD; Clinitek Status, Siemens). The mean concordance for semiquantitative urinalysis results between students and the technician and between students and the AD was fair (κ0.21-0.40) in dogs and cats; concordance was moderate between the technician and the AD (κ0.41-0.60) in dogs and good (κ0.61-0.80) in cats. For pH, the mean concordance between students and the technician and between the technician and the AD was good (ρ0.80-0.92) in dogs and cats; concordance was good between students and the AD (ρ0.80-0.92) in dogs and moderate (ρ0.59-0.79) in cats. Repeatability was higher ( < 0.001) for the technician and the AD than for a student. We found good agreement between UDA performed by an experienced operator and an AD in dogs and cats but found low reproducibility and low repeatability for urinalysis performed by an inexperienced operator.
Topics: Cats; Dogs; Animals; Cat Diseases; Reproducibility of Results; Observer Variation; Dog Diseases; Reagent Strips; Urinalysis
PubMed: 37326167
DOI: 10.1177/10406387231181579 -
Biosensors Dec 2023Ketones are well-known biomarkers of fat oxidation produced in the liver as a result of lipolysis. These biomarkers include acetoacetic acid and β-hydroxybutyric acid...
Ketones are well-known biomarkers of fat oxidation produced in the liver as a result of lipolysis. These biomarkers include acetoacetic acid and β-hydroxybutyric acid in the blood/urine and acetone in our breath and skin. Monitoring ketone production in the body is essential for people who use caloric intake deficit to reduce body weight or use ketogenic diets for wellness or therapeutic treatments. Current methods to monitor ketones include urine dipsticks, capillary blood monitors, and breath analyzers. However, these existing methods have certain disadvantages that preclude them from being used more widely. In this work, we introduce a novel acetone sensor device that can detect acetone levels in breath and overcome the drawbacks of existing sensing approaches. The critical element of the device is a robust sensor with the capability to measure acetone using a complementary metal oxide semiconductor (CMOS) chip and convenient data analysis from a red, green, and blue deconvolution imaging approach. The acetone sensor device demonstrated sensitivity of detection in the micromolar-concentration range, selectivity for detection of acetone in breath, and a lifetime stability of at least one month. The sensor device utility was probed with real tests on breath samples using an established blood ketone reference method.
Topics: Humans; Acetone; Body Fluids; Ketones; 3-Hydroxybutyric Acid; Biomarkers
PubMed: 38248381
DOI: 10.3390/bios14010004 -
Clinica Chimica Acta; International... Aug 2023To address the situation that the accuracy of concentration intervals (CI) corresponding to dipstick grades is not given by the manufacturers or literature, we developed...
BACKGROUND
To address the situation that the accuracy of concentration intervals (CI) corresponding to dipstick grades is not given by the manufacturers or literature, we developed a method that determined reasonable dipstick grades with concentration intervals (GCIs) based on the percent agreement (PA) and discussed the GCI application to comparability among currently dipstick tests.
METHODS
By comparing the results of 2 dipstick tests (iChem and KU-500) with the quantitative test (AU5800), the GCIs were verified and established based on the PAs, which were calculated and used as an indicator of GCI's accuracy. The overlap (percent) between the 2 GCIs with the same grade (2 dipstick devices), was calculated and used to evaluate the agreement between their test results.
RESULTS
After verification and adjustment, the GCI and PA combinations for iChem Velocity were as follows: - (<0.1 g/l, 85 %), ± (0.1-0.3 g/l, 66 %), 1+ (0.3-1 g/l, 78 %), 2+ (1-3 g/l, 74 %), 3+ (3-6 g/l, 77 %), and 4+ (≥6 g/l, 84 %). The determined GCI and PA combinations for KU-500 were: - (<0.1.2 g/l, 75 %), ± (0.12-0.5 g/l, 63 %), 1+ (0.5-1.2 g/l, 69 %), 2+ (1.2-3.2 g/l, 76 %), and 3+ (≥3.2 g/l, 82 %). The GCI overlaps between the 2 dipstick devices were - (83 %), ± (45 %), 1+ (56 %), 2+ (82 %), and 3+ or ≥3+ (94 %). The overall overlap was 72 %. Since the overlaps ± (45 %) and 1+ (56 %) were within the overlap reject limit for any grade (70 %), and the overall overlap (72 %) was within the overall overlap reject limit (80 %), the test results of the 2 devices were not comparable.
CONCLUSIONS
GCIs can be verified and established correctly based on PAs, and industry standards for dipstick tests can be established based on GCIs and PAs. Comparability between dipstick devices, historical data, and literature data can be roughly determined based on the overlap.
Topics: Humans; Sensitivity and Specificity; Urinalysis; Reagent Strips
PubMed: 37500032
DOI: 10.1016/j.cca.2023.117500 -
Lancet (London, England) Sep 2023Chronic kidney disease (CKD) has a rising global prevalence and is expected to become the fifth leading cause of death by 2030. Increased albuminuria defines the early... (Randomized Controlled Trial)
Randomized Controlled Trial
Participation rate and yield of two home-based screening methods to detect increased albuminuria in the general population in the Netherlands (THOMAS): a prospective, randomised, open-label implementation study.
BACKGROUND
Chronic kidney disease (CKD) has a rising global prevalence and is expected to become the fifth leading cause of death by 2030. Increased albuminuria defines the early stages of CKD and is among the strongest risk factors for progressive CKD and cardiovascular disease. The value of population screening for albuminuria to detect CKD in an early phase has yet to be studied. We aimed to evaluate the effectiveness of two home-based albuminuria population screening methods.
METHODS
Towards Home-based Albuminuria Screening (THOMAS) was a prospective, randomised, open-label implementation study that invited Dutch adults aged 45-80 years for albuminuria screening. Individuals were randomly assigned (1:1) to screening by applying either a urine collection device (UCD) that was sent by post to a central laboratory for measurement of the albumin-to-creatinine ratio (ACR) by immunoturbidimetry or to screening via a smartphone application that measures the ACR with a dipstick method at home. Randomisation was done with a four-block method via a web-based system and was stratified by age, sex, and socioeconomic status. If two or more individuals per household were invited to participate, these individuals were randomly assigned to the same group. In case of confirmed increased albuminuria at home, participants were invited for an elaborate screening in a regional hospital (Amphia Hospital, Breda, Netherlands) for CKD and cardiovascular risk factors. When abnormalities were found, participants were referred to their general practitioner for treatment. The primary outcomes were the participation rate and yield of the home-based screening and elaborate screening. Participation rate was assessed in the intention-to-screen population (ie, all participants who were invited for the home-based screening or elaborate screening). Yield was assessed in the per-protocol population (ie, all individuals who participated in the home-based screening or elaborate screening). An exploratory analysis assessed the sensitivity and specificity of both home-based screening methods. To this end, an additional quantitative ACR test was performed among people participating in the elaborate screening, and a substudy was performed among participants with a first negative home-based screening test, who were invited for an additional test. The study is registered with ClinicalTrials.gov, NCT04295889.
FINDINGS
15 074 participants were enrolled between Nov 14, 2019, and March 19, 2021. 7552 (50·1%) were randomly assigned to home-based albuminuria screening by the UCD method and 7522 (49·9%) were assigned to albuminuria screening by the smartphone application method. The participation rate of the home-based screening was 4484 (59·4% [95% CI 58·3-60·5]) of the 7552 invited individuals for the UCD method and 3336 (44·3% [43·2-45·5]) of 7522 invited individuals for the smartphone application method (p<0·0001). Increased ACR was confirmed by home-based testing in 150 (3·3% [95% CI 2·9-3·9]) of 4484 individuals for the UCD method and 171 (5·1% [4·4-5·9]) of 3336 indivduals for the smartphone application method. 124 (82·7% [95% CI 75·8-87·9]) of 150 individuals assigned to the UCD method and 142 (83·0% [76·7-87·9]) of 171 participants assigned to the smartphone application method attended the elaborate screening. Sensitivity to detect increased ACR was 96·6% (95% CI 91·5-99·1) for the UCD method and 98·1% (89·9-99·9) for the smartphone application method, and specificity was 97·3% (94·7-98·8) for the UCD method and 67·9% (62·0-73·3) for the smartphone application method, indicating that the test characteristics of only the UCD method were sufficient for screening. Albuminuria, hypertension, hypercholesterolaemia, and decreased kidney function were newly diagnosed in 77 (62·1%), 44 (35·5%), 30 (24·2%), and 27 (21·8%) of 124 participants for the UCD method, respectively. Of the 124 participants assigned to the UCD method who completed elaborate screening, 111 (89·5%) were referred to their general practitioner for treatment because of newly diagnosed CKD or cardiovascular disease risk factors or known risk factors outside the target range.
INTERPRETATION
Home-based screening of the general population for increased ACR using a UCD had a high participation rate and correctly identified individuals with increased albuminuria and yet unknown or known but outside target range CKD and cardiovascular risk factors. By contrast, the smartphone application method had a lower at-home participation rate than the UCD method and the test specificity was too low to accurately assess individuals for risk factors during the elaborate screening. The UCD screening strategy could allow for an early start of treatment to prevent progressive kidney function loss and cardiovascular disease in patients with CKD.
FUNDING
Dutch Kidney Foundation, Top Sector Life Sciences & Health of the Dutch Ministry of Economic Affairs.
Topics: Humans; Albuminuria; Cardiovascular Diseases; Creatinine; Netherlands; Prospective Studies; Renal Insufficiency, Chronic; Middle Aged; Aged; Aged, 80 and over
PubMed: 37597522
DOI: 10.1016/S0140-6736(23)00876-0 -
The Journal of Antimicrobial... Aug 2023Given the lack of accurate rapid diagnostics for urinary tract infection (UTI) in women, many countries have developed guidelines aiming to support appropriate... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVES
Given the lack of accurate rapid diagnostics for urinary tract infection (UTI) in women, many countries have developed guidelines aiming to support appropriate antibiotic prescribing, but some guidelines have not been validated. We performed a diagnostic accuracy validation study of two guidelines: Public Health England (GW-1263) and Scottish Intercollegiate Guidelines Network (SIGN160).
METHODS
We used data from women with symptoms suggestive of uncomplicated UTI from a randomized controlled trial comparing urine collection devices. Symptom information was recorded via baseline questionnaire and primary care assessment. Women provided urine samples for dipstick testing and culture. We calculated the number within each risk category of diagnostic flowcharts who had positive/mixed growth/no significant growth urine culture. Results were presented as positive/negative predictive values, with 95% CIs.
RESULTS
Of women aged under 65 years, 311/509 (61.1%, 95% CI 56.7%-65.3%) classified to the highest risk category (recommended to consider immediate antibiotic prescribing) and 80/199 (40.2%, 95% CI 33.4%-47.4%) classified to the lowest risk category (recommended to reassure that UTI is less likely) by the GW-1263 guideline (n = 810) had positive culture. For the SIGN160 guideline (n = 814), the proportion with positive culture ranged from 60/82 (73.2%, 95% CI 62.1%-82.1%) in those for whom immediate treatment was indicated to 33/76 (43.4%, 95% CI 32.3%-55.3%) in those recommended a self-care/waiting strategy.
CONCLUSIONS
Clinicians should be aware of the potential for diagnostic error when using diagnostic guidelines for managing uncomplicated UTI and making antimicrobial prescribing decisions. Infection cannot be excluded on the basis of symptoms and dipstick testing alone.
Topics: Humans; Female; Urinalysis; Urinary Tract Infections; Anti-Bacterial Agents; Predictive Value of Tests; Primary Health Care
PubMed: 37401673
DOI: 10.1093/jac/dkad212 -
Applied and Environmental Microbiology Jul 2023Campylobacter jejuni is recognized as the most common species in the genus Campylobacter that causes foodborne diseases. The main reservoirs harboring C. jejuni are...
Campylobacter jejuni is recognized as the most common species in the genus Campylobacter that causes foodborne diseases. The main reservoirs harboring C. jejuni are poultry products, which are associated with most illnesses, creating a demand for effective detection methods to achieve point-of-need diagnostics. We developed an easy-to-use, hybrid paper/polymer-based microfluidic device that integrates paper-based DNA extraction, isothermal nucleic acid amplification, and lateral flow detection. Overall, the recombinase polymerase amplification (RPA) reaction was completed in 20 min and demonstrated 100% specificity to C. jejuni, including 2 reference strains and 6 wild strains isolated from the agroecosystem, 9 other Campylobacter subspecies strains, and 11 non-Campylobacter strains. The limit of detection (LOD) was 46 CFU/mL with DNA extracted on the cellulose paper. The sensitivity was reduced to 460 CFU/mL on the integrated hybrid paper/polymer-based microfluidic device. This device could detect C. jejuni spiked at concentrations ranging from 10 to 10 CFU/g in chicken meat after an enrichment of 5 to 10 h. For C. jejuni levels of >10 CFU/g, it managed to confirm positive results immediately, without bacterial enrichment. RPA reagents and primers remained stable on the paper platform at 22°C for 12 h. After lyophilization and storage on paper, the RPA reaction showed consistent sensitivity for 3 days, and the LOD was reduced to 10 CFU/mL when storage was extended to 25 days. The use of this hybrid paper/polymer-based microfluidic device enabled detection of Campylobacter in foods with high specificity and sensitivity, demonstrating its potential as a reliable point-of-need diagnostic platform for on-site conditions due to its low cost, portability, and simplicity. The global health and economic burden of Campylobacter prompts the development of novel detection techniques that can be implemented in resource-limited and on-site settings. This study described point-of-need identification of C. jejuni using a hybrid paper/polymer-based microfluidic device that is easy to operate. This device had high specificity and sensitivity toward C. jejuni and significantly reduced the total analysis time compared to conventional culture-based methods. Nucleic acid extraction was simplified from intensive pipetting to a paper dipstick, making it more convenient for use in the field as a promising tool for future routine surveillance and outbreak investigation.
Topics: Animals; Campylobacter jejuni; Chickens; Campylobacter; Nucleic Acid Amplification Techniques; Lab-On-A-Chip Devices; Nucleic Acids; Sensitivity and Specificity
PubMed: 37382522
DOI: 10.1128/aem.00695-23 -
Talanta Dec 2023Dipstick-type lateral flow immunosensors are used widely for on-site detection of food allergens. The weakness of the immunosensors of this type, however, is their low...
Dipstick-type lateral flow immunosensors are used widely for on-site detection of food allergens. The weakness of the immunosensors of this type, however, is their low sensitivity. Contrary to current methods, that focus on improving detection capability through the introduction of novel labels or multistep protocols, this work exploits macromolecular crowding to modify and regulate the microenvironment of the immunoassay, thus promoting the interactions that are responsible for allergen recognition and signal generation. The effect of 14 macromolecular crowding agents was explored using, as a model, commercially available and widely applied dipstick immunosensors, which are already optimized in terms of reagents and conditions for peanut allergen detection. An about 10-fold improvement in detection capability was achieved by using polyvinylpyrrolidone, Mr 29,000, as a macromolecular crowder without compromising simplicity and practicality. The proposed approach is complementary to other methods of improving the sensitivity by using novel labels. Because biomacromolecular interactions have a fundamental role in all types of biosensors, we foresee that the proposed strategy will also find applications in other biosensors and analytical devices.
Topics: Allergens; Biosensing Techniques; Immunoassay; Macromolecular Substances
PubMed: 37421795
DOI: 10.1016/j.talanta.2023.124899 -
Frontiers in Oncology 2023The development and rapid progression of cancer are major social problems. Medical diagnostic techniques and smooth clinical care of cancer are new necessities that must... (Review)
Review
The development and rapid progression of cancer are major social problems. Medical diagnostic techniques and smooth clinical care of cancer are new necessities that must be supported by innovative diagnostic methods and technologies. Current molecular diagnostic tools based on the detection of blood protein markers are the most common tools for cancer diagnosis. Biosensors have already proven to be a cost-effective and accessible diagnostic tool that can be used where conventional laboratory methods are not readily available. Paper-based biosensors offer a new look at the world of analytical techniques by overcoming limitations through the creation of a simple device with significant advantages such as adaptability, biocompatibility, biodegradability, ease of use, large surface-to-volume ratio, and cost-effectiveness. In this review, we covered the characteristics of exosomes and their role in tumor growth and clinical diagnosis, followed by a discussion of various paper-based biosensors for exosome detection, such as dipsticks, lateral flow assays (LFA), and microfluidic paper-based devices (µPADs). We also discussed the various clinical studies on paper-based biosensors for exosome detection.
PubMed: 37456253
DOI: 10.3389/fonc.2023.1131435