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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 -
Nature Protocols Nov 2020The complexity of current nucleic acid isolation methods limits their use outside of the modern laboratory environment. Here, we describe a fast and affordable method to...
The complexity of current nucleic acid isolation methods limits their use outside of the modern laboratory environment. Here, we describe a fast and affordable method to purify nucleic acids from animal, plant, viral and microbial samples using a cellulose-based dipstick. Nucleic acids can be purified by dipping in-house-made dipsticks into just three solutions: the extract (to bind the nucleic acids), a wash buffer (to remove impurities) and the amplification reaction (to elute the nucleic acids). The speed and simplicity of this method make it ideally suited for molecular applications, both within and outside the laboratory, including limited-resource settings such as remote field sites and teaching institutions. Detailed instructions for how to easily manufacture large numbers of dipsticks in house are provided. Using the instructions, readers can create more than 200 dipsticks in <30 min and perform dipstick-based nucleic acid purifications in 30 s.
Topics: Animals; Bacteria; Cellulose; Humans; Nucleic Acid Amplification Techniques; Nucleic Acids; Plants; Time Factors; Viruses
PubMed: 33005038
DOI: 10.1038/s41596-020-0392-7 -
Analytical and Bioanalytical Chemistry Jul 2020This review presents the state-of-the-art of optical sensors for determination of biogenic amines (BAs) in food by publications covering about the last 10 years.... (Review)
Review
This review presents the state-of-the-art of optical sensors for determination of biogenic amines (BAs) in food by publications covering about the last 10 years. Interest in the development of rapid and preferably on-site methods for quantification of BAs is based on their important role in implementation and regulation of various physiological processes. At the same time, BAs can develop in different kinds of food by fermentation processes or microbial activity or arise due to contamination, which induces toxicological risks and food poisoning and causes serious health issues. Therefore, various optical chemosensor systems have been devised that are easy to assemble and fast responding and low-cost analytical tools. If amenable to on-site analysis, they are an attractive alternative to existing instrumental analytical methods used for BA determination in food. Hence, also portable sensor systems or dipstick sensors are described based on various probes that typically enable signal readouts such as photometry, reflectometry, luminescence, surface-enhanced Raman spectroscopy, or ellipsometry. The quantification of BAs in real food samples and the design of the sensors are highlighted and the analytical figures of merit are compared. Future instrumental trends for BA sensing point to the use of cell phone-based fully automated optical evaluation and devices that could even comprise microfluidic micro total analysis systems.
Topics: Biogenic Amines; Colorimetry; Food Analysis; Food Quality; Luminescent Measurements; Optical Devices; Spectrum Analysis, Raman
PubMed: 32382967
DOI: 10.1007/s00216-020-02675-9 -
Scientific Reports Nov 2020The objective of this study was to assess the diagnosis value of urinary inflammatory index (UII) and systemic immune-inflammation index (SII) for UTI. Nine inflammatory...
The objective of this study was to assess the diagnosis value of urinary inflammatory index (UII) and systemic immune-inflammation index (SII) for UTI. Nine inflammatory indexes including neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, SII and six UIIs were calculated for Receiver operating characteristic curve analysis to select which one is suitable for the screening of UTIs or distinguishing the types of bacteria. UII3, which calculated from leucocyte esterase (LE), nitrite, white blood cells and bacteria, was preferentially used as an indicator for the diagnosis of UTI when the threshold was set at 0.53. UII2 was more suitable for the distinction between groups when the cutoff is set to 0.94. Appropriate urinary inflammation index calculated by rapid urinalysis of urine dipstick and urine sediment can help us to predict urinary tract infection and bacterial type, and reduce the workload and costs of urine culture.
Topics: Aged; Bacteriuria; Blood Platelets; Carboxylic Ester Hydrolases; Female; Humans; Inflammation; Leukocyte Elastase; Leukocytes; Lymphocytes; Male; Mass Screening; Middle Aged; Neutrophils; Nitrites; ROC Curve; Reagent Kits, Diagnostic; Reproducibility of Results; Sensitivity and Specificity; Urinalysis; Urinary Tract Infections
PubMed: 33168850
DOI: 10.1038/s41598-020-76352-3 -
Danish Medical Journal Dec 2021Utility of dipstick analysis must be investigated in patients admitted to the emergency department. The aim of this study was to evaluate if urine dipstick analysis can...
INTRODUCTION
Utility of dipstick analysis must be investigated in patients admitted to the emergency department. The aim of this study was to evaluate if urine dipstick analysis can be used to detect significant bacteriuria. The cross-sectional study was performed in the Emergency Department of Copenhagen University Hospital - Herlev Hospital, Denmark.
METHODS
We recorded urine dipstick analysis of 500 adult patients admitted to the Emergency Department. Dipstick results were compared with urinary culture.
RESULTS
Sensitivity for leukocyte esterase (LE) was 80.9%, but specificity was 58%. The sensitivity of nitrite was 46.5%, and specificity was 90%. The positive predictive value (PPV) and negative predictive value (NPV) of LE for women were 54.5% and 75.9%; for men, 50.0% and 91.6%. PPV and NPV for nitrite in women were 85.9% and 66.8%; for men, 62.9% and 88.7%. Positive LE and positive nitrite had a PPV of 90.2% for women and 70.4% for men. Negative LE and negative nitrite had an NPV of 80.9% for women and 93.3% for men.
CONCLUSIONS
No single parameter or combination of parameters on the urine dipstick analysis can be used reliably to predict positive urine culture in women. The most accurate predictor of negative urine culture in men is the combination of negative nitrites and negative LE. To minimize unnecessary use of antibiotics, treatment can be delayed in female patients with positive urine dipstick until urine culture results are available.
FUNDING
none.
TRIAL REGISTRATION
not relevant.
Topics: Adult; Bacteriuria; Cross-Sectional Studies; Female; Humans; Male; Reagent Strips; Sensitivity and Specificity; Urinalysis; Urinary Tract Infections
PubMed: 34913433
DOI: No ID Found -
Biosensors Jul 2020Current available methods for the clinical diagnosis of urinary tract infection (UTI) rely on a urine dipstick test or culturing of pathogens. The dipstick test is rapid... (Review)
Review
Current available methods for the clinical diagnosis of urinary tract infection (UTI) rely on a urine dipstick test or culturing of pathogens. The dipstick test is rapid (available in 1-2 min), but has a low positive predictive value, while culturing is time-consuming and delays diagnosis (24-72 h between sample collection and pathogen identification). Due to this delay, broad-spectrum antibiotics are often prescribed immediately. The over-prescription of antibiotics should be limited, in order to prevent the development of antimicrobial resistance. As a result, there is a growing need for alternative diagnostic tools. This paper reviews applications of chemical-analysis instruments, such as gas chromatography-mass spectrometry (GC-MS), selected ion flow tube mass spectrometry (SIFT-MS), ion mobility spectrometry (IMS), field asymmetric ion mobility spectrometry (FAIMS) and electronic noses (eNoses) used for the diagnosis of UTI. These methods analyse volatile organic compounds (VOCs) that emanate from the headspace of collected urine samples to identify the bacterial pathogen and even determine the causative agent's resistance to different antibiotics. There is great potential for these technologies to gain wide-spread and routine use in clinical settings, since the analysis can be automated, and test results can be available within minutes after sample collection. This could significantly reduce the necessity to prescribe broad-spectrum antibiotics and allow the faster and more effective use of narrow-spectrum antibiotics.
Topics: Bacteria; Electronic Nose; Humans; Ion Mobility Spectrometry; Principal Component Analysis; Urinalysis; Urinary Tract Infections; Urine Specimen Collection; Volatile Organic Compounds
PubMed: 32717983
DOI: 10.3390/bios10080083 -
Risk Management and Healthcare Policy 2022Early case detection, treatment, and timely referral for better services can significantly reduce the negative outcomes of preeclampsia and eclampsia. However, evidence...
BACKGROUND
Early case detection, treatment, and timely referral for better services can significantly reduce the negative outcomes of preeclampsia and eclampsia. However, evidence on health facilities' readiness to provide such services and the associated challenges is limited in Ethiopia. Therefore, this study aimed to assess the readiness of Ethiopian health care facilities to manage preeclampsia and eclampsia.
METHODS
This study used the 2016 Ethiopia national emergency management of obstetrics and newborn care (EmONC) survey. This survey was a national cross-sectional census of health facilities that provided delivery services. Data on facility infrastructure, equipment and supplies were collected through a facility checklist, and interview health provider experiences. Cross tabulation, summarisation and chi square tests by facility type, location, and management authority were conducted.
RESULTS
There were 3804 health facilities included in the survey across all regions of Ethiopia. The majority of facilities (92%) were public/government managed with only 1% of available hospitals located in rural areas. Poor availability of dipsticks for proteinuria tests (55.3%), caesarean sections (7.9%), and ambulance services (18.4%) were reported across health facilities with high variations in terms of facility type, location, and type of managing authority. Diazepam was a widely available anticonvulsant compared with magnesium sulfate (MgSO), with more available in private for-profit facilities compared with public facilities. Nearly one third of health care providers were not trained to administer MgSO intravenously. The result indicated that the chi-square test was statistically significant at P < 0.001.
CONCLUSIONS AND RECOMMENDATIONS
There were notable gaps in readiness of facilities in detection and management of preeclampsia/eclampsia that increase maternal and perinatal mortality in Ethiopia. Therefore, availability of essential supplies, medications, and referrals are required. In addition, refresher training to healthcare providers on screening, diagnosis and management of preeclampsia/eclampsia and continuous supervision should be provided.
PubMed: 35734013
DOI: 10.2147/RMHP.S366055 -
Scientific Reports Aug 2020Analyzing electrolytes in urine, such as sodium, potassium, calcium, chloride, and nitrite, has significant diagnostic value in detecting various conditions, such as...
Analyzing electrolytes in urine, such as sodium, potassium, calcium, chloride, and nitrite, has significant diagnostic value in detecting various conditions, such as kidney disorder, urinary stone disease, urinary tract infection, and cystic fibrosis. Ideally, by regularly monitoring these ions with the convenience of dipsticks and portable tools, such as cellphones, informed decision making is possible to control the consumption of these ions. Here, we report a paper-based sensor for measuring the concentration of sodium, potassium, calcium, chloride, and nitrite in urine, accurately quantified using a smartphone-enabled platform. By testing the device with both Tris buffer and artificial urine containing a wide range of electrolyte concentrations, we demonstrate that the proposed device can be used for detecting potassium, calcium, chloride, and nitrite within the whole physiological range of concentrations, and for binary quantification of sodium concentration.
Topics: Biosensing Techniques; Calcium; Decision Making; Early Diagnosis; Electrolytes; Humans; Miniaturization; Nitrites; Potassium; Smartphone
PubMed: 32788641
DOI: 10.1038/s41598-020-70456-6 -
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 -
The American Journal of Tropical... Apr 2021Cholera is a severe acute, highly transmissible diarrheal disease which affects many low- and middle-income countries. Outbreaks of cholera are confirmed using...
Cholera is a severe acute, highly transmissible diarrheal disease which affects many low- and middle-income countries. Outbreaks of cholera are confirmed using microbiological culture, and additional cases during the outbreak are generally identified based on clinical case definitions, rather than laboratory confirmation. Many low-resource areas where cholera occurs lack the capacity to perform culture in an expeditious manner. A simple, reliable, and low-cost rapid diagnostic test (RDT) would improve identification of cases allowing rapid response to outbreaks. Several commercial RDTs are available for cholera testing with two lines to detect either serotypes O1 and O139; however, issues with sensitivity and specificity have not been optimal with these bivalent tests. Here, we report an evaluation of a new commercially available cholera dipstick test which detects only serotype O1. In both laboratory and field studies in Kenya, we demonstrate high sensitivity (97.5%), specificity (100%), and positive predictive value (100%) of this new RDT targeting only serogroup O1. This is the first field evaluation for the new Crystal VC-O1 RDT; however, with these high-performance metrics, this RDT could significantly improve cholera outbreak detection and improve surveillance for better understanding of cholera disease burden.
Topics: Adolescent; Adult; Child; Child, Preschool; Cholera; Clinical Laboratory Techniques; Diarrhea; Disease Outbreaks; Feces; Humans; Infant; Infant, Newborn; Kenya; Predictive Value of Tests; Reagent Kits, Diagnostic; Sensitivity and Specificity; Serogroup; Vibrio cholerae O1; Young Adult
PubMed: 33819171
DOI: 10.4269/ajtmh.20-1280