Rapid Test Research Articles

Rapid test to analyze bonded glycerin in biodiesel by solid-phase extraction and digital image processing

This work presents a simple, fast and low-cost test that can be used in the field to determine glycerin bound in biodiesel. The method uses solid phase extraction to separate six different samples of biodiesel into two fractions: fraction 1, composed mainly of fatty acid methyl esters, and fraction 2, composed mainly of bound glycerin, that is, monoacylglycerols, diacylglycerols and triacylglycerols. Fraction 2 underwent a colorimetric enzymatic reaction and the different color intensities obtained at different concentrations were acquired on a smartphone, the images were processed using the PhotoMetrix PRO application, for quantitative determination of the bound glycerin content of different biodiesel samples. The proposed method was validated by determining linearity (range of 0.006 % to 0.056 % by mass of glycerol for all color channels studied (red, green, blue, hue, saturation, intensity, brightness and value)), limit of detection (LoD) was 7.29 x 10–3 % and the LoQ was 2.41 x 10–2 % by mass. The highest coefficient (R2 = 0.9298) was obtained for the blue channel, chosen to validate the methodology. The results of the Cochran’s test on the analytical curve for the blue channel demonstrated homogeneity of variance; that is, the calculated C value (0.5805) was lower than the critical C value (0.6161). Its precision, based on relative standard deviation, was between 0.86 % and 1.59 %, which is acceptable for this parameter. Precision, based on recall, was in the range of 94.08 %. The proposed and reference methods (ASTM D 6584:2014) produced statistically similar results, with 95 % confidence, based on paired t-test results.

Low cost and real-time surveillance of enteric infection and diarrhoeal disease using rapid diagnostic tests in Cox’s Bazar, Bangladesh

BackgroundReal-time disease surveillance is an important component of infection control in at-risk populations. However, data on cases or from lab testing is often not available in many low-resource settings. Rapid diagnostic tests (RDT), including immunochromatographic assays, may provide a low cost, expedited source of infection data.MethodsWe conducted a pilot survey-based prevalence mapping study of enteric infection in Camp 24 of the camps for the forcibly displaced Rohingya population from Myanmar in Cox’s Bazar, Bangladesh. We randomly sampled the population and collected and tested stool from under-fives for eight pathogens using RDTs in January–March 2021 and September–October 2021. A Bayesian geospatial statistical model allowing for imperfect sensitivity and specificity of the tests was adapted.ResultsWe collected and tested 396 and 181 stools in the two data collection rounds. Corrected prevalence estimates ranged from 0.5% (Norovirus) to 27.4% (Giardia). Prevalence of Escherichia coli O157, Campylobacter, and Cryptosporidium were predicted to be higher in the high density area of the camp with relatively high probability (70–95%), while Adenovirus, Norovirus, and Rotavirus were lower in the areas with high water chlorination. Clustering of cases of Giardia and Shigella was also observed, although associated with relatively high uncertainty.ConclusionsWith an appropriate correction for diagnostic performance RDTs can be used to generate reliable prevalence estimates, maps, and well-calibrated uncertainty estimates at a significantly lower cost than lab-based studies, providing a useful approach for disease surveillance in these settings.

A survey of practice patterns and adherence to national and international guidelines on the management of Helicobacter pylori infection among gastroenterologists and gastroenterology fellows in India.

Patients and primary care providers alike benefit greatly from the expertise of gastroenterologists when it comes to managing Helicobacter pylori (H. pylori) infection. However, information on gastroenterologists' practices in the management of H. pylori infection is scarce in this part of the world. This study aimed at evaluating the practice patterns of gastroenterologists and gastroenterology fellows in India. This was a cross-sectional questionnaire-based survey of gastroenterologists and gastroenterology fellows working in India. Total 207 gastroenterologists and 53 fellows filled out the questionnaire. Responses were received from all around India. Approximately 70% of respondents perceive H. pylori to be a gastric pathogen, while 20% regard it as a commensal bacterium. While the proportion of respondents who chose a test and treat method (34.6%) for uninvestigated dyspepsia without alarm symptoms was comparable to empirical proton pump inhibitor (PPI) therapy (38.8%), about one-fifth chose a scope and treat strategy in this setting. Even in the absence of alarm signs, more than half of respondents (61.5%) preferred endoscopic biopsy to detect H. pylori. While rapid urease testing (RUT) was the preferred modality (80%) for detecting H. pylori, about one-third preferred single-site RUT (from the antrum). Only 40% followed the Updated Sydney protocol, while performing biopsies and a majority (78.8%) are unable to discontinue PPIs before testing for H. pylori. PPI-clarithromycin-based triple treatment was the preferred regimen (67%) for first-line eradication, while nearly a quarter of respondents did not utilize bismuth due to concerns about adverse effects. The survey reveals a lack of adherence to the currentH. pylori guidelines for diagnosis, testing and treatment among gastroenterologists and gastroenterology fellows in India. It is vital that scientific societies simplify guidelines, investigate challenges to their effective implementation and execute targeted interventions to increase adherence.

Rapid Molecular Diagnostics in Vulvovaginal Candidosis.

Vulvovaginal candidosis (VVC) is a common condition among women, with current diagnostic methods relying on clinical evaluation and laboratory testing. These traditional methods are often limited by the need for specialized training, variable performance, and lengthy diagnostic processes, leading to delayed treatment and inappropriate antifungal use. This review evaluates the efficacy of molecular diagnostic tools for VVC and provides guidance on their application in clinical practice. A literature search was conducted using PubMed to identify studies evaluating rapid diagnostic tests specifically for vulvovaginal Candida isolates. Inclusion criteria focused on studies utilizing molecular diagnostics for the detection of Candida species in VVC. Articles discussing non-vaginal Candida infections, non-English studies, and animal or in vitro research were excluded. Twenty-three studies met the inclusion criteria, predominantly evaluating nucleid acid amplification tests/polymerase chain reaction (NAAT/PCR) assays and DNA probes. PCR/NAAT assays demonstrated high sensitivity and specificity (>86%) for VVC diagnosis, outperforming conventional diagnostic methods. Comparatively, DNA probes, while simpler, exhibited lower sensitivity. The included studies were mostly observational, with only one randomized controlled trial. Emerging diagnostic technologies, including artificial intelligence and integrated testing models, show promise for improving diagnostic precision and clinical outcomes. Molecular diagnostics offer a significant improvement in VVC management, though traditional methods remain valuable in resource-limited settings.

The Concordance between GeneXpert MTB/RIF and Isothermal Amplification Assay for Detecting Mycobacterium tuberculosis

Tuberculosis (TB) is an infectious disease and one of the biggest causes of death worldwide. The main problem today is the lack of accurate and rapid tests to detect Mycobacterium tuberculosis (MTB). Several molecular methods have been developed to detect MTB. GeneXpert MTB/RIF® can detect MTB and rifampicin resistance simultaneously in <2 hours. Cross Priming Amplification (CPA) is one of the isothermal amplification assay methods that can detect MTB. Both of these methods are molecular rapid tests so they can detect MTB faster. This study aims to evaluate the concordance of GeneXpert MTB/RIF® results with CPA to detect MTB at Hasan Sadikin General Hospital, Bandung. This is an observational cross-sectional study. The subjects were patients with suspected pulmonary TB and examined with GeneXpert MTB/RIF® then CPA (Ustar EasyNAT MTC™) was also examined. This study used total sampling with 50 subjects and analyzed with Cohen's Kappa test. The results of GeneXpert MTB/RIF® and Ustar EasyNAT MTC™ in detecting MTB obtained Kappa of 0.662 (good agreement) with p-value <0.001. Of the 11 low positive samples on GeneXpert MTB/RIF® as many as 6 subjects (54.55%) had positive results, and 5 subjects (45.45%) had negative results on UStar EasyNAT MTC™. Meanwhile, of the 4 very low positive samples, there was only 1 sample with positive results on UStar EasyNAT MTC™. There is a match results between high and medium positive GeneXpert MTB/RIF® and UStar EasyNAT MTC™. However, there is a difference between low and very low positive results on GeneXpert MTB/RIF® and UStar EasyNAT MTC™.

Enhancing SRM Performance through Multi-Platform Optimization and FPGA-Based Real-Time Simulation

This paper proposes a multi-platform algorithm methodology in order to define firing angles of torque sharing functions (TSFs) for the indirect torque control of switched reluctance motors (SRM) through a hardware-in-the-loop (HIL) system. This proposal is used to achieve optimal levels of torque ripple and losses with accuracy and reliability, while taking advantage of real-time simulation. The analysis is performed assuming steady-state conditions of speed and torque reference for levels below the base speed, aiming to obtain firing angles ensuring optimal tracking performance. A novel methodology is proposed by using a grid search algorithm that handles the communication between Python, Code Composer, and the Typhoon HIL device. For that, an experimental data FPGA-based model with 500~ns of simulation time step is used to ensure highly accurate dynamic responses of current and electromagnetic torque. Moreover, controller-HIL (C-HIL) is used to have a safe and high fidelity testing environment, allowing rapid testing before transitioning to an experimental test bench. The simulation results are experimentally validated, demonstrating that the proposed strategy is effective and ensures optimal performance, taking into account peripheral systems of A/D, signal conditioning, PWM, and sensor emulation.

Rapid detection of SARS-CoV-2 variants by molecular-clamping technology-based RT-qPCR.

We have developed a multiplex reverse-transcription quantitative real-time PCR (RT-qPCR) testing platform for the rapid detection of SARS-CoV-2 variants using the xenonucleic acid (XNA)-based molecular-clamping technology. The XNA-based RT-qPCR assay can achieve high sensitivity with a limit of detection of about 100 copies/mL for variant detection which is much better than the next-generation sequencing (NGS) assay. Its turnaround time is about 4 hours with lower cost and a lot of Clinical Laboratory Improvement Amendments (CLIA) labs own the instrument and meet skillset requirements. This assay provides a rapid, reliable, and cost-effective testing platform for rapid detection and monitoring of known and emerging SARS-CoV-2 variants. This testing platform can be adopted by laboratories that perform routine SARS-CoV-2 PCR testing, providing a rapid and cost-effective method in lieu of NGS-based assays, for detecting, differentiating, and monitoring SARS-CoV-2 variants. This assay is easily scalable to any new variant(s) should it emerge.

The first report on detecting SARS-CoV-2 inside bacteria of the human gut microbiome: A case series on asymptomatic family members and a child with COVID-19

Many studies report the importance of using feces as source sample for detecting SARS-CoV-2 in patients with COVID-19 symptoms but who are negative to oropharyngeal/ nasopharyngeal tests. Here, we report the case of an asymptomatic child whose family members had negative results with the rapid antigen nasopharyngeal swab tests. The 21-month-old child presented with fever, diarrhea, bilateral conjunctivitis, and conspicuous lacrimation. In this study, analysis for the presence of SARS-CoV-2 in fecal samples by using Luminex technology allowed accurate detection of the presence of the viral RNA in the feces of the child and of all her relatives, which thus resulted to be positive but asymptomatic. It is the first time that SARS-CoV-2- is observed inside the bacteria of the human gut microbiome and outside a matrix resembling extracellular bacterial lysates, in agreement with a bacteriophage mechanism with the images obtained by transmission electron microscopy (TEM), post-embedding immunogold, and by fluorescence microscope. In addition to the typical observations of respiratory symptoms, accurate evaluation of clinical gastrointestinal and neurological symptoms, combined with efficient highly sensitive molecular testing on feces, represent an efficient approach for detecting SARS-CoV-2, and for providing the correct therapy in challenging COVID-19 cases, like the one here reported.

Development of a High-Resolution Melting Method for the Detection of Clarithromycin-Resistant Helicobacter pylori in the Gastric Microbiome.

Background: The issue of Helicobacter pylori (H. pylori) resistance to clarithromycin (CLR) has consistently posed challenges for clinical treatment. Hence, a rapid susceptibility testing (AST) method urgently needs to be developed. Methods: In the present study, 35 isolates of H. pylori were isolated from 203 gastritis patients of the Guangzhou cohort, and the antimicrobial resistance phenotypes were associated with their genomes to analyze the relevant mutations. Based on these mutations, a rapid detection system utilizing high-resolution melting (HRM) curve analysis was designed and verified by the Shenzhen cohort, which consisted of 38 H. pylori strains. Results: Genomic analysis identified the mutation of the 2143 allele from A to G (A2143G) of 23S rRNA as the most relevant mutation with CLR resistance (p < 0.01). In the HRM system, the wild-type H. pylori showed a melting temperature (Tm) of 79.28 ± 0.01 °C, while the mutant type exhibited a Tm of 79.96 ± 0.01 °C. These differences enabled a rapid distinction between two types of H. pylori (p < 0.01). Verification examinations showed that this system could detect target DNA as low as 0.005 ng/μL in samples without being affected by other gastric microorganisms. The method also showed a good performance in the Shenzhen validation cohort, with 81.58% accuracy, and 100% specificity. Conclusions: We have developed an HRM system that can accurately and quickly detect CLR resistance in H. pylori. This method can be directly used for the detection of gastric microbiota samples and provides a new benchmark for the simple detection of H. pylori resistance.

Evaluation of a point-of-care multiplex immunochromatographic assay for the diagnosis of typhoid: results from a retrospective diagnostic accuracy study.

Currently available diagnostic tests for typhoid have several limitations, including low sensitivity and specificity. Dual Path Platform Typhoid assay is a multiplex rapid test that detects IgA antibodies to lipopolysaccharide and hemolysin E antigen. It is considered to have high sensitivity and specificity, and its results were found to be highly correlated with ELISA results. However, very few studies have been conducted to evaluate this test and limited information about the accuracy of this test is present. Hence, this study evaluated the new typhoid test.

Uptake, Acceptability, and Results of SARS-CoV-2 Antigen Rapid Diagnostic Testing in Community Settings in Cameroon.

Mass gathering event restrictions were part of mitigation measures during the COVID-19 pandemic that were lifted as prevalence decreased and after vaccination rollout. We explored SARS-CoV-2 antigen rapid diagnostic test acceptability and positivity in community settings in Cameroon. In August-October 2022, community workers sensitized and referred individuals for COVID-19 testing to nearby testing points in Douala and Yaoundé. Participants consented to SARS-CoV-2 antigen rapid diagnostic testing, a survey, or both components. We describe the positivity rate, COVID-19-related history, and Likert-scale testing perceptions. Factors associated with testing acceptance were analyzed using logistic regression. Overall, 20.5% (2,449/11,945) of sensitized individuals visited testing points, and 1,864 (76.1%) were enrolled; 50.6% accepted the survey and testing (46.0% accepted survey only). Seven (0.7%) of 1,006 individuals tested positive. Most (71.8%; 1,292/1,800) considered community testing more accessible than hospital-based testing. Individuals accepting versus refusing testing differed in perceived COVID-19 risk (67%, 49%; P <0.001), belief in accurate test results (79%, 47%; P <0.001), and ability to test easily (96%, 55%; P <0.001). Males (adjusted odds ratio [aOR]: 1.26 [1.04-1.53]) and those over 50 years (aOR: 1.9 [1.4-2.7]), with symptoms (aOR: 1.80 [1.30-2.50]), and at least partial vaccination (aOR: 0.76 [0.58-0.99]) were significantly associated with test acceptance. Refusal reasons included lack of perceived need for testing (33.8%) and testing discomfort (26.3%). Although community-based testing was generally perceived as important, actual testing uptake was low. In future pandemics, community testing should be optimized by addressing misinformation, offering alternative testing modalities for greater comfort, creating demand, and tailoring approaches to maximize testing uptake.

Deep Learning-Enhanced Paper-Based Vertical Flow Assay for High-Sensitivity Troponin Detection Using Nanoparticle Amplification.

Successful integration of point-of-care testing (POCT) into clinical settings requires improved assay sensitivity and precision to match laboratory standards. Here, we show how innovations in amplified biosensing, imaging, and data processing, coupled with deep learning, can help improve POCT. To demonstrate the performance of our approach, we present a rapid and cost-effective paper-based high-sensitivity vertical flow assay (hs-VFA) for quantitative measurement of cardiac troponin I (cTnI), a biomarker widely used for measuring acute cardiac damage and assessing cardiovascular risk. The hs-VFA includes a colorimetric paper-based sensor, a portable reader with time-lapse imaging, and computational algorithms for digital assay validation and outlier detection. Operating at the level of a rapid at-home test, the hs-VFA enabled the accurate quantification of cTnI using 50 μL of serum within 15 min per test and achieved a detection limit of 0.2 pg/mL, enabled by gold ion amplification chemistry and time-lapse imaging. It also achieved high precision with a coefficient of variation of <7% and a very large dynamic range, covering cTnI concentrations over 6 orders of magnitude, up to 100 ng/mL, satisfying clinical requirements. In blinded testing, this computational hs-VFA platform accurately quantified cTnI levels in patient samples and showed a strong correlation with the ground truth values obtained by a benchtop clinical analyzer. This nanoparticle amplification-based computational hs-VFA platform can democratize access to high-sensitivity point-of-care diagnostics and provide a cost-effective alternative to laboratory-based biomarker testing.

ANTIBACTERIAL THERAPY IN SEPSIS PATIENTS

Today, sepsis, the cause of which is purulent-inflammatory processes of soft tissues, accounts for more than 45% of cases. In most multidisciplinary hospitals, the frequency of gram-positive and gram-negative sepsis is approximately the same. Antibacterial therapy (ABT) is the most important component of the complex therapy of sepsis, and early adequate empiric ABT leads to a decrease in mortality and the frequency of complications. ABT of sepsis at the beginning of treatment, in most cases, is empirical in nature, but it should be remembered that taking the material for microbiological research must be done before the start of antibacterial therapy! According to the principles adopted in the guideline "Sepsis - 3", the use of antibiotics for the treatment of sepsis is a necessary component, the effectiveness of which cannot be doubted. It should be remembered that a delay in the appointment of an antibacterial drug to patients with sepsis and septic shock for 1 hour leads to an increase in the risk of death of the patient by 7,6%. Empiric ABT should be initiated with a broad-spectrum regimen of one or more antibiotics in patients with sepsis or septic shock to cover all possible pathogens (including bacterial, possibly fungal, or viral). Empiric ABT should be narrowed after identification of the pathogen and determination of its sensitivity and/or when adequate clinical improvement is registered. There are no indications for long-term systemic antibacterial prophylaxis in patients with severe forms of inflammatory conditions of non-infectious origin (for example, severe pancreatitis, burns). Measurement of procalcitonin levels can be used to shorten the duration of antibacterial therapy in patients with sepsis. Rapid interpretation of the severity of the infectious process can be performed using ACCP/SCCM sepsis diagnostic criteria, organ dysfunction criteria (gSOFA, SOFA, MODS) or rapid procalcitonin test. Microbiological diagnosis of sepsis is the main factor in prescribing adequate ABT regimens. In the case when the same microorganism is released from the probable source of infection and from the peripheral blood, its etiological role in the development of sepsis should be considered as evidential. The standard for testing blood for sterility is the collection of material from two peripheral veins with an interval of up to 30 minutes, while blood from each vein must be collected in two vials. It is not permissible to take blood from the catheter! Building an ABT algorithm taking into account the etiology and characteristics of resistance of microorganisms to antibacterial drugs is the most optimal approach. Тoday, the optimal regimen of empiric ABT of sepsis with PON is carbapenems - as drugs that have the widest spectrum of action and to which the lowest level of resistance is observed among intra-hospital strains of gram(-) bacteria. In some cases, an alternative to carbapenems is cefepime, ceftaroline, protected by antipseudomonas β-lactams (cefaperazone/sulbactam, piperacillin/tazobactam) and "respiratory" fluoroquinolones. In cases of ineffectiveness of the indicated regimens of ABT, the feasibility of additional appointment of glycopeptides (vancomycin, teicoplanin or linezolid), as well as systemic antimycotics (fluconazole) should be evaluated. The latter should also be prescribed after 7-10 days after the start of ABT in a prophylactic dose of 150 mg per week.

Illustration of the Financial Impact of Usage of Initial Specimen Diversion Devices (ISDD) or Continued Educational Initiatives on the Costs from Blood Culture Contamination

Abstract Introduction/Objective Blood culture contamination (BCC) has the potential to lead to additional healthcare system costs and harm to patient. Two ways to reduce BCC have been explored in the literature and are economically modeled including initial specimen diversion devices (ISDD) and continued education on phlebotomy. Methods/Case Report A literature review on the economic costs of BCC, ISDD efficacy, and phlebotomy education to reduce BCC rates was undertaken. The reported average BCC at a veteran affairs medical center (VAMC), its reported rate during a month of phlebotomy training, the cost of an ISDD device at VAMC, and the average wage for 4 hours of phlebotomy manager time for training was noted. An illustrative economic model involving 100 patients was used at BCC rates of 1%, 2%, and 3% along with what had been observed at the VAMC was used for economic modeling. Results (if a Case Study enter NA) It was previously reported by Skoglund et al that in laboratories with rapid diagnostic testing modalities (such as MALDI-TOF or PCR testing), the cost per BCC event is $13,026 versus $8,287 in costs for a negative blood culture. ISDD efficacy in the literature reviewed (74.1% to 87.5%), continuous education efficacy (16.2% to 57.8%), ISDD device cost ($17.70 per device), and the hourly wage of a phlebotomy supervisor ($29.34) were noted. The reported average BCC rate from a regional VAMC was 1.33%, and during the month with education, the rate was 0.5%. From a model of 100 patients, ISDD device savings ranged from $1,741.60-$2,376.63 (1% BCR), $5,253.20-$6,523.25 (2% BCR), and $8,764.79-$10,669.88 (3% BCR). Education savings ranged from $755.98-$2,727.41 (1% BCR), $1,523.70-5,466.55 (2% BCR), and $2,291.42-$8,205.69 (3% BCR). The observed impact of education at the regional VAMC would have resulted in savings of $650.83 per 100 patients. Conclusion Both education and ISDD devices can result in significant savings from the costs of BCC.

Simultaneous determination of somatic cell count and total plate count in raw milk based on ATP bioluminescence assay

The somatic cell count (SCC) and total plate count (TPC) are essential quality indicators for raw milk. Traditional detection methods require separate measurements and rely on complex, large-scale instruments or cultivation techniques, which are both time-consuming and laborious. To address these challenges, this study developed a novel method for the simultaneous detection of SCC and TPC in the same raw milk sample using the ATP bioluminescence assay. This method utilizes oxy-ethylated iso-nonyl phenol (Neonol-10) and cetyltrimethylammonium bromide (CTAB) to selectively lyse somatic cells and microorganisms, respectively. This technique is straightforward to operate and can be completed within 2.5 h, with detection ranges of 1 × 10⁴ to 3 × 10⁶ cells/mL for SCC and 1 × 10⁵ to 5 × 10⁷ CFU/mL for TPC. Importantly, this technique meets the requirements of detection standards in China, European Union, Canada, United States, etc. For SCC or TPC in raw milk. Overall, this innovative approach does not rely on expensive equipment or facilities and the stepwise reagent addition procedure can be easily developed into an automated high-throughput system for rapid on-site testing of SCC and TPC in raw milk.

Evaluation of Hepatitis C Virus Transmission Through Endoscopy Procedures in the Country of Georgia.

Exposure to healthcare procedures might be a source of hepatitis C virus (HCV) transmission in Georgia, one of the few countries currently on track to eliminate hepatitis C. While there has been a history of iatrogenic transmission of HCV, the risk of HCV transmission related to endoscopic procedures has not been previously assessed in Georgia. The goal of this study was to assess HCV seroconversion among individuals undergoing endoscopic procedures to estimate the relative role and incidence of HCV infection attributable to endoscopic procedures. A prospective cohort study was conducted in four endoscopy units in two cities (Tbilisi and Kutaisi) of Georgia during April-September, 2021. Recruitment of study participants was conducted using convenience sampling, and every eligible patient was approached and invited to participate in the study. Study population included adults (age ≥ 18 years) who received an endoscopic procedure (gastroscopy, colonoscopy and bronchoscopy) in inpatient or outpatient unit at the study sites. HCV antibody (anti-HCV) testing was conducted using rapid diagnostic test (RDT) on the same day they underwent the endoscopic procedure. Patients with a non-reactive anti-HCV baseline test were retested after 6 months. Patients with reactive baseline tests were excluded from the study and linked to further testing and care. Participants with a reactive result on follow-up RDTs were retested using a lab-based anti-HCV and HCV ribonucleic acid (RNA) test. A total of 981 HCV antibody non-reactive participants were enrolled; 590 (64.8%) of them were reached and retested after 6 months. At retesting, two out of 590 (0.3%) individuals had a reactive anti-HCV result on RDT and both were negative on laboratory-based anti-HCV and HCV RNA tests. Based on the results of this study, endoscopic procedures were not shown to contribute to HCV transmission in Georgia.

Signaling Molecules in Pseudomonas aeruginosa Response to Antibiotics at Sub-Inhibitory Concentrations

Signaling Molecules are N-acylhomoserine lactones (AHLs) that form the Pseudomonas aeruginosa cell information system which determines gene expressions in a population dependent manner called quorum sensing (QS). Signal molecules, which are chemically varied, control genes expressions to antibiotics resistance, pathogenicity, motility, biofilm development, bioluminescence, secondary metabolite production, and plasmid transfer. This research was aimed to identify the signaling molecules in Pseudomonas aeruginosa response to antibiotics at sub-inhibitory concentrations. One hundred and fifty (150) clinical swab specimens were collected from urinary catheter wound and ear infection of patients and the swabs inoculated using standard microbiology method. The isolates were characterized based on the bacteriological methods such as morphology and biochemical tests. The isolates were further confirmed by species specific PCR by amplification of 16S rRNA and the amplicons were analyzed by gel electrophoresis; and further genomic sequencing was done and blast with NCBI database mining. Disc diffusion method was applied for the antibiotics susceptibility pattern. The isolates cell suspensions were analyzed by Gas Chromatography-Mass Spectrometry (GC-MS). The result of the isolation showed 22(59.46%) from wound infections, 12(32.43%) from ear infections and 3(8.11%) from urinary catheter. The isolates were Gram negative, produced β-hemolysis on blood agar and the morphology is small pigmented circular in form. The isolates showed positive result to catalase, oxidase, citrate, nitrate and indole tests. The amplification of 16S rRNA gene region resulted in the band size of 1500bp PCR product and the BLAST analysis gave 99% similarity. The resistant antibiotics susceptibility showed that Pseudomonas aeruginosa is multidrug resistant bacteria. The GC-MS results obtained from urinary catheter isolates showed four (4) signaling molecules such as N-Octanoyl-L-homoserine Lactone, N-Decanoyl-DL-Homoserine Lactone, N-Dodecanoyl-DL-Homoserine Lactone and N-Tetradecanoyl-L-Homoserine Lactone. Three (3) signaling molecules such as N-Octanoyl-L-homoserine Lactone, N-Decanoyl-DL-Homoserine Lactone and N-Tetradecanoyl-L-Homoserine Lactone were obtained from wound isolates. N-Tetradecanoyl-L-Homoserine Lactone was the only signaling molecule obtained from ear isolates. Further research should be done to develop rapid tests that could be possible to detect acyl homoserine specific to Pseudomonsa aeruginosa present to human samples and deliver results in real time. Signaling molecules inhibitors (SMI) are possible potential therapeutics that could produce the subsequent class of antibacterial drugs. The fundamental role of each signal molecule in the production of biofilms and virulent factors should also be investigated, as well as whether Pseudomonas aeruginosa needs one or more signaling molecules to form quorum sensing. Identification of the signals molecules (AHLs) of P. aeruginosa and developing signaling molecules inhibitors (SMI) can have an important prognostic, diagnostic and therapeutic value in human medicine for the treatment of P. aeruginosa infections.

Ultra-rapid detection of nuclear protein of severe fever with thrombocytopenia syndrome virus by colloidal gold immunochromatography assay.

In 2009, severe fever with thrombocytopenia syndrome virus (SFTSV), also known as the Dabie bandavirus (DBV), was first discovered in Henan, China. It is a tick-borne zoonotic virus with a fatality rate ranging from 6% to 30%. Currently, we lack safe and effective vaccines or antiviral drugs to treat SFTSV infection. Therefore, the development of a specific, sensitive, and cost-effective detection method is crucial. Using inactivated SFTSV and recombinant SFTSV nucleocapsid protein (SFTSV-NP), we repeatedly immunized mice with different adjuvants and obtained two monoclonal antibodies against SFTSV-NP, which were used to develop a colloidal gold immunochromatographic assay (ICA) rapid test kit for SFTSV. Compared with nucleic acid testing (gold standard), the ICA test strips are 97.67% accurate in testing clinical serum samples (36 cases of clinical serum samples and seven cases of whole blood samples). The test kit was 100% accurate in detecting different SFTSV strains. No false-positive results were generated when detecting other arboviruses. Therefore, our developed SFTSV test kit conveniently, rapidly, and effectively detects SFTSV.

Removal of Per- and Polyfluoroalkyl Substances (PFAS) in fixed bed anion exchange reactors: Factors determining PFAS uptake capacity and models predicting PFAS breakthrough

Per- and polyfluoroalkyl substances (PFAS) are widespread contaminants with adverse environmental and public health effects. Anion exchange (IX) processes can effectively remove many PFAS from water. Objectives of this research were to (1) quantify the effects of PFAS structure and background water matrix constituents [dissolved organic matter (DOM) and major inorganic anions (bicarbonate, chloride, sulfate, and nitrate)] on PFAS uptake capacity of IX resins (KIX), and (2) develop models that predict PFAS breakthrough in packed bed IX columns from PFAS structure and background water matrix characteristics. Rapid small-scale column tests were conducted with two IX resins and 18 water matrices to determine breakthrough curves and KIX values for 23 PFAS. A quantitative structure-property relationship (QSPR) was developed that predicts KIX for different PFAS from a newly developed concept, the normalized chain length (NCL). NCL for each PFAS was calculated using a group contribution method, in which the contributions of PFAS structural fragments to NCL were normalized to that of -CF2-, which was assigned a value of 1.00. Relative to -CF2-, contributions of the structural fragments -O-, -CH2-, >CF-CF3, -CHF-, and -SO3H to NCL for the purposes of KIX prediction were 0.34, -1.87, 1.70, 0.00, and 3.65, respectively. DOM and nitrate adversely impacted PFAS removal, while chloride, sulfate, and bicarbonate, when added at concentrations of up to 3 meq/L above native background levels, had negligible effects on KIX. Based on the obtained water matrix effects, pseudo-single solute models were developed for the two tested IX resins, with which PFAS breakthrough curves for fixed bed IX columns can be predicted using only the NCL and the total organic carbon and nitrate concentrations of the influent water.

Prognostic Value of Admission Lactate Levels in Critically Ill Patients: A Comparative Study With Sequential Organ Failure Assessment and Acute Physiology and Chronic Health Evaluation II Scores.

Introduction Critical illness refers to life-threatening conditions requiring mechanical or pharmacological intervention to maintain organ function. Prognostic models, such as the Sequential Organ Failure Assessment (SOFA) and Acute Physiology and Chronic Health Evaluation (APACHE) II scores, have been widely used to predict mortality in intensive care unit (ICU) patients. Lactate levels are emerging as a valuable biomarker in this context. This study aims to determine the prognostic value of lactate levels upon admission in critically ill patients and to assess their correlation with SOFA and APACHE II scores. Methods This descriptive cross-sectional study included 200 critically ill patients admitted to the emergency department over one year. Data on patient demographics, clinical findings, and laboratory results were collected, and lactate levels and SOFA and APACHE II scores were measured at the time of admission. Patients were followed throughout their hospital stay, with outcomes classified as survival or mortality. Receiver operating characteristic (ROC) curve analysis was used to evaluate the predictive value of lactate, SOFA, and APACHE II scores. Statistical analysis was performed using IBM SPSS Statistics for Windows, Version 27.0 (Released 2020; IBM Corp., Armonk, New York, United States). Results The mean age of the patients was 56.8±16.9 years; 110 (55%) were men, and 90 (45%) were women. In total, 79 patients (39.5%) were non-survivors, and 121 (60.5%) were survivors. Lactate levels were significantly higher in non-survivors (3.56±1.90 mmol/L) compared to survivors (1.47±0.82 mmol/L) (p<0.001). The SOFA and APACHE II scores were also significantly higher in non-survivors (SOFA: 6.35±3.19; APACHE II: 19.91±8.21) than in survivors (SOFA: 3.14±2.02; APACHE II: 12.45±5.76) (p<0.001). The ROC curve analysis showed that lactate had an area under the curve (AUC) of 0.909, SOFA had an AUC of 0.809, and APACHE II had an AUC of 0.769 for predicting mortality. Conclusions Lactate levels are a highly sensitive predictor of mortality in critically ill patients, with significant correlations to SOFA and APACHE II scores. Lactate, as a single rapid test, provides substantial prognostic information and can aid in early triage and clinical decision-making, particularly in resource-limited settings. A single arterial lactate measurement at admission is an effective tool for predicting patient outcomes in the ICU.