Novel automated antifungal susceptibility testing system for yeasts based on dual-detection algorithm of turbidimetry and colorimetry.

Introduction. The increasing prevalence and growing resistance of fungi present a significant peril to public health. There are only four classes of antifungal medicines available today, and few candidates are in clinical trials.Hypothesis/Gap Statement. Rapid and sensitive diagnostic techniques are lacking for most fungal pathogens, and those that do exist are expensive or hard to obtain.Aim. This study aimed to evaluate the feasibility of a novel automated antifungal susceptibility testing system, Fungus AST, in comparison to the broth microdilution method (BMD) recommended by the Clinical and Laboratory Standards Institute (CLSI).Methodology. A total of 101 clinical Candida spp. isolates were collected from the Zengcheng Branch of Nanfang Hospital and subjected to antifungal susceptibility testing. Antifungal susceptibility was assessed using the Fungus AST method and the BMD.Results. In this study, we introduce a novel automated antifungal susceptibility testing system, Fungus AST, which detects the turbidity and/or colour intensity of microdilution wells using a four-wavelength detection technology in real time and is designed to match the growth characteristics of strains over time. Based on our analysis, all reportable ranges of Fungus AST were suitable for clinical fungal isolates in PR China. Within ±twofold dilutions, reproducibility was 100 %. Considering the BMD as a referenced method, ten antifungal agents (anidulafungin, caspofungin, micafungin, fluconazole, voriconazole, posaconazole, itraconazole, amphotericin B, 5-flucytosine and nystatin) showed an essential agreement of >95 %. The category agreement of five antifungal agents (anidulafungin, caspofungin, micafungin, fluconazole and voriconazole) was excellent at >90 %. One Candida albicans isolate and voriconazole showed a major error (ME) (1.7 %), and no other ME or very ME agents were found.Conclusion. Given the above, it can be argued that the utilization of Fungus AST is a discretionary automated approach. More improvements are needed in Fungus AST compared to the BMD system for a wider range of clinical isolates, including different types of fungi.

SERS-active plasmonic metal NP-CsPbX3 films for multiple veterinary drug residues detection.

Sensitive and multiple veterinary drug residues detection is of important for food safety. Herein, uniform plasmonic Au nanobipyramids@Ag nanorods (Au NBP@Ag NR)-CsPbX3 films with strong surface-enhanced Raman scattering (SERS) activity were constructed. The effects of different CsPbX3 (X = Cl, Br, I, or mixed halogens) quantum dots (QDs) on the SERS performances of plasmonic metal NP films were investigated. CsPbI3 QDs with large dielectric constant could be served as the dielectric media to retard the attenuation of electromagnetic evanescent wave, inducing strong electromagnetic strength for SERS enhancement. Plasmon-induced metal-to-perovskite interfacial charge transfer transition also contributed to SERS enhancement. SERS-active plasmonic Au NBP@Ag NR-CsPbI3 films had excellent sensitivity and high reproducibility for quantitative, accurate and multiple detection of chloramphenicol, diazepam and malachite green in food matrix. This work deepened the understanding of the SERS enhancement mechanisms of plasmonic metal NP-perovskite hybrid heterostructures, showing potential prospects in food safety monitoring.

Tunable Preparation of SERS-Active Au-Ag Janus@Au NPs for Label-Free Staphylococcal Enterotoxin C Detection.

Trace staphylococcal enterotoxin C (SEC) in food poses a serious risk to human health, and it is vital to develop a sensitive and accurate approach for SEC monitoring. Herein, a surface-enhanced Raman scattering (SERS) aptasensor was developed for the quantitative detection of SEC. SERS-active gold-silver Janus@gold nanoparticles (Au-Ag Janus@Au NPs) were prepared and showed tunable solid and hollow nanostructures by simply controlling the pH values of the reaction system. Solid Au-Ag Janus@Au NPs exhibited intrinsic and enhanced SERS activity due to the intense plasmonic coupling effect between Au dots and Au-Ag Janus NPs, which was 2.27-fold and 17.46-fold higher than that of Au-Ag Janus NPs and hollow Au-Ag Janus@Au NPs, respectively. The attachment of multiple Au dots also protected Ag islands from oxidization, which increased the stability of Au-Ag Janus@Au NPs. Solid Au-Ag Janus@Au NPs served as a label-free, strong, and stable SERS detection probe and achieved sensitive and reliable detection of SEC. The limit of detection was as low as 0.55 pg/mL. This study will expand the application prospects of label-free SERS detection probes in complex systems for food safety monitoring.

Real-world effectiveness and protection of SARS-CoV-2 vaccine among patients hospitalized for COVID-19 in Xi'an, China, December 8, 2021, to January 20, 2022: A retrospective study.

Introduction: In December 2021, a large-scale epidemic broke out in Xi'an, China, due to SARS-CoV-2 infection. This study reports the effect of vaccination on COVID-19 and evaluates the impact of different vaccine doses on routine laboratory markers. Methods: The laboratory data upon admission, of 231 cases with COVID-19 hospitalized from December 8, 2021 to January 20, 2022 in Xi'an, including blood routine, lymphocyte subtypes, coagulative function tests, virus specific antibodies and blood biochemical tests were collected and analyzed. Results: Of the 231 patients, 21 were not vaccinated, 158 were vaccinated with two doses and 52 with three doses. Unvaccinated patients had a higher proportion of moderate and severe symptoms than vaccinated patients, while two-dose vaccinated patients had a higher proportion than three-dose vaccinated patients. SARS-CoV-2 specific IgG levels were significantly elevated in vaccinated patients compared with unvaccinated patients. Particularly, unvaccinated patients had lower counts and percentages of lymphocytes, eosinophils and CD8+ T-lymphocytes, and elevated coagulation-related markers. In addition, vaccination had no effect on liver and kidney function. Conclusions: Vaccination against SARS-CoV-2, inducing high IgG level and increased CD8+ T cells and eosinophils, and regulating coagulation function, can significantly attenuate symptoms of COVID-19, suggesting that the vaccine remains protective against SARS-CoV-2.

SERS-Active Composites with Au-Ag Janus Nanoparticles/Perovskite in Immunoassays for Staphylococcus aureus Enterotoxins.

The accurate detection of Staphylococcus aureus enterotoxins (SEs) is vital for food safety owing to their high pathogenicity, which may be performed with surface-enhanced Raman scattering (SERS) if SERS-active nanostructures are used. Herein, a Au-Ag Janus nanoparticle (NPs)/perovskite composite-engineered SERS immunoassay was developed for SEC detection. Plasmonic Au-Ag Janus NPs demonstrated inherent SERS activity from the 2-mercaptobenzoimidazole-5-carboxylic acid ligands. CsPbBr3@mesoporous silica nanomaterials (MSNs) were prepared and transformed into CsPb2Br5@MSNs in the aqueous phase. Paired SEC antibody-antigen-driven plasmonic Au-Ag Janus NP-CsPb2Br5@MSN composites were prepared. They showed amplified SERS activity, attributed to the depressed plasmonic decay due to electromagnetic field enhancement and the electron transfer mechanism. A positive relationship was established between SERS signals of composites and the SEC concentration. An additive-free SERS immunoassay was developed for simple, sensitive, and reproducible SEC detection. This study will be extended to develop multiple additive-free SERS-active plasmonic NP/perovskite composites that will open up the possibility of exploring more SERS detection probes for food safety monitoring.

Perovskite Nanomaterial-Engineered Multiplex-Mode Fluorescence Sensing of Edible Oil Quality.

Water-soluble fluorescence nanomaterials are widely applied for water-phase food safety monitoring. However, there is still a challenge for the development of oil-soluble fluorescence nanomaterials for oil-phase food safety detection. Particularly, the edible oil quality has a huge impact on human health, in which excessive acid number (AN), 3-chloro-1,2-propanediol (3-MCPD), and moisture content (MC) are critical monitoring factors. Herein, orange-emitting oil-soluble CsPbBr1.5I1.5 quantum dots (QDs) were prepared and applied for AN and 3-MCPD detection depending on fluorescence quenching and wavelength shifts. A "turn-off" fluorescence sensor and "wavelength-shift" fluorescence colorimetric sensor were fabricated for AN and 3-MCPD detection. Water-sensitive mesoporous silica-coated CsPbBr1.5I1.5 QDs were employed for the establishment of ratiometric fluorescence sensors for MC monitoring by introducing water-stable green-emitting CsPbBr3 nanosheets (NSs) as reference probes. Perovskite nanomaterial-engineered multiplex-mode fluorescence sensors were proposed for the detection of AN, 3-MCPD, and MC in edible oil, with the limits of detection (LODs) of 0.71 mg KOH/g, 39.8 µg/mL 3-MCPD, and 0.45% MC, respectively. This work not only expands the application of perovskite nanomaterials in the bioanalysis field but also provides new materials and novel approaches for the multiplex-mode oil-phase food safety monitoring.

Comparison of chemiluminescence immunoassay, enzyme-linked immunosorbent assay and passive agglutination for diagnosis of Mycoplasma pneumoniae infection.

OBJECTIVE: This study aimed to compare the performance of chemiluminescence immunoassay (CLIA), enzyme-linked immunosorbent assay (ELISA), and passive agglutination (PA) method in detecting Mycoplasma pneumoniae (MP) infection. METHODS: This study enrolled a total of 280 patients who were consecutively seen at the Nanfang Hospital of the Southern Medical University in Guangdong Province, China, between August and December 2016. Serum was collected and examined by CLIA, ELISA, and PA, respectively. RESULTS: There were 180 positive (64.3%) and 100 negative cases (35.7%) by PA, 184 positive (65.7%) and 96 negative cases (34.3%) by CLIA MP-immunoglobulin (Ig) M, 89 positive (31.8%) and 191 negative cases (68.2%) by CLIA MP-IgG, 196 positive (70%) and 84 negative cases (30%) by ELISA MP-IgM, and 114 positive (40.7%) and 166 negative cases (59.3%) by ELISA MP-IgG. Patients were allocated to two groups based on PA results. In PA-negative group (≤1:40), the positive rates of MP-IgM by CLIA were 22.8% and 51.2% and by ELISA were 33.3% and 53.5%, respectively. In the PA-positive group (1:80 to ≥1:1,280), MP-IgM negative cases showed a decreasing trend: 40%, 18%, 14.3%, 10%, and 6.7% (CLIA), and 43.3%, 8%, 14.3%, 5%, and 6.7% (ELISA). The consistency between CLIA/ELISA MP-IgM, -IgG, and -IgG+MP-IgM was >92% for negative cases and >75% for positive cases, resulting in an overall consistency rate >88%. The kappa coefficients were 0.804, 0.763, and 0.806, respectively. CONCLUSION: CLIA and ELISA have a higher sensitivity compared with PA. CLIA has a high concordance with ELISA. Moreover, CLIA has a higher specificity and sensitivity for the detection of IgM and IgG and should be used for the clinical diagnosis of MP infection.

A highly selective and sensitive dopamine and uric acid biosensor fabricated with functionalized ordered mesoporous carbon and hydrophobic ionic liquid.

An ordered mesoporous carbon material functionalized with carboxylic acid groups was synthesized. It was characterized by powder X-ray diffraction, transmission electron microscopy, Fourier transform IR spectroscopy and N(2) adsorption/desorption. Furthermore, this material was used to modify an electrode surface combined with a hydrophobic ionic liquid. The functionalized ordered mesoporous carbon/ionic liquid gel modified electrode shows excellent electrocatalytic performances for the oxidation of dopamine, uric acid and ascorbic acid. The presence of the ionic liquid promotes the electron transfer. Linear responses for dopamine and uric acid were obtained in the ranges of 0.1 to 500 µM and from 0.1 to 100 µM with detection limits of 4.1 and 2.5 nM (signal-to-noise ratio of 3), respectively, under optimum conditions. A quick and sensitive biosensor based on functionalized ordered mesoporous carbon and an ionic liquid has been developed for the first time for the detection of dopamine and uric acid in the presence of a large amount of ascorbic acid.

[Study on the analysis of mixed spectra of benzene homologs with Dolittle multivariate correction method].

Dolittle algorithm is a numerical analysis method with high accuracy and low cost. In the present paper, the Dolittle algorithm is introduced into chemometrics. Dolittle multivariate correction method was put forward for the first time and was applied to solve the problem of overlapped spectra of multi-components. In addition, Dolittle multivariate correction method was used to resolve the problem of spectrum of mixed system of benzene homologs. The result shows that the Dolittle multivariate correction method is superior to the K-matrix method. The relative standard deviation of the Dolittle multivariate correction method is from -6. 35% to 8. 70%, while the relative standard deviation of K-matrix is from -14. 76% to 13. 40%. It was demonstrated that Doolittle algorithm is effective in analytical chemistry.