CoVSense: Ultrasensitive Nucleocapsid Antigen Immunosensor for Rapid Clinical Detection of Wildtype and Variant SARS-CoV-2.

The widespread accessibility of commercial/clinically-viable electrochemical diagnostic systems for rapid quantification of viral proteins demands translational/preclinical investigations. Here, Covid-Sense (CoVSense) antigen testing platform; an all-in-one electrochemical nano-immunosensor for sample-to-result, self-validated, and accurate quantification of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid (N)-proteins in clinical examinations is developed. The platform's sensing strips benefit from a highly-sensitive, nanostructured surface, created through the incorporation of carboxyl-functionalized graphene nanosheets, and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) conductive polymers, enhancing the overall conductivity of the system. The nanoengineered surface chemistry allows for compatible direct assembly of bioreceptor molecules. CoVSense offers an inexpensive (<$2 kit) and fast/digital response (<10 min), measured using a customized hand-held reader (<$25), enabling data-driven outbreak management. The sensor shows 95% clinical sensitivity and 100% specificity (Ct<25), and overall sensitivity of 91% for combined symptomatic/asymptomatic cohort with wildtype SARS-CoV-2 or B.1.1.7 variant (N = 105, nasal/throat samples). The sensor correlates the N-protein levels to viral load, detecting high Ct values of ≈35, with no sample preparation steps, while outperforming the commercial rapid antigen tests. The current translational technology fills the gap in the workflow of rapid, point-of-care, and accurate diagnosis of COVID-19.

Comparative pathogenicity of infectious bronchitis virus Massachusetts and Delmarva (DMV/1639) genotypes in laying hens.

Infectious bronchitis (IB) is a highly contagious and acute viral disease of chicken caused by the infectious bronchitis virus (IBV) of the family Coronaviridae. Even with extensive vaccination against IB by the poultry industry, the occurrence of new IBV genotypes is a continuous challenge encountered by the global poultry industry. This experiment was designed to compare the pathogenicity of two IBV strains belonging to Massachusetts (Mass) and Delmarva DMV/1639 genotypes. Specific pathogen-free laying hens were challenged during the peak of production (30 weeks), keeping a mock-infected control group. During 21 days of observation following infection, a significant drop in egg production with miss-shaped and soft shells was observed in the DMV/1639 IBV-infected hens only. The DMV/1639 IBV infected group showed prolonged and higher cloacal viral shedding compared with the Mass IBV-infected group. At the end of the study (21 days post-infection), the viral genome loads in the respiratory, urogenital, and immune tissues were significantly higher in the DMV/1639 IBV-infected group compared with the Mass IBV-infected group. Macroscopic lesions such as distorted ova leading to egg peritonitis were observed only in the DMV/1639 IBV-infected group. Moreover, microscopic lesion scores were significantly higher in the lung, kidney, cecal tonsils, and oviduct of the DMV/1639 IBV-infected group compared with the Mass IBV-infected group. Finally, the apoptosis index in the kidney, ovary, magnum, isthmus, and shell gland was significantly higher in the DMV/1639 IBV-infected group compared with the control and Mass-infected groups. This study examined the pathogenicity of two IBV genotypes that are impacting the layer industry in North America.

A compact, low-cost, and binary sensing (BiSense) platform for noise-free and self-validated impedimetric detection of COVID-19 infected patients.

Electrochemical immuno-biosensors are one of the most promising approaches for accurate, rapid, and quantitative detection of protein biomarkers. The two-working electrode strip is employed for creating a self-supporting system, as a tool for self-validating the acquired results for added reliability. However, the realization of multiplex electrochemical point-of-care testing (ME-POCT) requires advancement in portable, rapid reading, easy-to-use, and low-cost multichannel potentiostat readers. The combined multiplex biosensor strips and multichannel readers allow for suppressing the possible complex matrix effect or ultra-sensitive detection of different protein biomarkers. Herein, a handheld binary-sensing (BiSense) bi-potentiostat was developed to perform electrochemical impedance spectroscopy (EIS)-based signal acquisition from a custom-designed dual-working-electrode immuno-biosensor. BiSense employs a commercially available microcontroller and out-of-shelf components, offering the cheapest yet accurate and reliable time-domain impedance analyzer. A specific electrical board design was developed and customized for impedance signal analysis of SARS-CoV-2 nucleocapsid (N)-protein biosensor in spiked samples and alpha variant clinical nasopharyngeal (NP) swab samples. BiSense showed limit-of-detection (LoD) down to 56 fg/mL for working electrode 1 (WE1) and 68 fg/mL for WE2 and reported with a dynamic detection range of 1 pg/mL to 10 ng/mL for detection of N-protein in spiked samples. The dual biosensing of N-protein in this work was used as a self-validation of the biosensor. The low-cost (∼USD$40) BiSense bi-potentiostat combined with the immuno-biosensors successfully detected COVID-19 infected patients in less than 10 min, with the BiSense reading period shorter than 1.5 min, demonstrating its potential for the realization of ME-POCTs for rapid and hand-held diagnosis of infections.

Bi-ECDAQ: An electrochemical dual-immuno-biosensor accompanied by a customized bi-potentiostat for clinical detection of SARS-CoV-2 Nucleocapsid proteins.

Multiplex electrochemical biosensors have been used for eliminating the matrix effect in complex bodily fluids or enabling the detection of two or more bioanalytes, overall resulting in more sensitive assays and accurate diagnostics. Many electrochemical biosensors lack reliable and low-cost multiplexing to meet the requirements of point-of-care detection due to either limited functional biosensors for multi-electrode detection or incompatible readout systems. We developed a new dual electrochemical biosensing unit accompanied by a customized potentiostat to address the unmet need for point-of-care multi-electrode electrochemical biosensing. The two-working electrode system was developed using screen-printing of a carboxyl-rich nanomaterial containing ink, with both working electrodes offering active sites for recognition of bioanalytes. The low-cost bi-potentiostat system (∼$80) was developed and customized specifically to the bi-electrode design and used for rapid, repeatable, and accurate measurement of electrochemical impedance spectroscopy signals from the dual biosensor. This binary electrochemical data acquisition (Bi-ECDAQ) system accurately and selectively detected SARS-CoV-2 Nucleocapsid protein (N-protein) in both spiked samples and clinical nasopharyngeal swab samples of COVID-19 patients within 30 min. The two working electrodes offered the limit of detection of 116 fg/mL and 150 fg/mL, respectively, with the dynamic detection range of 1-10,000 pg/mL and the sensitivity range of 2744-2936 Ω mL/pg.mm2 for the detection of N-protein. The potentiostat performed comparable or better than commercial Autolab potentiostats while it is significantly lower cost. The open-source Bi-ECDAQ presents a customizable and flexible approach towards addressing the need for rapid and accurate point-of-care electrochemical biosensors for the rapid detection of various diseases.

[Characteristics of soil seed bank and their correlations with soil factors in the early restoration period of Populus deltoides cutting slash in Lake South Dongting, China.] / å—æ´žåº­æ¹–æ¨æ ‘æ¸ ç†è¿¹åœ°æ¢å¤åˆæœŸåœŸå£¤ç§å­åº“ç‰¹å¾åŠå ¶ä¸ŽåœŸå£¤å› å­çš„å ³ç³».

To understand the potential role of soil seed bank in natural vegetation restoration of Populus deltoides cutting slash in Lake Dongting, the structure and diversity of soil seed bank and its relationship with vegetation and soil parameters were observed and analyzed on the lake beach in the first two years after P. deltoides cutting, with P. deltoides lake beach as control (CK). A total of 65 plant species germinated in soil seed bank, belonging to 59 genera and 23 families. The density of soil seed bank and number of species ranked as 1-year cutting slash (11810 seeds·m-2, 49 species)> 2-year cutting slash (9686 seeds·m-2, 44 species)> CK (6735 seeds·m-2, 29 species). Compared with CK, species diversity of the perennial mesophytes and hygrophytes in the soil seed bank and aboveground vegetation of cutting slash, as well as the similarity coefficient between soil seed bank and aboveground vegetation, increased. Soil water content and nutrient content increased, while the pH decreased. Soil water content and organic matter were closely related to the distribution of hydrophytes such as Polygonum hydropiper, while total potassium and phosphorus contents had a greater influence on the distribution of perennial species such as Phalaris arundinacea. In summary, during the natural restoration of P. deltoides cutting slash in Lake Dongting, with the changes of soil physicochemical properties, species richness and density of soil seed bank increased significantly, and the diversity of aboveground vegetation species therefore increased. Soil seed bank is an important propagule source for the restoration of wetland vegetation in cutting slash.

SalmoFresh™ effectiveness in controlling Salmonella on romaine lettuce, mung bean sprouts and seeds.

The purpose of this study was to determine the effectiveness of a commercial Salmonella bacteriophage mixture (SalmoFresh™ 6-phage strains) and to compare its effectiveness with a chlorinated water treatment to reduce Salmonella on produce and seeds at different temperatures and storage times. Two sets of experiments were designed to test phage and chlorinated water effectiveness on produce at 2, 10 and 25 °C at different storage times (1, 24, 48 and 72 h). First, SalmoFresh™ was applied to the surface of lettuce, mung bean sprouts and mung bean seeds that were spot-inoculated with a five Salmonella strain mixture (Newport, Braenderup, Typhimurium, Kentucky, and Heidelberg, 105 CFU/mL) by spraying phages onto lettuce (n = 48 pieces, 3×3 cm2 per treatment) and sprouts (n = 48 pieces per treatment). A second set of experiments (scaled-up) consisted in the application of phages by immersion to Salmonella adulterated lettuce (600 g), 300 g sprouts (300 g) or mung bean seeds (30 g) in a phage cocktail (108 PFU/mL) for 15 min (lettuce and sprouts) or 1 h (seeds). Another group of samples was washed with chlorinated water and yet another group was treated with a combination of chlorinated water followed by phage cocktail. Each experiment was repeated three times by quadruplicates. After the treatments for spot-inoculated and scaled-up experiments, lettuce and sprouts were separated into different lots (10 g/lot) and stored at 2, 10 and 25 °C; Salmonella was enumerated after 1, 24, 48 and 72 h. Adulterated phage-treated seeds were packaged and stored dry at 25 °C. Salmonella was enumerated after 72 h of storage. Groups of phage treated mung bean seeds (720 g) were germinated, and the reduction in Salmonella determined. Results of microplate virulence assays indicated that SalmoFresh™ reduced (P = 0.007) Salmonella by an average of 5.34 logs CFU/mL after 5 h at 25 °C. Spraying SalmoFresh™ onto lettuce and sprouts reduced Salmonella by 0.76 and 0.83 log10 CFU/g, respectively (P < 0.01). Immersion of produce in a phage solution was better at killing Salmonella P < 0.05) than spraying it onto the surface, reducing Salmonella by 2.43 and 2.16 log10 CFU/g on lettuce and sprouts, respectively. SalmoFresh™ was an effective biocontrol intervention to reduce Salmonella on lettuce and sprouts. On seeds, although a reduction was observed, Salmonella was able to grow exponentially during germination; therefore, the phage cocktail was not effective on mung bean seeds or sprouts obtained from adulterated seeds. The combination of hurdles, chlorination fallowed by the phage cocktail was the most effective treatment to reduce Salmonella on lettuce and sprouts.

The improvement of M1 polarization in macrophages by glycopeptide derived from Ganoderma lucidum.

Ganoderma lucidum (Fr.) Karst (Ganodermataceae) is a medicinal mushroom that has been extensively used in China for centuries to promote longevity and improve vigor without significant adverse effects. There is continuous interest in the bioactive properties of G. lucidum in view of its newly developed popularity in other regions besides Asia, such as Europe. Glycopeptide derived from G. lucidum (Gl-PS) is one of the main effective components isolated from this mushroom. The Gl-PS has been demonstrated pleiotropic with many bioactivities including immunomodulatory and antitumor effects. Macrophages are important cells involved in innate and adaptive immunity. Classically activated macrophages (M1) and alternatively activated macrophages (M2), with their different roles, display distinct cytokine profiles: M1 preferentially produces TNF-α, IL-6, and IL-12; conversely, M2 generates more IL-10 and arginase. Gl-PS might have the potential to promote macrophage M1 polarization by lipopolysaccharide (LPS). In this study, LPS was used to induce the M1 polarization. It was shown that the level of the TNF-α, IL-6, and IL-12 were increased and the IL-10 and arginase I were decreased in the polarized M1 macrophages after application of Gl-PS compared to the control. The results indicated the potential of Gl-PS to promote M1 polarization vs M2, with the health beneficial understanding of the bioactivities of Gl-PS.

Cytokine production suppression by culture supernatant of B16F10 cells and amelioration by Ganoderma lucidum polysaccharides in activated lymphocytes.

Some cytokines, such as interleukin-2 (IL-2), interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α), produced by lymphocytes might play an important role in anti-tumor immunity and their production is possibly suppressed by cancer. Amelioration of the suppression of cytokine production might contribute to cancer control. Ganoderma lucidum polysaccharides (Gl-PS), a versatile group of a component of G. lucidum and one with various bioactivities, might have this potential. In this study, analyses including reverse transcription and the polymerase chain reaction (RT-PCR), immunocytochemistry and Western blot were used to test the effects of Gl-PS on the production of IL-2, IFN-γ and TNF-α in mononuclear lymphocytes by incubating Gl-PS with mouse splenic mononuclear lymphocytes in the presence of B16F10 cell culture supernatant following activation by phytohemagglutinin. The RT-PCR, immunocytochemistry and Western blot assays showed that the production of IL-2, IFN-γ and TNF-α in mononuclear lymphocytes was suppressed by B16F10 cell culture supernatant at both the mRNA and protein levels, whereas the suppression was fully or partially ameliorated by Gl-PS. The amelioration by Gl-PS against the suppression of the production of IL-2, IFN-γ and TNF-α in mononuclear lymphocytes by B16F10 cell culture supernatant might contribute to cancer control.

Effects of the polysaccharide nucleic acid fraction of bacillus Calmette-Guérin on the production of interleukin-2 and interleukin-10 in the peripheral blood lymphocytes of patients with chronic idiopathic urticaria.

Urticaria is one of the most frequent dermatoses and its prevalence in the general population is estimated to be ~20%, whereas a substantial percentage of the cases may be classified as chronic idiopathic urticaria (CIU). The inflammatory response presenting with spontaneous wheals exhibits pro-inflammatory characteristics, involving a prominent role for lymphocytes with a mixed Th1/Th2 response in which interleukin (IL)-2 and IL-10 are prominently secreted by Th1 and Th2 cells, respectively. In CIU patients, it was demonstrated that IL-10 production was elevated and IL-2 reduced compared to controls. Therefore, inhibition of IL-10 and promotion of IL-2 production by the lymphocytes, indicating Th2 inhibition and Th1 promotion, may facilitate the treatment of CIU. Whether the polysaccharide nucleic acid fraction of bacillus Calmette-Guérin (BCG-PSN), which possesses multiple immunomodulatory properties, has that potential, remains to be elucidated. In this study, BCG-PSN was used on lymphocytes isolated from CIU patients, with healthy donors used as controls. Immunocytochemistry and ELISA were used to detect IL-2 and IL-10 production. It was demonstrated that the IL-2 production by the lymphocytes in the CIU group was significantly lower compared to that in the healthy control group and it increased sequentially with the increase of the concentration of BCG-PSN used. By contrast, the IL-10 production by the lymphocytes in the CIU group was significantly higher compared to that in the healthy control group and decreased sequentially with the increase of the concentration of BCG-PSN used. Thus, it may be concluded that the BCG-PSN has the potential to promote IL-2 and inhibit IL-10 production in the lymphocytes of CIU patients, facilitating the treatment of CIU.