SARS-CoV-2 Variants Detection Strategies in Wastewater Samples Collected in the Bangkok Metropolitan Region.

Wastewater surveillance is considered a promising approach for COVID-19 surveillance in communities. In this study, we collected wastewater samples between November 2020 and February 2022 from twenty-three sites in the Bangkok Metropolitan Region to detect the presence of SARS-CoV-2 and its variants for comparison to standard clinical sampling. A total of 215 wastewater samples were collected and tested for SARS-CoV-2 RNA by real-time PCR with three targeted genes (N, E, and ORF1ab); 102 samples were positive (42.5%). The SARS-CoV-2 variants were determined by a multiplex PCR MassARRAY assay to distinguish four SARS-CoV-2 variants, including Alpha, Beta, Delta, and Omicron. Multiple variants of Alpha-Delta and Delta-Omicron were detected in the wastewater samples in July 2021 and January 2022, respectively. These wastewater variant results mirrored the country data from clinical specimens deposited in GISAID. Our results demonstrated that wastewater surveillance using multiple signature mutation sites for SARS-CoV-2 variant detection is an appropriate strategy to monitor the presence of SARS-CoV-2 variants in the community at a low cost and with rapid turn-around time. However, it is essential to note that sequencing surveillance of wastewater samples should be considered complementary to whole genome sequencing of clinical samples to detect novel variants.

Quercetin enhances and modulates the fungal killing efficacy of chicken heterophils through immunological recognition, effector functions, and resolution.

Herbal compound, quercetin, has previously been shown its modulatory effects on mammalian neutrophils and avian counterpart. However, at this instance it is not clear how quercetin promotes its effects on fungal and yeast killing in chicken heterophils. In the present study, we have proved that quercetin exerts the significant modulatory effects against pathogenic yeast (Candida albicans) in freshly isolated heterophils from Thai native broiler chicken. This substance is shown to facilitate heterophil effector functions through the reduction of ROS generation, and promotion of phagocytosis and candidacidal killing. The quercetin effects on zymosan recognition and migration of cells toward zymosan are subtle, but insignificant differed from control, whereas cell migration towards live Candida is markedly differed. We also find the abundant release of heterophil extracellular traps (HETs) from quercetin-primed cells. From a gene expression standpoint, cells received quercetin display the up-regulation of fungal recognition and migratory genes. The quercetin shows anti-inflammatory function by suppression of pro-inflammatory cytokine genes as well as most of ROS-related genes. Collectively, our findings highlight and provide clues for a promising utilization of quercetin in chicken innate immunity to further combat the fungal infections.