Effects of BBIBP-CorV vaccine on gut microbiota and short-chain fatty acids in mice exposed to bis (2-ethylhexyl) phthalate and dioctyl terephthalate.

As the COVID-19 pandemic has progressed, increasing evidences suggest that the gut microbiota may play a crucial role in the effectiveness of SARS-CoV-2 vaccine. Thus, this study was aimed at investigating the influence of SARS-CoV-2 vaccine on the gut microbiota and short-chain fatty acids (SCFAs) of organisms exposed to environmental contaminants, i.e., plasticizers: phthalate esters. We found that in mice, exposure to dioctyl terephthalate (DOTP) and bis -2-ethylhexyl phthalate (DEHP) decreased the blood glucose level and white fat weight, induced inflammatory responses, caused damage to liver and intestinal tissues, and disrupted the gut microbiota composition and SCFAs metabolism. Specifically, the Bacteroidetes phylum was positively correlated with BBIBP-CorV vaccine, while acetic acid was negatively associated with the vaccine. Interestingly, the BBIBP-CorV vaccine somewhat alleviated tissue inflammation and reduced the contents of acetic acid and propionic acid in mice exposed to DEHP and DOTP. These findings were confirmed by a fecal microbiota transplantation assay. Overall, this study revealed that exposure to DEHP and DOTP adversely affects the gut microbiota and SCFAs, while the BBIBP-CorV vaccine can protect mice against these effects. This work highlighted the relationship between BBIBP-CorV vaccination, gut microbiome composition, and responses to plasticizers, which may facilitate the development and risk assessment of SARS-CoV-2 vaccines and environmental contaminants on microbiota health.

Sequence-encoded quantitative invader assay enables highly sensitive hepatitis B virus DNA quantification in a single tube without the use of a calibration curve.

Accurately quantifying hepatitis B virus DNA (HBV-DNA) in serum is important in dynamic monitoring and prognosis evaluation for patients with hepatitis B. Routine assays based on real-time polymerase chain reaction (qPCR) for HBV-DNA quantification usually require laborious calibration curves and may bring bias from the biological samples. To enable absolute quantification of HBV-DNA in a single tube, we described a modification of the conventional Q-Invader assay by separately encoding targeted DNA and artificially designed internal quantitative-standard DNA (QS-DNA) at the flaps of the corresponding downstream probes. Quantification of targeted HBV-DNA was readily achieved by the difference in the quantification cycle value (Ct) between itself and QS-DNA. Furthermore, spiked-in QS-DNA before DNA extraction allowed errors caused by DNA extraction to be corrected. Two different gene regions covering eight genotypes were encoded with the same flap to avoid false-negative results. The method demonstrates a high sensitivity, which enables accurate detection of as low as 2 copies of the HBV-DNA plasmid or 20 IU mL-1 HBV-DNA in serum in a single tube. Successful quantification of 50 clinical samples indicates that our method is cost-effective, labor-saving and reproducible, and promising for the ultra-sensitive quantification analysis of many types of pathogens other than HBV.