The present study tracked the city-wide dynamics of severe acute respiratory syndrome-corona virus 2 ribonucleic acids (SARS-CoV-2 RNA) in the wastewater from nine different wastewater treatment plants (WWTPs) in Jaipur during the second wave of COVID-19 out-break in India. A total of 164 samples were collected weekly between February 19th and June 8th, 2021. SARS-CoV-2 was detected in 47.2% (52/110) influent samples and 37% (20/54) effluent samples. The increasing percentage of positive influent samples correlated with the city’s increasing active clinical cases during the second wave of COVID-19 in Jaipur. Furthermore, wastewater-based epidemiology (WBE) evidence clearly showed early detection of about 20 days (9/9 samples reported positive on April 20th, 2021) before the maximum cases and maximum deaths reported in the city on May 8th, 2021. The present study further observed the presence of SARS-CoV-2 RNA in treated effluents at the time window of maximum active cases in the city even after tertiary disinfection treatments of ultraviolet (UV) and chlorine (Cl 2 ) disinfection. The average genome concentration in the effluents and removal efficacy of six commonly used treatments, activated sludge process + chlorine disinfection (ASP + Cl 2 ), moving bed biofilm reactor (MBBR) with ultraviolet radiations disinfection (MBBR + UV), MBBR + chlorine (Cl 2 ), sequencing batch reactor (SBR), and SBR + Cl 2 , were compared with removal efficacy of SBR + Cl 2 (81.2%) > MBBR + UV (68.8%) > SBR (57.1%) > ASP (50%) > MBBR + Cl 2 (36.4%). The study observed the trends and prevalence of four genes (E, RdRp, N, and ORF1ab gene) based on two different kits and found that prevalence of N > ORF1ab > RdRp > E gene suggested that the effective genome concentration should be calculated based on the presence/absence of multiple genes. Hence, it is imperative to say that using a combination of different detection genes (E, N, RdRp, & ORF1ab genes) increases the sensitivity in WBE. Graphical abstract

Development of fusion chimeras as potential vaccine candidates is considered as an attractive strategy to generate effective immune responses to more than one antigen using a single construct. Here, we described the design, production, purification and antigenicity of a fusion chimera (PfAMSP-Fu35), comprised of immunologically relevant regions of three vaccine target malaria antigens, PfAARP, PfMSP-3 and PfMSP-1. The recombinant PfAMSP-Fu35 is expressed as a soluble protein and purified to homogeneity with ease at a yield of ~ 7 mg L-1. Conformational integrity of the C-terminal fragment of PfMSP-1, PfMSP-119 was retained in the fusion chimera as shown by ELISA with conformation sensitive monoclonal antibodies. High titre antibodies were raised to the fusion protein and to all the three individual components in mice and rabbits upon immunization with fusion chimera in two different adjuvant formulations. The sera against PfAMSP-Fu35 recognized native parasite proteins corresponding to the three components of the fusion chimera. As shown by invasion inhibition assay and antibody mediated cellular inhibition assay, antibodies purified from the PfAMSP-Fu35 immunized serum successfully and efficiently inhibited parasite invasion in P. falciparum 3D7 in vitro both directly and in monocyte dependent manner. However, the invasion inhibitory activity of anti-AMSP-Fu35 antibody is not significantly enhanced as expected as compared to a previously described two component fusion chimera, MSP-Fu24. Therefore, it may not be of much merit to consider AMSP-Fu35 as a vaccine candidate for preclinical development.

BackgroundImmunological characterization of potential blood-stage malaria antigens would be a valuable strategy in the development of an effective vaccine. Identifying B and CD4+ T cell epitopes will be important in understanding the nature of immune response. A previous study has shown that Plasmodium falciparum apical asparagine-rich protein (PfAARP) stimulates immune response and induces potent invasion-inhibitory antibodies. Antibodies to PfAARP provide synergistic effects in inhibition of parasite invasion when used in combination with antibodies to other antigens. In the present study, an attempt was made to identify B cell and CD4+ T cell epitopes of PfAARP.MethodsBalb/c mice were immunized with recombinant PfAARP and both cellular and humoral responses were analysed at various time points. Computerized databases [immune epitope database (IEDB) and B cell epitope prediction (BCEPred)] were used to predict epitope sequences within PfAARP and predicted peptides were synthesized. In addition, nine 18 amino acid, long-overlapping peptides spanning the entire length of PfAARP were synthesized. Using these peptides, B cell and CD4+ T cell responses in PfAARP immunized mice were measured by ELISA and ELISPOT assays.ResultsHere, it is demonstrated that immunization of mice with PfAARP induced long-lasting, high-titre antibodies (4 months post immunization). Also, the recombinant protein was effective in inducing a pronounced Th1 type of immune response quantified by IFN-γ ELISA and ELISPOT. It was found that the predicted peptides did not represent the immunogenic regions of PfAARP. However, of the nine overlapping peptides, three peptides (peptides 3, 5 and 7) were strongly recognized by PfAARP-immunized sera and represented B cell epitopes. Also, peptide 3 elicited IFN- γ response, suggesting it to be a T-cell epitope.ConclusionsInduction of long-lasting humoral and cellular response on PfAARP immunization in mice underscores its possible use as a blood-stage malaria vaccine candidate. Mapping of immunogenic regions may help in designing fusion chimera containing immunologically relevant regions of other vaccine target antigens and/or for multi-component vaccine candidates.

The present study tracked the city-wide dynamics of severe acute respiratory syndrome-corona virus 2 (SARS-CoV-2) RNA in the wastewater from nine different wastewater treatment plants (WWTPs) in Jaipur during second wave of COVID-19 out-break in India. A total of 164 samples were collected weekly between February 19th and June 8th, 2021. SARS-CoV-2 was detected in 47.2% (52/110) influent samples and 37% (20/54) effluent samples. The increasing percentage of positive influent samples correlated with the city’s increasing active clinical cases during the second wave of COVID-19 in Jaipur. Furthermore, WBE based evidence clearly showed early detection of about 20 days (9/9 samples reported positive on April 20th, 2021) prior to the maximum cases & maximum deaths reported in the city on May 8th, 2021. The present study further observed the presence of SARS-CoV-2 RNA in treated effluents at the time window of maximum active cases in the city even after tertiary disinfection treatments of UV & Chlorine. The average genome concentration in the effluents and removal efficacy of six commonly used treatments; Activated Sludge Treatment + Chlorine disinfection (ASP + Cl2), Moving Bed Biofilm Reactor (MBBR) with Ultraviolet radiations disinfection (MBBR + UV), MBBR + Chlorine (Cl2), Sequencing Batch Reactor (SBR) and SBR + Cl2 were compared with removal efficacy of SBR + Cl2 (81.2%)> MBBR + UV (68.8%) > SBR (57.1%) > ASP (50%) > MBBR + Cl2(36.4%). The study observed the trends & prevalence of four genes (E, RdRp, N, and ORF1ab gene) based on two different kits and found that prevalence of N> ORF1ab >RdRp> E gene, suggested that the effective genome concentration should be calculated based on the presence/absence of multiple genes. Hence, it is imperative to say that using a combination of different detection genes (E, N, RdRp & ORF1ab genes) reduce false positives in WBE.Graphical AbstractHighlightsSuccessful application of WBE with prediction of 14-20 days for COVID-19 in JaipurA comparison of SARS-CoV-2 RNA removal efficacy of 9 WWTPs was investigatedSBR showed better performance than MBBR with SARS-CoV-2 RNA removal from wastewaterPresence of SARS-CoV-2 in effluents even after UV and Chlorine disinfectionUsing a combination of different detection genes reduce false positives in WBE

No abstract

No abstract