We made the first and successful attempt to detect SARS-CoV-2 genetic material in the vicinity wastewaters of an isolation centre i.e. Shaheed Bhulu Stadium, situated at Noakhali. Owing to the fact that isolation centre, in general, always contained a constant number of 200 COVID-19 patients, the prime objective of the study was to check if several drains carrying RNA of coronavirus are actually getting diluted or accumulated along with the sewage network. Our finding suggested that while the temporal variation of the genetic load decreased in small drains over the span of 50 days, the main sewer exhibited accumulation of SARS-CoV-2 RNA. Other interesting finding displays that probably distance of sampling location in meters is not likely to have a significant impact on gene detection concentration, although the quantity of the RNA extracted in the downstream of the drain was higher. These findings are of immense value from the perspective of wastewater surveillance of COVID-19, as they largely imply that we do not need to monitor every wastewater system, and probably major drains monitoring may illustrate the city health. Perhaps, we are reporting the accumulation of SARS-CoV-2 genetic material along with the sewer network i.e. from primary to tertiary drains. The study sought further data collection in this line to simulate conditions prevailed in the most of developing countries and to shed further light on decay/accumulation processes of the genetic load of the SARS-COV-2.
BackgroundOur present study was conducted to characterize the phytoconstituents present in the aqueous extract of Momordica charantia and evaluate the antimicrobial efficacy of silver-extract nanoparticles (Ag-Extract-NPs).MethodsSilver nanoparticles (AgNPs) were prepared by reducing AgNO3; and NaBH4 served as reducing agent. After screening of phytochemicals; AgNPs and aqueous extract were mixed thoroughly and then coated by polyaniline. These NPs were characterized by using Visual inspection, UV spectroscopy, FTIR, SEM and TEM techniques. Antimicrobial activities were assessed against Staphylococcus aureus, Salmonella typhi, Escherichia coli and Pseudomonas aeruginosa.ResultsAqueous extract of M. charantia fruits contain alkaloid, phenol, saponin etc. UV–Vis spectrum showed strong absorption peak around 408 nm. The presence of –CH, −NH, −COOH etc. stretching in FTIR spectrum of Ag-Extract-NPs endorsed that AgNPs were successfully capped by bio-compounds. SEM and TEM result revealed that synthesized NPs had particle size 78.5–220 nm. Ag-Extract-NPs showed 34.6 ± 0.8 mm zone of inhibition against E. coli compared to 25.6 ± 0.5 mm for ciprofloxacin. Maximum zone of inhibition for Ag-Extract-NPs were 24.8 ± 0.7 mm, 26.4 ± 0.4 mm, 7.4 ± 0.4 mm for S. aureus, P. aeruginosa and S. typhi. We found that Ag-Extract-NPs have much better antibacterial efficacy than AgNPs and M. charantia extract has individually. It is also noticed that gram negative bacteria (except S. typhi) are more susceptible to Ag-Extract-NPs than gram positive bacteria.ConclusionAg-Extract-NPs showed strong antibacterial activity. In order to make a reliable stand for mankind, further study is needed to consider determining the actual biochemical pathway by which AgNPs-extracts exert their antimicrobial effect.Electronic supplementary materialThe online version of this article (doi:10.1186/s12906-017-1843-8) contains supplementary material, which is available to authorized users.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.