Comparative analysis of human respiratory syncytial virus evolutionary patterns during the COVID-19 pandemic and pre-pandemic periods.

The COVID-19 pandemic has resulted in the implementation of strict mitigation measures that have impacted the transmission dynamics of human respiratory syncytial virus (HRSV). The measures also have the potential to influence the evolutionary patterns of the virus. In this study, we conducted a comprehensive analysis comparing genomic variations and evolving characteristics of its neutralizing antigens, specifically F and G proteins, before and during the COVID-19 pandemic. Our findings showed that both HRSV A and B exhibited an overall chronological evolutionary pattern. For the sequences obtained during the pandemic period (2019-2022), we observed that the HRSV A distributed in A23 genotype, but formed into three subclusters; whereas the HRSV B sequences were relatively concentrated within genotype B6. Additionally, multiple positively selected sites were detected on F and G proteins but none were located at neutralizing antigenic sites of the F protein. Notably, amino acids within antigenic site III, IV, and V of F protein remained strictly conserved, while some substitutions occurred over time on antigenic site Ø, I, II and VIII; substitution S389P on antigenic site I of HRSV B occurred during the pandemic period with nearly 50% frequency. However, further analysis revealed no substitutions have altered the structural conformations of the antigenic sites, the vial antigenicity has not been changed. We inferred that the intensive public health interventions during the COVID-19 pandemic did not affect the evolutionary mode of HRSV.

Dewatering of sewage sludge via thermal hydrolysis with ammonia-treated Fenton iron sludge as skeleton material.

In this study, the alkaline hydrothermal ferric carbon (AHFC), which was prepared by hydrothermal liquefaction method using Fenton iron sludge with NH3·H2O, was used as a skeleton materials for the dewatering of sewage sludge (SS) via thermal hydrolysis. NH2 functional group presented in the AHFC and nano-sized γ-Fe2O3 was anchored on the surface of AHFC. The NH2 functional group notably promoted thermal hydrolysis of SS from the increasing of TOC and TN value. γ-Fe2O3 showed adsorption effect to the water, resulting in decline of the dewatering rate of SS in present condition. When 100% of AHFC was added, dewatering rate of SS was decreased by 19.93% (at 160 °C), 4.50% (at 180 °C) and 8.34% (at 200 °C) respectively. 3D-EEM results showed that the degree of hydrolysis was deepened when AHFC was added for the intensity of soluble microbial products decline. AHFC promoted the decomposition of protein to form heterocycle compounds in the resulting cake according to in situ FTIR results. The nano γ-Fe2O3 catalysis to cake also can be observed for the activation energy was lower than blank in the range of 40˜60%. The study demonstrated concept and the effectiveness the reuse/recycle of the Fenton iron sludge for dewatering of SS.

Dynamics of antibiotic resistance genes in microbial fuel cell-coupled constructed wetlands treating antibiotic-polluted water.

Microbial fuel cell-coupled constructed wetlands (CW-MFCs) use electrochemical, biological, and ecological functions to treat wastewater. However, few studies have investigated the risks of antibiotic resistance genes (ARGs) when using such systems to remove antibiotics. Therefore, three CW-MFCs were designed to assess the dynamics of ARGs in filler biofilm and effluent over 5000 h of operation. The experimental results indicated that relatively high steady voltages of 605.8 mV, 613.7 mV, and 541.4 mV were obtained at total influent antibiotic concentrations of 400, 1,000, and 1600 µg L-1, respectively. The 16S rRNA gene level in the cathode layer was higher than those in the anode and two middle layers, but the opposite trend was observed for the sul and tet genes. The relative abundance of the three tested sul genes were in the order sulI > sulII > sulIII, and those of the five tet genes were in the order tetA > tetC > tetW > tetO > tetQ. The levels of sul and tet genes in the media biofilm showed an increase over the treatment period. The effluent water had relatively low abundances of sul and tet genes compared with the filler biofilm. No increases were observed for most ARGs over the treatment period, and no significant correlations were observed between the ARGs and 16S rRNA gene copy numbers, except for sulI and tetW in the effluent. However, significant correlations were observed among most of the ARG copy numbers.