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Houttuynia cordata is an herbal plant rich in polysaccharides and with several pharmacological activities. Human noroviruses (HuNoVs) are the most common cause of foodborne viral gastroenteritis throughout the world. In this study, H. cordata polysaccharide (HP), with a molecular weight of ~43 kDa, was purified from H. cordata water extract (HWE). The polysaccharide HP was composed predominantly of galacturonic acid, galactose, glucose, and xylose in a molar ratio of 1.56:1.49:1.26:1.11. Methylation and NMR analyses revealed that HP was a pectin-like acidic polysaccharide mainly consisting of α-1,4-linked GalpA, β-1,4-linked Galp, β-1,4-linked Glcp, and β-1,4-linked Xylp residues. To evaluate the antiviral activity of H. cordata extracts, we compared the anti-norovirus potential of HP with HWE and ethanol extract (HEE) from H. cordata by plaque assay (plaque forming units (PFU)/mL) for murine norovirus-1 (MNV-1), a surrogate of HuNoVs. Viruses at high (8.09 log10 PFU/mL) or low (4.38 log10 PFU/mL) counts were mixed with 100, 250, and 500 μg/mL of HP, HWE or HEE and incubated for 30 min at room temperature. H. cordata polysaccharide (HP) was more effective than HEE in reducing MNV-1 plaque formation, but less effective than HWE. When MNV-1 was treated with 500 μg/mL HP, the infectivity of MNV-1 decreased to an undetectable level. The selectivity indexes of each sample were 1.95 for HEE, 5.74 for HP, and 16.14 for HWE. The results of decimal reduction time and transmission electron microscopic revealed that HP has anti-viral effects by deforming and inflating virus particles, thereby inhibiting the penetration of viruses in target cells. These findings suggest that HP might have potential as an antiviral agent in the treatment of viral diseases.

Background: Due to the widespread use of broad-spectrum antibiotics, the problem of antibiotic resistance has become an increasingly serious global threat. One of the key mechanisms of Escherichia coli resistance to beta-lactam antibiotics is the production of beta-lactamase enzymes, which poses a dilemma for clinicians in selecting antibiotics when faced with resistant bacterial infections. However, research on the reversal of bacterial resistance is limited. Methods: This study involved the preparation of Iris tectorum extract and detection of its effects on antibiotics sensitivity, extended-spectrum beta-lactamase (ESBL) gene expression, and histidine kinase phosphorylation levels in β-lactam antibiotic-resistant Escherichia coli. Additionally, analyses of the active ingredients of Iris tectorum extract were conducted with a liquid chromatography–mass spectrometer, and the binding sites were predicted by molecular docking. Results: Iris tectorum extract could restore the sensitivity of Escherichia coli to beta-lactam antibiotics and reduce the expression levels of ESBL genes and histidine phosphorylation levels. The active ingredients of Iris tectorum extract may be irigenin and tectorigenin, and these two small molecules could bind to histidine kinase to inhibit phosphorylation. Conclusions: Iris tectorum extract may serve as an antibiotic adjuvant, restoring the sensitivity of antibiotic-resistant bacteria by inhibiting histidine kinase phosphorylation, thereby alleviating the problem of Escherichia coli resistance to β-lactam antibiotics.

ABSTRACT Bacteria, especially pathogenic bacteria, were detected in order to estimate the safety of drinking water distribution systems (DWDSs). Sixteen biofilms and 12 water samples (six retained and six flowing) were collected from a city DWDS in eastern China. Biofilms were observed using scanning electron microscopy. Cultivable bacteria of biofilms were counted by heterotrophic plate counts, ranging from 3.61 × 101 to 1.67 × 106 CFU·cm−2. Coliforms, Salmonella, Shigella, Vibrio and Legionella were separated by Eosin-Methylene Blue (EMB) agar, Salmonella chromogenic medium, Shigella chromogenic medium, Thiosulfate Citrate Bile Salts Sucrose (TCBS) agar and Buffered Charcoal Yeast Extract (BCYE) agar and 13/16, 8/16, 7/16, 6/16, 0/16 biofilm samples were found to be positive, respectively. Retained and flowing water samples were collected to estimate the influence of hydrodynamic conditions on biofilm detachment. All six retained water samples were positive for bacteria, the count ranged from 1.2 × 103 to 2.8 × 104 CFU·mL−1 and 2/6, 3/6, 2/6, 0/6, 0/6 samples were positive for coliforms, Salmonella, Shigella, Legionella and Vibrio, respectively. While only three of six flowing water samples were bacteria positive, the counts ranged from 102 to 103 CFU·mL−1, 2/6 were coliform positive and no pathogens were detected under testing. The results show that there are pathogens in DWDS biofilms, which can cause health-related problems if detached from their surfaces. In this study, 16 biofilms and 12 water samples from metropolitan drinking water distribution systems were collected and screened for pathogenic bacteria in order to estimate the hygiene and safety of drinking water distribution systems.

Background Transmitted drug resistance (TDR) is becoming an obstacle to the success of antiretroviral therapy (ART) as the HIV epidemic continues to spread. This study aimed to investigate the characteristics of TDR and the molecular epidemiology of ART-naive HIV-1 infections in Lishui. Methods A total of 481 plasma samples were collected from ART-naive HIV-1 infections in Lishui between 2020 and 2023. The sequences acquired from infections were used to analyze the characteristics of genotype, TDR, and molecular transmission network. Results This study discovered that the three most prevalent subtypes among the 455 sequences successfully obtained from infections in Lishui were CRF08_BC (35.8%), CRF07_BC (26.4%), and CRF01_AE (25.9%). The overall prevalence of TDR was 12.1%, and the K103N (2.4%) was the most frequent mutation. Multivariate analysis showed that CRF08_BC (OR = 5.401, P  < 0.001) and CD4 + cell concentration of 200–499 cells/µL (OR = 1.684, P  = 0.030) were associated with a higher risk of entering the molecular transmission network and clustering, whereas the current address in other cities (OR = 0.328, P  = 0.004), junior middle school (OR = 0.472, P  = 0.006), and junior college or above (OR = 0.387, P  = 0.045) were associated with a lower risk of clustering. Conclusions This study revealed that the prevalence of TDR was at an intermediate level of drug resistance, and high levels of resistance were predominantly concentrated in efavirenz (EFV) and nevirapine (NVP) among the NNRTIs. Middle-aged and older infections represented a significant proportion of the molecular transmission network. This suggests that HIV surveillance and targeted prevention and treatment interventions are essential to reduce the risk of HIV transmission.

Background The widespread selective pressure of antibiotics in the environment has led to the propagation of antibiotic resistance genes (ARGs). However, the mechanisms by which microbes balance population growth with the enrichment of ARGs remain poorly understood. To address this, we employed microcosm cultivation at different antibiotic (i.e., Oxytetracycline, OTC) stresses across the concentrations from the environmental to the clinical. Paired with shot-gun metagenomics analysis and quantification of bacterial growth, trait-based assessment of soil microbiota was applied to reveal the association between key ARG subtypes, representative bacterial taxa, and functional-gene features that drive the growth of ARGs. Results Our results illuminate that resistome variation is closely associated with bacterial growth. A non-monotonic change in ARG abundance and richness was observed over a concentration gradient from none to 10 mg/l. Soil microbiota exposed to intermediate OTC concentrations (i.e., 0.1 and 0.5 mg/l) showed greater increases in the total abundance of ARGs. Community compositionally, the growth of representative taxa, i.e., Pseudomonadaceae was considered to boost the increase of ARGs. It has chromosomally carried kinds of multidrug resistance genes such as mexAB - oprM and mexCD-oprJ could mediate the intrinsic resistance to OTC. Streptomycetaceae has shown a better adaptive ability than other microbes at the clinical OTC concentrations. However, it contributed less to the ARGs growth as it represents a stress-tolerant lifestyle that grows slowly and carries fewer ARGs. In terms of community genetic features, the community aggregated traits analysis further indicates the enhancement in traits of resource acquisition and growth yield is driving the increase of ARGs abundance. Moreover, optimizations in energy production and conversion, alongside a streamlining of bypass metabolic pathways, further boost the growth of ARGs in sub-inhibitory antibiotic conditions. Conclusion The results of this study suggest that microbes with competitive lifestyles are selected under the stress of environmental sub-inhibitory concentrations of antibiotics and nutrient scarcity. They possess greater substrate utilization capacity and carry more ARGs, due to this they were faster growing and leading to a greater increase in the abundance of ARGs. This study has expanded the application of trait-based assessments in understanding the ecology of ARGs propagation. And the finding illustrated changes in soil resistome are accompanied by the lifestyle switching of the microbiome, which theoretically supports the ARGs control approach based on the principle of species competitive exclusion. 4ZqjNsN9dRS1iWJDwru5hL Video Abstract

The management of biosafety laboratories for pathogenic microorganisms is directly related to public health and the effectiveness of biological experiments. However, persistent non-compliance issues in biosafety level 2 (BSL-2) laboratory management remain a challenge. This study aimed to assess the quality control of BSL-2 laboratories for pathogenic microorganisms in Lishui. By combining the Biosafety Online Supervision Systems and on-site inspections, this study assessed the quality control of 73 medical institutions and the 128 biosafety laboratories under their management in Lishui. The results discovered that the 73 medical institutions had low compliance rates in several fields: Responsibilities of the biosafety management (80.82%), development of system documentation (65.75%), risk assessment (84.56%), training of laboratory personnel (82.19%), and biosafety labeling (52.05%). Additionally, 128 laboratories had low pass rates for the access control management system (85.94%), hand/eye wash and shower stations (85.94%), and biosafety cabinet operations (89.06%). This study demonstrates that future efforts should focus on strengthening laboratory personnel training and implementing biosafety management responsibilities to ensure safe and regulation-compliant operations in laboratories handling pathogenic microorganisms.

Noroviruses (NoVs) are the main cause of acute gastroenteritis in all ages worldwide. The aim of this study was to produce the recombinant P protein of norovirus and to demonstrate its blocking effect. In this study, the engineered strains were induced to express the P protein of NoVs GII.4, which was identified using SDS-PAGE and ELISA as having the capacity to bind to histo-blood group antigens (HBGAs). Rabbits were immunized to obtain neutralizing antibodies. ELISA and ISC-RT-qPCR were used to determine the blocking efficacy of the neutralizing antibody to human norovirus (HuNoV) and murine norovirus (MNV). The recombinant P protein (35 KD) was obtained, and the neutralizing antibody was successfully prepared. The neutralizing antibody could block the binding of the P protein and HuNoV to HBGAs. Neutralizing antibodies can also block MNV invasion into host cells RAW264.7. The recombinant P protein expressed in E. coli can induce antibodies to block HuNoV and MNV. The recombinant P protein of NoVs GII.4 has the value of vaccine development.

Foodborne diseases are currently the most critical food safety issue in the world. There are not many hazard identification and exposure assessments for foodborne viruses (Norovirus GI, GII, Hepatitis A Virus, Rotavirus, Adenovirus) in shellfish. Multiplex qPCR for the simultaneous detection of five foodborne viruses was established and used to assess infection risk based on a 1-year pathogenesis study. The sensitivity, specificity and reproducibility of the multiplex qPCR method are consistent with that of conventional qPCR, which saves more time and effort. Overall, 37.86% of shellfish samples had one or more foodborne viruses. Risk assessment formulae and matrices were used to develop risk assessments for different age groups, different seasons and different shellfish. The annual probability of contracting a foodborne virus infection from shellfish is greater than 1.6 × 10−1 for all populations, and even for infants aged 0–4 years, it is greater than 1.5 × 10−2, which is much higher than the risk thresholds recommended by WHO (10−6) and the US EPA (10−4). High risk (level IV) is associated with springtime, and medium risk (level III) is associated with Mussel consumption. This study provides a basis for the risk of foodborne viral infections in people of different ages, in different seasons, and by consuming different shellfish.

Background Influenza represents a serious public health concern. The emergence of resistance to anti-influenza drugs underlines the need to develop new drugs. This study aimed to evaluate the anti-influenza viral activity and possible mechanisms of 12 phenanthrenes from the medicinal plant Bletilla striata (Orchidaceae family). Methods Twelve phenanthrenes were isolated and identified from B. striata. Influenza virus A/Sydney/5/97 (H3N2) propagated in embryonated chicken eggs was used. Phenanthrenes mixed with the virus were incubated at 37 °C for 1 h and then inoculated into 9-day-old embryonated chicken eggs via the allantoic route to survey the antiviral activity in vivo. A (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) (MTS)-based assay was performed to evaluate the reduction of cytopathic effect induced by H3N2 on Madin-Darby canine kidney (MDCK) cells. The hemagglutination inhibition assay was used to study the blockage of virus receptors by the phenanthrenes, and the neuraminidase (NA) inhibition assay to evaluate the effects of the release of virus. The synthesis of influenza viral matrix protein mRNA in response to compound treatment was measured by real-time polymerase chain reaction. Results This study showed that phenanthrenes 1, 2, 3, 4, 6, 9, 10, 11, and 12 significantly inhibited the viruses in vivo, with inhibition rates of 20.7, 79.3, 17.2, 34.5, 34.5, 34.5, 44.8, 75.9, and 34.5%, respectively. In MDCK models, the phenanthrenes did not show significant antiviral activity when administered as pretreatment, while phenanthrenes 2, 3, 4, 6, 7 10, and 11 exhibited inhibitory activities as simultaneous treatment with 50% inhibition concentration (IC50) ranging from 14.6 ± 2.4 to 43.3 ± 5.3 μM. The IC50 ranged from 18.4 ± 3.1 to 42.3 ± 3.9 μM in the post-treatment assays. Compounds 1, 3, 4, 6, 10, and 11 exhibited an inhibitory effect on NA; and compounds 2, 3, 4 6, 7, 10, and 11 resulted in the reduced transcription of virus matrix protein mRNA. However, no compound could inhibit hemagglutination by the influenza virus. Conclusion Phenanthrenes from B. striata had strong anti-influenza viral activity in both embryonated eggs and MDCK models, and diphenanthrenes seemed to have stronger inhibition activity compared with monophenanthrenes.