Evaluation and comparison of three virucidal agents on inactivation of Nipah virus.

Modern human activity is profoundly changing our relationship with microorganisms with the startling rise in the rate of emerging infectious diseases. Nipah virus together with Ebola virus and SARS-CoV-2 are prominent examples. Since COVID-19 and the West African Ebola virus disease outbreak, different chemical disinfectants have been developed for preventing the direct spread of viruses and their efficacy has also been evaluated. However, there are currently no published efficacy studies for the chemical disinfection of Nipah virus. In this study, the virucidal efficacy of three disinfectants (Micro-Chem Plus detergent disinfectant cleaner, FWD and Medical EtOH) against Nipah virus was evaluated in quantitative suspension tests including. Our results showed that the > 4 log reduction achieved for all products in inactivating Nipah virus in 15 s. Even, 19% ethanol was able to inactivate Nipah virus when applied for at least 8 min contact time. Comparative analysis displayed virucidal efficacy of each of the evaluated disinfectants against SARS-CoV-2, Ebola virus and Nipah virus, with only minor differences in working concentrations and contact times required for complete inactivation. We expect that our study can assist in decontamination in healthcare settings and high level biosafety laboratories and can be beneficial to control for emerging enveloped viruses.

Evaluating the virucidal activity of four disinfectants against SARS-CoV-2.

BACKGROUND: The recent COVID-19 pandemic highlights the need for efficacious virucidal products to limit the spread of SARS-CoV-2. Several studies have suggested that alcohol-based sanitizers and some disinfectants are effective. While virucidal activity data of low-level disinfectants are lacking and some conclusions are not clear yet. METHODS: We evaluated the virucidal activity of 2 quaternary ammonium compounds (QAC) disinfectants (MICRO-CHEM PLUS and FWD), W30 (an amphoteric surfactant), and Medical EtOH against SARS-CoV-2. Suspension tests covering different concentration and contact time were performed using the integrated cell culture-qPCR method. RESULTS: Each of disinfectants was effective at inactivating SARS-CoV-2. MCP and FWD are highly effective within 15 seconds. W30 is also efficient within 2 minutes at concentration of 1%. Consistent with previous report, our results also demonstrated that 38% ethanol was sufficient to completely inactivate virus, which proved the method used in this study is feasible. CONCLUSIONS AND DISCUSSION: QAC disinfectants, MCP and FWD, are highly effective for the inactivation of SARS-CoV-2, which making them practical for use in health care setting and laboratories where prompt disinfection is important. The low-level disinfectant based on amphoteric surfactant, W30, which may present in commonly available household hygiene agents is also able to inactivate SARS-CoV-2.

A human antibody of potent efficacy against SARS-CoV-2 in rhesus macaques showed strong blocking activity to B.1.351.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), which causes coronavirus disease-2019 (COVID-19), interacts with the host cell receptor angiotensin-converting enzyme 2 (hACE2) via its spike 1 protein during infection. After the virus sequence was published, we identified two potent antibodies against the SARS-CoV-2 receptor binding domain (RBD) from antibody libraries using a phage-to-yeast (PtY) display platform in only 10 days. Our lead antibody JMB2002, now in a Phase 1 clinical trial (ChiCTR2100042150), showed broad-spectrum in vitro blocking activity against hACE2 binding to the RBD of multiple SARS-CoV-2 variants, including B.1.351 that was reportedly much more resistant to neutralization by convalescent plasma, vaccine sera and some clinical-stage neutralizing antibodies. Furthermore, JMB2002 has demonstrated complete prophylactic and potent therapeutic efficacy in a rhesus macaque disease model. Prophylactic and therapeutic countermeasure intervention of SARS-CoV-2 using JMB2002 would likely slow down the transmission of currently emerged SARS-CoV-2 variants and result in more efficient control of the COVID-19 pandemic.

Biosafety Level 4 Laboratory User Training Program, China.

Experienced, qualified personnel certified to work in high-level biocontainment laboratories contribute to the safe operation of these facilities. China began a training program for laboratory users after establishing its first Biosafety Level 4 laboratory, the Wuhan National Biosafety Laboratory (Level 4) of the Chinese Academy of Sciences. We provide an overview of the content of this training program, which can serve as a reference for developing national norms for high-containment laboratory training.

Nucleoprotein-based indirect enzyme-linked immunosorbent assay (indirect ELISA) for detecting antibodies specific to Ebola virus and Marbug virus.

Full-length nucleoproteins from Ebola and Marburg viruses were expressed as His-tagged recombinant proteins in Escherichia coli and nucleoprotein-based enzyme-linked immunosorbent assays (ELISAs) were established for the detection of antibodies specific to Ebola and Marburg viruses. The ELISAs were evaluated by testing antisera collected from rabbit immunized with Ebola and Marburg virus nucleoproteins. Although little cross-reactivity of antibodies was observed in anti-Ebola virus nucleoprotein rabbit antisera, the highest reactions to immunoglobulin G (IgG) were uniformly detected against the nucleoprotein antigens of homologous viruses. We further evaluated the ELISA's ability to detect antibodies to Ebola and Marburg viruses using human sera samples collected from individuals passing through the Guangdong port of entry. With a threshold set at the mean plus three standard deviations of average optical densities of sera tested, the ELISA systems using these two recombinant nucleoproteins have good sensitivity and specificity. These results demonstrate the usefulness of ELISA for diagnostics as well as ecological and serosurvey studies of Ebola and Marburg virus infection.

Compound ion salt, a novel low-sodium salt substitute: from animal study to community-based population trial.

BACKGROUND: Salt restriction, an important approach for primary and secondary prevention of hypertension, is undermined by unsatisfactory adherence. A salt-restriction study tested the efficacy and safety of a compound ion salt (CISalt) with low sodium content in an animal model and in a community-based population. METHODS: In part 1, 8-week-old male spontaneously hypertensive rats (SHRs) were fed 1% CISalt in the study group and 8% or 1% normal salt (NSalt) in controls (n = 10 each) for 12 weeks. Blood pressure (BP) and urinary electrolytes were measured every 3 weeks. After 12 weeks, collagen deposition in the heart and kidney and the levels of angiotensin II (Ang II) and nitric oxide (NO) in plasma and renal cortex were measured. In part 2, a single-blind, randomized, 6-month controlled trial with CISalt was conducted in 248 persons (age >or=65 years) in 10 rural communities. Plasma renin activity and Ang II were included in blood and urinary measures at baseline and 6 months. RESULTS: Reduced BP urinary protein excretion and reduced collagen in the heart and kidneys were significantly different in animals fed CISalt compared to controls. In human studies, at 6 months, mean systolic BP (SBP) was decreased by 9.6 mm Hg (95% confidence interval (CI): 13.1 to 6.1, P < 0.001) and diastolic BP (DBP) by 5.3 mm Hg (95% CI: 7.9 to 2.6, P < 0.001), respectively, compared to controls; urinary sodium excretion also decreased by 67.4 mmol/24 h (95% CI: 84.8 to 50.0, P < 0.001), and plasma renin activity was slightly increased by 0.19 ng/ml/h (95% CI: 0.04-0.33, P = 0.013). No adverse cardiovascular events were reported. CONCLUSIONS: In these studies, CISalt lowered BP and showed end-organ protection in hypertensive animals and BP reduction in humans. CISalt appears to be a safe and acceptable strategy to reduce BP.

Cloning and sequence analysis of the phytoene synthase gene from a unicellular chlorophyte, Dunaliella salina.

Phytoene synthase (Psy) catalyzing the dimerization of two molecules of geranylgeranyl pyrophosphate (GGPP) to phytoene may be rate limiting for the synthesis of beta-carotene in Dunaliella salina. To elucidate the carotenogenic pathway in D. salina, the complete Psy gene was first isolated by genome walking technology and suppression PCR. Subsequently, RT-PCR was performed to obtain the Psy cDNA of 1260 bp, which codes 420 amino acids. The Psy gene of total length of 2982 bp was found to consist of five exons and four introns when compared with the cDNA sequence. The D. salina Psy amino acid has a 78-89% similarity with many other higher plants, but a phylogenic analysis shows a closer relationship between the microalgal and cyanobacterial Psy.

[Study on the properties of methyl parathion hydrolase from Pseudomonas sp. WBC-3].

A methyl parathion degradation enzyme, or methyl parathion hydrolase (MPH, EC 3.1.8.1), locating in the soluble intracellular fraction of Pseudomonas sp. WBC-3, was purified 49.1-fold to homogeneity by one-step ion exchange chromatography. The physical and chemical properties of the purified MPH were studied. The purified MPH displayed relatively broad optimal temperature around 40 degrees. The activity of MPH was affected by pH and the optimal pH was 11.0. Cd2+ and Fe2+ could enhance the catalytic efficiency of MPH while Hg2+, Zn2+, Al3+ and Bi3+ showed inhibition effect. With methyl parathion as the optimal substrate, the Km was 0.0807mmol/L and the kcat was 2.1 x 10(6) min(-1). In addition, the comparison of native and subunit molecular weights of MPH suggested that this enzyme was a monomer of approximate 34kD.

[Mitochondrial myopathy and mitochondrial encephalomyopathy].

OBJECTIVE: To investigate the symptomatic, biochemical, and pathological characteristics of mitochondrial myopathy and mitochondrial encephalomyopathy. METHODS: Physical examination, electromyography, electroencephalography, cranial CT or MRI, serum enzymological examination, and light microscopy and electron microscopy of muscle biopsy specimens were made among twenty-one in-patients with the diagnosis of mitochondrial myopathy and mitochondrial encephalopathy. All the patients were followed up for more than 5 years. RESULTS: Four patients died of lung infection, epilepticism or multiple organ failure 3, 4, 6, and 8 years after the onset of disease. One patient had already survived for 12 years. Among the 6 patients with the original diagnosis of mitochondrial myopathy, the diagnosis of two was changed as myoclonus epilepsy with ragged fiber (MERRF) 5 and 6 years after the onset. Among the seven patients whose disease was originally diagnosed as chronic progressive external ophthalmoplegia the diagnosis was changed as mitochondrial encephalomyopathy with lactic acidemia and stroke like episodes seven years after the onset. CONCLUSION: It is not difficult to diagnose mitochondrial myopathy and mitochondrial encephalomyopathy based on the symptomatical, biochemical, and pathological characteristics. However, the clinical manifestations of these diseases may change during the progress of the disease. Follow-up is highly recommended.