Humoral immune response to authentic circulating severe acute respiratory syndrome coronavirus 2 variants elicited by booster vaccination with distinct receptor-binding domain subunits in mice.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants could induce immune escape by mutations of the spike protein which are threatening to weaken vaccine efficacy. A booster vaccination is expected to increase the humoral immune response against SARS-CoV-2 variants in the population. We showed that immunization with two doses of wild type receptor-binding domain (RBD) protein, and booster vaccination with wild type or variant RBD protein all significantly increased binding and neutralizing antibody titers against wild type SARS-CoV-2 and its variants in mice. Only the booster immunization by Omicron (BA.1)RBD induced a strong antibody titer against the omicron virus strain and comparable antibody titers against all the other virus strains. These findings might shed the light on coronavirus disease 2019 booster immunogens.

Murine diabetic models for dengue virus infection.

Dengue virus (DENV) is a critical public health concern in tropical and subtropical regions worldwide. Thus, immunocompetent murine models of DENV infection with robust viremia are required for vaccine studies. Diabetes is highly prevalent worldwide, making it frequent comorbidity in patients with dengue fever. Therefore, murine models are needed to understand viral pathogenesis and disease progression. Acquired-induced and inherently diabetic C57BL/6 and db/db mice were inoculated with DENV-3 via the tail vein. After infection, both the diabetic C57BL/6 and db/db mice showed obvious weight loss with clinical manifestations. Quantitative reverse-transcription polymerase chain reaction revealed robust and replicable viremia in the two types of diabetic mice. Immunohistochemical detection showed persistent DENV-3 infection in the liver. Enzyme-linked immunosorbent assay for cytokine detection revealed that diabetic mice showed more severe inflammatory responses than did nondiabetic mice, and significant histological alterations were observed in diabetic mice. Thus, the diabetic mice were more susceptible to DENV infection than the nondiabetic mice. Taken together, we established two types of immunocompetent diabetic mice for DENV infection, which can be used to further study the mechanisms of dengue pathogenesis in diabetes and to develop antiviral pharmaceuticals and treatments.

The effects of Japanese encephalitis virus antibodies on Zika virus infection.

Recently, Zika virus (ZIKV) has become more widespread, thus attracting global attention. The vaccine against Japanese encephalitis virus (JEV) is currently used in China, being included in planned immunisation regimes. Although ZIKV and JEV are closely related mosquito-borne Flaviviruses, and a complex cross-immune response within flaviviruses has been demonstrated, the effect of JEV vaccination on ZIKV infection has not been well described. Thus, this study aimed to explore the impact of different titres of anti-JEV antibodies (Abs) against ZIKV infection using sera from healthy human donors in Guangzhou and anti-JEV rabbit polyclonal antibodies (pAbs) in vitro and vivo. Human anti-JEV Ab titres were tested at decreasing concentrations as the age increased. A neutralising effect on ZIKV infection was observed when anti-JEV Ab titres in human sera or rabbit pAbs were high (the corresponding age was under 30 years). Even though a lower titre in human sera showed no apparent effect, whereas rabbit pAbs had an antibody-dependent enhancement(ADE)effect, we proved an ADE effect in vivo for the first time. This study suggests that individuals over 60 years of age are at high risk for JEV and ZIKV infection, and screening this age group for infection should strengthen. Furthermore, a deep exploration of the relationship between anti-JEV Abs and ZIKV infection is needed.

Research advancements in the neurological presentation of flaviviruses.

Owing to the large-scale epidemic of Zika virus disease and its association with microcephaly, properties that allow flaviviruses to cause nervous system diseases are an important area of investigation. At present, although potential pathogenic mechanisms of flaviviruses in the nervous system have been examined, they have not been completely elucidated. In this paper, we review the possible mechanisms of blood-brain barrier penetration, the pathological effects on neurons, and the association between virus mutations and neurotoxicity. A hypothesis on neurotoxicity caused by the Zika virus is presented. Clarifying the mechanisms of virulence of flaviviruses will be helpful in finding better antiviral drugs and optimizing the treatment of symptoms.

Effect of stock density on the microbial community in biofloc water and Pacific white shrimp (Litopenaeus vannamei) gut microbiota.

Biofloc technology is an efficient approach for intensive shrimp culture. However, the extent to which this process can influence the composition of intestinal microbial community is still unknown. Here, we surveyed the shrimp intestinal bacteria as well as the floc water from three biofloc systems with different stock densities. Our study revealed a similar variation trend in phylum taxonomy level between floc bacteria and gut microbiota. Microbial community varied notably in floc water from different stock densities, while a core genus with dominating relative abundance was detected in gut samples. Extensive variation was discovered in gut microbiota, but still clustered into groups according to stock density. Our results indicated that shrimp intestinal microbiota as well as bacteria aggregated in flocs assembled into distinct communities from different stock densities, and the intestinal communities were more similar with the surrounding environment as the increase of stock density and resulting high floc biomass. The high stock density changed the core gut microbiota by reducing the relative abundance of Paracoccus and increasing that of Nocardioides, which may negatively influence shrimp performance. Therefore, this study helps us to understand further bacteria and host interactions in biofloc system.

Localized surface plasmon resonance (LSPR) excitation on single silver nanoring with nanoscale surface roughness.

With the expansion of the application of high-sensitivity Surface-enhanced Raman scattering (SERS) technique, micro SERS-active substrates with rich optical properties and high-level functions are desired. In this study, silver nanorings with nanoscale surface roughness were fabricated as a new type of enclosed quasi-2D micro-SERS-active substrate. Highly-crystalline spherical and hemispherical silver nanoprotrusions were densely and uniformly distributed over the entire surface of the nanorings. The SERS signals were significantly enhanced on the roughened silver nanorings which were mainly derived from the maximal localized surface plasmon resonance (LSPR) points at the junctions between adjacent coupled nanoprotrusions on the roughened nanorings. The mapping image shows a uniform and intense LSPR enhancement over the nanorings, owing to the uniform and dense distribution of silver nanoprotrusions and the resulting uniform distribution of maximal LSPR points on the roughened nanorings. The dark-field spectra further indicated that the single roughened silver nanoring had significant LSPR enhancement, a wide LSPR frequency-range response, and adaptability for SERS enhancement. Notably, both the measured and simulated results demonstrate that the maximal LSPR enhancement at the junctions between the nanoprotrusions, which are distributed on the inner surface of the silver nanoring, is higher than that on the outer surface because of the plasmon-focusing effect of the enclosed silver nanoring, which leads to the lateral asymmetrical distribution of LSPR intensity, indicating more LSPR and SERS features. These results indicate that single roughened silver nanorings exhibit excellent performance as a new type of enclosed quasi-2D silver nanoring micro-SERS-active substrate, microzone LSPR catalysis, and micro/nanodevices.

The step-by-step assembly mechanism of secreted flavivirus NS1 tetramer and hexamer captured at atomic resolution.

Flaviviruses encode a conserved, membrane-associated nonstructural protein 1 (NS1) with replication and immune evasion functions. The current knowledge of secreted NS1 (sNS1) oligomers is based on several low-resolution structures, thus hindering the development of drugs and vaccines against flaviviruses. Here, we revealed that recombinant sNS1 from flaviviruses exists in a dynamic equilibrium of dimer-tetramer-hexamer states. Two DENV4 hexameric NS1 structures and several tetrameric NS1 structures from multiple flaviviruses were solved at atomic resolution by cryo-EM. The stacking of the tetrameric NS1 and hexameric NS1 is facilitated by the hydrophobic ß-roll and connector domains. Additionally, a triacylglycerol molecule located within the central cavity may play a role in stabilizing the hexamer. Based on differentiated interactions between the dimeric NS1, two distinct hexamer models (head-to-head and side-to-side hexamer) and the step-by-step assembly mechanisms of NS1 dimer into hexamer were proposed. We believe that our study sheds light on the understanding of the NS1 oligomerization and contributes to NS1-based therapies.

Ultrasonic enhanced liquid-liquid interfacial reaction for improving the synthesis of Iron-doped carbon dots (Fe-CDs) for achieving superior photocatalytic performance.

The precise and controllable preparation of carbon nanomaterials under mild conditions poses a great challenge, especially for metal-catalysed multiphase preparation. This work proposes an efficient method that utilizing high-density ultrasound to enhance the liquid-liquid interfacial reaction system. Iron-doped carbon dots (Fe-CDs) are successfully synthesized in such a normal temperature and atmospheric-pressure reaction condition. It is shown that transient cavitation provides a high-temperature and high-pressure microenvironment for the preparation of Fe-CDs. Moreover, the size of the reactant droplets is reduced from 200.0 ± 17.3 µm to 8.1 ± 2.9 µm owing to the acoustic flow and cavitation effects, which increases the specific surface area of the two reacting phases and improves the mass transfer coefficient by more than 252.0 %. As a result, the yield increases by more than an order of magnitude (from 0.7 ± 0.1 % to 11.9 ± 0.2 %) and the Fe doping rate reaches 20.9 %. The photocatalytic oxidation conversion of 1,4-Dihydropyridine (1,4-DHP) using the obtained Fe-CDs is as high as 98.2 %. This research gives a new approach for the efficient and safe production of Fe-CDs, which is promising for industrial applications.

A High-Precision Bandgap Reference with Chopper Stabilization and V-Curve Compensation Technique.

The MEMS sensor converts the physical signal of nature into an electrical signal. The output signal of the MEMS sensor is so weak and basically in the low-frequency band that the MEMS sensor interface circuit has a rigorous requirement for the noise/offset and temperature coefficient, especially in the bandgap reference block. However, the traditional amplifier has low-frequency noise and offset voltage, which will decrease the precision of the bandgap reference. In order to satisfy the need of the MEMS sensor interface circuit, a high-precision and low-noise bandgap reference is proposed in this paper. A novel operational amplifier with a chopper-stabilization technique is adopted to reduce offset and low-frequency noise. At the same time, the V-curve compensation circuit is used to realize the second-order curvature compensation. The circuit is implemented under the 0.18 µm standard of the CMOS process. The test result shows that the temperature coefficient of the bandgap is 2.31 ppm/°C in the range of -40-140 °C, while the output voltage noise is only 616 nV/sqrt(Hz)@1 Hz and the power-supply rejection ratio is 73 dB@10 kHz. The linear adjustment rate is 0.33 mV/V for supply voltages of 1.2-1.8 V at room temperature, the power consumption is only 107 µW at 1.8 V power supply voltage, and the chip active area is 0.21 × 0.28 mm2.

Cold-Chain-Food-Related COVID-19 Surveillance in Guangzhou between July 2020 and December 2022.

OBJECTIVE: To monitor severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA contamination in samples linked to imported cold-chain food and assess the situation from the implementation of a centralized supervision warehouse system in Guangzhou, Guangdong Province, China. METHODS: Swabs of workers and frozen-food-related samples were collected between July 2020 and December 2023 in Guangzhou, Guangdong Province. SARS-CoV-2 RNA was extracted and analyzed by a real-time quantitative polymerase chain reaction using the commercially available SARS-CoV-2 nucleic acid test kit. The risk level and food source were monitored simultaneously. RESULTS: A total of 283 positive cold-chain events were found in Guangzhou since the first cold-chain-related event of the coronavirus disease 2019 pandemic was identified in July 2020. Most positive samples were a low-to-medium risk, and the cycle threshold value was >30. No live virus was detected, and no staff came into direct contact with a live virus. In total, 87.63% of positive events were identified through sampling and testing at the centralized food warehouse. CONCLUSION: Cold-chain food has a relatively low risk of transmitting SARS-CoV-2. Centralized food storage can be used as an effective method to control this risk, and this measure can also be used for other food-related, contact-transmitted diseases.

EDIII-Fc induces protective immune responses against the Zika virus in mice and rhesus macaque.

Zika virus can infect the fetus through the placental barrier, causing ZIKV congenital syndrome and even miscarriage, which can cause great harm to pregnant women and infants. Currently, there is no vaccine and drug available to combat the Zika virus. In this study, we designed a fusion protein named EDIII-Fc, including the EDIII region of Zika E protein and human IgG Fc fragment, and obtained 293T cells that stably secreted EDIII-Fc protein using the lentiviral expression system. Mice were immunized with the EDIII-Fc protein, and it was observed that viral replication was significantly inhibited in the immunized mice compared to non-immunized mice. In rhesus macaques, we found that EDIII-Fc effectively induce the secretion of neutralizing antibodies and T cell immunity. These experimental data provide valid data for further use of Zika virus E protein to prepare an effective, safe, affordable Zika vaccine.

Identification of an effective fraction from Ampelopsis Radix with anti-dengue virus activities in vitro and in vivo.

ETHNOPHARMACOLOGICAL RELEVANCE: Dengue virus (DENV) infection is a global public health issue without effective therapeutic interventions. Chinese medicine with heat-clearing and detoxifying properties has been frequently used in the treatment of viral infection. Ampelopsis Radix (AR) is a traditional Chinese medicine for clearing heat and detoxification that has been widely used in the prevention and treatment of infectious diseases. However, no studies on the effects of AR against viral infection have been reported, thus far. AIM OF THE STUDY: To explore the anti-DENV activities of the fraction (AR-1) obtained from AR both in vitro and in vivo. MATERIALS AND METHODS: The chemical composition of AR-1 was identified by liquid chromatography-tandem MS (LC‒MS/MS). The antiviral activities of AR-1 were studied in baby hamster kidney fibroblast BHK-21 cells, ICR suckling mice and induction of interferon α/ß (IFN-α/ß) and IFN-γ R-/- (AG129) mice. RESULTS: Based on LC‒MS/MS analysis, 60 compounds (including flavonoids, phenols, anthraquinones, alkaloids and other types) were tentatively characterized from AR-1. AR-1 inhibited the cytopathic effect, the production of progeny virus and the synthesis of viral RNA and proteins by blocking DENV-2 binding to BHK-21 cells. Moreover, AR-1 significantly attenuated weight loss, decreased clinical scores and prolonged the survival of DENV-infected ICR suckling mice. Critically, the viral load in blood, brain and kidney tissues and the pathological changes in brain were remarkably alleviated after AR-1 treatment. Further study on AG129 mice showed that AR-1 obviously improved the clinical manifestations and survival rate, reduced viremia, attenuated gastric distension and relieved the pathological lesions caused by DENV. CONCLUSIONS: In summary, this is the first report that AR-1 exhibits anti-DENV effects both in vitro and in vivo, which suggests that AR-1 may be developed as a therapeutic candidate against DENV infection.

Liang-Ge-San inhibits dengue virus serotype 2 infection by reducing caveolin1-induced cytoplasmic heat shock protein 70 translocation into the plasma membrane.

BACKGROUND: Dengue virus (DENV) is a major public health threat. However, there are no specific therapeutic drugs for DENV. Many Chinese heat-cleaning formulas, such as Liang-Ge-San (LGS), have been frequently used in the virus-induced diseases. The antiviral effect of LGS has not been reported yet. PURPOSE: In this study, the effect of LGS on the inhibition of dengue virus serotype 2 (DENV-2) was investigated and the relevant mechanism was explored. METHODS: High-performance liquid chromatography was applied to analyze the chemical characterization of LGS. The in vitro antiviral activities of LGS against DENV-2 were evaluated by time-of-drug-addition assay. The binding of heat shock protein 70 (Hsp70) and envelope (E) protein or caveolin1 (Cav1) were analyzed by immunofluorescence and immunoprecipitation assays. Then the role of Cav1 in the anti-DENV-2 effects of LGS was further examined. DENV-2 infected Institute of Cancer Research suckling mice (n = 10) and AG129 mice (n = 8) were used to examine the protective effects of LGS. RESULTS: It was found that geniposide, liquiritin, forsythenside A, forsythin, baicalin, baicalein, rhein, and emodin maybe the characteristic components of LGS. LGS inhibited the early stage of DENV-2 infection, decreased the expression levels of viral E and non-structural protein 1 (NS1) proteins. LGS also reduced E protein and Hsp70 binding and attenuated the translocation of Hsp70 from cytoplasm to the cell membrane. Moreover, LGS decreased the binding of Hsp70 to Cav1. Further study showed that the overexpression of Cav1 reversed LGS-mediated E protein and Hsp70 inhibition in the plasma membrane. In the in vivo study, LGS was highly effective in prolonging the survival time, reducing viral loads. CONCLUSION: This work demonstrates for the first time that LGS exerts anti-DENV-2 activity in vitro and in vivo. LGS decreases DENV-2-stimulated cytoplasmic Hsp70 translocation into the plasma membrane by Cav1 inhibition, thereby inhibiting the early stage of virus infection. These findings indicate that LGS may be a candidate for the treatment of DENV.

N-Butanol Extract of Glycyrrhizae Radix et Rhizoma Inhibits Dengue Virus through Targeting Envelope Protein.

BACKGROUND: At present, about half of the world's population is at risk of being infected with dengue virus (DENV). However, there are no specific drugs to prevent or treat DENV infection. Glycyrrhizae Radix et Rhizome, a well-known traditional Chinese medicine, performs multiple pharmacological activities, including exerting antiviral effects. The aim of this study was to investigate the anti-DENV effects of n-butanol extract from Glycyrrhizae Radix et Rhizome (GRE). METHODS: Compounds analysis of GRE was conducted via ultra-performance liquid chromatography/tandem mass spectrometry (UHPLC-MS/MS). The antiviral activities of GRE were determined by the CCK-8 assay, plaque assay, qRT-PCR, Western blotting, and the immunofluorescence assay. The DENV-infected suckling mice model was constructed to explore the antiviral effects of GRE in vivo. RESULTS: Four components in GRE were analyzed by UHPLC-MS/MS, including glycyrrhizic acid, glycyrrhetnic acid, liquiritigenin, and isoliquiritigenin. GRE inhibited the attachment process of the virus replication cycle and reduced the expression of the E protein in cell models. In the in vivo study, GRE significantly relieved clinical symptoms and prolong survival duration. GRE also significantly decreased viremia, reduced the viral load in multiple organs, and inhibited the release of pro-inflammatory cytokines in DENV-infected suckling mice. CONCLUSIONS: GRE exhibited significant inhibitory activities in the adsorption stage of the DENV-2 replication cycle by targeting the envelope protein. Thus, GRE might be a promising candidate for the treatment of DENV infection.

Phylogeny and molecular evolution of the first local monkeypox virus cluster in Guangdong Province, China.

The first local mpox outbreak in Guangdong Province, China occurred in June 2023. However, epidemiological data have failed to quickly identify the source and transmission of the outbreak. Here, phylogeny and molecular evolution of 10 monkeypox virus (MPXV) genome sequences from the Guangdong outbreak were characterized, revealing local silent transmissions that may have occurred in Guangdong whose mpox outbreaks suggested a molecular epidemiological correlation with Portugal and several regions of China during the same period. The lineage IIb C.1, which includes all 10 MPXV from Guangdong, shows consistent temporal continuity in both phylogenetic characteristics and unique molecular evolutionary mutation spectrum, reflected in the continuous increase of single nucleotide polymorphisms (SNPs) and shared mutations over time. Compared with the Japan MPXV, the Guangdong MPXV showed higher genomic nucleotide differences and separated 14 shared mutations from the B.1 lineage, comprising 6 non-synonymous mutations in genes linked to host regulation, virus infection, and virus life cycle. The unique mutation spectrum with temporal continuity in IIb C.1, related to apolipoprotein B mRNA-editing catalytic polypeptide-like 3, promotes rapid viral evolution and diversification. The findings contribute to understanding the ongoing mpox outbreak in China and offer insights for developing joint prevention and control strategies.

A simple and effective aerosol pathogen disinfection test for a flowing air disinfector.

Aerosol transmission is an important disease transmission route and has been especially pertinent to hospital and biosafety laboratories during the SARS-CoV-2 pandemic. The thermal resistance of airborne SARS-CoV-2 is lower than that of Bacillus subtilis spores, which are often used to test the effectiveness of SARS-CoV-2 and other pathogen disinfection methods. Herein, we propose a new method to test the disinfection ability of a flowing air disinfector (a digital electromagnetic induction air heater) using B. subtilis spores. The study provides an alternative air disinfection test method. The new test system combined an aerosol generator and a respiratory filter designed in-house and could effectively recover spores on the filter membrane at the air outlet after passing through the flowing air disinfector. The total number of bacterial spores used in the test was within the range of 5 × 105-5 × 106 colony-forming units (CFUs) specified in the technical standard for disinfection. The calculation was based on the calculation method in Air Disinfection Effect Appraisal Test in Technical Standard for Disinfection (2002 Edition). At an air speed of 3.5 m/s, we used a digital electromagnetic induction air heater to disinfect flowing air containing 4.100 × 106 CFUs of B. subtilis spores and determined that the minimum disinfection temperature was 350 °C for a killing rate of 99.99%. At 400 °C, additional experiments using higher spore concentrations (4.700 × 106 ± 1.871 × 105 CFU) and a higher airspeed (4 m/s) showed that the killing rate remained>99.99%. B. subtilis spores, as a biological indicator for testing the efficiency of dry-heat sterilization, were killed by the high temperatures used in this system. The proposed method used to test the flowing air disinfector is simple, stable, and effective. This study provides a reference for the development of test systems that can assess the disinfection ability of flowing air disinfectors.

Severe Acute Respiratory Syndrome Coronavirus 2 ORF8 Protein Inhibits Type I Interferon Production by Targeting HSP90B1 Signaling.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a global pandemic that has currently infected over 430 million individuals worldwide. With the variant strains of SARS-CoV-2 emerging, a region of high mutation rates in ORF8 was identified during the early pandemic, which resulted in a mutation from leucine (L) to serine (S) at amino acid 84. A typical feature of ORF8 is the immune evasion by suppressing interferon response; however, the mechanisms by which the two variants of ORF8 antagonize the type I interferon (IFN-I) pathway have not yet been clearly investigated. Here, we reported that SARS-CoV-2 ORF8L and ORF8S with no difference inhibit the production of IFN-ß, MDA5, RIG-I, ISG15, ISG56, IRF3, and other IFN-related genes induced by poly(I:C). In addition, both ORF8L and ORF8S proteins were found to suppress the nuclear translocation of IRF3. Mechanistically, the SARS-CoV-2 ORF8 protein interacts with HSP90B1, which was later investigated to induce the production of IFN-ß and IRF3. Taken together, these results indicate that SARS-CoV-2 ORF8 antagonizes the RIG-I/MDA-5 signaling pathway by targeting HSP90B1, which subsequently exhibits an inhibitory effect on the production of IFN-I. These functions appeared not to be influenced by the genotypes of ORF8L and ORF8S. Our study provides an explanation for the antiviral immune suppression of SARS-CoV-2 and suggests implications for the pathogenic mechanism and treatment of COVID-19.

Vimentin Inhibits Dengue Virus Type 2 Invasion of the Blood-Brain Barrier.

Dengue virus (DENV) causes dengue fever, which is prevalent in the tropical and subtropical regions, and in recent years, has resulted in several major epidemics. Vimentin, a cytoskeletal component involved in DENV infection, is significantly reorganized during infection. However, the mechanism underlying the association between DENV infection and vimentin is still poorly understood. We generated vimentin-knockout (Vim-KO) human brain microvascular endothelial cells (HBMECs) and a Vim-KO SV129 suckling mouse model, combining the dynamic vimentin changes observed in vitro and differences in disease course in vivo, to clarify the role of vimentin in DENV-2 infection. We found that the phosphorylation and solubility of vimentin changed dynamically during DENV-2 infection of HBMECs, suggesting the regulation of vimentin by DENV-2 infection. The similar trends observed in the phosphorylation and solubility of vimentin showed that these characteristics are related. Compared with that in control cells, the DENV-2 viral load was significantly increased in Vim-KO HBMECs, and after DENV-2 infection, Vim-KO SV129 mice displayed more severe disease signs than wild-type SV129 mice, as well as higher viral loads in their serum and brain tissue, demonstrating that vimentin can inhibit DENV-2 infection. Moreover, Vim-KO SV129 mice had more disordered cerebral cortical nerve cells, confirming that Vim-KO mice were more susceptible to DENV-2 infection, which causes severe brain damage. The findings of our study help clarify the mechanism by which vimentin inhibits DENV-2 infection and provides guidance for antiviral treatment strategies for DENV infections.

Pulmonary tuberculosis screening in emigrants and travellers: A retrospective analysis of Guangzhou Port in China.

BACKGROUND: China is beginning to transform from a migrant exporting country to a migrant importing country. Our study aimed to assess risks of imported tuberculosis among travellers and to determine risk factors, to tailor institutional guidelines. METHODS: We conducted an observational, retrospective, population-based cohort study. Molecular epidemiology surveillance methods were used to screen travellers for cases of pulmonary tuberculosis (PTB) at Guangzhou Port in China from January 2010 to December 2016. RESULTS: A total of 165,369 travellers from 190 countries and regions were screened for PTB. The rate of suspected PTB, laboratory confirmed rate, and the total detection rate in emigrants were significantly higher than those in travellers (p<0.01). There were four differences in the PTB screening process between emigrants and travellers. According to the transmission risk degree of the tuberculosis, forty high-risk PTB importing countries were divided into five levels. The travellers diagnosed with PTB were significantly younger than the emigrants (p<0.01). The distribution of genotypes differed significantly between the travellers and emigrants (p<0.001). CONCLUSIONS: PTB screening process in travellers at ports should include a risk assessment of high-risk groups. It should reduce diagnosis time by rapid molecular detection methods and strengthen drug resistant (DR) transmission and monitoring of imported PTB strains through molecular genotyping at ports.

Dengue virus is involved in insulin resistance via the downregulation of IRS-1 by inducing TNF-α secretion.

During the epidemic, the individuals with underlying diseases usually have a higher rate of mortality. Diabetes is highly prevalent worldwide, making it a frequent comorbidity in dengue fever patients. Therefore, understanding the relationship between dengue virus (DENV) infection and diabetes is important. We first demonstrated that DENV-3 infection down-regulated the expression of IRS-1. In vitro, treatment of HepG2 cells with TNF-α inhibitors and siRNA proved that after DENV-3 infection in HepG2 cells, cellular TNF-α secretion was increased, which negatively regulated IRS-1, thereby leading to an insulin-resistant state. In vivo, DENV-3 induced insulin resistance (IR) in hepatocytes by promoting the secretion of TNF-α and inhibiting the expression of IRS-1 was proved. In vivo approaches also showed that after DENV-3 infection, TNF-α levels in the serum of C57BL/6 mice with insulin resistance increased, and upon TNF-α antagonist III treatment, IRS-1 expression in the liver, reduced by infection, was upregulated. In addition, transcriptomic analysis revealed more negative regulatory events in the insulin receptor signaling pathway after DENV-3 infection. This is the first report of a link between DENV-3 infection and insulin resistance, and it lays a foundation for further research.