Biomedical and environmental sciences : BES最新文献

Objective: The purpose of this study was to investigate the bacterial communities of biting midges and ticks collected from three sites in the Poyang Lake area, namely, Qunlu Practice Base, Peach Blossom Garden, and Huangtong Animal Husbandry, and whether vectors carry any bacterial pathogens that may cause diseases to humans, to provide scientific basis for prospective pathogen discovery and disease prevention and control.

Methods: Using a metataxonomics approach in concert with full-length 16S rRNA gene sequencing and operational phylogenetic unit (OPU) analysis, we characterized the species-level microbial community structure of two important vector species, biting midges and ticks, including 33 arthropod samples comprising 3,885 individuals, collected around Poyang Lake.

Results: A total of 662 OPUs were classified in biting midges, including 195 known species and 373 potentially new species, and 618 OPUs were classified in ticks, including 217 known species and 326 potentially new species. Surprisingly, OPUs with potentially pathogenicity were detected in both arthropod vectors, with 66 known species of biting midges reported to carry potential pathogens, including Asaia lannensis and Rickettsia bellii, compared to 50 in ticks, such as Acinetobacter lwoffii and Staphylococcus sciuri. We found that Proteobacteria was the most dominant group in both midges and ticks. Furthermore, the outcomes demonstrated that the microbiota of midges and ticks tend to be governed by a few highly abundant bacteria. Pantoea sp7 was predominant in biting midges, while Coxiella sp1 was enriched in ticks. Meanwhile, Coxiella spp., which may be essential for the survival of Haemaphysalis longicornis Neumann, were detected in all tick samples. The identification of dominant species and pathogens of biting midges and ticks in this study serves to broaden our knowledge associated to microbes of arthropod vectors.

Conclusion: Biting midges and ticks carry large numbers of known and potentially novel bacteria, and carry a wide range of potentially pathogenic bacteria, which may pose a risk of infection to humans and animals. The microbial communities of midges and ticks tend to be dominated by a few highly abundant bacteria.

Objective: Viral encephalitis is an infectious disease severely affecting human health. It is caused by a wide variety of viral pathogens, including herpes viruses, flaviviruses, enteroviruses, and other viruses. The laboratory diagnosis of viral encephalitis is a worldwide challenge. Recently, high-throughput sequencing technology has provided new tools for diagnosing central nervous system infections. Thus, In this study, we established a multipathogen detection platform for viral encephalitis based on amplicon sequencing.

Methods: We designed nine pairs of specific polymerase chain reaction (PCR) primers for the 12 viruses by reviewing the relevant literature. The detection ability of the primers was verified by software simulation and the detection of known positive samples. Amplicon sequencing was used to validate the samples, and consistency was compared with Sanger sequencing.

Results: The results showed that the target sequences of various pathogens were obtained at a coverage depth level greater than 20×, and the sequence lengths were consistent with the sizes of the predicted amplicons. The sequences were verified using the National Center for Biotechnology Information BLAST, and all results were consistent with the results of Sanger sequencing.

Conclusion: Amplicon-based high-throughput sequencing technology is feasible as a supplementary method for the pathogenic detection of viral encephalitis. It is also a useful tool for the high-volume screening of clinical samples.

Objective: Hypertriglyceridemic waist (HW), hypertriglyceridemic waist-to-height ratio (HWHtR), and waist-to-hip ratio (WHR) have been shown to be indicators of cardiometabolic risk factors. However, it is not clear which indicator is more suitable for children and adolescents. We aimed to investigate the relationship between HW, HWHtR, WHR, and cardiovascular risk factors clustering to determine the best screening tools for cardiometabolic risk in children and adolescents.

Methods: This was a national cross-sectional study. Anthropometric and biochemical variables were assessed in approximately 70,000 participants aged 6-18 years from seven provinces in China. Demographics, physical activity, dietary intake, and family history of chronic diseases were obtained through questionnaires. ANOVA, χ ² and logistic regression analysis was conducted.

Results: A significant sex difference was observed for HWHtR and WHR, but not for HW phenotype. The risk of cardiometabolic health risk factor clustering with HW phenotype or the HWHtR phenotype was significantly higher than that with the non-HW or non-HWHtR phenotypes among children and adolescents (HW: OR = 12.22, 95% CI: 9.54-15.67; HWHtR: OR = 9.70, 95% CI: 6.93-13.58). Compared with the HW and HWHtR phenotypes, the association between risk of cardiometabolic health risk factors (CHRF) clustering and high WHR was much weaker and not significant (WHR: OR = 1.14, 95% CI: 0.97-1.34).

Conclusion: Compared with HWHtR and WHR, the HW phenotype is a more convenient indicator withhigher applicability to screen children and adolescents for cardiovascular risk factors.

Objective: China is among the 30 countries with a high burden of tuberculosis (TB) worldwide, and TB remains a public health concern. Kashgar Prefecture in the southern Xinjiang Autonomous Region is considered as one of the highest TB burden regions in China. However, molecular epidemiological studies of Kashgar are lacking.

Methods: A population-based retrospective study was conducted using whole-genome sequencing (WGS) to determine the characteristics of drug resistance and the transmission patterns.

Results: A total of 1,668 isolates collected in 2020 were classified into lineages 2 (46.0%), 3 (27.5%), and 4 (26.5%). The drug resistance rates revealed by WGS showed that the top three drugs in terms of the resistance rate were isoniazid (7.4%, 124/1,668), streptomycin (6.0%, 100/1,668), and rifampicin (3.3%, 55/1,668). The rate of rifampicin resistance was 1.8% (23/1,290) in the new cases and 9.4% (32/340) in the previously treated cases. Known resistance mutations were detected more frequently in lineage 2 strains than in lineage 3 or 4 strains, respectively: 18.6% vs. 8.7 or 9%, P < 0.001. The estimated proportion of recent transmissions was 25.9% (432/1,668). Multivariate logistic analyses indicated that sex, age, occupation, lineage, and drug resistance were the risk factors for recent transmission. Despite the low rate of drug resistance, drug-resistant strains had a higher risk of recent transmission than the susceptible strains (adjusted odds ratio, 1.414; 95% CI, 1.023-1.954; P = 0.036). Among all patients with drug-resistant tuberculosis (DR-TB), 78.4% (171/218) were attributed to the transmission of DR-TB strains.

Conclusion: Our results suggest that drug-resistant strains are more transmissible than susceptible strains and that transmission is the major driving force of the current DR-TB epidemic in Kashgar.

Objective: Combination immunotherapy strategies targeting OX40, a co-stimulatory molecule that can enhance antitumor immunity by modulating the proliferation, differentiation, and effector function of tumor-infiltrating T cells, have attracted much attention for their excellent therapeutic effects. In this study, we aimed to evaluate the antitumor efficacy of combined anti-OX40 and hepatitis B core virus-like particles (HBc VLPs) therapy using a mouse colon cancer model.

Methods: Humanized B-hOX40 mice were injected subcutaneously with MC38 colon tumor cells and treated with HBc VLPs+anti-hOX40 antibody. Tumor growth was monitored. Flow cytometric analysis was performed to evaluate the populations of T cell subsets in the tumors.

Results: The combination of anti-OX40 with HBc VLPs resulted in a significant delay in tumor growth, suggesting that a potent antitumor immunity was induced by the combination therapy. Further studies revealed that HBc VLPs+anti-OX40 treatment induced a significant increase in effector T cells (Teffs) and a significant decrease in regulatory T cells (Tregs) in the tumor microenvironment (TME), which accounted for the synergistic antitumor effect of anti-OX40 in combination with HBc VLPs.

Conclusion: Combination therapy of anti-hOX40 and HBc VLPs provides synergistic antitumor activity in colon cancer-bearing mice, which may represent a potential design strategy for cancer immunotherapy.

Objective: This study aimed to compare the current Essen rabies post-exposure immunization schedule (0-3-7-14-28) in China and the simple 4-dose schedule (0-3-7-14) newly recommended by the World Health Organization in terms of their safety, efficacy, and protection.

Methods: Mice were vaccinated according to different immunization schedules, and blood was collected for detection of rabies virus neutralizing antibodies (RVNAs) on days 14, 21, 28, 35, and 120 after the first immunization. Additionally, different groups of mice were injected with lethal doses of the CVS-11 virus on day 0, subjected to different rabies immunization schedules, and assessed for morbidity and death status. In a clinical trial, 185 rabies-exposed individuals were selected for post-exposure vaccination according to the Essen schedule, and blood was collected for RVNAs detection on days 28 and 42 after the first immunization.

Results: A statistically significant difference in RVNAs between mice in the Essen and 0-3-7-14 schedule groups was observed on the 35th day ( P < 0.05). The groups 0-3-7-14, 0-3-7-21, and 0-3-7-28 showed no statistically significant difference ( P > 0.05) in RVNAs levels at any time point. The post-exposure immune protective test showed that the survival rate of mice in the control group was 20%, whereas that in the immunization groups was 40%. In the clinical trial, the RVNAs positive conversion rates on days 28 (14 days after 4 doses) and 42 (14 days after 5 doses) were both 100%, and no significant difference in RVNAs levels was observed ( P > 0.05).

Conclusion: The simple 4-dose schedule can produce sufficient RVNAs levels, with no significant effect of a delayed fourth vaccine dose (14-28 d) on the immunization potential.

Objective: This study aimed to explore the association of single nucleotide polymorphisms (SNP) in the matrix metalloproteinase 2 (MMP-2) signaling pathway and the risk of vascular senescence (VS).

Methods: In this cross-sectional study, between May and November 2022, peripheral venous blood of 151 VS patients (case group) and 233 volunteers (control group) were collected. Fourteen SNPs were identified in five genes encoding the components of the MMP-2 signaling pathway, assessed through carotid-femoral pulse wave velocity (cfPWV), and analyzed using multivariate logistic regression. The multigene influence on the risk of VS was assessed using multifactor dimensionality reduction (MDR) and generalized multifactor dimensionality regression (GMDR) modeling.

Results: Within the multivariate logistic regression models, four SNPs were screened to have significant associations with VS: chemokine (C-C motif) ligand 2 (CCL2) rs4586, MMP2 rs14070, MMP2 rs7201, and MMP2 rs1053605. Carriers of the T/C genotype of MMP2 rs14070 had a 2.17-fold increased risk of developing VS compared with those of the C/C genotype, and those of the T/T genotype had a 19.375-fold increased risk. CCL2 rs4586 and MMP-2 rs14070 exhibited the most significant interactions.

Conclusion: CCL2 rs4586, MMP-2 rs14070, MMP-2 rs7201, and MMP-2 rs1053605 polymorphisms were significantly associated with the risk of VS.

As a reducing salt, sodium sulfite could deprive oxygen in solution, which could mimic hypoxic stress in Caenorhabditis elegans. In this study, the wild-type Escherichia coli strain MG1655 was used to examine the inhibition of sodium sulfite-induced hypoxia by observing the bacterial growth curves. We also analyzed the growth curves of mutant strains (for arcA/B, soxR/S, fnr, and oxyR) related to E. coli hypoxic pathways to reveal roles of the related genes during hypoxia. The ultrastructure of hypoxia-inhibited bacteria were also observed using transmission electron microscopy. Sodium sulfite could maintain hypoxic condition of bacterial culture for 8 h with concentrations over 40 mmol/L. Complete ultrastructure of the bacteria indicated sodium sulfite did inhibit bacterial growth and division. Among the hypoxia genes, fnr and arcB played key roles in sodium sulfite-induced hypoxia. This study showed that sodium sulfite could be used as a novel hypoxia revulsant for bacterial cultures.

Objective: To evaluate the diagnostic value of histopathological examination of ultrasound-guided puncture biopsy samples in extrapulmonary tuberculosis (EPTB).

Methods: This study was conducted at the Shanghai Public Health Clinical Center. A total of 115 patients underwent ultrasound-guided puncture biopsy, followed by MGIT 960 culture (culture), smear, GeneXpert MTB/RIF (Xpert), and histopathological examination. These assays were performed to evaluate their effectiveness in diagnosing EPTB in comparison to two different diagnostic criteria: liquid culture and composite reference standard (CRS).

Results: When CRS was used as the reference standard, the sensitivity and specificity of culture, smear, Xpert, and histopathological examination were (44.83%, 89.29%), (51.72%, 89.29%), (70.11%, 96.43%), and (85.06%, 82.14%), respectively. Based on liquid culture tests, the sensitivity and specificity of smear, Xpert, and pathological examination were (66.67%, 72.60%), (83.33%, 63.01%), and (92.86%, 45.21%), respectively. Histopathological examination showed the highest sensitivity but lowest specificity. Further, we found that the combination of Xpert and histopathological examination showed a sensitivity of 90.80% and a specificity of 89.29%.

Conclusion: Ultrasound-guided puncture sampling is safe and effective for the diagnosis of EPTB. Compared with culture, smear, and Xpert, histopathological examination showed higher sensitivity but lower specificity. The combination of histopathology with Xpert showed the best performance characteristics.