61 research outputs found

    QCR7 affects the virulence of Candida albicans and the uptake of multiple carbon sources present in different host niches

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    BackgroundCandida albicans is a commensal yeast that may cause life-threatening infections. Studies have shown that the cytochrome b-c1 complex subunit 7 gene (QCR7) of C. albicans encodes a protein that forms a component of the mitochondrial electron transport chain complex III, making it an important target for studying the virulence of this yeast. However, to the best of our knowledge, the functions of QCR7 have not yet been characterized.MethodsA QCR7 knockout strain was constructed using SN152, and BALb/c mice were used as model animals to determine the role of QCR7 in the virulence of C. albicans. Subsequently, the effects of QCR7 on mitochondrial functions and use of carbon sources were investigated. Next, its mutant biofilm formation and hyphal growth maintenance were compared with those of the wild type. Furthermore, the transcriptome of the qcr7Δ/Δ mutant was compared with that of the WT strain to explore pathogenic mechanisms.ResultsDefective QCR7 reduced recruitment of inflammatory cells and attenuated the virulence of C. albicans infection in vivo. Furthermore, the mutant influenced the use of multiple alternative carbon sources that exist in several host niches (GlcNAc, lactic acid, and amino acid, etc.). Moreover, it led to mitochondrial dysfunction. Furthermore, the QCR7 knockout strain showed defects in biofilm formation or the maintenance of filamentous growth. The overexpression of cell-surface-associated genes (HWP1, YWP1, XOG1, and SAP6) can restore defective virulence phenotypes and the carbon-source utilization of qcr7Δ/Δ.ConclusionThis study provides new insights into the mitochondria-based metabolism of C. albicans, accounting for its virulence and the use of variable carbon sources that promote C. albicans to colonize host niches

    A Loop-Mediated Isothermal Amplification Assay for Rapid Detection of Cyprinid Herpesvirus 2 in Gibel Carp ( Carassius auratus gibelio

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    A rapid and sensitive loop-mediated isothermal amplification (LAMP) assay for Cyprinid herpesvirus 2 (CyHV-2) detection in gibel carp was developed. Following cloning and sequencing of the putative DNA helicase gene of CyHV-2 isolate from China, a set of four specific primers was designed based on the sequence. The MgCl2 concentration and the reaction temperature were optimized to 6 mM, 64°C, respectively. LAMP products were detected by visual inspection of a color change due to addition of SYBR Green I stain. The specificity and sensitivity of the LAMP assay were determined. No cross-reaction was observed with other fish DNA viruses including eel herpesvirus, koi herpesvirus, and Chinese giant salamander iridovirus. The LAMP assay was found to be equally sensitive as nested PCR. A comparative evaluation of 10 fish samples using LAMP and nested PCR assays showed an overall correlation in positive and negative results for CyHV-2. These results indicate that the LAMP assay is simple, sensitive, and specific and has a great potential use for CyHV-2 detection in the laboratory and field

    Dietary supplementation of <em>Astragalus</em> fermentation products improves the growth performance, immunological characteristics, and disease resistance of crucian carp (<em>Carassius auratus</em>)

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    The fermentation products of Astragalus have been acknowledged for their ability to enhance immune functions. This study assessed the impact of incorporating Astragalus, fermented with Lactobacillus plantarum and Bacillus coagulans, on crucian carp's growth, disease resistance, and immunological characteristics. The experimental groups were fed with common feed (C), C + Astragalus (A), A + Lactobacillus plantarum (AL), A + Bacillus coagulans (AB), and AL + Bacillus coagulans (ALB). The fermented products were mixed with common feed at a 1:99 ratio, and crucian carp were fed 2% of their body weight for four weeks, with sampling conducted on days 3, 7, 14, 21, and 28. Disease resistance was evaluated using Aeromonas hydrophila (A. hydrophila) at a concentration of 0.2 mL (1.0×10^7 CFU/mL). The final weights in the AL, AB, and ALB groups significantly increased compared to the C group. The ALB group exhibited elevated serum albumin levels, alkaline phosphatase, intestinal lipase, protease enzyme, C3, and IgM gene expression compared to the C group. At the same time, alanine aminotransferase, aspartate aminotransferase, and glucose contents were significantly reduced. The survival rate significantly increased in all experimental groups after treatment with A. hydrophila. In conclusion, Astragalus products fermented with Lactobacillus plantarum and Bacillus coagulans could effectively improve crucian carp's growth, disease resistance, and immune response

    Influence of loneliness burden on cardio-cerebral vascular disease among the Chinese older adult: a national cohort study

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    BackgroundAdverse psychosocial factors play an important role in cardio-cerebral vascular disease (CCVD). The aim of this study was to evaluate the impact of the cumulative burden of loneliness on the risk of CCVD in the Chinese older adult.MethodsA total of 6,181 Chinese older adult over the age of 62 in the monitoring survey of the fourth Sample Survey of the Aged Population in Urban and Rural China (SSAPUR) were included in this study. The loneliness cumulative burden (scored by cumulative degree) was weighted by the loneliness score for two consecutive years (2017–2018) and divided into low- and high-burden groups. The outcome was defined as the incidence of CCVD 1 year later (2018–2019). A multivariate logistic regression model was used to examine the relationship between the cumulative burden of loneliness and the new onset of CCVD.ResultsAmong participants, 18.9% had a higher cumulative burden of loneliness, and 11.5% had a CCVD incidence within 1 year. After multivariate adjustment, the risk of developing CCVD in the high-burden group was approximately 37% higher than that in the low-burden group (OR 1.373, 95%CI 1.096–1.721; p = 0.006). Similar results were obtained when calculating the burden based on cumulative time. Longitudinal change in loneliness was not significantly associated with an increased risk of CCVD. A higher cumulative burden of loneliness may predict a higher risk of developing CCVD in older adult individuals aged 62–72 years or in those with diabetes.ConclusionThe cumulative burden of loneliness can be used to assess the risk of new-onset CCVD in the older adult in the short term

    Prevalence and potential risk factors of self-reported diabetes among elderly people in China: A national cross-sectional study of 224,142 adults

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    AimTo evaluated the prevalence and potential risk factors of self-reported diabetes among the elderly in China, by demographic data, socioeconomic factors, and psychological factors.MethodsDescriptive analysis and Chi-square analysis were used to assess the prevalence and variation between self-reported diabetes and non-diabetes by demographic data, living habits, socioeconomic factors and comorbidities. Univariate and multivariate logistic regression were used to describe the odds ratios (OR) of diabetes prevalence in different groups, while stratification analysis was performed to describe prevalence based on gender, age, and urban/rural areas.Results215,041 elderly adults (102,692 males and 112,349 females) were eventually included in the analysis. The prevalence of self-reported diabetes among the elderly in China is about 8.7%, with the highest prevalence in Beijing (20.8%) and the lowest prevalence in Xizang (0.9%). Logistic regression analysis showed that urban area (P &lt; 0.001), older age (65–84 years old, P &lt; 0.001), female (P &lt; 0.001), higher income(P &lt; 0.001), poor sleep quality (P = 0.01) and some other factors were potential risk factors for diabetes.ConclusionsThis study illustrates the prevalence and potential risk factors of diabetes among the elderly in China Meanwhile, these results provide information to assist the government in controlling non-communicable diseases in the elderly

    Tea saponin reduces the damage of Ectropis obliqua to tea crops, and exerts reduced effects on the spiders Ebrechtella tricuspidata and Evarcha albaria compared to chemical insecticides

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    Background Tea is one of the most economically important crops in China. However, the tea geometrid (Ectropis obliqua), a serious leaf-feeding pest, causes significant damage to tea crops and reduces tea yield and quality. Spiders are the most dominant predatory enemies in the tea plantation ecosystem, which makes them potentially useful biological control agents of E. obliqua. These highlight the need for alternative pest control measures. Our previous studies have shown that tea saponin (TS) exerts insecticidal activity against lepidopteran pests. Here, we investigate whether TS represents a potentially new alternative insecticide with no harm to spiders. Methods We investigated laboratory bioactivities and the field control properties of TS solution against E. obliqua. (i) A leaf-dip bioassay was used to evaluate the toxicity of TS to 3rd-instar E. obliqua larvae and effects of TS on the activities of enzymes glutathione-S-transferase (GST), acetylcholinesterase (AChE), carboxylesterase (CES) and peroxidase (POD) of 3rd-instar E. obliqua larvae in the laboratory. (ii) Topical application was used to measure the toxicity of 30% TS (w/v) and two chemical insecticides (10% bifenthrin EC and 50% diafenthiuron SC) to two species of spider, Ebrechtella tricuspidata and Evarcha albaria. (iii) Field trials were used to investigate the controlling efficacy of 30% TS against E. obliqua larvae and to classify the effect of TS to spiders in the tea plantation. Results The toxicity of TS to 3rd-instar E. obliqua larvae occurred in a dose-dependent manner and the LC50 was 164.32 mg/mL. Activities of the detoxifying-related enzymes, GST and POD, increased in 3rd-instar E. obliqua larvae, whereas AChE and CES were inhibited with time by treatment with TS. Mortalities of E. tricuspidata and E. albaria after 48 h with 30% TS treatment (16.67% and 20%, respectively) were significantly lower than those with 10% bifenthrin EC (80% and 73.33%, respectively) and 50% diafenthiuron EC (43.33% and 36.67%, respectively). The highest controlling efficacy of 30% TS was 77.02% at 5 d after treatment, which showed no difference to 10% bifenthrin EC or 50% diafenthiuron SC. 30% TS was placed in the class N (harmless or slightly harmful) of IOBC (International Organization of Biological Control) categories for natural enemies, namely spiders. Conclusions Our results indicate that TS is a botanical insecticide that has a good controlling efficacy in E. obliqua larvae, which suggests it has promise as application in the integrated pest management (IPM) envisaged for tea crops

    Extracellular Proteome Analysis of Leptospira interrogans serovar Lai

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    Leptospirosis is one of the most important zoonoses. Leptospira interrogans serovar Lai is a pathogenic spirochete that is responsible for leptospirosis. Extracellular proteins play an important role in the pathogenicity of this bacterium. In this study, L. interrogans serovar Lai was grown in protein-free medium; the supernatant was collected and subsequently analyzed as the extracellular proteome. A total of 66 proteins with more than two unique peptides were detected by MS/MS, and 33 of these were predicted to be extracellular proteins by a combination of bioinformatics analyses, including Psortb, cello, SoSuiGramN and SignalP. Comparisons of the transcriptional levels of these 33 genes between in vivo and in vitro conditions revealed that 15 genes were upregulated and two genes were downregulated in vivo compared to in vitro. A BLAST search for the components of secretion system at the genomic and proteomic levels revealed the presence of the complete type I secretion system and type II secretion system in this strain. Moreover, this strain also exhibits complete Sec translocase and Tat translocase systems. The extracellular proteome analysis of L. interrogans will supplement the previously generated whole proteome data and provide more information for studying the functions of specific proteins in the infection process and for selecting candidate molecules for vaccines or diagnostic tools for leptospirosis.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140174/1/omi.2013.0043.pd

    Effects of Dietary Enterococcus faecalis YFI-G720 on the Growth, Immunity, Serum Biochemical, Intestinal Morphology, Intestinal Microbiota, and Disease Resistance of Crucian Carp (Carassius auratus)

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    Diseases of crucian carp (Carassius auratus) are closely related to intestinal parameters. Enterococcus faecalis has strong colonization ability in the intestinal tract, and produces natural antibiotics, bacteriocin, and other bacteriostatic substances, which can effectively inhibit some pathogenic bacteria and improve the intestinal microenvironment. This study aimed to assess the effects of E. faecalis YFI-G720 which was isolated from the intestinal of crucian carp on the growth, immunity, intestinal health, and disease resistance of crucian carp. Fish (48.16 &plusmn; 0.55 g) were fed four diets, commercial diet or diet containing E. faecalis at 105 CFU/g (EF1), 106 CFU/g (EF2), or 107 CFU/g (EF3) for 28 days. The results showed that supplementation of E. faecalis significantly improved the weight gain ratio (WGR) and the specific growth rate (SGR) compared with control group (p &lt; 0.05). Intestinal mucosal epithelial cells in EF2 were intact and normal, but there was obvious vacuolation in CG. Compared with CG, serum C3 and IgM in EF2 were significantly increased at the end of the experiment (p &lt; 0.05), and serum alkaline phosphatase was significantly higher in all experimental groups (p &lt; 0.05). Among studied immune-related genes, expression was detected by qPCR, C3, IgM, and IL-1&beta;were upregulated in all experimental groups to varying degrees from 14 days, with highest expression in EF2 at 28 days. Intestinal microbiota structure analyzed through high-throughput sequencing, and the results showed that the relative abundance of Aeromonas and Acinetobacter decreased while Cetobacterium increased in all experimental groups, with the greatest changes in EF2. Challenge tests showed that fish fed E. faecalis were more resistant to Aeromonas veronii (p &lt; 0.05). In conclusion, dietary E. faecalis YFI-G720 at 106 CFU/g can improve the health status, immune parameters, intestinal microbiota composition, and disease resistance of crucian carp
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