Spatiotemporal successions of shrimp gut microbial colonization: high consistency despite distinct species pool.

Aquatic animals encounter suites of novel planktonic microbes during their development. Although hosts have been shown to exert strong selection on their gut microbiota from surrounding environment, to what extent and the generality that the gut microbiota and the underlying ecological processes are affected by biotic and abiotic variations are largely unclear. Here, these concerns were explored by coupling spatiotemporal data on gut and rearing water bacterial communities with environmental variables over shrimp life stages at spatially distant locations. Shrimp gut microbiotas significantly changed mirroring their development, as evidenced by gut bacterial signatures of shrimp life stage contributing 95.5% stratification accuracy. Shrimp sourced little (2.6%-15.8%) of their gut microbiota from their rearing water. This microbial resistance was reflected by weak compositional differences between shrimp farming spatially distinct locations where species pools were distinct. Consistently, the assembly of shrimp gut microbiota was not adequately explained by the rearing water variables and bacterial community, but rather by host-age-associated biotic features. The successions of shrimp gut microbiota were droved by replacement (ßsim), rather than by nestedness (ßnes), while those of bacterioplankton communities were equally governed by replacement and nestedness. Our study highlights how shrimp gut bacterial community assembly is coupled to their development, rearing species pool, and that the successional pattern of host-associated communities is differed from that of free-living bacteria.

Integrating molecular and ecological approaches to identify potential polymicrobial pathogens over a shrimp disease progression.

It is now recognized that some gut diseases attribute to polymicrobial pathogens infections. Thus, traditional isolation of single pathogen from disease subjects could bias the identification of causal agents. To fill this gap, using Illumina sequencing of the bacterial 16S rRNA gene, we explored the dynamics of gut bacterial communities over a shrimp disease progression. The results showed significant differences in the gut bacterial communities between healthy and diseased shrimp. Potential pathogens were inferred by a local pathogens database, of which two OTUs (affiliated with Vibrio tubiashii and Vibrio harveyi) exhibited significantly higher abundances in diseased shrimp as compared to healthy subjects. The two OTUs cumulatively contributed 64.5% dissimilarity in the gut microbiotas between shrimp health status. Notably, the random Forest model depicted that profiles of the two OTUs contributed 78.5% predicted accuracy of shrimp health status. Removal of the two OTUs from co-occurrence networks led to network fragmentation, suggesting their gatekeeper features. For these evidences, the two OTUs were inferred as candidate pathogens. Three virulence genes (bca, tlpA, and fdeC) that were coded by the two candidate pathogens were inferred by a virulence factor database, which were enriched significantly (P < 0.05 in the three cases, as validated by qPCR) in diseased shrimp as compared to healthy ones. The two candidate pathogens were repressed by Flavobacteriaceae, Garvieae, and Photobacrerium species in healthy shrimp, while these interactions shifted into synergy in disease cohorts. Collectively, our findings offer a frame to identify potential polymicrobial pathogen infections from an ecological perspective.

The effect of health literacy and self-management efficacy on the health-related quality of life of hypertensive patients in a western rural area of China: a cross-sectional study.

BACKGROUND: Hypertension is a common and frequently occurring chronic disease of the cardiovascular system. Besides the pathological factors, the occurrence and exacerbation of hypertension are also associated with many factors of lifestyle and behaviors. Thus hypertensive patients' Health-related quality of life (HRQL) is not only influenced by the disease itself but also by many subjective factors such as health literacy and self-management efficacy, especially in the deeper part of southwestern China and thus is less developed compared to the other places. The purpose of this study was to examine the association between the HRQL of hypertensive patients and health literacy and self-management efficacy as well as how they affect the HRQL, so as to provide a theoretical reference for improving the HRQL of patients with hypertension in less developed areas. METHODS: This was a cross-sectional study of baseline data from a clustered randomized controlled trial. The study design had passed a cross-national peer review and accepted grants by the China Medical Board. It was also registered in the Chinese Clinical Trial Registry (ChiCTR-OOR-14005563). A standardized questionnaire adapted from a previous validated WHO questionnaire was used for the survey which included detailed questions about patient's socio-demographic characteristics and self-reported information. Patients' HRQL was measured by the Mandarin version of the 36-item Short Form. We used the validated Mandarin version of the Self-Efficacy for Managing Chronic Disease 6-Item Scale to assess patients' self-management efficacy. The validated three-item Brief Health Literacy Screening (BHLS) was used to measure the patients' health literacy. A structural equation model was constructed, and p ≤ 0.05 was taken as significant. RESULTS: Demographic characteristics, health literacy and self-management efficacy have all significant effects on HRQL. Age, education level, self-management efficacy and health literacy were significantly related to the HRQL. The constructed model had a good fit for the data according to the model fit indices. Based on the model, health literacy (r = 0.604, p = 0.029) and Self-management efficacy (r = 0.714, p = 0.018) have a significant impact on HRQL. Demographic characteristics were inversely related to HRQL (r = -0.419, p = 0.007), but have a significant impact on health literacy (r = 0.675, p = 0.029) and self-management efficacy (r = 0.379, p = 0.029). At the same time, self-management efficacy was positively correlated to health literacy (r = 0.413, p < 0.01). CONCLUSIONS: Age, education level, self-management efficacy and health literacy were all related to the HRQL of patient with hypertension, which means that patients who are more elderly and have lower education level, low self-management efficacy and poor health literacy get worse HRQL. This may imply the necessary to introduce routine assessment of health literacy and self-management efficacy into assessment procedures for hypertensive patients' health management. Such assessment can help professionals to identify the population at greatest risk for poor health outcomes and low well-being in the future. In clinical practice, effective interventions such as direct guidance and education to raise the self-management efficacy and enhance health literacy might improve the HRQL of patients with hypertension. TRIAL REGISTRATION: Retrospectively registered Chinese Clinical Trial Registry ( ChiCTR-OOR-14005563 ). Name of registry: Effects of the integrated delivery system and payment system of community-based intervention on rural patients of chronic diseases in Qianjiang District, China Date of registration: Retrospectively registered 23 November 2014. Date of enrolment of the first participant to the trial: 5 July 2012.

Sediment prokaryotic assembly, methane cycling, and ammonia oxidation potentials in response to increasing antibiotic pollution at shrimp aquafarm.

Antibiotic pollution poses serious threats to public health and ecological processes. However, systematic research regarding the interactive effects of increasing nutrient and antibiotic pollutions on the prokaryotic community, particularly taxa that contribute to greenhouse gas emissions, is lacking. By exploring the complex interactions that occur between interkingdom bacteria and archaea, biotic and abiotic factors, the responses of sediment prokaryotic assembly were determined along a significant antibiotic pollution gradient. Bacterial and archaeal communities were primarily governed by sediment antibiotic pollution, ammonia, phosphate, and redox potential, which further affected enzyme activities. The two communities nonlinearly responded to increasing antibiotic pollution, with significant tipping points of 3.906 and 0.979 mg/kg antibiotics, respectively. The combined antibiotic concentration-discriminatory taxa of bacteria and archaea accurately (98.0% accuracy) diagnosed in situ antibiotic concentrations. Co-abundance analysis revealed that the methanogens, methanotrophs, sulfate-reducing bacteria, and novel players synergistically contributed to methane cycling. Antibiotic pollution caused the dominant role of ammonia-oxidizing archaea in ammonia oxidation at these alkaline sediments. Collectively, the significant tipping points and bio-indicators afford indexes for regime shift and quantitative diagnosis of antibiotic pollution, respectively. Antibiotic pollution could expedite methane cycling and mitigate nitrous oxide yield, which are previously unrecognized ecological effects. These findings provide new insights into the interactive biological and ecological consequences of increasing nutrient and antibiotic pollutions.

[Bacterial Community Composition in Channel Sediment in Response to Mariculture Wastewater Drainage].

The impact of mariculture on the ecological environment of sediments in surrounding waters is intensely debated. Microbial communities are considered to be keystone indicators of lineage responses to changes in environmental quality. To examine the mariculture effects, we collected channel sediment from four sites in the culture area including oneintake canal, one outfall, and two outlet canals. On the basis of bacterial 16S rRNA gene and phospholipid fatty acid (PLFA) technology, we used Illumina MiSeq sequencing applied to the analysis results to explore the effects of mariculture wastewater drainage on the bacterial community structures in the sediment. The results revealed that Proteobacteria, including γ-Proteobacteria, δ-Proteobacteria, and α-Proteobacteria, were the dominant lineages of bacteria at the four sites. The microbial biomass of the sediment increased significantly owing to the effects of mariculture wastewater drainage. The relative abundance of Actinobacteria and ammoniated microorganisms decreased, whereas the relative abundance of Bacteroidetes increased. The results of non-metric multidimensional scaling (NMDS) analysis indicated that most of the sediment bacterial communities clustered by influent and effluent. The diversity indicated that the mariculture wastewater drainage decreased the bacterial diversity, and redundancy analysis (RDA) indicated that the most obvious correlation occurred between ammonia nitrogen and bacterial community structures. In summary, the mariculture wastewater drainage resulted in significant changes in the physical and chemical properties and structures of bacterial communities in the aquaculture channel sediment. This indicates that the long-term direct discharge of aquaculture wastewater would excessively contaminate a channel environment and might further pose a threat to the offshore ecological environment.

Bacterioplankton community responses and the potential ecological thresholds along disturbance gradients.

Increasing intensity and frequency of coastal pollutions are the trajectory to be expected due to anthropogenic pressures. However, it is still unclear how and to what extent bacterioplankton communities respond to the two factors, despite the functional importance of bacterioplankton in biogeochemical cycles. In this study, significant organic pollution index (OPI) and offshore distance gradients, as respective proxies of disturbance intensity and disturbance frequency, were detected in a regional scale across the East China Sea. A multiple regression on matrices (MRM) revealed that the biogeography of bacterioplankton community depended on spatial scale, which was governed by local characters. Bacterioplankton community compositions (BCCs) were primarily governed by the conjointly direct (-0.28) and indirect (-0.48) effects of OPI, while offshore distance contributed a large indirectly effect (0.52). A SEGMENTED analysis depicted non-linear responses of BCCs to increasing disturbance intensity and disturbance frequency, as evidenced by significant tipping points. This was also true for the dominant bacterial phyla. Notably, we screened 30 OPI-discriminatory taxa that could quantitatively diagnose coastal OPI levels, with an overall 79.3% accuracy. Collectively, the buffer capacity of bacterioplankton communities to increasing disturbance intensity and disturbance frequency is limited, of which the significant tipping points afford a warning line for coastal management. In addition, coastal pollution level can be accurately diagnosed by a few OPI-discriminatory taxa.

[Effects of Organic Pollutants on the Bacterioplankton Community in Hangzhou Bay].

Hangzhou Bay suffers from intensive anthropogenic disturbances and a huge amount of terrestrial inputs, and thus has become one of the most seriously contaminated coastal zones in China. There is evidence that microbes play a dominant role in pollutant biodegradation and serve as biomarkers for pollution levels. However, it remains unclear how the bacterioplankton communities respond to organic contaminants. To fill this knowledge gap, we collected surface water samples (0.5 m below the surface layer) from 13 sites across Hangzhou Bay and 8 control sites across its adjacent offshore areas. Using Illumina sequencing based on analysis of the bacterial 16S rRNA gene, we explored the effects of increasing organic pollution levels on the bacterioplankton community compositions (BCCs). The results revealed that the organic pollution level (A) in Hangzhou Bay (13.2±1.6) was significantly (P<0.001) higher than in the control zone (5.4±3.0). The distribution and diversity of bacterioplankton communities were significantly distinct between the two zones. The dominant bacterioplankton lineages in Hangzhou Bay were γ-Proteobacteria (24.4%±5.5%), α-Proteobacteria (16.5%±7.7%), and Planctomycetes (13.9%±8.6%), whereas those in the adjacent zones were Cyanobacteria (20.1%±7.5%), Bacteroidetes (18.4%±1.5%), Actinobacteria (17.5%±4.2%), γ-Proteobacteria (16.6%±1.2%), and α-Proteobacteria (14.3%±1.7%). Multivariate regression tree (MRT) analysis showed that the bacterioplankton community diversity was primarily affected by suspended particulates (SP), nitrite, oil, and organic pollutants, which respectively explained 22.0%, 6.5%, 6.0%, and 5.5% of the variance in diversity. Redundancy analysis (RDA) illustrated that the bacterioplankton community distribution was controlled by organic pollutants, COD, Chla, TN, nitrate, and salinity, which cumulatively governed 71.0% of the variation in BCCs. Organic pollutants alone controlled 6.5% variance, which was higher than any other single factor. Additionally, 35 sensitive species were identified via the indicator value method and their relative abundances were significantly associated (P<0.05 in each case) with the organic pollution level, thereby indicating their potential for evaluating coastal pollution. Collectively, our work demonstrates that BCCs are sensitive to coastal pollution and provides biomarkers for elevated pollution levels.