Diversities and Shifts of Microbial Communities Associated with Farmed Oysters (Crassostrea gigas) and Their Surrounding Environments in Laoshan Bay Marine Ranching, China.

Pacific oysters (Crassostrea gigas) are widely cultured in Chinese marine ranching with high economic value. However, mass death of farmed oysters has occurred frequently in recent years because of diseases and environmental disturbance (e.g., high temperatures). In order to analyze the potential relationships between microorganisms and the death of farmed oysters, we compared the dynamics of bacterial and protist communities in oysters at different growth phases using high-throughput sequencing. The results showed that the microbial communities in farmed oysters significantly changed and were markedly different from microbes in natural oysters and the surrounding environments. The number of biomarker taxa among farmed oysters and their surrounding environments decreased gradually with the growth of oysters. During the mass death of farmed oysters, the microbial communities' abundance of ecological function genes changed, and the correlations among microorganisms disappeared. These results enrich our understanding of the dynamics of microbial communities in farmed oysters at different growth phases, illustrating the characteristics of interactions among microorganisms during the mass death of farmed oysters. Our study is beneficial to promote the healthy aquaculture of oysters.

Seasonal variations and co-occurrence networks of bacterial communities in the water and sediment of artificial habitat in Laoshan Bay, China.

Marine bacteria in the seawater and seafloor are essential parts of Earth's biodiversity, as they are critical participants of the global energy flow and the material cycles. However, their spatial-temporal variations and potential interactions among varied biotopes in artificial habitat are poorly understood. In this study, we profiled the variations of bacterial communities among seasons and areas in the water and sediment of artificial reefs using 16S rRNA gene sequencing, and analyzed the potential interaction patterns among microorganisms. Distinct bacterial community structures in the two biotopes were exhibited. The Shannon diversity and the richness of phyla in the sediment were higher, while the differences among the four seasons were more evident in the water samples. The seasonal variations of bacterial communities in the water were more distinct, while significant variations among four areas were only observed in the sediment. Correlation analysis revealed that nitrite and mud content were the most important factors influencing the abundant OTUs in the water and sediment, respectively. Potential interactions and keystone species were identified based on the three co-occurrence networks. Results showed that the correlations among bacterial communities in the sediment were lower than in the water. Besides, the abundance of the top five abundant species and five keystone species had different changing patterns among four seasons and four areas. These results enriched our understanding of the microbial structures, dynamics, and interactions of microbial communities in artificial habitats, which could provide new insights into planning, constructing and managing these special habitats in the future.

Comparative analysis of microbial communities between water and sediment in Laoshan Bay marine ranching with varied aquaculture activities.

We profiled and compared the bacterial and protist community compositions and dynamics in the Laoshan Bay marine ranching involving varied aquaculture activities. The dominant species, differential species and community compositions among the five aquaculture areas, two habitats and two periods were significantly different. The relationships between microbial communities and environmental factors were analyzed. We found that microbial communities in the water were more sensitive to the environmental changes than sediment, and the responses of bacterial and protist communities to the disturbances were varied. To meet the challenges of higher aquaculture density, the proportion of the positive correlations among co-occurrence networks in the water increased markedly from July to November; while the positive proportion in the sediment was stable. Potential ecological interactions and keystone taxa between bacteria and protists were studied. These results advanced our understanding of how mariculture stressors affect microbial communities in marine ranching.

Clinical investigation of acute myocardial infarction according to age subsets.

A growing number of 'Young' patients less than 40 years of age are being hospitalized with a diagnosis of acute myocardial infarction (AMI) due to increased prevalence of risk factors for atherosclerosis. The aim of this study was to compare clinical characteristics and performances of AMI between young and elderly patients. We conducted a retrospective study to compare AMI in young patients and elder patients. Based on the medical record databases in our hospital, we enrolled 114 'young' AMI patients (age ≤42 years) and 179 'elder' AMI patients (≥60 years), and then collected and analyzed their demographic information, clinical performances, and coronary angiography results. In the young AMI group, the proportion of male patients was higher than that in the elder AMI group (94.7 vs. 64.2%, P<0.05). Compared with the elder AMI patients, young patients had higher rates of smoking history and positive family medical history, but lower rates of hypertension and diabetes. Elder patients with AMI were more likely to develop various clinical performances, and multiple-branch lesions; however, young AMI patients had relatively fewer symptoms, and the tissue lesions were more limited. The clinical profiles of AMI in young patients were different from that in elder AMI patients. Specific interventions should be carried out to prevent and control the prevalence of AMI in the young population.