Rapid Identification of Bacterial Species Associated with Bronchiectasis via Metagenomic Approach

Bronchiectasis is a chronic lung disorder and a number of bacterial pathogens are involved.However,30%-40% of sputum and purulent samples in good quality failed to grow any pathogenic bacteria,making it difficult to confirm the pathogen.In this study,we collected bronchoalveolar lavage fluid from a bronchiectasis patient undergoing acute exacerbation,and sent for 16 S rDNA pyrosequencing by a 454 GS Junior machine.Metagenomic analysis showed the composition of bacterial community in sample was complex.More than a half of reads（51.3%） were from Pseudomonas aeruginosa.This result was corresponding with the culture result but came out 2 d earlier,which is meaningful for early diagnosis and treatment.The detection with 16 S rDNA pyrosequencing technology is more sensitive and rapid than routine culture,and can detect the co-infection or symbiosis in airway,giving us a novel and convenient approach to perform rapid diagnosis.

Plant Biodiversity and Structure of Robusta Coffee (Coffea canephora var. robusta) Agroforests in Cameroon

Agroforests are man-made ecosystems in which crops are associated with a main perennial species like Robusta Coffee Agroforests (RCAs), which is counted among the main modes of perennial crops production in Cameroon. Despite the rich ecosystem services provided, the diversity of Associated Species (AS) found in these RCAs and the structure of the landscapes they form remain little known in Cameroon. The current study aimed to inventory AS and characterize the structure of RCAs in four sites (Ayos, Malantouen, Melong and Nkongsamba) belonging to three robusta coffee production basins in Cameroon. A systematic inventory with dendrometric measurements of the wood AS and coffee trees was carried out on 120 one-hectare plot unit, i.e. 30 plots per site. The results showed that 102 AS belonging to 83 genera and 41 families were identified in these RCAs. The RCAs of Ayos in the dense rainforest zone with bimodal rainfall pattern were the most diverse with 71 species, followed by those of Melong and Nkongsamba with respectively 39 and 33 species respectively in the dense rainforest zone with monomodal rainfall pattern, and Malantouen with 33 species in the high savannahs of the west. Structurally, average coffee tree and AS densities founded ranged from 1208 - 1456 plants/ha and 71 - 214 stems/ha and those of basal area from 7.29 - 17.40 m2/ha for coffee trees and 7.97 - 16.14 m2/ha for AS in function of site. Basis on the vertical stratification, the proportion of the 3 - 6 m stratum, which is mainly represented by introduced AS, varied from 38% - 62% depending on the site. The results of this study showed that RCAs contribute to the conservation of plant biodiversity, given the specific richness identified in these ecosystems.

A comparison of species composition and stand structure between planted and natural mangrove forests in Shenzhen Bay,South China

Aims For assisting faster restoration of damaged or severely disturbed coastal ecosystems,selected mangrove species have been planted on previously mangrove-inhabited sites of the tropical and subtropical coasts of southern China.The objective of this study was to understand the stand dynamics of the planted mangroves and their functional traits in comparison with natural mangrove forests under similar site conditions.Methods Species composition,stand density,tree size distribution,and aboveground production were investigated along three transects in a 50-year-old planted mangrove stand and three transects in an adjacent natural mangrove stand in Shenzhen Bay,South China.Measurements were made on tree distribution by species,stand structure,and aboveground biomass(AGB)distribution.Analyses were performed on the spatial patterns of tree size distribution and species association.Important Findings We found that the planted and natural mangrove stands did not differ in stand density,average diameter at breast height(DBH),species composition,and AGB.Spatial distribution of AGB and frequency at species level were also similar between the planted and natural stands.However,the traits in stand structure were more variable in the planted stand than in the natural stand,indicating higher spatiotemporal heterogeneity in the development and succession of planted mangroves.Geostatistical analyses show that both DBH and AGB were spatially auto-correlated within a specific range in the direction perpendicular to coastline.More than 60%of the variance in these attributes was due to spatial autocorrelation.The Ripley’s K-function analysis shows that the two dominant species,Kandelia obovata and Avicennia marina,clumped in broader scales in the natural stand than in the planted stand and displayed significant interspecific competition across the whole transect.It is suggested that interspecific competition interacts with spatial autocorrelation as the underlying mechanism shaping the mangrove structure.This study demonstrates that at age 50,mangrove plantations can perform similarly in stand structure,spatial arrangement of selected stand characteristics and species associations to the natural mangrove forests.

Community Structure of Urban Forest and Disposition Characteristics of Trees in Hefei Ring Park

Themethods of vegetation ecology were used to analyze the community structure of Hefei Ring Park, andspecies composition, distribution patternoftree heightand DBH weredescribed.Through calculation of tree growth index and association correlation of component species, the community structures were analyzed. The results showed that community structures are complex, there are 22 pairs of species with positive association, and tree individual in the following communities grow well and are more stable, the majorarePlatycladus orientalis-Prunuscerasifera f.atropurpurea-Osmanthusfragrans, Robinia pseduacacia- Ligustrum lucidum,Robinia pseudoacacia-Ginkgobiloba-Photinia serrulata,Populuscadadensis-Ligustrum lucidum-Osmanthusfragrans, Sophora japonica-Ligustrum lucidum-Buxussinica, Cyclobalanopsis glauca- Distylium racemosum.