Morphological,biochemical, physiological and molecular aspects of the response of Fusobacterium nucleatum exposed to subinhibitory concentrations of antimicrobials

Subinhibitory concentrations (SICs) of antimicrobials may result in alterations in bacterial biology with implications for its potential aggression. This has considerable importance for the resident microbiota. Our aim was to analyze the effects of SICs of antimicrobials on the morphological, biochemical, physiological and molecular characteristics of the resident anaerobic Fusobacterium nucleatum. Fourteen strains were obtained from F. nucleatum ATCC 25586, selected by culturing on SICs of ampicillin, ampicillin/sulbactam, clindamycin, chloramphenicol, levofloxacin, metronidazole and piperacillin/tazobactam and subsequent culturing in the absence of drugs. Antimicrobial susceptibility, bacterial morphology, biochemical profiles and biofilm formation were evaluated. Genotyping and analysis of protein profiles were also performed. The antimicrobial susceptibility patterns showed that most of the derived strains were less sensitive to the antimicrobials, even after culturing them without drugs. Morphological and cell complexity alterations were observed, mainly in strains grown in SICs of β-lactam; these strains also expressed a reduced ability for biofilm formation. The other strains showed an increase in biofilm formation but no apparent morphological changes. Alterations were observed in the carbohydrate metabolism patterns and in the activity of microbial enzymes. Several proteins were positively or negatively regulated and there was polymorphism in the DNA from all derived strains. Therefore, SICs of antimicrobials induce alterations in F. nucleatum, which directly impact its biology. These results emphasize the risk of inadequate antibioticotherapy, which may have serious implications for clinical microbiology and infectious diseases and also may interfere with the host–bacteria relationship.     

Inheritance of fertility in broiler chickens

Background

The fertility of a chicken''s egg is a trait which depends on both the hen that lays the egg and on her mate. It is also known that fertility of an individual changes over the laying period.

Methods

Longitudinal models including both random genetic and permanent environmental effects of both the female and her male mate were used to model the proportion of fertile eggs in a pedigree broiler population over the ages 29-54 weeks.

Results

Both the male and the female contribute to variation in fertility. Estimates of heritability of weekly records were typically 7% for female and 10% for male contributions to fertility. Repeatability estimates ranged from 24 to 33%, respectively. The estimated genetic variance remained almost constant for both sexes over the laying period and the genetic correlations between different ages were close to 1.0. The permanent environment components increased substantially towards the end of the analyzed period, and correlations between permanent environment effects at different ages declined with increasing age difference The heritability of mean fertility over the whole laying period was estimated at 13% for females and 17% for males. A small positive correlation between genetic effects for male and female fertility was found.

Conclusion

Opportunities to improve fertility in broiler stocks by selection on both sexes exist and should have an impact throughout the laying period.     

Diversity of Bacteria Carried by Pinewood Nematode in USA and Phylogenetic Comparison with Isolates from Other Countries

Pine wilt disease (PWD) is native to North America and has spread to Asia and Europe. Lately, mutualistic relationship has been suggested between the pinewood nematode (PWN), Bursaphelenchus xylophilus the causal nematode agent of PWD, and bacteria. In countries where PWN occurs, nematodes from diseased trees were reported to carry bacteria from several genera. However no data exists for the United States. The objective of this study was to evaluate the diversity of the bacterial community carried by B. xylophilus, isolated from different Pinus spp. with PWD in Nebraska, United States. The bacteria carried by PWN belonged to Gammaproteobacteria (79.9%), Betaproteobacteria (11.7%), Bacilli (5.0%), Alphaproteobacteria (1.7%) and Flavobacteriia (1.7%). Strains from the genera Chryseobacterium and Pigmentiphaga were found associated with the nematode for the first time. These results were compared to results from similar studies conducted from other countries of three continents in order to assess the diversity of bacteria with associated with PWN. The isolates from the United States, Portugal and China belonged to 25 different genera and only strains from the genus Pseudomonas were found in nematodes from all countries. The strains from China were closely related to P. fluorescens and the strains isolated from Portugal and USA were phylogenetically related to P. mohnii and P. lutea. Nematodes from the different countries are associated with bacteria of different species, not supporting a relationship between PWN with a particular bacterial species. Moreover, the diversity of the bacteria carried by the pinewood nematode seems to be related to the geographic area and the Pinus species. The roles these bacteria play within the pine trees or when associated with the nematodes, might be independent of the presence of the nematode in the tree and only related on the bacteria''s relationship with the tree.     

Development and Validation of the Self-Acceptance Scale for Persons with Early Blindness: The SAS-EB

Investigations of self-acceptance are critical to understanding the development and maintenance of psychological health. However, valid and reliable instruments for measuring self-acceptance in persons with early blindness have yet to be developed. The current research describes three studies designed to develop and validate the Self-acceptance Scale for Persons with Early Blindness (SAS-EB). In Study 1, we developed the initial item pool. Thirty-three items were generated, based on data from specialized literature and from 2 focus groups. Items were organized in a three-factor structure, theoretically predicted for SAS-EB - (1) body acceptance, (2) self-protection from social stigmas, and (3) feeling and believing in one''s capacities. In Study 2, information obtained from a panel of 9 experts and 22 persons with early blindness representing the target population was used to refine the initial item pool, generating a new pool of 27 items. In Study 3, 318 persons with early blindness (141 women and 177 men), between 18 and 60 years of age (M = 37.74 years, SD = 12.37) answered the new pool of 27 items. After the elimination of 9 items using confirmatory factor analysis, we confirmed the theoretical three-factor structure of the SAS-EB. Study 3 also provided support for the scale''s internal consistency and construct validity. Finally, the psychometric properties of the SAS-EB, its utility, and its limitations are discussed along with considerations for future research.     

Determination of Parameters for the Supercritical Extraction of Antioxidant Compounds from Green Propolis Using Carbon Dioxide and Ethanol as Co-Solvent

The aim of this study was to determine the best processing conditions to extract Brazilian green propolis using a supercritical extraction technology. For this purpose, the influence of different parameters was evaluated such as S/F (solvent mass in relation to solute mass), percentage of co-solvent (1 and 2% ethanol), temperature (40 and 50°C) and pressure (250, 350 and 400 bar) using supercritical carbon dioxide. The Global Yield Isotherms (GYIs) were obtained through the evaluation of the yield, and the chemical composition of the extracts was also obtained in relation to the total phenolic compounds, flavonoids, antioxidant activity and 3,5-diprenyl-4-hydroxicinnamic acid (Artepillin C) and acid 4-hydroxycinnamic (p-coumaric acid). The best results were identified at 50°C, 350 bar, 1% ethanol (co-solvent) and S/F of 110. These conditions, a content of 8.93±0.01 and 0.40±0.05 g/100 g of Artepillin C and p-coumaric acid, respectively, were identified indicating the efficiency of the extraction process. Despite of low yield of the process, the extracts obtained had high contents of relevant compounds, proving the viability of the process to obtain green propolis extracts with important biological applications due to the extracts composition.     

Vegetation structure determines insect herbivore diversity in seasonally dry tropical forests

Vegetation structure can often determine insect herbivore fauna in forests, but this mechanism has been demonstrated in seasonally dry tropical forests (SDTFs) only at small spatial scales. In this study we evaluated the effects of the geographical location of SDTFs and vegetation structure on insect herbivore communities (leaf-chewing and sap-sucking guilds) in three Brazilian ecoregions (Cerrado, Cerrado/Caatinga transition, and Caatinga). We tested the following predictions: (1) insect herbivore species composition, richness, abundance and beta diversity differ among forests in different ecoregions; (2) insect richness, abundance and beta diversity are positively related to tree richness and density; (3) spatial turnover of species is the primary mechanism that generates herbivorous insect β-diversity in different ecoregions, and is positively influenced by tree richness. The composition, richness, and abundance of herbivorous insects differed over SDFs along the gradient of Cerrado and Caatinga. Both herbivore guilds responded positively to tree richness. Tree density only determined the richness and abundance of sap-sucking herbivores. Insect β-diversity was similar among Cerrado and transition areas, but lower in Caatinga itself; β-diversity was also positively affected by tree richness. Species turnover, as opposed to nestedness, was the main mechanism generating β-diversity, but itself was not related to tree richness. We demonstrate in this study the importance of landscape diversity and availability of local resources for herbivorous insect communities, and we emphasize the importance of SDTF conservation in different ecoregions as a result of species turnover.     

Principal-components analysis of Brazilian Indian anthropometric data

Analysis of nine characteristics on 1,205 males and 932 females from 12 tribes or groups of tribes indicated a poor relationship between morphology and language, as well as moderate agreement with the variability expected considering geography only. Two samples in the Xingu area studied during an interval of half a century (1897-1947) showed remarkable similarity. The conformity of the Caingang morphology with those of other tribes and the distinctiveness of the Xavante and Tenetehara has been amply confirmed.     

Gαo/i-stimulated proteosomal degradation of RGS20: A mechanism for temporal integration of Gs and Gi pathways

The G_s and G_i pathways interact to control the levels of intracellular cAMP. Although coincident signaling through G_s and G_i-coupled receptors can attenuate G_s-stimulated cAMP levels, it is not known if prior activation of the G_i pathway can affect signaling by G_s-coupled receptors. We have found that activated Gα_o/i interact with RGS20, a GTPase activating protein for members of the Gα_ο/i family. Interaction between Gα_o/i and RGS20 results in decreased cellular levels of RGS20. This decrease was induced by activated Gα_o and Gα_i2 but not by Gα_q, Gα_i1 or Gα_i3. The Gα_o/i-induced decrease in RGS20 can be blocked by proteasomal inhibitors lactacystin or MG132. Activated Gα_o stimulates the ubiquitination of RGS20. The serotonin-1A receptor that couples to G_o/i reduces the levels of RGS20 and this effect is blocked by lactacystin, suggesting that G_o/i promotes the degradation of RGS20. Expression of RGS20 attenuates the inhibition of β-adrenergic receptor-induced cAMP levels mediated by the serotonin-1A receptor. Prior activation of the serotonin-1A receptor results in loss of the RGS20-mediated attenuation, and the loss of attenuation is blocked when lactacystin is included during the prior treatment. These observations suggest that G_o/i-coupled receptors, by stimulating the degradation of RGS20, can regulate how subsequent activation of the G_s and G_i pathways controls cellular cAMP levels, thus allowing for signal integration.     

Pollen consumed by the solitary bee Tetrapedia diversipes (Apidae: Tetrapediini) in a tropical agroecosystem

Pollen analysis of the larval food supply is an important tool for identifying the plants that provide the floral resources used by bees. The present study documents the pollen sources consumed by larvae of the solitary bee Tetrapedia diversipes in a tropical agroecosystem. A total of 60 pollen types were recorded with three families being the most important. Euphorbiaceae (60.5%), Malpighiaceae (16.8%) and Asteraceae (12.2%) pollen had the greatest representation in the samples examined. The pollen of Dalechampia dioscoreifolia predominated in the diet of the larvae of T. diversipes (RF?=?56.35%) and indicates the importance of this plant in maintaining populations of this solitary bee.