33 research outputs found
Antimicrobial Activity and Genetic Profile of Enteroccoci Isolated from Hoopoes Uropygial Gland
Symbiotic microorganisms may be directly transferred from parents to offspring or acquired from a particular environment that animals may be able to select. If benefits for hosts vary among microbial strains, natural selection may favour hosts holding the most beneficial one. Enterococci symbionts living in the hoopoe (Upupa epops) uropygial gland are able to synthesise bacteriocins (antimicrobial peptides that inhibit the growth of competitor bacteria). We explored variability in genetic profile (through RAPD-PCR analyses) and antimicrobial properties (by performing antagonistic tests against ten bacterial indicator strains) of the different isolates obtained from the uropygial glands of hoopoe females and nestlings. We found that the genetic profile of bacterial isolates was related to antimicrobial activity, as well as to individual host identity and the nest from which samples were obtained. This association suggest that variation in the inhibitory capacity of Enterococci symbionts should be under selection.This work was financed by Ministerio de Ciencia e Innovación (Spanish National Government) and FEDER founds (projects CGL2010-19233-C03-01, and CGL2010-19233-C03-03), and Junta de Andalucía (P09-RNM-4557)
The Hoopoe's Uropygial Gland Hosts a Bacterial Community Influenced by the Living Conditions of the Bird
Molecular methods have revealed that symbiotic systems involving bacteria are mostly based on whole bacterial communities. Bacterial diversity in hoopoe uropygial gland secretion is known to be mainly composed of certain strains of enterococci, but this conclusion is based solely on culture-dependent techniques. This study, by using culture-independent techniques (based on the 16S rDNA and the ribosomal intergenic spacer region) shows that the bacterial community in the uropygial gland secretion is more complex than previously thought and its composition is affected by the living conditions of the bird. Besides the known enterococci, the uropygial gland hosts other facultative anaerobic species and several obligated anaerobic species (mostly clostridia). The bacterial assemblage of this community was largely invariable among study individuals, although differences were detected between captive and wild female hoopoes, with some strains showing significantly higher prevalence in wild birds. These results alter previous views on the hoopoe-bacteria symbiosis and open a new window to further explore this system, delving into the possible sources of symbiotic bacteria (e.g. nest environments, digestive tract, winter quarters) or the possible functions of different bacterial groups in different contexts of parasitism or predation of their hoopoe host.This work was supported by the Ministerio de Ciencia y Tecnología (projects CGL2005-06975/BOSFEDER; CGL2007-61251/BOSFEDER), the Ministerio de Ciencia e Innovación (projects CGL2009-14006/BOSFEDER; CGL2010-19233-C03-01/BOSFEDER; CGL2010-19233-C03-03/BOSFEDER), the Ministerio de Economía y Competitividad (projects CGL2013-48193-C3-1-P/BOSFEDER; CGL2013-48193-C3-2-P/BOSFEDER), and the Junta de Andalucía (RNM 345, P09-RNM-4557). SMRR received a grant from the Ministerio de Ciencia e Innovación (FPI program, BES-2011-047677)
Traditional medicinal plant use in Northern Peru: tracking two thousand years of healing culture
This paper examines the traditional use of medicinal plants in Northern Peru, with special focus on the Departments of Piura, Lambayeque, La Libertad, Cajamarca, and San Martin. Northern Peru represents the center of the old Central Andean "Health Axis," stretching from Ecuador to Bolivia. The roots of traditional healing practices in this region go at least as far back as the Moche period (AC 100–800). Although about 50% of the plants in use reported in the colonial period have disappeared from the popular pharmacopoeia, the plant knowledge of the population is much more extensive than in other parts of the Andean region. 510 plant species used for medicinal purposes were collected, identified and their vernacular names, traditional uses and applications recorded. The families best represented were Asteraceae with 69 species, Fabaceae (35), Lamiaceae (25), and Solanaceae (21). Euphorbiaceae had twelve species, and Apiaceae and Poaceae 11 species. The highest number of species was used for the treatment of "magical/ritual" ailments (207 species), followed by respiratory disorders (95), problems of the urinary tract (85), infections of female organs (66), liver ailments (61), inflammations (59), stomach problems (51) and rheumatism (45). Most of the plants used (83%) were native to Peru. Fresh plants, often collected wild, were used in two thirds of all cases, and the most common applications included the ingestion of herb decoctions or the application of plant material as poultices
Smoking cessation opportunities in severe mental illness (tobacco intensive motivational and estimate risk — TIMER—): study protocol for a randomized controlled trial
There is an increased risk of premature death in people with severe mental illness (SMI). Respiratory
disorders and cardiovascular disease are leading causes of increased mortality rates in these patients, and tobacco
consumption remains the most preventable risk factor involved. Developing new tools to motivate patients
towards cessation of smoking is a high priority. Information on the motivational value of giving the lung age and
prevention opportunities is unknown in this high-risk population. In the context of community care, screening and early detection of lung damage could potentially
be used, together with mobile technology, in order to produce a prevention message, which may provide
patients with SMI with a better chance of quitting smoking.This study receives funding by the Spanish Ministry of Economy, Industry
and Competitiveness, Instituto Carlos III (FIS PI16/00802)
Symbiotic association between hoopoes and antibiotic-producing bacteria that live in their uropygial gland
1. It has been recently showed that one bacterial strain isolated from the uropygial gland of a nestling hoopoe Upupa epops produced antimicrobial peptides active against a broad spectrum of pathogenic bacteria. These bacteria might thus mediate antimicrobial properties of the uropygial secretions as a consequence of the symbiotic association with hoopoes. 2. We study antimicrobial properties of white (from males and non-breeding females) and brown (from nestlings and breeding females) uropygial gland secretions of hoopoes Upupa epops, as well as the association with the presence of bacteria living inside their uropygial gland. 3. We found that brown, but not white secretions contained bacteria and showed antimicrobial activity against the feather degrading bacterium Bacillus licheniformis. The antagonistic activity of bacterial colonies was mediated by antimicrobial peptides because protease inhibited antimicrobial properties. 4. All except one identified bacterium in aerobic cultures were of the genus Enterococcus, and the microscopic study of uropygial secretions and glands confirmed a high density of bacteria within the gland. 5. Furthermore, we studied potential benefits of antimicrobial peptides produced by symbiotic bacteria of hoopoes by adding protease to incubating nests. 6. The experiment increased bacterial growth and hatching failures in hoopoes but not in spotless starlings Sturnus unicolor, a species that does not harbour bacteria in its uropygial gland. 7. Thus, microbiological, anatomical and ecological results suggest a tight symbiotic interaction between bacteria that produce antibiotic substances and the hoopoes. © 2008 The Authors.Peer Reviewe
Environmental Factors Shape the Community of Symbionts in the Hoopoe Uropygial Gland More than Genetic Factors
Exploring processes of coevolution of microorganisms and their hosts is a new imperative for life sciences. If bacteria protect
hosts against pathogens, mechanisms facilitating the intergenerational transmission of such bacteria will be strongly selected by
evolution. By disentangling the diversity of bacterial strains from the uropygium of hoopoes (Upupa epops) due to genetic relatedness
or to a common environment, we explored the importance of horizontal (from the environment) and vertical (from parents)
acquisition of antimicrobial-producing symbionts in this species. For this purpose, we compared bacterial communities
among individuals in nonmanipulated nests; we also performed a cross-fostering experiment using recently hatched nestlings
before uropygial gland development and some nestlings that were reared outside hoopoe nests. The capacity of individuals to
acquire microbial symbionts horizontally during their development was supported by our results, since cross-fostered nestlings
share bacterial strains with foster siblings and nestlings that were not in contact with hoopoe adults or nests also developed the
symbiosis. Moreover, nestlings could change some bacterial strains over the course of their stay in the nest, and adult females
changed their bacterial community in different years. However, a low rate of vertical transmission was inferred, since genetic
siblings reared in different nests shared more bacterial strains than they shared with unrelated nestlings raised in different nests.
In conclusion, hoopoes are able to incorporate new symbionts from the environment during the development of the uropygium,
which could be a selective advantage if strains with higher antimicrobial capacity are incorporated into the gland and could aid
hosts in fighting against pathogenic and disease-causing microbes.Peer reviewe
Enterocin Cross-Resistance Mediated by ABC Transport Systems
In their struggle for life, bacteria frequently produce antagonistic substances against competitors. Antimicrobial peptides produced by bacteria (known as bacteriocins) are active against other bacteria, but harmless to their producer due to an associated immunity gene that prevents self-inhibition. However, knowledge of cross-resistance between different types of bacteriocin producer remains very limited. The immune function of certain bacteriocins produced by the Enterococcus genus (known as enterocins) is mediated by an ABC transporter. This is the case for enterocin AS-48, a gene cluster that includes two ABC transporter-like systems (Transporter-1 and 2) and an immunity protein. Transporter-2 in this cluster shows a high similarity to the ABC transporter-like system in MR10A and MR10B enterocin gene clusters. The aim of our study was to determine the possible role of this ABC transporter in cross-resistance between these two different types of enterocin. To this end, we designed different mutants (Tn5 derivative and deletion mutants) of the as-48 gene cluster in Enterococcus faecalis and cloned them into the pAM401 shuttle vector. Antimicrobial activity assays showed that enterocin AS-48 Transporter-2 is responsible for cross-resistance between AS-48 and MR10A/B enterocin producers and allowed identification of the MR10A/B immunity gene system. These findings open the way to the investigation of resistance beyond homologous bacteriocins.This research was funded by Junta de Andalucía (Programa Operativo FEDER Andalucía 2014–2020), grant number A-BIO-083-UGR18. C.T.-P. was funded by Plan Estatal de Garantía Juvenil (Fondo Social Europeo, Gobierno de España, Ref. PEJ2018-003019-A).Ye
Projecting future air temperature of Hong Kong for the 21st century and its implications on urban planning and design.
近幾十年來,全球氣候變化──特別是城市氣候變化──影響城市環境及居民生活質素的程度已引起公眾廣泛的討論。然而,過去研究一般採用之低空間解析度並不足夠為城市規劃及設計提供完善的資訊,引致對於氣候變化缺乏充分的考慮。高密度的城市環境(如香港)需要高時間解析度的氣候數據以制定有效的適應和減緩策略來應對未來氣候的變化。本研究採用線性迴歸技術,以預測未來香港市區和郊區的氣溫。本研究利用氣象站和統計延伸得出之基線氣溫數據來建立統計降尺度模型,以預測未來香港市區和郊區之平均氣溫、最高氣溫和最低氣溫。根據結果顯示,統計降尺度模型能夠有效建立大氣氣象參數和本港氣溫兩者之間的關係,尤其春季、秋季和冬季之氣溫預測表現理想。另外,冬季氣溫的上升趨勢則出現較大的升幅。研究結果亦顯示夜間氣溫的上升趨勢一般比日間為高。在未來的日子,郊區的溫度上升亦將會比市區為高。隨著城市化的影響納入預測溫度因素之中,預計郊區的氣溫將超過城市核心(天文台總部之氣象站),而郊區暖化的速度亦比市區和近郊為高。本研究發現統計降尺度方法能有助利用全球氣候模型(GCM)提供之數據,以預測未來氣候之變化。城市規劃與設計過程是需要大量的數據進行評估氣候變化對城市環境的影響之研究,儘管統計降尺度方法有一定程度的局限性,它仍然是一個低成本而有效的方法。根據未來預測之氣溫,本研究具體指出未來之氣候變化對於城市規劃和設計過程的影響,亦提出了一系列於不同規劃層面適用之適應和減緩措施的建議。The effects of global climate change on urban environment have been widely discussed in recent decades. In particular, changes in urban climate have received much attention as they affect the living quality of urban dwellers. However, the coarse spatial scales employed in recent climate change studies were found to be insufficient in the context of urban planning and design. It leads to the lack of information on the changing urban climate and insufficient consideration of climate change in urban planning and design processes. In high-density cities like Hong Kong, the complex urban environment requires climatic data at very fine temporal resolution in order to formulate effective adaptation and mitigation strategies for future climate change.The present study employed regression techniques to establish empirical relationship between large-scale predictor variables and local predictands in order to obtain future air temperature of urban and rural areas of Hong Kong. 40-year baseline conditions of local air temperature were obtained from both the observational and statistically extended temperature record. Monthly means of daily mean, maximum, and minimum air temperatures for both daytime and night-time were calculated for establishing statistical downscaling (SD) models to project future air temperature of urban and rural areas of Hong Kong.The results suggest that regression-based downscaling techniques are able to capture the relationship between large-scale atmospheric conditions and station-scale meteorological parameters. The SD models performed particularly well in winter and considerably satisfactory results were obtained in spring and autumn. Night-time temperature trends generally exhibited greater increases than daytime trends. Seasonal variations were present with greatest increases observed in winter. Rural areas would likely experience greater warming than the urban areas in the future. With urbanization effect incorporated into the projected temperature series, it was found that air temperature projected for suburban stations would exceed that for the urban core. Rural warming also exhibited a higher rate than those observed in suburban and urban stations.The present study shows that statistical downscaling approach provides a method to obtain information about future climatic conditions at local scale by using GCM outputs which are widely accepted to be useful tools to assist climate change studies. Despite of the limitations that historical climate would persist in projected climatic series, it allows a low-cost but effective measure for climate impact assessments, particularly in the context of urban planning and design, which requires extensive data for a wide range of studies. Based on the projected air temperature, implications of future climate change on urban planning and design of potential development were discussed and recommendations on potential adaptation and mitigation measures at different planning levels were also presented.Detailed summary in vernacular field only.Detailed summary in vernacular field only.Detailed summary in vernacular field only.Detailed summary in vernacular field only.Lau, Ka Lun.Thesis (Ph.D.) Chinese University of Hong Kong, 2013.Includes bibliographical references (leaves 159-173).Abstracts also in Chinese