Screening for antimicrobial activity of ten medicinal plants used in Colombian folkloric medicine: A possible alternative in the treatment of non-nosocomial infections

BACKGROUND: The antimicrobial activity and Minimal Inhibitory Concentration (MIC) of the extracts of Bidens pilosa L., Bixa orellana L., Cecropia peltata L., Cinchona officinalis L., Gliricidia sepium H.B. & K, Jacaranda mimosifolia D.Don, Justicia secunda Vahl., Piper pulchrum C.DC, P. paniculata L. and Spilanthes americana Hieron were evaluated against five bacteria (Staphylococcus aureus, Streptococcus β hemolític, Bacillus cereus, Pseudomonas aeruginosa, and Escherichia coli), and one yeast (Candida albicans). These plants are used in Colombian folk medicine to treat infections of microbial origin. METHODS: Plants were collected by farmers and traditional healers. The ethanol, hexane and water extracts were obtained by standard methods. The antimicrobial activity was found by using a modified agar well diffusion method. All microorganisms were obtained from the American Type Culture Collection (ATCC). MIC was determined in the plant extracts that showed some efficacy against the tested microorganisms. Gentamycin sulfate (1.0 μg/ml), clindamycin (0.3 μg/ml) and nystatin (1.0 μg/ml) were used as positive controls. RESULTS: The water extracts of Bidens pilosa L., Jacaranda mimosifolia D.Don, and Piper pulchrum C.DC showed a higher activity against Bacillus cereus and Escherichia coli than gentamycin sulfate. Similarly, the ethanol extracts of all species were active against Staphylococcus aureus except for Justicia secunda. Furthermore, Bixa orellana L, Justicia secunda Vahl. and Piper pulchrum C.DC presented the lowest MICs against Escherichia coli (0.8, 0.6 and 0.6 μg/ml, respectively) compared to gentamycin sulfate (0.9 8g/ml). Likewise, Justicia secunda and Piper pulchrum C.DC showed an analogous MIC against Candida albicans (0.5 and 0.6 μg/ml, respectively) compared to nystatin (0.6 μg/ml). Bixa orellana L, exhibited a better MIC against Bacillus cereus (0.2 μg/ml) than gentamycin sulfate (0.5 μg/ml). CONCLUSION: This in vitro study corroborated the antimicrobial activity of the selected plants used in folkloric medicine. All these plants were effective against three or more of the pathogenic microorganisms. However, they were ineffective against Streptococcus β hemolytic and Pseudomonas aeruginosa. Their medicinal use in infections associated with these two species is not recommended. This study also showed that Bixa orellana L, Justicia secunda Vahl. and Piper pulchrum C.DC could be potential sources of new antimicrobial agents

Turnip yellow mosaic virus in Chinese cabbage in Spain: Commercial seed transmission and molecular characterization

[EN] Seed transmission of Turnip yellow mosaic virus (TYMV, genus Tymovirus) was evaluated in the whole seeds and seedlings that emerged from three commercial Chinese cabbage (Brassica pekinensis) seed batches. Seedlings in the cotyledon stage and adult plants were assayed for TYMV by DAS-ELISA and confirmed by RT-PCR. The proportion of whole seeds infected with TYMV was at least 0.15 %. The seeds of the three seed batches were grown in Petri dishes, and surveyed in the cotyledon stage in trays that contained a peat:sand mixture grown in greenhouses or growth chambers, which were analysed in the cotyledon and adult stages. The seed-to-seedling transmission rate ranged from 2.5 % to 2.9 % in two different seed batches (lot-08 and lot-09, respectively). Spanish isolates derived from turnip (Sp-03) and Chinese cabbage (Sp-09 and Sp-13), collected in 2003, 2009 and 2013 in two different Spanish regions, were molecularly characterised by analysing the partial nucleotide sequences of three TYMV genome regions: partial RNA-dependent RNA polymerase (RdRp), methyltransferase (MTR) and coat protein (CP) genes. Phylogenetic analyses showed that the CP gene represented two different groups: TYMV-1 and TYMV-2. The first was subdivided into three subclades: European, Australian and Japanese. Spanish isolate Sp-03 clustered together with European TYMV group, whereas Sp-09 and Sp-13 grouped with the Japanese TYMV group, and all differed from group TYMV-2. The sequences of the three different genomic regions examined clustered into the same groups. The results suggested that Spanish isolates grouped according to the original hosts from which they were isolated. The inoculation of the Spanish TYMV isolates to four crucifer plants species (turnip, broccoli, Brunswick cabbage and radish) revealed that all the isolates infected turnip with typical symptoms, although differences were observed in other hosts.Alfaro Fernández, AO.; Serrano, A.; Tornos, T.; Cebrian Mico, MC.; Córdoba-Sellés, MDC.; Jordá, C.; Font San Ambrosio, MI. (2016). Turnip yellow mosaic virus in Chinese cabbage in Spain: Commercial seed transmission and molecular characterization. EUROPEAN JOURNAL OF PLANT PATHOLOGY. 146(2):433-442. doi:10.1007/s10658-016-0929-3S4334421462Assis Filho, M., & Sherwood, J. L. (2000). Evaluation of seed transmission of Turnip yellow mosaic virus and Tobacco mosaic virus in Arabidopsis thaliana. Phytopathology, 90, 1233–1238.Benetti, M. P., & Kaswalder, F. (1983). Trasmisione per seme del virus del mosaico giallo rapa. Annali dell Istituto Sperimentale per la Patologia Vegetale, 8, 67–70.Blok, J., Mackenzie, A., Guy, P., & Gibbs, A. (1987). 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Matthews’ plant virology (4a ed.1001 pp). San Diego: Academic Press.Johansen, E., Edwards, M. C., & Hampton, R. O. (1994). Seed transmission of viruses: current perspectives. Annual Review of Phytopathology, 32, 363–386.Kirino, N., Inoue, K., Tanina, K., Yamazaki, Y., & Ohki, S. T. (2008). Turnip yellow mosaic virus isolated from Chinese cabbage in Japan. Journal of General Plant Pathology, 74, 331–334.Markham, R., & Smith, K. S. (1949). Studies on the virus of turnip yellow mosaic. Parasitology, 39, 330–342.Mathews, R. E. F. (1980). Turnip yellow mosaic virus, CMI/AAB Descriptions of plant virus No. 230 (No. 2 revised). Kew: Commonwealth Mycology Institute/Association of Applied Biologists.Mitchell, E. J., & Bond, J. M. (2005). Variation in the coat protein sequence of British isolates of Turnip yellow mosaic virus and comparison with previously published isolates. Archives of Virology, 150, 2347–2355.Pagán, I., Fraile, A., Fernández-Fueyo, E., Montes, N., Alonso-Blanco, C., & García-Arenal, F. (2010). Arabidopsis thaliana as a model for the study of plant-virus co-evolution. Philosophical Transations of the Royal Society Biological Sciences, 365, 1983–1995.Paul, H. L., Gibbs, A., & Wittman-Liebold, B. (1980). The relationships of certain Tymoviruses assessed from the amino acid composition of their coat proteins. Intervirology, 13, 99–109.Pelikanova, J. (1990). Garlic mustard a spontaneous host of TYMV. Ochrana Rostlin, 26, 17–22.Procházková, Z. (1980). Host range and symptom differences between isolates of Turnip mosaic virus obtained from Sisymbrium loeselii. Biologia Plantarum, 22, 341–347.Rimmer, S. R., Shtattuck, V. I., & Buchwaldt, L. (2007). Compendium of brassica diseases (1ª Edición ed.p. 117). USA: APS press.Rot, M. E., & Jelkman, W. (2001). 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Nestedness of Ectoparasite-Vertebrate Host Networks

Determining the structure of ectoparasite-host networks will enable disease ecologists to better understand and predict the spread of vector-borne diseases. If these networks have consistent properties, then studying the structure of well-understood networks could lead to extrapolation of these properties to others, including those that support emerging pathogens. Borrowing a quantitative measure of network structure from studies of mutualistic relationships between plants and their pollinators, we analyzed 29 ectoparasite-vertebrate host networks—including three derived from molecular bloodmeal analysis of mosquito feeding patterns—using measures of nestedness to identify non-random interactions among species. We found significant nestedness in ectoparasite-vertebrate host lists for habitats ranging from tropical rainforests to polar environments. These networks showed non-random patterns of nesting, and did not differ significantly from published estimates of nestedness from mutualistic networks. Mutualistic and antagonistic networks appear to be organized similarly, with generalized ectoparasites interacting with hosts that attract many ectoparasites and more specialized ectoparasites usually interacting with these same “generalized” hosts. This finding has implications for understanding the network dynamics of vector-born pathogens. We suggest that nestedness (rather than random ectoparasite-host associations) can allow rapid transfer of pathogens throughout a network, and expand upon such concepts as the dilution effect, bridge vectors, and host switching in the context of nested ectoparasite-vertebrate host networks

Human subcortical brain asymmetries in 15,847 people worldwide reveal effects of age and sex

The two hemispheres of the human brain differ functionally and structurally. Despite over a century of research, the extent to which brain asymmetry is influenced by sex, handedness, age, and genetic factors is still controversial. Here we present the largest ever analysis of subcortical brain asymmetries, in a harmonized multi-site study using meta-analysis methods. Volumetric asymmetry of seven subcortical structures was assessed in 15,847 MRI scans from 52 datasets worldwide. There were sex differences in the asymmetry of the globus pallidus and putamen. Heritability estimates, derived from 1170 subjects belonging to 71 extended pedigrees, revealed that additive genetic factors influenced the asymmetry of these two structures and that of the hippocampus and thalamus. Handedness had no detectable effect on subcortical asymmetries, even in this unprecedented sample size, but the asymmetry of the putamen varied with age. Genetic drivers of asymmetry in the hippocampus, thalamus and basal ganglia may affect variability in human cognition, including susceptibility to psychiatric disorders

Genetic diversity in the Andes:variation within and between the South American species of <i>Oreobolus</i> R. Br. (Cyperaceae)

This is the author accepted manuscript. The final version is available from Springer Verlag via the DOI in this record.This study examines genetic relationships among and within the South American species of Oreobolus that span the temperate and tropical Andes hotspots and represent a good case study to investigate diversification in the Páramo. A total of 197 individuals covering the distributional range of most of these species were sequenced for the nuclear ribosomal internal transcribed spacer (ITS) and 118 individuals for three chloroplast DNA regions (trnL-F, trnH-psbA and rpl32-trnL). Haplotype networks and measures of genetic diversity were calculated at different taxonomic and geographic levels. To test for possible geographic structure, a spatial analysis of molecular variance (SAMOVA) was undertaken and species relationships were recovered using a coalescent-based approach. Results indicate complex relationships among the five South American species of Oreobolus, which are likely to have been confounded by incomplete lineage sorting, though hybridization cannot be completely discarded as an influence on genetic patterns, particularly among the northern populations of O. obtusangulus and O. cleefii. We report a case of cryptic speciation in O. obtusangulus where northern and southern populations of morphologically similar individuals are genetically distinct in all analyses. At the population level, the genetic evidence is consistent with contraction and expansion of islands of Páramo vegetation during the climatic fluctuations of the Quaternary, highlighting the role of these processes in shaping modern diversity in that ecosystem.This work was funded by a School of Biological Sciences Scholarship provided through The University of Edinburgh. We thank the herbaria at Aarhus University, (Denmark), Naturalis (The Netherlands) and Reading University (Great Britain) for making material available for DNA extraction. We also thank three anonymous reviewers for their valuable comments and James Nicholls from The University of Edinburgh for assistance with the *BEAST analysis

Risk factors associated with Trypanosoma cruziexposure in domestic dogs from a rural community in Panama

Chagas disease, caused by Trypanosoma cruzi infection, is a zoonosis of humans, wild and domestic mammals,including dogs. In Panama, the main T. cruzi vector is Rhodnius pallescens, a triatomine bug whose main naturalhabitat is the royal palm, Attalea butyracea. In this paper, we present results from three T. cruzi serological tests(immunochromatographic dipstick, indirect immunofluorescence and ELISA) performed in 51 dogs from 24 housesin Trinidad de Las Minas, western Panama. We found that nine dogs were seropositive (17.6% prevalence). Dogswere 1.6 times more likely to become T. cruzi seropositive with each year of age and 11.6 times if royal palms wherepresent in the peridomiciliary area of the dog’s household or its two nearest neighbours. Mouse-baited-adhesivetraps were employed to evaluate 12 peridomestic royal palms. All palms were found infested with R. pallescens withan average of 25.50 triatomines captured per palm. Of 35 adult bugs analysed, 88.6% showed protozoa flagellates intheir intestinal contents. In addition, dogs were five times more likely to be infected by the presence of an additionaldomestic animal species in the dog’s peridomiciliary environment. Our results suggest that interventions focused onroyal palms might reduce the exposure to T. cruzi infection