European stone fruit Yellows phytoplasma in Japanese plum and Myrobalan plum in Bosnia and Herzegovina

Stone fruits from commercial as well as abandoned orchards were evaluated for European Stone Fruit Yellows phytoplasma (ESFY) presence during 2004-2007 years. Orchards were monitored in western and southern districts of Bosnia and Herzegovina. In the first survey conducted in period of 2004 till 2005 the causal agent of ESFY was identified on peach (Prunus persica) and apricot (Prunus armeniaca) plants in both surveyed districts. During 2007, a new survey was performed and samples were taken from symptomatic and symptomless plants of European plum (Prunus domestica), Japanese plum (Prunus salicina), Myrobalan plum (Prunus cerasifera) and cherry (Prunus avium). Samples were analyzed using real-time PCR and nested PCR approaches. In this extended survey, the presence of ESFY phytoplasma was additionally identified in Japanese plum and myrobalan plum trees.Keywords: Bosnia and Herzegovina, myrobalan plum, Japanese plum, phytoplasma, ESFY, PC

Pome fruit viruses in Bosnia and Herzegovina

During autumn 2005 and summer 2006, field surveys were carried out to assess the sanitary status of pome fruit trees in Bosnia and Herzegovina. Inspections were done in the main pome fruit growing areas including 10 orchards, 2 nurseries and one varietal collection. A total of 65 apple and 50 pear cultivars were tested by biological indexing for the presence of Apple chlorotic leaf spot virus (ACLSV), Apple stem pitting virus (ASPV), Apple stem grooving virus (ASGV) and Apple mosaic virus (ApMV). The average infection level was 81%. Both species showed a similar infection rate (83% for apple and 78% for pear). The most frequent viruses of apple were ACLSV (72%) and ASPV (69%), and of pear ASGV (69%) and ACLSV (64%). The same samples were also tested by ELISA, with a lower virus detection rate compared to the biological indexing. Multiplex RT-PCR results of 20 randomly selected apple cultivars were in line with biological indexing. Results of our surveys report for the first time th e presence of ACLSV, ASPV, ASGV and ApMV on pome fruits in Bosnia and Herzegovina.Keywords: Malus, biological indexing, ELISA, multiplex RT-PCR, sanitary statu

Schizophyllum commune: The main cause of dying trees of the Banja Luka arbored walks and parks

In the frame of investigation of the main cause of dying trees of the main arbored walks (Mladena Stojanovića Aley and Park), the investigation of the presence and diversity of macrofungi in Banja Luka City were undertaken in the period 2006-2011. Relatively poor generic diversity of lignicolous (pathogenic or potentially pathogenic and saprotrophic) macrofungi with only 16 species representing this group (13 basidiomycets: Schizophyllum commune, Fomes fomentarius, Stereum hirsutum, Coriolus versicolor, Flammulina velutipes, Pseudotrametes gibbosa, Ganoderma applanatum, G. lucidum, G. adspersum, Polyporus squamosus, Meripilus giganteus, Laetiporus sulphureus, Auricu­laria auricula-judae, and 3 ascomycets: Nectria cinnabarina, Xylaria hypoxylon, X. poly­morpha) were recorded. Such a poor qualitative composition of this very important fungal group could be explained by the reduction in the number of plant species in arbored walks and alleys, as well as the reduction in the number of fungi resistant to heavy air pollution caused by nearby (1-5m) fuel combustion in engines. Although only preliminary, our results pointed to the necessity of conservation and protection of the most beautiful features of Banja Luka and its alleys and arbored walks, by undertaking the measures of curing damaged trees and treating them with fungicides in order to wipe out the epiphytia caused in more than 95% of cases (dated May 2011) by Split-gill (Schizophyllum commune), present on dead wood but also on damaged trees of Aesculus hyppocastaneum (127 trees), Tilia cordata (124 trees), Tilia platyphyllos (36 trees), Tilia argentea (40 trees), Acer negundo (20 trees), Platanus acerifolia (2 trees), Robinia pseudoacacia (3 trees), Fraxinus ornus (1 tree), Betula pendula (1 tree), Catalpa sp. (2 trees), etc. Altogether, during the last decade, around 200 trees collapsed or were sanitary cut in Banja Luka arbored walk from the Malta site to the Green bridge, a total length around 5 km. The reason for this was primarily due to Split-gill fungus and the restoration of arbored walks in the streets extremely polluted by engine fuel consumption in the zone of Mladena Stojanovića street. By analyzing the trees along the City of Banja Luka main street it could be concluded that, besides the appearance of suffocation of plants, due to wide asphalt surfaces that are located immediately next to the tree-trunks and heavy air pollution, fungi caused illnesses are the most important cause of the decline of trees. With its great adaptation to arid climate and ability to resist to the air pollution, Schizophyllum commune turned out to be the most aggressive and successful universal fungal invader of trees from old alleys, even threatening immuno­compromised human individuals. However, man and his direct or indirect impacts contrib­ute to the dying of trees much faster than the fungal pathogens in the busiest and most polluted Mladena Stojanovića street

Detection by tissue printing hybridization of Pome fruit viroids in the mediterranean basin

Available data on the incidence and biodiversity of pome fruit viroids in the Mediterranean basin are limited. Before starting a research survey to fill this gap, a tissue-printing hydridization (TPH) method to detect Apple scar skin viroid (ASSVd), Pear blister canker viroid (PBCVd) and Apple dimple fruit viroid (ADFVd) has been developed and validated. Afterward, TPH was used in large-scale indexing of pome fruit viroids in Bosnia and Herzegovina, Malta, Lebanon and Turkey. A total of about 1,000 trees was randomly collected and tested. Positive results obtained by TPH were confirmed by at least one additional detection method (RT-PCR and/or Northern-blot hybridization) and viroids were finally identified by sequencing full-length cDNA clones. PBCVd was detected in 13%, 12.4% and 5.4% of the tested pear trees in Bosnia and Herzegovina, Malta and Turkey, respectively, showing a wider diffusion of this viroid than expected. In contrast, ASSVd was never detected and ADFVd was only found in symptomatic trees (cv. Starking Delicious) in Lebanon, confirming a restricted presence of these viroids in the Mediterranean basin. Altogether, these data support the use of TPH as an easy and valuable tool for exploring pome fruit viroid spread. Keywords: Viroid disease, viroid spread, pome fruit trees, detection methods, molecular hybridizatio

Cluster analysis of higher-education competitiveness in selected European countries

The subject of research in this paper is higher-education competitiveness on account of its impact on the enhancement of social and economic competitiveness, as well as on the growth of human capital and creation of social knowledge. The purpose of this paper is to group the selected European countries according to higher-education competitiveness, by means of the hierarchical cluster analysis method, with a special focus on the position of Serbia. Higher-education competitiveness in the chosen countries is analysed by means of three indicators of competitiveness: the ratio of the number of students per number of inhabitants, the number of students per number of employed, as well as the amount of budgetary funds allocated per student. The research results indicate different higher-education competitiveness in the analysed countries and also the fact that, according to this analysis, Serbia is in the group of countries with low competitiveness of higher education

First Report of Stolbur Phytoplasma Associated with Maize Redness Disease of Maize in Bosnia and Herzegovina

Maize redness (MR), caused by stolbur phytoplasma (16SrXII-A, ‘Candidatus phytoplasma solani’) and vectored by the cixiid planthopper Reptalus panzeri (Löw), is a severe and emerging disease of maize in southeastern Europe (2). Symptoms of MR include midrib, leaf, and stalk reddening, followed by desiccation of the entire plant, abnormal ear development, and incomplete kernel set. MR may cause significant economic losses (2). During 2010, 2011, and 2012, the presence of MR-like symptoms on maize accompanied by significant yield losses were frequently observed in maize fields in the Semberija region of northeastern Bosnia and Herzegovina. From mid-June to early July, potential vectors were collected using mouth-aspirators from maize plants in fields at three locations in the Semberija region where MR-like symptoms were previously observed. At the end of July, symptomatic maize plants were collected from six fields in the same region for phytoplasma identification. In addition, we sampled asymptomatic johnsongrass (Sorghum halepense L.), bindweed (Convolvulus arvensis L.), and volunteer wheat (Triticum aestivum L.) in areas adjacent to maize fields with MR-like symptoms, as potential phytoplasma reservoirs (2,3). A total of 49 plants (38 maize, 6 johnsongrass, 3 bindweed, and 2 wheat) and 43 R. panzeri were tested for the presence of stolbur phytoplasma. Leaves of four maize seedlings, grown in insect-proof greenhouse conditions, were used as controls. Total DNA was extracted from roots of each plant and R. panzeri using the CTAB methods (2). Initial phytoplasma detection was conducted on 16S rRNA gene using nested PCR assay with phytoplasma universal primers P1/P7 and F2n/R2 (4). Subsequently, all phytoplasma positive samples were retested employing stolbur-specific Stol11 protocol with the f2r/f3r2 primer set (1). Molecular characterization of identified phytoplasmas was performed by PCR-RFLP analysis of the tuf gene (3) and by sequence analyses of the 16S rRNA nested PCR products (GenBank Accession No. KC852868). All samples that tested positive on 16S rRNA gene using phytoplasma generic primers gave positive reaction in assays with stolbur-specific primers. Stolbur phytoplasma was identified in 36 of 49 plant samples (34 of 38 symptomatic maize plants and in 2 of 6 johnsongrass) and in 2 of 43 R. panzeri individuals. None of the control plants, bindweed, or wheat samples were positive for the presence of any phytoplasma. Tuf gene RFLP analyses enabled affiliation of all isolates to the stolbur type tuf-b. Comparison of the 16S rRNA sequence using BLAST analyses further confirmed identification of the phytoplasmas as being ‘Candidatus phytoplasma solani.’ The obtained sequence showed 100% identity with ‘Candidatus phytoplasma solani’ from corn in Serbia (JQ730750). These data clearly demonstrated association of stolbur phytoplasma with MR symptoms on maize in Semberija, which represents the first report of the MR disease and stolbur phytoplasma in maize, R. panzeri, and johnsongrass in Bosnia and Herzegovina. In the Semberija region, maize-wheat crop rotation is a traditional practice, which is a key factor for MR occurrence and persistence (2). References: (1) D. Clair et al. Vitis 42:151, 2003. (2) J. Jović et al. Phytopathology 99:1053, 2009. (3) M. Langer and M. Maixner. Vitis 43, 191, 2004. (4) I. M. Lee et al. Int. J. Syst. Bacteriol. 48:1153, 1998. </jats:p

Effect of Antibiotic Treatment on the Intestinal Metabolome▿

The importance of the mammalian intestinal microbiota to human health has been intensely studied over the past few years. It is now clear that the interactions between human hosts and their associated microbial communities need to be characterized in molecular detail if we are to truly understand human physiology. Additionally, the study of such host-microbe interactions is likely to provide us with new strategies to manipulate these complex systems to maintain or restore homeostasis in order to prevent or cure pathological states. Here, we describe the use of high-throughput metabolomics to shed light on the interactions between the intestinal microbiota and the host. We show that antibiotic treatment disrupts intestinal homeostasis and has a profound impact on the intestinal metabolome, affecting the levels of over 87% of all metabolites detected. Many metabolic pathways that are critical for host physiology were affected, including bile acid, eicosanoid, and steroid hormone synthesis. Dissecting the molecular mechanisms involved in the impact of beneficial microbes on some of these pathways will be instrumental in understanding the interplay between the host and its complex resident microbiota and may aid in the design of new therapeutic strategies that target these interactions

Inhibition of Salmonella Host Cell Invasion by Dimethyl Sulfide▿

We show that dimethyl sulfoxide (DMSO) inhibits Salmonella hilA expression and that this inhibition is stronger under anaerobiosis. Because DMSO can be reduced to dimethyl sulfide (DMS) during anaerobic growth, we hypothesized that DMS was responsible for hilA inhibition. Indeed, DMS strongly inhibited the expression of hilA and multiple Salmonella pathogenicity island 1 (SPI-1)-associated genes as well as the invasion of cultured epithelial cells. Because DMSO and DMS are widespread in nature, we hypothesize that this phenomenon may contribute to environmental sensing by Salmonella

Impact of Salmonella Infection on Host Hormone Metabolism Revealed by Metabolomics ▿

The interplay between pathogens and their hosts has been studied for decades using targeted approaches, such as the analysis of mutants and host immunological responses. Although much has been learned from such studies, they focus on individual pathways and fail to reveal the global effects of infection on the host. To alleviate this issue, high-throughput methods, such as transcriptomics and proteomics, have been used to study host-pathogen interactions. Recently, metabolomics was established as a new method to study changes in the biochemical composition of host tissues. We report a metabolomic study of Salmonella enterica serovar Typhimurium infection. Our results revealed that dozens of host metabolic pathways are affected by Salmonella in a murine infection model. In particular, multiple host hormone pathways are disrupted. Our results identify unappreciated effects of infection on host metabolism and shed light on mechanisms used by Salmonella to cause disease and by the host to counter infection