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In the present study we evaluate the potential of essential oil and extracts obtained from Greek oregano (Origanum vulgare ssp. hirtum (Link) Ietswaart) to inhibit the mycelial growth of economically important plant pathogens from genus Phytophthora. The metabolite profiles of the essential oil, exudate, extract and methanolic polarity-based fractions were analyzed by GC/MS. The inhibitory activity of the essential oil and extracts against P. nicotianae var. nicotianae, P. rosacearum, P. citricola, P. plurivora and P. cryptogea was evaluated in an in vitro bioassay. Carvacrol (55.48%), p-cymene (11.06%) and γ-terpinene (15.04%) were the most abundant in the essential oil composition. In the acetone exudate and non-polar fraction, the main compound was carvacrol (48.15% and 50.34% respectively). In least amount carvacrol was found in the methanolic extract (13.24%) and completely absent in the polar fraction, where carbohydrates were the most abundant. All Phytophthora isolates responded to extracts and essential oil treatments with a decline of the vegetative growth to a different extend. A complete inhibitory effect was observed with P. nicotianae var. nicotianae in the essential oil, nonpolar fraction, acetone exudate and methanol extract variants, while the mycelial growth of P. cryptogea and P. plurivora was inhibited to a moderate degree. P. rosacearum was the most tolerant among tested oomycete representatives in these variants. We conclude that the economically important Phytophthora species, investigated in this study are susceptible to the impact of essential oil, methanol extract, the methanol's non-polar fraction, and acetone exudates of the aromatic plant O. vulgare subsp. hirtum. Essential oil, methanol extract, acetone exudate and non-polar fraction of Greek oregano are rich of carvacrol and could find further application in different sustainable crop protection systems. [ABSTRACT FROM AUTHOR]

Background and objectives: Zika virus is a flavivirus transmitted by Aedes mosquitos. A discussed transmission route is by blood transfusion due to the large number of ZIKV asymptomatic cases. The objective of the study was to estimate the ZIKV IgG seroprevalence and RNA presence in blood donors from a Hemotherapy Service in Southern Brazil due to the fact that until the end of 2016, 851 ZIKV suspected cases, 51.2% of which were with autochthons transmission were reported in this Brazilian region. Materials and methods: Five hundred blood samples were collected from blood donors between 5 December 2016 and 6 January 2017 in the Hemotherapy Service of Santa Maria, Rio Grande do Sul, Brazil. All samples were tested for the presence of ZIKV RNA by the use of TaqMan® real‐time PCR and 182 of these were serologically assessed for ZIKV IgG. Results: No samples showed positive results for ZIKV RNA. However, the serological survey detected one positive sample for ZIKV IgG and four samples with optical density values in the grey zone (consequently three of them confirmed as Dengue IgG‐positive). This indicates a 0.55% seroprevalence of ZIKV IgG among volunteer blood donors in the city of Santa Maria, Rio Grande do Sul State, Brazil. Conclusion: Our results demonstrate that although the transfusion risk of ZIKV in the south part of the country can be currently considered as low, further outbreaks cannot be excluded due to lack of herd immunity to ZIKV. Our study adds to the national and global prevalence of ZIKV among blood donors and its implications for the transfusion safety. [ABSTRACT FROM AUTHOR]

Presents an approach for the determination of vibrational-mode frequency spectrum in elastically anisotropic circular unelectroded quartz plates by solving the motion equation with the help of Mathieu functions. Information on harmonic overtone resonant frequencies in unelectroded quartz plates; Overview of measured and calculated frequencies for three quartz plates for the first harmonic overtones; Determination of eigenfrequency spectrum.

There are more than 100 species that belong to the fungus-like genus Phytophthora, many of which can cause severe damage to plants in both natural and agricultural ecosystems. The availability of techniques for detection and identification are crucial for monitoring and control of these pathogens. In recent years, new methods using molecular approaches have been developed. However, the majority of them are designed to detect single Phytophthora species. Techniques that are able to target multiple species in one sample would offer advantages, especially for the assessment of Phytophthora diversity in the environment. This paper describes a multiplex assay for simultaneous detection and identification of 26 members of Phytophthora down to species level and another 22 to clade or subclade level through target-specific primer extension ( TSPE) and the Luminex xTAG array detection system. The assay starts with PCR amplification of two genomic regions, ITS and coxI, followed by a multiplex TSPE reaction with clade-, subclade- and species-specific probes. As a result, biotin- dCTP labelled products are generated and subsequently detected through hybridization with a set of anti-TAG coupled, colour-coded paramagnetic beads. The specificity of the method has been tested using DNA extracts from over 400 isolates representing 110 Phytophthora species and subspecies. The sensitivity and robustness have been determined by the use of DNA mixtures, dilution series and environmental samples. Thus the developed technique allows simultaneous identification of multiple Phytophthora species, particularly useful for the detection of these pathogens in environmental samples such as soil, water and plant tissue. [ABSTRACT FROM AUTHOR]