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Iron oxide magnetic nanoparticles functionalized by nisin /
No full textOver the last decades iron oxide magnetic nanoparticles, mostly magnetite (Fe3O4) and maghemite (γ–Fe2O3), have increasingly attracted attention as an efficient tool in various fields of application [1]. Here, we present the preparation and characterization of iron oxide magnetic nanoparticles functionalized by nisin. Nisin is naturally produced by Lactococcus lactis subsp. lactis as a small cationic peptide composed of 34 amino acid residues and is a well-known bacteriocin approved as a food additive for food preservation [2]. Iron oxide magnetic nanoparticles were prepared by the co-precipitation method and characterized by X-ray diffraction method. Magnetic nanoparticles were stabilized by citric, ascorbic, gallic, or glucuronic acid coating and were functionalized by nisin using a simple and low-cost adsorption method (Fig. 1). Nisin loading was confirmed by FT-IR spectra, thermogravimetric analysis, and dynamic light scattering methods. Nisin-loaded iron oxide magnetic nanoparticles were stable for at least six weeks as judged by zeta-potential and hydrodynamic diameter measurements. The functionality of nisin-loaded iron oxide magnetic nanoparticles was demonstrated on Grampositive bacteria. Functionalized nanoparticles could find their application in innovative and emerging technologies as antimicrobials
Search for the substantiation of reasonable native elemental background values and reference variables in topsoil on glaciogenic and postglacial deposits in a Vilnius peri-urban area /
No full textGeochemical indices used to identify the emerging anomalies of potentially harmful elements in topsoil depend on background values (BVs). For urban sites, it is reasonable to estimate native BVs through the targeted selection of peri-urban sampling sites or by distinguishing a useful background subset (BS) within the peri-urban dataset. Here, the goals were to examine the influence of Quaternary deposits on various types of topsoil variables, identify the variables most helpful for cluster analysis intended for the choice of background subset (BS), and compare background values (BVs) based on different background subsets. Composite topsoil samples from a peri-urban area were used for the determination of the following variables: contents of 26 elements and components of the bulk mineralogical composition, as well as the sand, silt, and clay fractions and loss-on-ignition (LOI) at 550 °C and at 950 °C. Although Quaternary lithology influences topsoil elemental contents or granulometric fractions, percentages of illite, kaolinite, orthoclase, quartz, albite, dolomite, and LOI at 550 °C, the choice of BS, according to it, is not recommended, as BVs based on topsoil texture are superior. However, cluster analysis using topsoil fractions 63 μm or the contents of Al, Fe, K, Ti, Ga, Nb, Rb, and Si are preferable. It is recommended to use these reference variables for the selection of BS
Molecular based identification of Accipiter hawks as possible definitive hosts of numerous Sarcocystis spp /
No full textMolecular detection of African swine fever virus and trypanosomes in horseflies (Diptera: Tabanidae) /
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Can crickets recognise bacterially contaminated feed? Gryllus assimilis odour perception of Escherichia coli /
No full textEdible crickets Acheta domesticus and Gryllus assimilis are worldwide mass-reared insects. They are recognised as a sustainable source of protein in the food and feed industries and, in relation to this, must comply with food safety requirements. In this study, we assessed the self-protective ability of crickets to recognise potentially hazardous bacteria-contaminated feed. A two-choice test was carried out to estimate the crickets' preference between the bacteria-contaminated and control feed. Three bacterial species were tested as potential contaminants: Escherichia coli, Pseudomonas aeruginosa and Bacillus subtilis. A. domesticus did not recognise feed contaminated with any of the bacterial species tested. G. assimilis avoided E. coli-contaminated feed, while the other two bacteria did not cause differences in feeding behaviour. The study of gas chromatography-electroantennogram detection showed that E. coli released a volatile compound, which was olfactory perceived by both males and females of G. assimilis. The compound was identified as indole. In a behavioural test, crickets spent less time feeding on indole-contaminated feed compared to control feed. Hence, indole induced an avoidance response in G. assimilis. It can be concluded that G. assimilis perceives and recognises some bacteria contaminants and thereby avoids spoiled feed
DNA barcoding of morphologically characterized mosquitoes belonging to the genus Mansonia from the Atlantic Forest and Brazilian Savanna /
No full textThe identification of mosquito species is necessary for determining the entomological components of disease transmission. However, identification can be difficult in species that are morphologically similar. The cytochrome c oxidase subunit I (COI) DNA barcode region is considered a valuable and reliable diagnostic tool for mosquito species recognition, including those that belong to species complexes. Mansonia mosquitoes are found in forests near swampy areas. They are nocturnal and are highly attracted to light. Hematophagous adult females exhibit aggressive biting behavior and can become infected with and transmit pathogens during their feeding, including some epizootic viruses and avian malaria. In Brazil, twelve Mansonia species have been reported. In a recent study from the São Paulo Zoo in Brazil, three morphologically distinct species were collected and identified, namely: Mansonia (Mansonia) indubitans, Ma. (Man.) pseudotitillans and Ma. (Man.) titillans. However, confirmation of these species by molecular identification was unsuccessful due to a lack of COI sequences in the GenBank database. Thus, this research aimed to describe the COI DNA barcode sequences of some morphologically characterized Mansonia (Man.) species from Brazil and to determine their utility in delimiting species collected from the Atlantic Forest and Brazilian Savanna. Accordingly, we provide tools for the genetic identification of species that play a significant role in pathogen transmission in wildlife and potentially humans. We show that the delimitation of Mansonia species via five different approaches based on COI DNA sequences (BI, NJ, ASAP, bPTP and GMYC) yield basically the same groups identified by traditional taxonomy, and we provide the identification of specimens that were previously identified only up to the subgenus level. We also provide COI sequences from two Mansonia species that were not previously available in sequence databases, Ma. wilsoni and Ma. pseudotitillans, and thus contribute to the ongoing global effort to standardize DNA barcoding as a molecular means of species identification
A record of a melanistic forest dormouse Dryomys nitedula in Lithuania, with a review of colour anomalies in dormice (Gliridae) /
No full textA melanistic forest dormouse Dryomys nitedula was recorded among 125 individuals marked in a small isolated local population in central Lithuania. Until now, a totally black individual of D. nitedula was captured only in western Ukraine. A review of the literature on colour anomalies in European dormouse species has shown that this phenomenon is rare in dormice. Several black hazel dormice Muscardinus avellanarius were recorded in the same locality in northern Germany in 1972 and 2015, and one such dormouse was captured in the UK. Partial albino M. avellanarius was recorded in Germany. Two melanistic garden dormice Eliomys quercinus were collected in the Czech Republic, an albino specimen in France and a flavistic specimen in Germany. In the edible dormouse Glis glis, melanistic, albino, isabelline and flavistic individuals were recorded, all from Slovenia and the Czech Republic. Among aberrant-coloured European dormice, melanistic individuals were documented most often. Tail-tip albinism is more frequent among M. avellanarius, and this trait was recorded in several countries
Host cells of Leucocytozoon (Haemosporida, Leucocytozoidae) gametocytes, with remarks on the phylogenetic importance of this character /
No full textLeucocytozoon parasites remain poorly investigated in comparison to other haemosporidians. The host cell inhabited by their blood stages (gametocytes) remains insufficiently known. This study aimed to determine the blood cells inhabited by Leucocytozoon gametocytes in different species of Passeriformes and to test if this feature has a phylogenetic importance. We microscopically analyzed blood films stained with Giemsa from six different bird species and individuals and used PCR-based methods for parasite lineage identification. The DNA sequences obtained were applied for phylogenetic analysis. Leucocytozoon parasite from the song thrush Turdus philomelos (cytochrome b lineage STUR1), the blackbird Turdus merula (undetermined lineage), the garden warbler Sylvia borin (unknown lineage) inhabited erythrocytes, a parasite from the blue tit Cyanistes caeruleus (PARUS4) infects lymphocytes, while in the wood warbler Phylloscopus sibilatrix (WW6) and the common chiffchaff Phylloscopus collybita (AFR205) they were found inhabiting thrombocytes. Parasites infecting thrombocytes were closely related, while the parasites infecting erythrocytes were placed in three different clades, and the one found in lymphocytes was placed in a separate clade. This shows that the determination of host cells inhabited by Leucocytozoon parasites can be phylogenetically important and should be considered in future species descriptions. Noteworthy, phylogenetic analysis might be used for the prediction of which host cells parasite lineages might inhabit