Presence of potential bacterial pathogens in a municipal drinking water supply system

The quality of drinking water is a major public concern, but the detection of most potential pathogens is not always included in drinking water hygienic monitoring or is only assessed with highly biased cultivation-based methods. In this study, the occurrence of Pseudomonas aeruginosa and Legionella spp. was examined with taxon-specific PCRs in samples taken at ten points of a municipal drinking water supply system in three months. Sequence analysis confirmed the positivity of samples and revealed a diverse community of legionellae. The results showed that chlorination was an important and effective disinfection method against pathogenic bacteria in drinking water, but pathogenic bacteria could reoccur in the system farther away from the chlorination point. No strong correlation was found between the presence of the investigated potentially pathogenic bacteria and the measured abiotic and biotic parameters within the investigated range. It is hypothesized that instead of physicochemical parameters, the main factors influencing the presence of pathogens in the drinking water were rather the composition of the microbial community, the biotic interactions between individual non-pathogenic and pathogenic microorganisms (competition or promotion of growth) and the structure of biofilm grown on the inner surface of the supply system

Synthesis, thermal stability and unknown properties of Fe1–xAlxVO4 solid solution

A continuous solid solution Fe1-xAlxVO4 was synthesized by conventional ceramic method and characterized by DTA, XRD, IR, UV-Vis/DRS and Mössbauer spectroscopy. Fe1-xAlxVO4 crystallizes in a triclinic system and is isostructural with FeVO4 and AlVO4. With increasing content of Al3+ ions substituted for Fe3+ in the matrix structure of FeVO4 a contraction of crystal lattice was observed, accompanied by shifts of IR absorption bands towards higher wavenumbers and shifts of UV absorption bands towards shorter wavelength. On the basis of the results of UV-Vis investigations, the band gap energies were calculated. The solid solution sample of composition Fe0.67Al0.33VO4 was found to have the highest melting point from among all examined samples, which equals to 870°C. Moreover, the solid product of incongruent melting of Fe1-xAlxVO4 for 0.75 >x≥ 0.5 is Fe1-xAlxVO4 solid solution, richer in iron. On the grounds of Mössbauer investigation, the partition of iron and aluminum ions over three accessible crystallographic sites was established. Fe0.5Al0.5VO4 sample was successfully used as a reactant for Fe4Al4V10W16O85 preparation

Origin of amphibole megacrysts in the Pliocene-Pleistocene basalts of the Carpathian-Pannonian region

Major and trace element compositions, stable H and O isotope compositions and Fe3+ contents of amphibole megacrysts of Pliocene-Pleistocene alkaline basalts have been investigated to obtain information on the origin of mantle fluids beneath the Carpathian-Pannonian region. The megacrysts have been regarded as igneous cumulates formed in the mantle and brought to the surface by the basaltic magma. The studied amphiboles have oxygen isotope compositions (5.4±0.2 ‰, 1 σ), supporting their primary mantle origin. Even within the small δ18O variation observed, correlations with major and trace elements are detected. The negative δ18O-MgO and the positive δ18O-La /Sm(N) correlations are interpreted to have resulted from varying degrees of partial melting. The halogen (F, Cl) contents are very low (<0.1 wt. %), however, a firm negative (F+Cl)-MgO correlation (R2 = 0.84) can be related to the Mg-Cl avoidance in the amphibole structure. The relationships between water contents, H isotope compositions and Fe3+ contents of the amphibole megacrysts revealed degassing. Selected undegassed amphibole megacrysts show a wide δD range from -80 to -20 ‰. The low δD value is characteristic of the normal mantle, whereas the high δD values may indicate the influence of fluids released from subducted oceanic crust. The chemical and isotopic evidence collectively suggest that formation of the amphibole megacrysts is related to fluid metasomatism, whereas direct melt addition is insignificant

Viral subpopulation variability in different batches of Infectious bronchitis virus (IBV) vaccines based on GI-23 lineage: Implications for the field

The control of infectious bronchitis (IB) is largely based on routine vaccine administration, often using live-attenuated vaccines. However, their capability to replicate and be transmitted among animals and farms implies significant risks. The detection of strains genetically related to vaccines complicates the diagnostic process and understanding of the viral molecular epidemiology. Moreover, reversion to virulence and associated clinical outbreaks can occur although the underlying mechanism are often unknown. In the present study, three vaccine vials, based on IBV GI-23 lineage (also known as Variant2) were deep sequenced through Next Generation Sequencing (NGS) to investigate the presence and features of viral subpopulations. To elucidate the consequences in the field and identify potential markers suitable for a DIVA strategy, the S1 sequences of strains originating from farms in different countries were sequenced and classified based on the knowledge of their vaccination history and similarity with the applied vaccine. Although all considered vaccine batches shared the same consensus sequence, different subpopulations were identified suggesting independent and poorly constrained evolutionary processes. When compared with strains sampled from farms, the vaccine consensus sequences and the respective subpopulations clustered with vaccine strains and no genetic features were consistently shared with field strains. Therefore, if vaccine-induced outbreaks occur, they are more likely to originate from in vivo evolution rather than selection of already present subpopulations. Although some amino acid residues were most commonly detected in field or vaccine strains, no consistent marker could be identified. The occurrence of subpopulations within IBV GI-23-based vaccines and variability featuring different production batches was demonstrated. Being such a phenomenon apparently driven by random genetic drift rather than directional selection, the differentiation between field and vaccine-derived strains appears extremely challenging based on sequence analysis alone. The knowledge of farm management and vaccination history should thus be considered for a proper epidemiological investigation. © 2022 Elsevier B.V

Temperature and pressure effects on the spin state of ferric ions in the [Fe(sal2-trien)][Ni(dmit)2] spin crossover complex

Thermal and pressure effects have been investigated on the [Fe(sal2-trien)][Ni(dmit)2] spin crossover complex by means of Mössbauer spectroscopic, calorimetric, X-ray diffraction and magnetic susceptibility measurements. The complex displays a complete thermal spin transition between the and spin states of FeIII near 245 K with a hysteresis loop of ca. 30 K. This transition is characterised by a change of the enthalpy, ?HHL=7 kJ/mol, entropy, ?SHL=29 J/Kmol, and the unit cell volume, ?VHL=15.4 Å3. Under hydrostatic pressures up to 5.7 kbar the thermal transition shifts to higher temperatures by ca. 16 K/kbar. Interestingly, at a low applied pressure of 500 bar the hysteresis loop becomes wider (ca. 61 K) and the transition is blocked at ~50% upon cooling, indicating a possible (irreversible) structural phase transition under pressure

Trace element and C-O-Sr-Nd isotope evidence for subduction-related carbonate-silicate melts in mantle xenoliths (Pannonian Basin, Hungary)

Carbonate globules have been found in amphibole-bearing glass veins of peridotite xenoliths from Szentbékálla (Balaton Highland, Central Hungary). Strong resorption of amphibole suggests multiple fluid-melt infiltration. Textural features of carbonate globules and the surrounding silicate glass indicate a magmatic melt origin for the carbonate and exclude the possibility of significant alteration. The application of the cpx structural barometer for clinopyroxenes formed in the silicate glass indicates high-pressure vein formation. Laser-ablation ICP-MS analyses revealed trace element zoning within the carbonate. Uniform profiles observed for various elements within the carbonate indicate that the zoning is related to non-diffusive mixing during carbonate–silicate interaction rather than to element diffusion. The trace element composition of the centers of the globules (e.g. low Ce/Pb and Nd/Pb ratios) suggests a crustal origin for the carbonate melt. The C, O, and Sr isotope compositions of the calcite globules (13C about ?14‰; 18O about 22‰; 87Sr/86Sr=0.70533) also argue for a crustal origin of the carbonate melt. Trace element and C–O–Sr isotopic compositions of calcite globules suggest that the carbonate melt was derived from subducted material. Injection of the carbonate melt into the peridotite triggered amphibole melting. The carbonate and silicate melts intermingled, but their interaction was confined to the margins of carbonate globules. Preservation of trace element zoning and element diffusion calculations indicate that the vein-hosting peridotite was rapidly brought to the surface after the carbonate melt injection