Sarcocystis rileyi emerging in Hungary: is rice breast disease underreported in the region?

Reports of Sarcocystis rileyi-like protozoa (‘rice breast disease’) from anseriform birds had been rare in Europe until the last two decades, when S. rileyi was identified in northern Europe and the UK. However, despite the economic losses resulting from S. rileyi infection, no recent accounts are available on its presence (which can be suspected) in most parts of central, western, southern and eastern Europe. Between 2014 and 2019, twelve mallards (Anas platyrhynchos) were observed to have rice breast disease in Hungary, and the last one of these 12 cases allowed molecular identification of S. rileyi, as reported here. In addition, S. rileyi was molecularly identified in the faeces of one red fox (Vulpes vulpes). The hunting season for mallards in Hungary lasts from mid-August to January, which in Europe coincides with the wintering migration of anseriform birds towards the south. Based on this, as well as bird ringing data, it is reasonable to suppose that the first S. rileyi-infected mallards arrived in Hungary from the north. on the other hand, red foxes (Vulpes vulpes), which are final hosts of S. rileyi, are ubiquitous in Hungary, and our molecular finding confirms an already established autochthonous life cycle of S. rileyi in the region. Taken together, this is the first evidence for the occurrence of S. rileyi in Hungary and its region

Calcium Activation of Ryanodine Receptor Channels—Reconciling RyR Gating Models with Tetrameric Channel Structure

Despite its importance and abundance of experimental data, the molecular mechanism of RyR2 activation by calcium is poorly understood. Recent experimental studies involving coexpression of wild-type (WT) RyR2 together with a RyR2 mutant deficient in calcium-dependent activation (Li, P., and S.R. Chen. 2001. J. Gen. Physiol. 118:33–44) revealed large variations of calcium sensitivity of the RyR tetramers with their monomer composition. Together with previous results on kinetics of Ca activation (Zahradníková, A., I. Zahradník, I. Györke, and S. Györke. 1999. J. Gen. Physiol. 114:787–798), these data represent benchmarks for construction and testing of RyR models that would reproduce RyR behavior and be structurally realistic as well. Here we present a theoretical study of the effects of RyR monomer substitution by a calcium-insensitive mutant on the calcium dependence of RyR activation. Three published models of tetrameric RyR channels were used either directly or after adaptation to provide allosteric regulation. Additionally, two alternative RyR models with Ca binding sites created jointly by the monomers were developed. The models were modified for description of channels composed of WT and mutant monomers. The parameters of the models were optimized to provide the best approximation of published experimental data. For reproducing the observed calcium dependence of RyR tetramers containing mutant monomers (a) single, independent Ca binding sites on each monomer were preferable to shared binding sites; (b) allosteric models were preferable to linear models; (c) in the WT channel, probability of opening to states containing a Ca2+-free monomer had to be extremely low; and (d) models with fully Ca-bound closed states, additional to those of an Monod-Wyman-Changeaux model, were preferable to models without such states. These results provide support for the concept that RyR activation is possible (albeit vanishingly small in WT channels) in the absence of Ca2+ binding. They also suggest further avenues toward understanding RyR gating

Bartonella DNA in heart tissues of bats in central and eastern Europe and a review of phylogenetic relations of bat-associated bartonellae

Background: Bats are among the most widely distributed mammals worldwide and can represent hosts or reservoirs for a number of different pathogens. Bartonella spp. are opportunistic bacterial pathogens, which are transmitted by a large variety of arthropods. The aim of this study was to investigate the presence and host-associations of these Gram-negative bacteria in heart tissues of bats collected in four different countries from eastern and central Europe and to analyze their phylogenetic relationship with other bat-associated bartonellae. Results: The results of this study show for the first time the presence of Bartonella spp. DNA in heart tissues of bats from central and eastern Europe. The overall prevalence of the infection was 1.38%. Phylogenetic analysis identified four new Bartonella spp. sequences, which were closely related with other Bartonella previously isolated from bats in Europe and North America. Conclusions: The gltA sequences of Bartonella spp. showed considerable heterogeneity in the phylogenetic analysis resulting in six different clades. Our study demonstrated the presence of Bartonella spp. only in heart tissues of bats from Romania, with two new bat species recorded as hosts (Myotis cf. alcathoe and Pipistrellus pipistrellus

Anaplasmataceae closely related to Ehrlichia chaffeensis and Neorickettsia helminthoeca from birds in Central Europe, Hungary

Increasing amount of data attest that (in the context of vector-borne infections) birds are not only important as hosts of blood-sucking arthropod vectors, but also as reservoirs of vector-borne pathogens. From 2015 to 2019 cadavers of 100 birds (from 45 species, nine orders) were collected in Hungary, and their organs were screened for DNA from a broad range of vector-borne bacteria with PCR and sequencing. Molecular analyses revealed the presence of Anaplasmataceae, and sequencing identified bacteria closely related to Neorickettsia helminthoeca and Ehrlichia chaffeensis in a Eurasian teal (Anas crecca)and a song thrush (Turdus philomelos), respectively. All samples were PCR negative for rickettsiae, borreliae, Francisella and Coxiella spp., as well as for piroplasms. To our knowledge, this is the first report of a Neorickettsia and an Ehrlichia sp., which belong to the phylogenetic groups of N. helminthoeca and E. chaffeensis, respectively, from Europe. The potential presence of these two vector-borne bacteria needs to be taken into account during future studies on the eco-epidemiology of Anaplasmataceae in Europe

A Desmodesmus communis zöldalga rézzel szembeni érzékenységének és réz-akkumulációjának jellemzése

Napjaink egyik legfontosabb problémája a környezetszennyezés. A fő szennyezők közé sorolhatók bizonyos fémek, köztük a réz, mely bár esszenciális, nagy dózisban toxikussá válik. Az egyik leggyakrabban előforduló fémszennyező hazai felszíni vizeinkben, vagy a szennyvizekben. Munkánk során egy széles körben elterjedt zöldalga faj, a Desmodesmus communis rézzel szembeni érzékenységét, valamint rézmegkötő-képességét kísértük figyelemmel különböző rézkoncentrációk mellett. Alacsonyabb rézkoncentráció (0,2 mg l-1) a tenyészetek növekedését serkentette. Az 1 mg l-1 és ettől nagyobb réz koncentrációval kezelt tenyészetekben a cönóbiumszám és a klorofill tartalom alapján egyaránt növekedésgátlás volt kimutatható. Az élő sejtek rézeltávolításával csak 1 mg l-1 koncentrációig kell számolni. A megkötött réz mennyisége a tenyésztés első felében volt a legmagasabb, és nagyobbrészt intracellulárisan történt. Az eredmények azt mutatják, hogy az általunk vizsgált D. communis faj rézre érzékeny, és már az 1 mg l-1 rézkoncentráció csaknem teljes növekedésgátlást okozott, így az élő sejtek rézeltávolításban való alkalmazása nem javasolt. Eredményeinket az irodalmi adatokkal összevetve megállapítható, hogy a rézzel szembeni tolerancia és a rézmegkötő képesség fajspecifikus, sőt a fajon belül, izolátumonként is mutathat eltéréseket

Bats and ticks: host selection and seasonality of bat-specialist ticks in eastern Europe

Background: Parasites may actively seek for hosts and may use a number of adaptive strategies to promote their reproductive success and host colonization. These strategies will necessarily influence their host specificity and seasonality. Ticks are important ectoparasites of vertebrates, which (in addition to directly affecting their hosts) may transmit a number of pathogens. In Europe, three hard tick species (Ixodidae: Ixodes ariadnae, I. simplex and I. vespertilionis) and at least two soft tick species (Argasidae: Argas transgariepinus and A. vespertilionis) are specialized for bats. Methods: Here we report data on the host range of these ticks and the seasonality of tick infestation on wild caught bats in south-east Europe. We collected 1803 ticks from 30 species of bats living in underground shelters (caves and mines) from Romania and Bulgaria. On the basis of tick–host associations, we tested several hypotheses on host–parasite evolutionary adaptations regulating host specificity, seasonality and sympatric speciation. Results: We observed significant differences in host specificity and seasonality of abundance between the morphologically different bat specialist ticks (I. simplex and I. vespertilionis) likely caused by their host choice and their respective host-seeking behavior. The two highly generalist, but morphologically similar tick species (I. ariadnae and I. vespertilionis) showed temporal differences in occurrence and activity, thus exploiting significantly different host communities while occurring in geographical sympatry. Conclusions: We conclude that bat-specialist ticks show a wide range of adaptations to their hosts, with differences in specificity, seasonality of occurrence, the prevalence and intensity of infestation and all these contribute to a successful division of temporal niches of ticks sharing morphologically similar hosts occurring in geographical sympatry

Generációs különbségek és motiváció az élelmiszeriparban

A változó gazdasági és környezeti tényezők közepette a vállalatok egyik meghatározó problémája továbbra is a munkaerő fluktuációja. A vezetők a pandémiás időszak egyik nem várt hatásaként szembesültek azzal a ténnyel, hogy a munkavállalók reakciói megváltoztak, gyakrabban és gyorsabban váltanak munkahelyet. Tanulmányunkban a generációk közötti motivációs különbségeket elemeztük. A szakirodalmi előzmények bizonyítják, hogy a generációk értékrendjében jelentős különbségek alakultak ki, amelyeket az ösztönzés és motiválás során prioritásként kell kezelni. Kutatásunkat élelmiszeripari nagyvállalatok munkavállalói körében valósítottuk meg. Az adatgyűjtés hólabda módszerrel történt, amely során 126 válaszadóból álló adatbázist alakítottunk ki. Az adatelemzés során ANOVA elemzést és LSD post hoc típusú tesztet alkalmaztunk. Eredményeinek szerint a generációk között igazolhatóak a motivációs különbségek, amelyekre a vezetőknek a motivációs stratégiájukban és gyakorlatukban építeni szükséges. A Z és Y generációs munkavállalók nehezebben tudnak azonosulni a szervezeti célokkal és nagyobb arányban terveznek munkahelyet váltani. A szervezeteknek paradigmát kell váltani a belső kommunikáció gyakorlatában, annak érdekében, hogy a vállalati „üzenetek” minden munkatárs számára célba érjen