Ferenc Baska

Bovine besnoitiosis emerging in Central-Eastern Europe, Hungary.

BackgroundBesnoitia besnoiti, the cause of bovine besnoitiosis, is a cyst-forming coccidian parasite that has recently been shown to be spreading in several Western and Southern European countries.FindingsClinical cases of bovine besnoitiosis were confirmed for the first time in Hungary, by histological, serological and PCR analyses.ConclusionsThis is the first report of autochthonous bovine besnoitiosis in Central-Eastern Europe. The emergence of bovine besnoitiosis in this region represents a further example, when human activity (i.e. cattle trading) is the main factor involved in the geographical spread of an infectious disease.

Polyunsaturated fatty acids synergize with lipid droplet binding thalidomide analogs to induce oxidative stress in cancer cells.

BackgroundCytoplasmic lipid-droplets are common inclusions of eukaryotic cells. Lipid-droplet binding thalidomide analogs (2,6-dialkylphenyl-4/5-amino-substituted-5,6,7-trifluorophthalimides) with potent anticancer activities were synthesized.ResultsCytotoxicity was detected in different cell lines including melanoma, leukemia, hepatocellular carcinoma, glioblastoma at micromolar concentrations. The synthesized analogs are non-toxic to adult animals up to 1 g/kg but are teratogenic to zebrafish embryos at micromolar concentrations with defects in the developing muscle. Treatment of tumor cells resulted in calcium release from the endoplasmic reticulum (ER), induction of reactive oxygen species (ROS), ER stress and cell death. Antioxidants could partially, while an intracellular calcium chelator almost completely diminish ROS production. Exogenous docosahexaenoic acid or eicosapentaenoic acid induced calcium release and ROS generation, and synergized with the analogs in vitro, while oleic acid had no such an effect. Gene expression analysis confirmed the induction of ER stress-mediated apoptosis pathway components, such as GADD153, ATF3, Luman/CREB3 and the ER-associated degradation-related HERPUD1 genes. Tumor suppressors, P53, LATS2 and ING3 were also up-regulated in various cell lines after drug treatment. Amino-phthalimides down-regulated the expression of CCL2, which is implicated in tumor metastasis and angiogenesis.ConclusionsBecause of the anticancer, anti-angiogenic action and the wide range of applicability of the immunomodulatory drugs, including thalidomide analogs, lipid droplet-binding members of this family could represent a new class of agents by affecting ER-membrane integrity and perturbations of ER homeostasis.

Epidemiological investigations of bovine besnoitiosis in Hungary

It usually gains proper attention, when blood-sucking arthropod species in Europe show northward spreading, in part due to climate change and global warming. Accordingly, it is well known, that the geographical regions where pathogens transmitted by these as biological vectors are endemic, also may extend towards the north. However, it is mostly less emphasized, that for vector-borne pathogens present in Western Europe the risk of eastward emergence is also possible, if they have competent vectors in the central and/or eastern part of our continent. Besnoitia besnoiti (Apicomplexa: Sarcocystidae) is a cyst-forming coccidian parasite that may cause severe lesions (with usually high seroprevalence, but low morbidity and mortality) in cattle as intermediate hosts. Wild ruminants are also susceptible. As a unique example among cystogenic coccidia, the main transmission route of B. besnoiti appears to be mechanical by blood-sucking dipterans (tabanid and stable flies), although it is also possible iatrogenically (with hypodermic needles) and most likely with close contact between animals. Bovine besnoitiosis has been endemic to South-Western Europe for more than a century, but a significant geographical expansion was observed during the last decade to other parts of the formerly endemic countries and to countries neighboring France. During the autumn of 2013 bovine besnoitiosis was diagnosed in a beef cattle herd in Hungary (for the first time in Central-Eastern Europe), following the import of Aubrac heifers and bulls from France in the previous two years. The preliminary serological herd screening with ELISA shows that even after the 2nd year of the presence of imported animals (with high prevalence of B. besnoiti infection), seropositivity among local animals, which originally belonged to the herd, is low. Based on ELISA results venereal transmission (from imported, infected bulls to local, uninfected cows) appears to be either rare or unlikely. The seroprevalence of besnoitiosis decreased significantly among calves born to the group of imported mother cows. The risk of infection seems to be high, when calves stay with their mother during suckling (for 6-7 months), and if animals are kept in the same stable (although physically separated) during the main fly season. Confirmation of the ELISA results is done with immunoblot and IFAT. All seropositive cattle are now kept at a distance of several kilometres from other groups of animals, prior to culling. Molecular and sero-epidemiological evaluation of the situation continues with the aim of preventing the spread of the disease and regaining the epidemiological status of Hungary as exempt of bovine besnoitiosis.

Occurrence of two myxosporean species, Myxobolus hakyi sp. n. and Hoferellus pulvinatus sp. n., in Pangasianodon hypophthalmus fry imported from Thailand to Europe as ornamental fish

Fingerlings of the sutchi catfish Pangasianodon hypophthalmus, a favorite food fish in South Asia, is regularly imported by European fish traders and sold in pet fish shops. In shipments from Thailand, a skin and a kidney infection of this fish caused by myxosporean parasites was found both in Hungary and Russia. In the skin of the fish, small millet-sized nodules containing great numbers of a Myxobolus species were found, while in the renal glomeruli, spores and sporogonic stages of a Hoferellus species developed. The skin-infecting species described as Myxobolus hakyi sp. n. had 15.9 × 6.6-µm-sized spores with elongated polar capsules, while the renal species described as Hoferellus pulvinatus sp. n. had roundish spores with a size of 6.5 × 5.0 µm and had a characteristic pillow-like structure at its posterior end. Besides morphology, histology of infection and 18S rDNA sequences were studied.

Sarcocystis-infection of cattle in Hungary

BackgroundReports on Sarcocystis-infection of cattle are outdated or lacking in many European countries, including those in the Central-Eastern part of the continent. Therefore, to assess the prevalence of Sarcocystis spp. among bovids in Hungary, a countrywide survey was initiated. In addition, fulminant deaths of four cattle, that showed clinical signs and post mortem lesions resembling acute sarcocystiosis (“Dalmeny disease”), were investigated.MethodsDuring the countrywide survey individual heart and oesophagus samples were collected at slaughterhouses from 151 beef cattle and from 15 buffalo, kept in 31 places of Hungary. Analysis for Sarcocystis spp. was carried out with conventional PCRs for the 18S rDNA gene and gel electrophoresis, followed by sequencing of 36 strongly positive samples. Mortality cases were evaluated by histological, molecular, bacteriological and virological analyses of samples from various organs.ResultsAmong slaughtered cattle the rate of Sarcocystis-infection was 66%. S. cruzi was identified as the most prevalent species in aurochs-like breed, and the zoonotic S. hominis in Hungarian grey cattle. Concerning the sudden deaths of cattle, Sarcocystis-infection could not be demonstrated in organs showing haemorrhages, but S. cruzi cysts were present in the muscles. In one case “S. sinensis” was molecularly identified in the blood (indicating sarcocystaemia). Results of analyses for bacterial/viral pathogens were negative.ConclusionsS. cruzi appears to be the most prevalent Sarcocystis sp. in cattle in Hungary, followed by the zoonotic S. hominis. However, the rate of infection with both species was shown to differ between cattle breeds. The suspected role of Sarcocystis spp. as causative agents of the fatal cases could not be confirmed.

Description of the song of the bush-cricket Saga rammei Kaltenbach, 1965 (Orthoptera: Tettigoniidae)

A detailed description of the spectrographic and oscillographic features of the male calling song of Saga rammei is presented for the first time. The study is based on Macedonian specimens. The song of S. rammei is a mainly amplitude-modulated signal having wide-band frequency spectrum containing well detectable frequency components between 15 kHz and 80 kHz (intensity maximum between 20–30 kHz). The male song is a sequence of echemes, which are composed of evenly and quickly repeated diplo-hemisyllabic syllables. Echemes begin with a gradually crescending initial part that leads to the main part of the echeme, where the peak amplitude of the syllables is nearly constant. This structure is similar to those described in other European Saga species (S. hellenica, S. campbelli, S. natoliae). However, the results suggest that amongst the European Saga species S. rammei produces the shortest echemes composed of the lowest number of syllables repeated with the highest syllable repetition rate and that the species sings with the shortest echeme repetition period. Those quantitative features make the song of S. rammei distinct and easily recognisable, and therefore could be used by females or males for species recognition.

Vector-borne transmission of Besnoitia besnoiti by blood-sucking and secretophagous flies: epidemiological and clinicopathological implications

BackgroundBovine besnoitiosis has been recently diagnosed in a three-parted herd of 796 Aubrac and Charolais beef cattle in Hungary. A large scale serological, histological and molecular survey was initiated in order to uncover important factors in the local epidemiology of the disease.FindingsBlood samples were collected (three times from the whole herd, and repeatedly from selected animals) for serological screening by ELISA. In addition, various organs from aborted fetuses and newborn calves, skin and colostrum samples of seropositive heifers/cows, and ticks collected from the cattle were histologically and/or molecularly analysed for the presence of Besnoitia besnoiti.All fetal and calf tissues, as well as colostrum and tick samples from cows were PCR negative. Based on ELISA results, only very few local cows seroconverted after mating with imported, infected bulls, and not necessarily as a consequence of this event. Among calves that were born to seropositive, imported cows and stayed with their mother until weaning at seven months of age, seroprevalence decreased significantly, but remained high. At the same time, 28 calves born from seropositive cows, but separated from their dams immediately after receiving colostrum, were successfully reared and remained uninfected.Following a second herd-level screening, all Aubrac cattle (except for heifer calves) and all seropositive Charolais cows and bulls were culled. Manifestation of the disease is currently sporadic. Among chronically affected heifers two types of skin lesions were noted, and histological evaluation indicated marked distension of sweat gland ducts with membrane-bound structures (resembling cystozoites) in their contents.ConclusionsTransmission through natural mating, as well as transplacental, colostral and tick-borne transmission of B. besnoiti was either unlikely or did not occur. However, the risk for spreading of the infection was high, when calves stayed with their mother during suckling, and if animals were kept in the same stable (although physically separated) during the main fly season. Herd replacement and generation exchange (i.e. early weaning and artificial feeding) appear to be the successful strategies for the local eradication of bovine besnoitiosis. Adding to the already known mechanical transmission of B. besnoiti by blood-sucking flies, results of the present study suggest that secretophagous flies should also be evaluated as potential vectors of this coccidium species.

Histological lesions in vascular tissues of bovine herpes virus type 4-infected rabbits.

The gamma-herpes virus bovine herpes virus type 4 (BoHV-4) is distributed worldwide in cattle populations with unknown pathogenicity. Bovine endothelial cells were recently shown to be susceptible to BoHV-4 infection in vitro and this virus accelerated the cholesterol-induced atherosclerotic process in rabbits. In this study, the in vivo effect of BoHV-4 on cardiovascular tissue was investigated by intravenous infection of rabbits fed a cholesterol free diet. Inflammatory lesions of vascular tissue in aortic and valvular endothelial cells, and smooth muscle cells were detected by H&E staining, PCR, IF, EM immunohistochemistry, while virus isolation was used to detect virus particles. Acute and chronic vasculitis, signs of chronic endocarditis, with mononuclear cell accumulation and a fresh thrombus was found. Herpes viruses have already been thought to initiate cardio-vascular disorders, now this paper shows that a bovine gamma-herpes virus could also be a causative agent of vascular lesions in mammals fed a normal diet. BoHV-4-infection of rabbits could serve as a useful animal model for research into virus-induced human cardio-vascular diseases.