Safety evaluation of a proprietary food-grade, dried fermentate preparation of Saccharomyces cerevisiae.

A safety evaluation was performed for EpiCor, a product produced by a proprietary fermentation process using Saccharomyces cerevisiae. Studies included the following assays: bacterial reverse mutation, mouse lymphoma cell mutagenicity, mitogenicity assay in human peripheral lymphocytes, and a cytochrome P450 ([CYP] CYP1A2 and CYP3A4) induction assessment as well as 14-day acute, 90-day subchronic, and 1-year chronic oral toxicity studies in rats. No evidence of genotoxicity or mitogenicity was seen in any of the in vitro or in vivo studies. The CYP assessment showed no interactions or inductions. No toxic clinical symptoms or histopathological lesions were observed in the acute, subchronic, or chronic oral toxicity studies in the rat. Results of the studies performed indicate that EpiCor does not possess genotoxic activity and has a low order of toxicity that is well tolerated when administered orally. The no observable adverse effect level (NOAEL) was 1500 mg/kg body weight (bw)/d for the 90-day study and 800 mg/kg bw/d for the 1 year study, for the highest doses tested.

Reproductive features and faecal progesterone metabolite profile in female ferrets.

Elevated post-partum progesterone metabolite (P(4) -met) levels have been recently postulated to occur in lactating lynxes. The aims of this study were to monitor reproductive features in female ferrets, changes in the faecal P(4) -met concentrations throughout the breeding season and ovarian activity in post-partum lactating and non-lactating (NL) female ferrets. Our results indicate that coinciding with the results described in the lynx, elevated faecal P4-met concentrations occur in lactating ferrets, furthermore, that the duration of elevated secretion of P(4) seems to be dependent on the duration of lactation (P4-met at delivery, n=47: <500 ng/g; 5-7 days after delivery, during lactation, n=47: ≥ 500-800 ng/g; in females weaned at delivery, n=4: baseline levels). Three days after ovariohysterectomy of lactating females, P(4) -met concentrations decreased to baseline levels. In lactating females, the ovarian stroma is more active than that in NL ones implicating that the ovary is at least in part responsible for the elevated P4-met concentrations. Ovaries of lactating females contained many luteinized cells either as luteinized granulose cells in the wall of late pre-antral/early antral follicles or as corpus luteum (CL)-like structures. Early resumption of the entire ovarian activity (developed follicles and oestrus) occurs in NL post-partum females, while final follicular development is blocked (follicles stalls at antral stage) in the lactating ones (however, occasionally lactational oestrus may occur). We suppose that the elevated faecal P4-met during lactation together with suckling and other hormonal effects may contribute to prevention of early returning to oestrus in nursing female ferrets.

Single- and repeated-dose oral toxicity studies of citicoline free-base (choline cytidine 5'-pyrophosphate) in Sprague-Dawley rats.

The dietary supplement Citicoline free-base (choline cytidine 5'-pyrophosphate) was toxicologically evaluated in Sprague-Dawley rats using oral gavage. In an acute 14-day study, 2000 mg/kg was well tolerated. In a 90-day study, 100, 350, and 1000 mg/kg/day doses resulted in no mortality. In males, slight significant increases in serum creatinine (350 and 1000 mg/kg/day), and decreases in urine volume (all treated groups) were observed. In females, slight significant increases in total white blood cell and absolute lymphocyte counts (1000 mg/kg/day), and blood urea nitrogen (BUN) (100 and 350, but not 1000 mg/kg/day) were noted. A dose-related increase in renal tubular mineralization, without degenerative or inflammatory reaction, was found in females (all treated groups) and two males (1000 mg/kg/day). Renal mineralization in rats (especially females) is influenced by calcium:phosphorus ratios in the diet. A high level of citicoline consumption resulted in increased phosphorus intake in the rats, and likely explains this result.

Investigation of field outbreaks of turkey haemorrhagic enteritis in Hungary.

Epidemiological, pathological, serological and virological investigations are reported on turkey haemorrhagic enteritis virus (THEV) infection in Hungarian turkey flocks. The pathogenesis of infection in experimentally infected turkeys and chickens, as well as the usefulness of polymerase chain reaction (PCR)/sequencing method for epidemiological investigation and for the differentiation of vaccine and field strains of THEV was also studied. Since the first recognition of the disease in Hungary in the late 1970s, until recently the disease has been diagnosed sporadically in its mild form. In the last few years (2000-2005), however, the number of outbreaks and the severity of the disease increased (9-23 affected flocks/year). Most of the outbreaks occurred at the age of 6 to 8 weeks and was complicated with Escherichia coli infection. The antibody levels to THEV in turkey flocks gradually declined till 5-7 weeks of age, and then they increased sharply due to natural infection with THEV. The immune response to vaccination (at 5 weeks of age) showed no significant antibody level increase one week postvaccination, but four weeks later the antibody level reached high values and then remained at this high level. The agar gel immunodiffusion (AGID) test to detect turkey adenovirus A (TAdV-A) antigen and PCR methods for THEV-specific DNA gave similarly positive results if spleens with pathognomonic lesions were tested; however, PCR proved to be more sensitive in cases with less characteristic pathological lesions. Nucleotide sequence alignment of PCR products amplified from Hungarian field strains and the Domermuth vaccine strain and that of the published THEV hexon sequences in GenBank database revealed slight differences between the sequences.

Effects of nickel supply on the fattening performance and several biochemical parameters of broiler chickens and rabbits.

Broiler chicken and rabbit experiments were carried out to study the effects of nickel (Ni) supplementation on growth performance and Ni metabolism. ROSS cockerels and New Zealand White female rabbits were fed a diet containing Ni in concentrations of 0, 50 and 500 mg/kg in dry matter (DM). Dietary supplementation of 50 mg Ni/kg slightly improved the body weight gain (BWG) and had a beneficial effect on the feed conversion efficiency (FCE) in broiler chickens. However, Ni added at a level of 500 mg/kg significantly (P < 0.05) reduced the BWG by 10% and resulted in significantly (P < 0.05) worse (2.3 +/- 0.2 kg/kg) FCE. The relative weight of the liver in cockerels was significantly (P < 0.05) decreased by Ni as compared to the control group (1.7 and 2.1% vs. 2.6%). The activity of AST and CHE enzymes was increased insignificantly by dietary supplementation of 500 mg Ni/kg, indicating damage of the liver parenchyma. The results of serum biochemistry were confirmed by a mild or moderate form of pathological focal fatty infiltration of the liver in broilers. Supplemental Ni of 50 mg/kg concentration resulted in non-significantly increased BWG in rabbits. Ni added to the diet at a level of 500 mg/kg reduced the digestibility of crude protein by 3-4% and that of crude fibre by 20-25% in rabbits. Approx. 98% of the ingested Ni was lost from the body via the faeces, 0.5-1.5% via the urine and approx. 1% was incorporated into the organs of rabbits. As a result of dietary supplementation of 50 and 500 mg Ni/kg, Ni accumulated in the kidneys (4.9 +/- 0.5 and 17.1 +/- 3.1 vs. 1.9 +/- 0.3 mg/kg DM), ribs (10.3 +/- 0.4 and 10.4 +/- 0.6 vs. 9.1 +/- 0.6 mg/kg DM), heart (1.4 +/- 0.2 and 2.5 +/- 0.4 vs. 1.0 +/- 0.1 mg/kg DM) and liver (1.3 +/- 0.1 and 2.2 +/- 0.2 vs. 0.9 +/- 0.05 mg/kg DM), as compared to the control animals. It can be stated that supplementation of the diet with 50 mg Ni/kg had slight but non-significant beneficial effects on the growth performance of broiler chickens and rabbits.

The role of egg drop syndrome virus in acute respiratory disease of goslings.

An outbreak of severe acute respiratory disease characterized by tracheitis and bronchitis was observed in young goslings on a large-scale goose farm in Hungary. Histological examination revealed amphophilic intranuclear inclusion bodies in the superficial epithelial cells of the trachea and bronchi. Adenovirus-like particles were detected by electron microscopy, and the virus isolated from the trachea and the lungs was identified as egg drop syndrome (EDS) virus by serological and genomic examination. The clinical and pathological signs were reproduced by intratracheal administration of the virus isolate to 1-day-old goslings free of EDS antibodies. The presence of EDS virus DNA in different organs of the naturally and experimentally infected goslings was detected by polymerase chain reaction. This is the first report on the involvement of EDS virus in severe respiratory disease of geese.

Infectious stunting syndrome associated with disturbances of mineral metabolism and bone development in broiler chickens.

On a broiler farm with a rearing capacity of about 200,000 chickens, a disease characterised by growth retardation, variability in chick size, 'leg weakness', diarrhoea and increased mortality at 3 weeks of age occurred repeatedly, in several successive broiler flocks. Gross and histopathological findings were dominated by widening of the hypertrophic and ossification layers of the physes of long bones as well as by thickening, unevenness and defective calcification of the cartilage trabeculae. In the parathyroid gland, vacuolar degeneration of the cytoplasm of glandular epithelial cells, connective tissue proliferation and, here and there, cyst formation were seen. Additional findings included severe cerebellar oedema and neuronal degeneration. The pancreatic, myocardial and intestinal changes typical of infectious stunting syndrome (ISS) occurred only in a mild form. Four-week-old chickens exhibiting 'leg weakness' had significantly lower blood inorganic phosphate concentration and tibial ash content as compared to healthy chickens. The disease was successfully transmitted by oral administration of small intestinal homogenate from affected chickens. In a second experiment, however, the disease could not be transmitted with intestinal homogenate sterilized by irradiation. Large doses of vitamin D3 reduced the rate of growth retardation and defective calcification of bones. The digestive enzyme activities of the pancreas and small intestinal mucosa of 'infected' chickens were decreased as is typical of ISS.

Fumonisin B1 contamination of maize and experimental acute fumonisin toxicosis in pigs.

The fumonisin B1 content of 69 visibly mouldy and 23 mould-free maize samples grown in Hungary in 1993-1995 was determined by high-performance liquid chromatography (HPLC). Fumonisin B1 was found to occur in 70-73% of the mouldy samples. The mycotoxin level increased from year to year: the highest fumonisin B1 concentration was 75.1 mg/kg. The samples that were mould-free on visual inspection showed a much lower prevalence of fumonisin B1 contamination (30%) and contained fumonisin B1 in markedly lower concentrations (average, 1.52 mg/kg; maximum concentration, 5.1 mg/kg). Using the Fusarium moniliforme strain designated 14/A, isolated from the sample that had the highest mycotoxin concentrations, fumonisin B1 toxin was produced on maize by an internationally accepted procedure. Subsequently, two weaned piglets were fed a diet containing 330 mg fumonisin B1 per kg of feed. The experimental animals developed hydrothorax and pulmonary oedema, and died in 5-6 days. The clinical symptoms and pathological lesions were consistent with those of porcine pulmonary oedema (PPE) diagnosed in the USA in 1989-1990, as well as with those of a disease entity that had already been described in Hungary in the 1950s as the so-called fattening or unique pulmonary oedema of pigs but considered to be of unknown aetiology. The results of the feeding trial confirm that this pig disease, which has occurred in Hungary for a long time, is caused by the mycotoxin fumonisin B1.

Complex study of the physiological role of cadmium. IV. Effects of prolonged dietary exposure of broiler chickens to cadmium.

A 274-day long cadmium (Cd) feeding trial was carried out with broiler cockerel chickens. The diet of the control group (Cd-0, n = 6) contained no added Cd, whereas to the diet of group Cd-25 and group Cd-75 (n = 10 each) 25 ppm and 75 ppm Cd was added, respectively, in the form of CdSO4. The chickens were subjected to examinations described in detail earlier (Bokori et al., 1995b). In addition, the relative mass of five different organs (heart, liver, testis, spleen and brain), expressed as % of the body mass, was also determined. The clinical, gross and histopathological examinations and the assay of organs for mineral element content led to the following main findings. The feeding of diets containing 25 or 75 ppm Cd for more than 9 months did not cause signs indicative of acute Cd toxicosis or mortality in either group. The body mass gain of group Cd-75 chickens markedly decreased. Prolonged Cd exposure of the cockerels increased the relative mass of the liver and heart and markedly decreased that of the testes. The change in mass was proportional to the Cd load. The Cd-fed chickens developed focal pathological fatty infiltration of the liver, histiocytic infiltration of the jejunal mucosa and focal lympho-histiocytic interstitial infiltration and fibrosis of the kidney, which supports the view that prolonged Cd exposure leads to the development of subacute-chronic tissue changes in the kidney. The Cd content of the organs increased by one to three orders of magnitude, in direct proportion to the Cd load. The Cd content of most organs was 2 to 3 times as high as the value reported for broilers exposed to a similar Cd load lasting for 68 days (Bokori et al., 1995b). This indicates that the degree of Cd accumulation is markedly influenced by the duration of the Cd exposure. The highest Cd content was demonstrated in the kidney (724 mg/kg of dry matter). The Cd exposure markedly lowered the Zn, Mo and B content of the bones and the Ni content of the myocardium.

Bacteriologically confirmed cases of ovine epididymo-orchitis caused by Brucella ovis in Sub-Carpathia.

During the eradication of Brucella ovis infection from five large breeding ram flocks of Sub-Carpathia (The Ukraine), the genital organs of 55 rams culled because of seropositivity in the agar-gel precipitation (AGP) test and ELISA were subjected to gross pathological, histopathological and bacteriological examination. The results of these examinations, as well as the properties of B. ovis strains isolated for the first time in the region are reported. Thirty-three out of the 55 pairs of epididymides and testicles (60%) showed gross lesions (chronic epididymitis associated with the formation of spermatocele, sperm granuloma or abscess). From the 55 pairs of epididymides and testicles examined, a total of 26 B. ovis strains were isolated: of them, 24 (92.3%) originated from breeding rams while 2 (7.7%) from ram hoggets kept together with the breeding rams. Seven out of the 26 B. ovis strains (26.9%) were cultured from the epididymides of rams which did not show palpable epididymal and/or testicular lesions. It is emphasized that chronic inflammatory processes were observed in both epididymides even if the clinically palpable epididymo-orchitis occurred unilaterally. Three out of the 26 B. ovis strains were derived from AGP-positive but ELISA-negative, while 5 from ELISA-positive but AGP-negative rams. The remaining B. ovis strains were isolated from the genital organs of rams found seropositive both by the AGP test and by ELISA. The cultural, morphological and most important biochemical properties of the 26 sub-Carpathian B. ovis strains were identical with those of the reference strain designated Weybridge 63/290 (NCTC 10512).

Pathomorphological changes caused by T-2 trichothecene fusariotoxin in geese.

T-2 trichothecene fusariotoxin was administered to 110 laying geese and 33 ganders in the active egg production period through a tube at 2-day intervals on a total of 10 occasions. After the treatment, the geese were subjected to detailed pathomorphological examination. In the ovaries of layers, a cessation of follicle maturation and follicle degeneration dependent on the toxin dose were observed, accompanied by ovulation and consequent peritonitis in the birds that died and in some of those killed by bleeding. Additional findings included involution of the oviduct, lymphocyte depletion, necrosis and amyloidosis in the spleen, catarrhal enteritis, signs of colloid stasis in the thyroid and large numbers of secretory granules in the cytoplasm of the adrenaline-producing cells of the adrenal gland. In the ganders, toxin administration did not reduce the intensity of spermatogenesis but in the spleen, intestine and endocrine glands it caused changes similar to those seen in the layers.

Additional data on Mycoplasma disease of goslings.

Epidemiological, pathomorphological, histological and microbiological studies on 272 gosling from 51 flocks showed that disease occurred generally at 3 to 4 weeks of age with morbidity of 15 to 25% and mortality of 3 to 8%. It was characterized by respiratory and nervous symptoms accompanied by serous-fibrinous inflammation of the mucosal membrane of the respiratory tract, pericardium and cerebral membranes. Mycoplasmas of 1220 type were isolated from trachea and airsac walls of 50% of the samples tested, but no adeno or reoviruses could be detected in homogenates of trachea and airsac wall, and no serological response indicative of Derzsy's disease could be demonstrated. E. coli, Ps. aeruginosa, S. typhimurium and Sir. pyogenes were occasionally cultured from the heart and liver of goslings. Cloacal and oviduct swabs and phallus lympha samples from five parent goose flocks also frequently revealed 1220 type mycoplasmas.

Experimental infection of weaned calves and lambs with two strains of bovine adenovirus type 2.

The pathogenicity of two genetically different strains of bovine adenovirus type 2 (BAV-2) was tested in a double cross experimental infection of weaned lambs and calves. One of the virus strains was isolated from cattle and represented BAV-2 subgroup "A", while the other was isolated from sheep and belonged to subgroup "B" (Belák et al., 1983). The two virus strains caused infection both in lambs and calves; the viruses were repeatedly reisolated and definite seroconversion was found in all four groups. However, remarkable differences were observed in the pathogenicity: the most intensive virus multiplication and shedding, the most severe clinical symptoms and histopathological lesions were observed in the lamb group infected with the ovine isolate.

Demonstration of Clostridium septicum infection in a goose flock.

Clostridium septicum infection causing 5.0 to 5.2% mortality is reported for the first time in the literature from six-week-old growing geese in three flocks comprising 5,200, 5,500 and 5,900 geese, respectively. The affected birds exhibited weakness, uncoordinated movement, ataxia and, frequently, oblique position of the head and neck (torticollis) as well as signs indicative of dysequilibrium. The affected birds died within 18-24 h. Gross pathological examination revealed anaemia, hepatitis with map-like necroses of irregular outline (Fig. 1), acute enteritis, pulmonary oedema and cardiac dilatation. Light and electron-microscopic examination showed that the sinusoids of the liver were markedly dilated (Fig. 2) and filled with serous exudate and gas (Figs 2 and 3), and the hepatocytes surrounding them exhibited severe oedema (Fig. 4). Among the hepatocytes, ciliated bacteria 7-10 mu in length and 1-3 mu in width, bounded by a well-defined cell wall and often showing signs of spore formation were observed (Figs 5 and 6). By bacteriological examination the pathogen was isolated, its properties were studied, and the clinical entity of malignant oedema was experimentally reproduced by intramuscular injection of guinea-pigs and rabbits. The applied antibiotic (oxytetracycline) and furazolidone therapy proved effective.

Acute toxicological experiment of T-2 toxin in rabbits.

Rabbits were treated with a single oral dose (1, 2, 4, 6, 8, 10 or 15 mg/kg body mass) of T-2 fusariotoxin. Doses of 4 mg or higher killed the animals in 24 to 48 h. As opposed to the controls, in the treated rabbits gross pathological and histopathological examinations revealed acute catarrhal gastroenteritis, necrosis of lymphoid cells of the gastrointestinal mucosa, centrolobular dystrophy of the liver, necrosis of cells of the mononuclear phagocyte system (MPS) in the liver, tubulonephrosis, focal dystrophy of the adrenal cortex, lymphocyte depletion involving both T- and B-cell-dependent zones of the lymphoid organs (spleen, lymph, ampulla ilei), and depletion and necrosis of the myelopoietic cell colonies of the bone marrow. Similar but milder changes were observed in surviving rabbits exsanguinated 48 h after treatment. In addition to the direct damage done to the digestive tract mucosa and liver, the toxin severely damaged the cells participating in humoral and cell-mediated immunity and in the local defence of the intestinal mucosa, and markedly impaired phagocytosis and granulocytopoiesis. In another experiment rabbits were given oral doses of 2 mg/kg body mass T-2 toxin daily for several days. One rabbit was killed by bleeding every day. In rabbits killed beyond day 7 there was subacute catarrhal gastritis, emaciation, and hypertrophy of the adrenal cortex.

Isolation of a reticuloendotheliosis-like virus from naturally occurring lymphoreticular tumours of domestic goose.

Naturally occurring lymphoreticular tumours were found in an adult goose flock. Diffuse and/or nodular lymphoma-like tumours occurred in the spleen, liver, pancreas, intestines and rarely in other internal organs. Osteopetrosis-like lesions and signs of other diseases such as amidostomosis, enteritis, arthritis and air sacculitis were also observed. The tumourous lesions consisted of proliferations of undifferentiated lymphoblasts and slightly differentiated plasmablasts of the bursal system of lymphocytes. Tumour cell proliferation was usually associated with parenchymal atrophy and occasionally with amyloid depositions along the walls of capillaries of the spleen and the liver. In tissue cultures, chloroform sensitive, typical C-type virus particles of about 100 nm were isolated. The isolate incorporated 3H-uridine, banded at about 1.19 to 1.20 g/cm(3) in sucrose gradient ultracentrifugation and was shown to be antigenically related to the reticuloendotheliosis group of avian retroviruses. In transmission experiments with chickens and geese, one of the four tested reticuloendotheliosis virus-positive cellular field materials caused a highly lethal neoplastic disease similar in cytology to that seen in the natural disease outbreak within four weeks after infection. The other three cellular field materials and the tissue-culture-propagated virus isolates induced either a runting disease syndrome or a similar chronic neoplasia to that found in the naturally diseased geese during an experimental period of 30 weeks. Reticuloendotheliosis virus was reisolated from the experimentally inoculated birds, and antibodies to the T strain of reticuloendotheliosis virus were also demonstrated in sera of surviving chickens. Neither Marek's disease virus nor avian leukosis-sarcoma viruses could be demonstrated in tissue cultures or in chickens of transmission experiments. The reported transmissible lymphoreticular tumours of domestic goose seem to be associated with infection of a new isolate of the reticuloendotheliosis group of viruses designated as Reticuloendotheliosis Virus Hungary-2 (REV-H-2).

Epidemiology and significance of Q fever in Hungary.

In Hungary, Coxiella (C.) burnetii infections were diagnosed for the first time in 1956 in a few dairy and sheep farms. Q fever associated with abortion was first demonstrated in 1983 during laboratory diagnostic examination of fetuses and placentae. From case history data and on-the-spot investigations it is clear that in cattle stocks abortion caused by C. burnetii occurs sporadically, whereas in sheep flocks numerous abortions may take place within a short time. Losses caused by Q fever on the affected large-scale farms amount to 5-15%, which arise partly from reduced calf or lamb crop and partly from the death of offspring born with poor viability and being highly susceptible to neonatal disease. Altogether 87 cases of human disease caused by C. burnetii have been reported in the Hungarian literature. Instead of typical pneumonia, in recent years sporadic cases of granulomatous hepatitis were a constant finding accompanied by a characteristic blood picture and high titres of specific antibodies.