Use of computed tomography and histopathologic review for lung lesions produced by the interaction between Mycoplasma hyopneumoniae and fumonisin mycotoxins in pigs.

Mycoplasma hyopneumoniae has a primary role in the porcine respiratory disease complex (PRDC). The objective of this study was to determine whether fumonisin mycotoxins influence the character and/or the severity of pathological processes induced in the lungs of pigs by Mycoplasma hyopneumoniae. Four groups of pigs (n = 7/group) were used, one fed 20 ppm fumonisin B1 (FB1) from 16 days of age (group F), one only infected with M. hyopneumoniae on study day 30 (group M), and a group fed FB1 and infected with M. hyopneumoniae (group MF), along with an untreated control group (group C). Computed tomography (CT) scans of infected pigs (M and MF) on study day 44 demonstrated lesions extending to the cranial and middle or in the cranial third of the caudal lobe of the lungs. The CT images obtained on study day 58 showed similar but milder lesions in 5 animals from group M, whereas lungs from 2 pigs in group MF appeared progressively worse. The evolution of average pulmonary density calculated from combined pixel frequency values, as measured by quantitative CT, was significantly influenced by the treatment and the age of the animals. The most characteristic histopathologic lesion in FB1-treated pigs was pulmonary edema, whereas the pathomorphological changes in Mycoplasma-infected pigs were consistent with catarrhal bronchointerstitial pneumonia. FB1 aggravated the progression of infection, as demonstrated by severe illness requiring euthanasia observed in 1 pig and evidence of progressive pathology in 2 pigs (group MF) between study days 44 and 58.

Pathologic lesions caused by coinfection of Mycoplasma gallisepticum and H3N8 low pathogenic avian influenza virus in chickens.

Chickens were infected under experimental conditions with Mycoplasma gallisepticum and low pathogenic avian influenza (LPAI) strain A/mallard/Hungary/19616/07 (H3N8). Two groups of chickens were aerosol challenged with M. gallisepticum strain 1226. Seven days later, one of these groups and one mycoplasma-free group was challenged with LPAI H3N8 virus; one group without challenge remained as negative control. Eight days later, the birds were euthanized and examined for gross pathologic and histologic lesions. The body weight was measured, and the presence of antimycoplasma and antiviral antibodies was tested before the mycoplasma challenge, before the virus challenge, and at the end of the study to confirm both infections. Chickens in the mycoplasma-infected group developed antibodies against M. gallisepticum but not against the influenza virus. Chickens of the group infected with the influenza virus became serologically positive only against the virus, while the birds in the coinfected group developed antibodies against both agents. The LPAI H3N8 virus strain did not cause decrease in body weight and clinical signs, and macroscopic pathological lesions were not present in the chickens. The M. gallisepticum infection caused respiratory signs, airsacculitis, and peritonitis characteristic of mycoplasma infection. However, the clinical signs and pathologic lesions and the reduction in weight gain were much more significant in the group challenged with both M. gallisepticum and LPAI H3N8 virus than in the group challenged with M. gallisepticum alone.

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.

Effect of different concentrations of Bacillus subtilis on growth performance, carcase quality, gut microflora and immune response of broiler chickens.

1. An experiment was conducted to study the effects of different Bacillus subtilis concentrations on productivity, carcase quality, immune response and the gut microflora of broiler chickens. 2. There were 5 treatment groups: control, with no added Bacillus subtilis supplementation; and 4 treatment groups receiving feed supplemented with different concentrations of B. subtilis. 3. Weight gain was significantly higher and the feed conversion rate was significantly better in all groups receiving feed supplemented with B. subtilis, regardless of its concentration. The groups given B. subtilis supplementation produced relatively bigger breasts, and smaller carcases and thighs, compared with the control group. 4. The appearance of increased diffuse lymphohistiocytic infiltration and solitary lymphoid follicles in the mucosa, and a stronger response to NDV vaccination, indicate increased immunological responses in chickens fed with the B. subtilis supplemented diet. 5. The higher inclusion rate of B. subtilis did not increase Lactobacillus concentrations in the ileum or in the caecum, but decreased the E. coli population significantly.

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.

Effects of oral L-carnitine, L-lysine administration and exercise on body composition and histological and biochemical parameters in pigeons.

The purpose of this study was to examine whether L-carnitine and its precursor L-lysine could have any beneficial effect in racing pigeons, and if so, whether this effect is influenced by the extent of exercise (short-distance flight: 135 km vs. long-distance flight: 580 km). Birds were divided into seven groups of animals. Group 1: negative control, no flight, no treatment, Group 2: positive control, placebo treatment before the short-distance flight, Group 3: 200 mg/day L-carnitine treatment before the short-distance flight, Group 4: 400 mg/day L-lysine treatment before the short-distance flight, Group 5: positive control, placebo treatment before the long-distance flight, Group 6: 200 mg/day L-carnitine treatment before the long-distance flight, Group 7: 400 mg/day L-lysine treatment before the long-distance flight. L-carnitine, L-lysine and distilled water (placebo) were orally administered (tube feeding) for 7 days before flight. Just after returning home, blood samples were collected and analyzed for glucose, fructosamine, cholesterol, triglycerides and thiobarbituric acid reactive substances. Pigeons were euthanized using carbon dioxide as an inhalation agent, and the whole body was subjected to proximate analysis. The status at arrival was referred to as a basis for comparison. Sex did not affect the measured parameters. As a result of the L-carnitine and L-lysine administrations, the body fat mobilization was higher during the 580 km flight, whereas no changes were noted during the 135 km flight. The main changes in the measured blood parameters were caused by the extent of exercise. This experiment considered the extent of exercise as a factor potentially modulating L-carnitine supplementation effects. In conclusion, flight distance affected several parameters but the supplements of L-carnitine and L-lysine were not effective in the tested situations.

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.

Pacheco's disease in a Hungarian zoo bird population: a case report.

An epizootic of Pacheco's disease is reported from a zoo bird population. The infection was introduced by wild-captured Patagonian conures (Cyanoliseus patagonus) despite 61 days of quarantine. The disease affected several parrot species and, interestingly, three out of seven bearded barbets (Lybius dubius). The mortality rate was 30.93%. Autopsy revealed abdominal hyperaemia with liver haemorrhages and, in less rapid cases, yellowish discoloration and fragility of the liver. Death was caused by the collapse of circulation. Histopathology demonstrated liver cell necrosis, disintegration of the lobular structure, and a few intranuclear inclusion bodies. Icosahedral virions were detected by electron microscopy. The virus was isolated in the allantoic cavity of embryonated chicken eggs as well as in chicken embryo fibroblast cell culture. A 281-bp-long fragment of psittacid herpesvirus DNA was detected by PCR in cell culture material and liver samples of the affected birds. To our knowledge this is the first report of Pacheco's disease in bearded barbets as well as the first occurrence of Pacheco's disease in Hungary.

Experimental study on the role of Brachyspira alvinipulli in intestinal spirochaetosis of geese.

Ten one-day-old goslings were inoculated orally with a Brachyspira alvinipulli strain isolated from the large intestine of geese that had died of intestinal spirochaetosis (Group A), 10 day-old goslings were inoculated orally with a B. hyodysenteriae strain (Group B), and a third group of 10 goslings (Group C) served as uninfected control. The goslings were observed daily for clinical signs. They were sacrificed on days 7, 14, 21 and 35 days postinfection (PI), and necropsied. Segments of the large intestine were subjected to histopathological, immunohistochemical, electron microscopic (TEM, SEM) and microbiological examinations. Mortality did not occur during the experimental period. However, in both groups the caecum of the goslings killed by bleeding was slightly dilated, in its lumen there was a watery, yellowish and frothy content, and the mucous membrane was slightly swollen. By histopathological, immunohistochemical and electron microscopic examination, B. alvinipulli and B. hyodysenteriae could be detected in the caecum or colon, in the lumen of the glands and sometimes among the glandular epithelial cells in goslings of the respective groups, and could be reisolated from these organs by culturing. A mild inflammation of the intestinal mucosa was also noted. In transverse section of the brachyspirae, numerous (16-22) periplasmic flagella could be detected inside the outer sheath, also depending on the plane of section.

Acute and subchronic toxicity studies of cryogenically-frozen, cryomilled, Pelodiscus sinensis (Japanese soft-shelled turtle--suppon) powder administered to the rat.

Sprague-Dawley rats received "cryogenically-frozen suppon" (CFS), a cryomilled product derived for the Japanese soft-shelled turtle (Pelodiscus sinensis), widely consumed for its nutritious value and medicinal properties, especially for the maintenance of normal blood pressure and insulin levels, and in women for the treatment of menopausal symptoms. In this acute study, a single limit dose of 2.0 g/kg was given po. common to 10 male and 10 female rats. No adverse effects or mortality were observed during a 14-day period and at gross pathological examination. In the subchronic study, CFS was administered as oral daily doses of 100, 350, and 1000 mg/kg administered for 97 days, resulting in no mortality, no changes in body weight, food and water consumption, hematological and serum chemistry parameters, organ weights, or gross pathology or histopathology. The only treatment related finding was a characteristic excited behavior observed in several male rats from the second or third week of treatment, distributed evenly in all male treatment groups but not affecting all males. The number of excited animals did not change over time, the syndrome occurred in all test item treated male groups with similar incidence. None of the females was so affected.

The efficacy of valnemulin (Econor) in the control of disease caused by experimental infection of calves with Mycoplasma bovis.

Mycoplasma bovis infection was experimentally induced in groups of six young calves. A further group was uninfected and served as a control. Ten days after infection, medication with either enrofloxacin (Baytril, Bayer) or valnemulin (Econor, Novartis) was instituted via the milk replacer for a further 10 days, after which all calves were killed. Infection resulted in depression, pyrexia, inappetance and prominent respiratory signs. Arthritis occurred in two animals and two (unmedicated) animals died. At post-mortem examination extensive lesions were present in the lungs and M. bovis was re-isolated from infected unmedicated calves' lungs. Medication with either enrofloxacin or valnemulin resulted in a rapid diminution of clinical signs, restoration of appetite and reversal of weight loss. Isolation of Pasteurella multocida from the calves' lungs was suppressed by both medicaments. Valnemulin resulted in a more rapid reduction of clinical scores and eliminated M. bovis from the lungs more effectively than enrofloxacin.

Comparative pathological studies on domestic geese (Anser anser domestica) and Muscovy ducks (Cairina moschata) experimentally infected with parvovirus strains of goose and Muscovy duck origin.

Parvovirus infection of Muscovy ducks caused by a genetically and antigenically distinct virus has been reported from Germany, France, Israel, Hungary, some Asian countries and the USA. The pathological changes include those of degenerative skeletal muscle myopathy and myocarditis, hepatitis, sciatic neuritis and polioencephalomyelitis. In the study presented here, day-old and 3-week-old goslings and Muscovy ducks were infected experimentally with three different parvovirus strains (isolates of D-216/4 from the classical form of Derzsy's disease, D-190/3 from the enteric form of Derzsy's disease, and strain FM from the parvovirus disease of Muscovy ducks). All three parvovirus strains caused severe disease in both day-old and 3-week-old Muscovy ducks but in the goslings only the two strains of goose origin (D-216/4 and D-190/3) caused disease with high (90-100%) mortality when infection was performed at day old. Strain FM (of Muscovy duck origin) did not cause any clinical signs or pathological lesions in the goslings. In the day-old goslings and Muscovy ducks the principal pathological lesions were severe enteritis with necrosis of the epithelial cells (enterocytes) of the mucous membrane and the crypts of Lieberkühn, and the formation of intranuclear inclusion bodies. Other prominent lesions included hepatitis and atrophy (lymphocyte depletion) of the lymphoid organs (bursa of Fabricius, thymus, spleen). In goslings infected with the strain originating from the classical form of Derzsy's disease mild myocarditis was also detected. After infection at three weeks of age, growth retardation, feathering disorders, myocardial lesions (degeneration of cardiac muscle cells, lympho-histiocytic infiltration) and hepatitis were the most prominent lesions in both geese and Muscovy ducks. In addition to the lesions observed in the geese, muscle fibre degeneration, mild sciatic neuritis and polioencephalomyelitis were also observed in the Muscovy ducks infected with any of the three parvovirus strains.

An anti-CD3 epsilon serum detects T lymphocytes in paraffin-embedded pathological tissues in many animal species.

The in situ identification of T cells has been difficult and restricted to frozen tissue samples of a limited range of species. In this study, we demonstrate that an antiserum recognizing a phylogenetically conserved part of the CD3 epsilon cytoplasmic tail detects T cells of many avian and mammalian species in formalin-fixed paraffin-embedded tissue sections. This antiserum enables the morphological characterization of normal and pathological lymphoid tissues and lymphoid infiltrations in experimental work and in animal disease.

Testing the compatibility of a combination of tiamulin/chlortetracycline 1:3 premix (Tetramutin-Novartis) given in feed at different levels with salinomycin in chickens.

The compatibility of salinomycin (SA) (60 mg/kg feed) and Tetramutin (TM), a combination of tiamulin (TI) and chlortetracycline (CTC) in a 1:3 ratio, included in varying concentrations, was tested in broiler chickens. Assessment was based on clinical signs, body weight gain, feed conversion efficiency, gross pathological lesions and histological lesions in liver, heart and pectoral muscles, as well as analysis of blood for lactate dehydrogenase (LDH), aspartate dehydrogenase (AST) and creatine phosphokinase (CPK) activity. It was shown that chickens can be safely treated in feed for 7 days with TM containing TI concentrations of 33 or 55mg/kg feed together with SA at 60mg/kg. However, higher levels of TI (100 and 150 mg/kg feed) caused some adverse effects. There was no mortality but there was mild depression, 'leg weakness' accompanied by specific histological lesions in pectoral muscles (obliteration of cross-striation and swelling of muscle fibres, nuclei of muscle cells, hyalinization and destruction of sarcoplasm), a mild increase of AST activity, and a significant increase of CPK and LDH activity in blood. These latter two parameters can be used as an early indication of TI and SA incompatibility.

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.

Horizontal transmission of Aujeszky's disease virus from sheep to pigs.

Eight 2-month-old merino lambs were inoculated intranasally with different (10(2.0)-10(5.0)TCID50) amounts of Aujeszky's disease virus (ADV). Electron microscopic studies indicated that ADV replicated in extra-neural sites, in the epithelial cells of the mucosa of the upper and lower respiratory tract. Although the virus was excreted continuously in nasal discharges, horizontal transmission to contact lambs failed. The surviving exposed and contact lambs had no demonstrable antibodies against ADV and they were susceptible when challenged by ADV. However, the virus was transmitted to susceptible pigs in contact with the exposed lambs. One of the five contact pigs showed characteristic clinical signs of Aujeszky's disease, developed a nonsuppurative meningoencephalomyelitis and ADV was recovered from the brain, nasal discharge and other organs. Restriction enzyme analysis of DNA from this virus confirmed the sheep origin of the isolate. The other 4 pigs seroconverted. ADV infection in sheep is therefore a possible source of infection for pigs, but the lack of horizontal transmission in sheep was confirmed.

Aujeszky's disease of sheep: experimental studies on the excretion and horizontal transmission of the virus.

Five 5-month-old merino lambs were nasally inoculated with 10(5.0) TCID50 of Aujeszky's disease virus (ADV). The dynamics of virus excretion in the nasal discharges--in agreement with the histologic findings--indicated that ADV also replicates in extraneural sites, in the upper and lower parts of the respiratory tract. The virus was excreted continuously in the nasal discharges, even during the incubation period. The titres, with certain fluctuations, increased gradually up to the final stage of the fatal disease. Following the onset of the clinical disease, the titre of excreted virus (ranging from 10(4.0) to 10(6.0) TCID50/0.1 ml) was comparable with the ADV content found in the nasal discharge of naturally infected piglets. However, the horizontal transmission of ADV to contact lambs failed.

Intestinal absorption of colostral lymphoid cells in newborn piglets.

Intestinal absorption of colostral lymphoid cells was studied in 23 piglets of four sows (sows A, B, C and D). From the colostrum and blood of the sows the lymphoid cells were isolated with Ficoll-Paque and labelled with technetium (Na99mTcO4). In the 7th hour after birth, 5-ml volumes of the cell suspensions were injected, following laparotomy, directly into the stomach (piglets of sow A) or into the jejunum (piglets of sow B), whereas piglets of sows C and D received the suspensions through a naso-oesophageal tube. Cryostat sections of duodenum, jejunum and lymph node samples of piglets killed by bleeding 8 h after the treatment were examined by autoradiography. It was found that lymphoid cells present in the colostrum of a piglet's own mother were absorbed from the digestive tract and, via the lymphatic vessels, were transported to the mesenteric lymph nodes. Electron microscopy revealed that absorption took place intercellularly. Colostral cells of sows other than a piglet's own mother were observed only in the epithelial layer of the mucous membrane. The lymphoid cells isolated from the sows' blood and heat-treated colostral lymphoid cells were not absorbed. The results indicate that in the pig, an animal having an epitheliochorial placenta, the colostral lymphoid cells are absorbed from the digestive tract and, hence, they can confer an active cellular immunity on the newborn piglets.

Toxicity of methylsulfonylmethane in rats.

Methylsulfonylmethane (MSM) is a popular dietary supplement used in a variety of conditions including pain, inflammation, allergies, arthritis, parasitic infections and the maintenance of normal keratin levels in hair, skin and nails. Despite its popularity, there is little published toxicology data on MSM. The objective of this study was to evaluate the acute and subchronic toxicity of MSM in rats at a dose five to seven times the maximum recommended dose in humans. MSM administered in a single gavage dose of 2 g/kg resulted in no adverse events or mortality. MSM administered as a daily dose of 1.5 g/kg for 90 days by gavage resulted in no adverse events or mortality. Necropsy did not reveal any gross pathological lesions or changes in organ weights. Renal histology of treated animals was normal. It is concluded that MSM is well tolerated in rats at an acute dose of 2 g/kg and at a subacute chronic dose of 1.5 g/kg.