Neuropathology mediated through caspase dependent extrinsic pathway in goat kids naturally infected with PPRV.

Peste des petits ruminant (PPR), a highly contagious viral disease of small ruminants, is characterized by erosive stomatitis and pneumo-enteritis. However, its neurovirulence potential as observed with other morbilliviruses has not been fully investigated. The present study describes the neuropathological alterations induced by PPR virus through apoptotic pathway. A total number of 12 carcasses of local breed goat kids of either sex were received for postmortem examination. The clinical history was described as symptoms of mucopurulent nasal discharge, high to low grade fever, erosive stomatitis, dyspnoea and profuse watery diarrhoea followed by mortality of 35 goat kids within a week. The pathoanatomical lesions and immunohistochemical demonstration of PPRV antigen in lungs, intestine, spleen and lymph nodes confirmed PPR disease in goats. Grossly, five brain specimens showed moderate to severe leptomeningeal congestion during necropsy. Microscopically, brain sections showed leptomeningitis and nonsuppurative encephalitis characterized by vascular congestion, haemorrhages in the parenchyma, perivascular cuffing with mild to moderate mononuclear cells (mainly lymphocytes and few macrophages), focal to diffuse microgliosis, neuronal degeneration, satellitosis and neuronophagia. Immunolabelling of viral antigen was observed in the cytoplasm of neurons and glial cells. The RT-PCR amplification of N gene fragment also confirmed the presence of PPRV in the brain. The strong immunoreactivity of Caspase-3, Caspase-8 and comparatively lower expression of caspase-9 along with the absence of any reactivity for Apaf-1 antigen in the brain sections indicated the role of caspase dependent extrinsic pathway in inducing neuropathological changes. The presence of apoptotic neurons in the brain by TUNEL assay further confirmed the apoptosis and strong immunoreactivity of iNOS in neurons which suggested the generation of oxidative stress, that might have induced the apoptosis. The overall findings confirm the neurovirulence potential of PPR virus, via the extrinsic pathway of apoptosis, in natural cases of PPR disease in goat kids.

Clinical and pathological comparison of Astragalus lentiginosus and Ipomoea carnea poisoning in goats.

The indolizidine alkaloid swainsonine, found in some Astragalus and Oxytropis (i.e., locoweed) species, is a potent cellular glycosidase inhibitor that often poisons livestock. Other toxic genera such as some Ipomoea species also contain swainsonine as well as calystegines which are similar polyhydroxy alkaloids. The toxicity of calystegines is poorly characterized; however, they are also potent glycoside inhibitors capable of intestinal and cellular glycoside dysfunction. The objective of this study was to directly compare A. lentiginosus and I. carnea poisoning in goats to better characterize the role of the calystegines. Three groups of four goats each were treated with ground alfalfa (control), I. carnea or A. lentiginosus to obtain daily doses of 0.0, 1.5, and 1.5 mg swainsonine/kg bw per day, respectively, for 45 days. Animals were observed daily and weekly body weights, serum enzyme activities, and serum swainsonine concentrations were determined. At day 45 all animals were euthanized and necropsied. Goats treated with A. lentiginosus and I. carnea developed clinical disease characterized by mild intention tremors and proprioceptive deficits. Goats treated with A. lentiginosus developed clinical disease sooner and with greater consistency. No differences in body weight, serum swainsonine concentrations and serum enzyme activity were observed between goats treated with A. lentiginosus and I. carnea. Additionally, there were no differences in the microscopic and histochemical studies of the visceral and neurologic lesions observed between goats treated with A. lentiginosus and I. carnea. These findings suggest that I. carnea-induced clinical signs and lesions are due to swainsonine and that calystegines contribute little or nothing to toxicity in goats in the presence of swainsonine.

Seroprevalence of Coxiella burnetii among domestic ruminants and horses in Poland.

Coxiella burnetii is the causative agent of Q fever. The cases of the disease are recorded in various species, including domestic animals. The aim of this investigation was to estimate the seroprevalence of C. burnetii in ruminants including cattle, sheep, goats, and horses. Totally, 2082 serum samples from 936 goats, 933 cattle, 89 sheep, and 124 horses, including various horse breeds, were tested by ELISA or complement fixation test. The examination revealed that Polish horses are seronegative while in the populations of cattle and small ruminants, seropositive animals are presented. The percentage of seropositive cattle, goats and sheep was 4.18, 6.30, and 13.48, respectively.

Vaccination of goats with glyceraldehyde-3-phosphate dehydrogenase DNA vaccine induced partial protection against Haemonchus contortus.

Owing to its critical functions in worm physiology, glyceraldehyde-3-phosphate dehydrogenase in Haemonchus contortus (HcGAPDH) is potential candidates for vaccine to control haemonchosis. In this study, DNA vaccine expressing HcGAPDH antigen was tested for protection against experimental H. contortus infections in goats. Fifteen goats (9-10 months of age) were allocated into three trial groups. Group 1 was vaccinated with HcGAPDH DNA vaccine twice on days 0 and 14, and then challenged with 5000 infective H. contortus L3 (third stage larvae) on days 28. Group 2 was an unvaccinated positive control group challenged with H. contortus L3 on days 28. Group 3 was an unvaccinated negative control group that was not challenged with L3. By the method of RT-PCR and Western-blot, transcription and expression of HcGAPDH DNA vaccine were identified at local injection sites post immunizations, respectively. After immunization with the DNA vaccine, significantly high levels of serum IgG, serum IgA, mucosal IgA, CD4(+) T lymphocytes and B lymphocytes were generated. Also, increased numbers of blood eosinophils and decreased haemoglobin level after challenge were observed in the vaccinated group. Meanwhile, cumulative mean faecal worm egg counts and worm burdens in vaccinated group were reduced by 34.9% and 37.73%, respectively. In brief, recombinant HcGAPDH DNA vaccine induced partial immune response against H. contortus infection in goats.

Hypocortisolism in the South African angora goat: the role of 3betaHSD.

South African Angora goats are susceptible to cold stress, due to their inability to produce sufficient levels of cortisol. During adrenal steroidogenesis the production of cortisol relies on the activity of two key enzymes, namely cytochrome P450 17alpha-hydroxylase and 3beta-hydroxysteroid dehydrogenase. Cytochrome P450 17alpha-hydroxylase has previously been identified as a factor contributing to hypocortisolism in the South African Angora goat. In this comparative study, the catalytic activity of Angora and ovine 3beta-hydroxysteroid dehydrogenase, which differ by five amino acid residues, was characterized. The conversion of 17-hydroxypregnenolone and dehydroepiandosterone to their corresponding products, 17-hydroxyprogesterone and androstenedione, by the two enzymes differed significantly. The enzymes were subsequently co-expressed with Angora P450 17alpha-hydroxylase. Major differences were observed in pregnenolone metabolism with a significant reduction in the formation of the cortisol precursor, 17-hydroxyprogesterone, by cells expressing Angora 3beta-hydroxysteroid dehydrogenase, implicating 3beta-hydroxysteroid dehydrogenase as an additional factor contributing to hypocortisolism in the South African Angora goat.

The role of lactate dehydrogenase, alkaline phosphatase and aspartate aminotransferase in the diagnosis of subclinical intramammary infections in dairy sheep and goats.

The objective was to investigate the changes occurring in the activities of the enzymes lactate dehydrogenase (LDH), alkaline phosphatase (ALP) and aspartate aminotransferase (AST) in sheep and goat milk as a result of subclinical intramammary infections (IMI) and to evaluate the use of these enzymes for the diagnosis of subclinical IMI in dairy sheep and goats. A total of 206 samples of sheep milk and 162 samples of goat milk, obtained from equal udder halves, were used in the study. For each species they were divided into two groups: a no-infection group and a subclinical infection group. Activities of LDH, ALP and AST were significantly higher in the subclinical infection group than in the no-infection group (P<0.05) in both sheep (LDH: 350.42+/-11.25 v. 120.91+/-4.41; ALP: 2773.43+/-105.18 v. 2189+/-94.24; AST: 29.57+/-0.74 v. 17.32+/-0.46) and goats (LDH: 354.07+/-13.33 v. 103.79+/-3.75; ALP: 311.13+/-25.74 v. 137.24+/-19.62; AST: 27.59+/-6.42 v. 15.87+/-0.45). The activity of LDH was identified as indicator for subclinical IMI in both sheep and goats. The optimum cut-off values for LDH activity, offering the highest diagnostic sensitivity (DSn) and diagnostic specificity (DSp), determined by receiver operating characteristic (ROC) analysis, were at 197 U/l, 185 U/l and 197 U/l for sheep, goats and both species, respectively. DSn for sheep, goats and both species at these cut-off values was 92.8%, 98.2% and 94.0%, whereas DSp was 95.4%, 96.3% and 96.3%, respectively. It was concluded that the determination of LDH activity in milk serum is a sensitive and reliable method for the detection of subclinical IMI in dairy sheep and goats.

Pathogenic effects of the coccidium Eimeria ninakohlyakimovae in goats.

Twenty-four coccidia-free goats were reared artificially in indoor cages and allocated to 6 groups of 4 animals each. At 20 days of age, goats in groups 1-3 received 10(4),10(5) and 10(6) sporulated oocysts of Eimeria ninakohlyakimovae per goat, respectively, each as a single dose. Goats in group 4 received daily doses increasing over a 3-week period, starting with 100/day for the first week, followed by 1000, and 10,000/day in weeks 2, 3, respectively. Goats in group 5 received 10(4) oocysts following a challenge dose of 10(6) oocysts on day 32. Goats in group 6 were kept as uninoculated controls. Infected animals showed diarrhoea and weight loss. Goats in group 4 showed longer periods of diarrhoea and patency than other infected goats. Goats in group 5 showed the same severe clinical signs as those in group 3 but produced very low oocyst output after a challenge dose. The diarrhoea was associated with a reduction in alkaline phosphatase activity and increases in packed cell volume and haemoglobin. No significant differences were found in serum aspartate aminotransferase, alanine aminotransferase, total protein, albumin, globulin, Na+, K+,Cl- between groups during 48 days after inoculation. There were no serum enzyme indications of damage to the liver. Histological examination performed 100 days after inoculation revealed that inoculated goats had mild subacute to chronic proliferative enteritis in the lower small intestine and the large intestine, and the mesenteric lymph nodes, gallbladders and livers also showed slight histological lesions. The results showed that E. ninakohlyakimovae was highly pathogenic.

Serological changes in goats experimentally infected with Fasciola gigantica in Buea sub-division of S.W.P. Cameroon.

Based on the recent increase in the rearing of West African Dwarf (WAD) goats in this environment, a study of biochemical parameters was carried out in healthy and infected goats to obtain baseline data for monitoring the health and productive indices in breeding programmes for the goats. The results revealed variations in some of the parameters studied. The serum minerals potassium, chlorine and bicarbonate did not show any significant differences (P>0.05) between the infected and control groups of goats, but there was a significant difference (P<0.0001) in sodium, calcium and urea levels. For serum lipids cholesterol and triglyceride, there were significant (P<0.0001) differences between the infected and control group. This goes same for serum proteins, albumin and total proteins. However, serum enzymes, serum glutamic oxaloacetic transaminase (SGOT) and gamma glutamyl transferase (GGT) were not significantly different (P>0.05) between the infected and control groups. There was a significant difference (P<0.0001) in alkaline phosphatase (ALP) and serum glutamic pyruvic transaminase (SGPT) between the infected and control groups.

Immunohistochemical study of constitutive neuronal and inducible nitric oxide synthase in the central nervous system of goat with natural listeriosis.

The expression of both constitutive and inducible forms of nitric oxide synthase (NOS) was investigated by immunohistochemical staining of formalin-fixed paraffin-embedded sections in normal and Listeria monocytogenes-infected brains of goats. In normal control goats, a small number of neurons showed immunoreactivity of both iNOS and nNOS, and the number of iNOS-positive neurons was higher than the number of nNOS-positive neurons. In natural listeriosis, listeria antigens were easily immunostained in the inflammatory cells of microabscesses. In this lesion, the immunoreactivity of iNOS in neurons was more intense than the control, but nNOS was not. In microabscesses, nNOS was weakly visualized in macrophages and neutrophils, while iNOS was expressed in macrophages, but not in neutrophils. These findings suggest that normal caprine brain cells, including neurons, constitutively express iNOS and nNOS, and the expressions of these molecules is increased in Listeria monocytogenes infections. Furthermore, inflammatory cells, including macrophages, expressing both nNOS and iNOS may play important roles in the pathogenesis of bacterial meningoencephalitis in goat.

Inducible nitric oxide synthase is expressed in joints of goats in the late stage of infection with caprine arthritis encephalitis virus.

We have studied the expression of the inducible form of nitric oxide synthase (iNOS) in joints of goats infected with the caprine arthritis encephalitis virus (CAEV). Nitric oxide generated by iNOS is thought to play an important role in the pathogenesis of various types of arthritis, especially rheumatoid arthritis (RA) in humans. Surprisingly, iNOS immunoreactivity was found only in joints of long-term infected goats with severe clinical arthritis, whereas-despite the presence of high numbers of inflammatory cells in the synovial tissue-no iNOS immunoreactivity was detected in mildly arthritic and in short-term experimentally infected goats. Most iNOS-positive cells expressed neither MHC class II nor CD68, which suggests that they were fibroblast-like synoviocytes. In situ hybridization studies showed that there was no correlation between iNOS immunoreactivity and detectable virus expression in the joint. In addition, infection of macrophages in vitro-the major host cells of CAEV in vivo-did not lead to increased iNOS mRNA expression. In response to stimulation, similar levels of iNOS expression were observed in infected and in uninfected macrophages. These findings suggest that the expression of iNOS is a feature of late-stage chronic arthritis and is not involved in the development of the inflammatory lesions. Both the lack of co-localization of iNOS protein and viral transcripts in the joint and the finding that CAEV does not stimulate the expression of iNOS in vitro further suggest that iNOS is not directly induced by the virus or the anti-viral immune response in the joint, that it may well, however, be involved in tissue remodelling or scar formation.

Studies on experimental chlamydial mastitis in goat histoenzymology.

Two strains of Chlamydia psittaci (one isolated from aborted goat foetus and the other from brain of a buffalo calf that had died of meningoencephalitis) were injected intracisternally into six goats to produce experimental mastitis. Cryostat sections of 7-8 microns thickness, obtained from udder, teat, liver and kidney of infected and control animals were incubated for histoenzymic demonstration of alkaline-(AKPase), acid-(ACPase) and adenosine-tri-(ATPase) phosphatases; lactate-(LDH) and succinate-(SDH) dehydrogenases and for reduced nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-D). Results demonstrated that AKPase and NADPH-D declined while ACPase accumulated in acinar cells of udder while both NADPH-D and ACPase decreased in teat sinus epithelium. Hepatic canaliculi in perilobular areas of liver lobules registered complete absence of AKPase and ATPase. Hepatocytes and renal tubules accumulated LDH, SDH and NADPH-D. The interstitial connective tissue of udder and kidney presented higher levels of AKPase. Comparison of results with biochemical alterations in the level of these enzymes revealed striking discrepancies which seem to arise because of failure of biochemical procedures to discriminate between functional cells of tissue and inflammatory cells. The functional significance of histoenzymic alterations has been discussed.

Effect of caprine arthritis-encephalitis virus infection on milk cell count and N-acetyl-beta-glucosaminidase activity in dairy goats.

Bacteriology, somatic cell counts (SCC) and N-acetyl-beta-glucosaminidase (NAGase) activity determinations were conducted on milk samples collected from does in three dairy herds with caprine arthritis-encephalitis virus (CAEV) infection. In two herds, CAEV-infected does were more likely to have a subclinical bacterial infection of the udder than CAEV-free does (P < 0.05). Does with CAEV but no bacterial udder infection had significantly greater mean SCC and NAGase activity than CAEV-free does without udder infection (P < 0.01). In two herds, changes in milk SCC and NAGase associated with CAEV infection were similar to those produced by coagulase-negative staphylococcal infections. The findings confirm that indirect indicators of bacterial mastitis infection may have reduced specificity in dairy goat herds with CAEV.

A gelatin test to detect activity and stability of proteases produced by Dichelobacter (Bacteroides) nodosus.

Previously reported tests to distinguish thermostable and thermolabile proteases of Dichelobacter nodosus used hide powder azure as a test substrate. This paper describes an alternative test for protease stability using gelatin, an inexpensive and convenient substrate. The test required less equipment and time than the hide powder tests, and simplified the testing of multiple samples. Proteases from 2965 isolates of D. nodosus from samples collected as part of a footrot eradication scheme were tested using the gelatin method, 1707 produced thermostable, and 1258 produced thermolabile protease. Production of thermostable protease was used to identify isolates of D. nodosus which had the potential to cause the virulent form of ovine footrot. Comparisons were made with a hide powder test on 47 isolates. Further characterisation of all proteases was undertaken using polyacrylamide gel electrophoresis. Isoenzyme patterns of thermostable protease producing isolates were identified as S1 (1688 isolates) and S2 (19) whilst thermolabile protease producing isolates showed patterns U1 (1104 isolates), U2 (40), U3 (32), U4 (47), U5 (6), U6 (28) and S1 (1).

Possible beta-mannosidosis chimera. Altered expression of metabolic perturbations.

An aberrant beta-mannosidosis phenotype in a 5-month-old triplet goat kid was characterized by a late postnatal onset of mild neurological symptoms. Necropsy examination revealed relatively normal myelination; however, the distribution of cytoplasmic vacuolation in the kidney and brain was similar to that observed in neonatal beta-mannosidosis. Variable engraftment of donor stem cells, resulting from transplacental transfusion of stem cells from a normal sibling during the immunotolerant period, may have modified the expected severe beta-mannosidosis phenotype. This investigation was designed to determine the effects of a possible chimeric state on organ-specific metabolic perturbations. Residual beta-mannosidase enzyme activity was found in plasma, kidney, liver and spleen but not in brain. Other lysosomal enzyme activities were comparable to normal values. Immunoreactive beta-mannosidase was estimated to be less than 10% of normal levels. Kidney, brain grey matter and brain white matter contained 33%, 12% and 4%, respectively, of the oligosaccharides expected in the organs of beta-mannosidosis animals. There were no detectable oligosaccharides or cytoplasmic vacuolation in the liver or spleen. Studies of this possible chimera provided preliminary evidence for the efficacy of prenatal treatment of early-onset neurodegenerative disorders.

Changes in levels of transaminases in goats experimentally infected with Trypanosoma congolense.

Goats were experimentally infected with Trypanosoma congolense and then treated with Berenil after 9 days of infection. The infection produced increases in glutamate oxalacetate transaminase (GOT) and glutamate pyruvic transaminase (GPT) values. Mean GOT values in infected West African dwarf goats were generally lower than in infected Red Sokoto goats. Treatment with Berenil did not produce any significant effect on their levels probably because of the relapse infection recorded in this study.

The role of prostaglandin H synthase in 3-methylindole-induced pneumotoxicity in goat.

1. Aspirin and indomethacin were used to investigate the role of prostaglandin H synthase (PHS) system in 3-methylindole (3MI)-induced pneumotoxicity. 2. A functional test was developed to detect the inhibitory effect of oral doses of aspirin and indomethacin on PHS activity based on thromboxane B2 (TXB2) production from thrombin-stimulated platelets in whole blood. 3. Goats which received oral doses of aspirin or indomethacin before administration of 3MI (0.1 g 3MI/kg body wt) showed a reduced severity in clinical signs and pathological lesions in the lung than those that received 3MI alone. 4. There was no difference in the severity of the disease between the control and the aspirin-treated animals if aspirin was given after 3MI administration. 5. The protective effect of inhibitors when administered before, but not after, 3MI dosing suggests it is the inhibition of PHS activity in activation of 3MI, not in production of prostanoids which prevented the disease process.

Enzootic nasal tumour of goats: demonstration of a type D-related retrovirus in nasal fluids and tumours.

Nasal exudate and tumour tissue from goats with enzootic nasal tumours were shown to contain a reverse transcriptase activity associated with a particle of buoyant density typical of retroviruses. The same particle contained a 25,000 Mr protein that cross-reacted with the p27 of Mason-Pfizer monkey virus (MPMV) and with p25 of sheep pulmonary adenomatosis retrovirus. It also contained a low Mr protein related to p10-12 of MPMV.

Biochemical alterations in serum and cerebrospinal fluid in experimental acidosis in goats.

Experimental acidosis was induced in six goats aged between one and two years by administration of whole wheat grain at 100 g kg-1 bodyweight given intraruminally. Blood and cerebrospinal fluid (CSF) samples were collected from these goats before administration of wheat grain (0 hour) and thereafter at 12, 24, 48, 72, 96 and 120 hour intervals. These were analysed for serum enzyme activities and physicochemical characters of CSF. Significantly (P less than 0.05) higher activities of amylase (at 12 hours), lactate dehydrogenase (12 to 48 hours), creatine phosphokinase (12 to 48 hours), aspartate aminotransferase (12 to 24 hours), and gamma-glutamyl transferase (12 to 96 hours) were found in serum samples of acidotic goats. Changes in CSF included decrease of pH and chloride content and higher glucose values. No difference was seen in the physical character of CSF collected at different time intervals from acidotic goats.

Effect of nickel deficiency on biochemical variables in serum, liver, heart and kidneys of goats.

Nickel deficiency was induced in 2- to 4-year-old goats by feeding 0.1 mg Ni/kg dry matter with a semisynthetic diet. The control group consumed 5.0 mg Ni/kg d.m. Activity of several enzymes (SDH, LDH, HBDH, AST, ALT, ALD, CK, CHE) was determined in the serum, liver, heart and kidneys. Serum urea-N level was also measured and transmission electron microscopic (TEM) examinations were performed. Signs characteristic of nickel deficiency (retarded growth, increased mortality of dam and offspring, parakeratosis of the skin) appeared in the low-nickel group. The activity of SDH and ALD, as well as the level of urea-N was significantly lower in the serum of Ni-deficient animals than in the control. Ni-deficient animals also had significantly lower enzyme activities in the heart (SDH, HBDH, AST, ALT, ALD and CK), liver (SDH and CHE) and kidneys (HBDH and CK). Electron micrographs showed degeneration of cardiac and skeletal muscle in the Ni-deficient animals. Ni deficiency elicited changes primarily in the heart and these resulted in depressed activity of several enzymes.