Immunosuppressive potential and pathogenicity of an avian adenovirus isolate involved in hydropericardium syndrome in broilers.

The role of avian adenovirus isolate PARC-1 as an immunosuppressive agent was investigated using a Newcastle disease virus (NDV) vaccine immune response procedure. The immunosuppressive effect on the humoral immune response was investigated up to 21 days after inoculation with adenovirus. Infected chickens showed a serologic response to NDV that was reduced compared with that of the controls. To further investigate the effect of the virus on major lymphoid organs, the pattern of virus dissemination in various organs was studied at various time intervals after inoculation. Spleen, thymus, bursa of Fabricius, and cecal tonsils of broilers were examined using a dot-immunobinding assay. The virus was found to have a predilection for lymphoid organs, and virus from lymphoid organs was capable of producing disease when inoculated into healthy chickens. The relationship of virus predilection to its immunosuppressive effect also was studied.

Leishmania infecting man and wild animals in Saudi Arabia. 4. Canine cutaneous leishmaniasis in the Eastern Province.

Cutaneous leishmaniasis was detected in 4 of 117 feral dogs, none of which presented any evidence of visceral involvement, in the Al-Hassa area of Saudi Arabia where neither Leishmania infantum nor L. tropica are transmitted. The parasites isolated from 3 of the animals were identified by biochemical techniques as L. major, L. arabica and Leishmania zymodeme 62 respectively. Clinically, and in their histology, the lesions closely resembled those caused in man in the same geographical area by L. major. Dogs are probably victims rather than reservoirs of Leishmania.

Experimental cholecystitis in goats caused by mature Fasciola gigantica.

Mature Fasciola gigantica obtained from naturally infected cattle were surgically transferred into the gallbladders of six fluke-free goats. Two of the goats died at two and 19 weeks and the remaining four were slaughtered at 12, 48, 48 and 80 weeks after the transfer. Nine of 20 transferred F gigantica were recovered from the gallbladder and common hepatic duct of the experimental goats. The walls of gallbladders and bile ducts were thickened by epithelial proliferation, fibrosis and mononuclear cell infiltration. Large numbers of globule leucocytes were present in the epithelium of gallbladders and common hepatic ducts as well as in minute intrahepatic bile ducts. Very few mast cells were observed in these locations. Globule leucocytes in two goats were positive for argentaffin reaction with Gomori hexamine silver stain. The proliferative cholecystitis in experimental goats was similar to adenomatous cholecystitis in cattle naturally infected with fascioliasis. Globule leucocytes had no obvious deleterious effects on the parasites.

Onchocerciasis in camels (Camelus dromedarius) in Saudi Arabia.

During a survey in 1980-81, 125 of 478 (26.2%) camels in Saudi Arabia were found infected with onchocerciasis. The prevalence rates in local and imported camels were 93/272 (34.2%) and 32/206 (15.5%), respectively. The disease was characterized by hard nodules in the connective tissue around the nuchal ligaments and in the subcutis. The nodules consisted of cavities containing live, degenerate or dead Onchocerca fasciata, inflammatory cells, fibrosis and calcification. The microfilariae were concentrated in the skin over the head and neck regions and often caused mild non-suppurative dermatitis.

Microorganisms associated with abscesses of sheep and goats in the south of Iran.

A total of 86 abscesses (45 and 41) abscesses of sheep and goats, respectively) were examined for their causal agents; 44 of these abscesses were located subcutaneously, and the remaining 42 were in lungs, livers, intestines, and udders. A total of 23 different types of microorganisms were isolated from 78 abscesses; bacteria were not detected in the remaining eight abscesses. Microorganisms isolated were: species of the genera Corynebacterium, Staphylococcus, and Streptococcus and Pasteurella, Escherichia coli, and other gram-negative rods. Peptostreptococcus anaerobius and Eubacterium tortuosum were isolated in pure culture from one abscess each in goats. Two to four different microorganisms were associated with 25 of the 86 abscesses. It was determined that 11 isolates of Corynebacterium pyogenes, 2 isolates of Pasteurella haemolytica, 1 of P multocida, and 1 of C pseudotuberculosis were lethal to mice. Two of the C pyogenes isolates from subcutaneous spreading abscesses of goats were pathogenic for rabbits; these two isolates produced similar suppurative inflammation in goats experimentally, but did not cause death. As determined by experimental inoculation, goats were more susceptible than sheep to the two isolates. In nature, subcutaneous abscesses of goats associated with C pyogenes were of a more diffusive type which resulted in generalization of the infection and death of the animals. Postmortem examination of ten goats dying of field infection showed the presence of larvae of the warble-fly Przhevalskiana silenus at the site of infection.

Besnoitiosis in wild and domestic goats in Iran.

Besnoitia cysts and lesions were observed in the skin, blood vessels, epididymis and testes of two wild goats (Capra aegagrus) and in the subcutaneous tissues of two domestic goats (Capra hircus) in the Fars Province of Iran. The seminiferous tubules in the wild goats showed aspermatogenesis, degeneration and atrophy of germinal epithelium.

Bovine onchocerciasis caused by Onchocerca armillata and O. gutturosa.

Onchocerca armillata was found in 284 (28%) of 1,016 aortas, and O. gutturosa in 82 (28.87%) of 284 nuchal ligaments and in 11 (7.85%) of 140 rumenosplenic areas in specimens from cattle slaughtered during a 12-month period. Adult parasites were not found in 600 hides. Gross lesions included parasitic tunnels, nodules, roughening and calcification in the aortic walls. The connective tissue of nuchal ligaments and rumenosplenic areas was increased in amount, was gelatinous and brown and had afew nodules, Microscopically there were acute changes with oedema, haemorrhages and cellular infiltrations predominatly by eosinophils. There were chronic granulomatous reactions characterized by accumulation of macrophages, lymphocytes, plasma cells, giant cells, calcification and fibrosis around degenerate and dead parasites. Neutral fat was in parasites and surrounding cells. Both changes often occurred in the same specimen and many samples had parasites but no tissue reaction. Hypersensitivity, foreign-body reactions and parasitic toxins apparently were involved in the genesis of these lesions.

Detection of antibodies to Mycobacterium johnei by counterimmunoelectrophoresis.

Counterimmunoelectrophoresis (CIE) was applied in the detection of antibodies to Mycobacterium johnei in 110 sheep, 11 goat and 31 cattle sera and compared to immunodiffusion (ID) test. One per cent Noble agar, 7 ml per slide of 5 cm x 10 cm; barbitone-tris buffer, mu = 0.03, pH 8.6; a constant current of 5 mA per slide and M johnei protoplasmic antigen at 4 mg per ml were found to impart high sensitivity to CIE and give rapid results. CIE detected 97 sheep, 11 goat and 31 cattle positive sera, a total of 139, as compared to 44, 11, 28 and 83 respectively, detected by ID. Strongly positive sera could be demonstrated within 30 minutes by CIE and the test was run for only 90 minutes while earliest reactions were not observed before 18 hours and some reactions took 144 hours to develop in ID test.

Cardiac myopathies in neonatal lambs: histological and histochemical studies.

White muscle disease (WMD), a selenium-responsive cardiac myopathy in neonatal lambs has been described from southern Iran. 15 lambs in terminal condition were referred to our lab. All the lambs were observed with the affected hearts. The lambs examined were between the postnatal ages of 1 week and 3 months. Gross changes included chalky-white appearance of entire endocardium of right ventricle and subendocardial plaques in the interventricular septum and left ventricular wall. Histologically the affected myofibrils showed swelling, acidophilia, fragmentation, segmental and patchy myonecrosis, round muscle cell nuclei, loss of sarcoplasm and sarcolemmal collapse. Purkinje fibers were relatively unaffected. Histochemical studies including Von Kossa and other stains indicated marked deposition of calcium salts in the cytoplasm of the damaged myofibrils. Calcium salts appeared as uniform, fine granules in relation to individual fiber striations. It appears that rapid accumulation of calcium into the damaged cells possibly interferes with the mitochondrial activity. As mitochondria bind excessive calcium, their capacity to respire and phosphorylate is depressed thus causing myocardial necrosis. The cardiac myopathy noted in our investigation is probably due to selenium deficiency in the soil of southern Iran. When selenium was given, it resulted in the fast recovery of the affected neonatal lambs. Moreover, no further cases of this disease (WMD) were reported after such treatments.