PRNP haplotype distribution in Moroccan goats.

Susceptibility/resistance to scrapie in sheep and goats is influenced by host prion protein gene (PRNP) genotype. In this study, we report the analysis of prion protein gene polymorphisms in 137 goats of two Moroccan populations: D'man and Chaouni. We found seven previously described amino acid polymorphisms at codons 37, 127, 137, 142, 154, 222 and 240, as well as three known silent mutations. In addition, we identified three new allelic variants: 101R and 139S in D'man goats and 145D in D'man and Chaouni individuals. The high frequency of the resistant allele 154H could offer genetic protection against the disease to the analysed animals. A total of 12 haplotypes and 28 genotypes were found, the distribution of which shows significant differences between both groups. Moreover, haplotype frequencies were compared with bibliographic data showing that the haplotype distribution of PRNP in Moroccan populations is genetically similar to Southern Italian and Greek goats.

Experimental toxicity of Peganum harmala seeds.

Peganum harmala is plant known since the first century A.D. and still, currently used for therapeutic purposes. Harmaline, the active principle of the plant seeds, and its derivatives, cause visual troubles, loss of coordination, agitation and delirium, and, at high doses, it can produce paralysis. The present study was initiated to evaluate the use and manipulation of therapeutic doses of aqueous extract of P. harmala. Wistar rats were orally dosed acutely and the LD(50) obtained was 2.70+/-0.05g/kg. In chronic studies aqueous extract of P. harmala administered orally for six times a week at doses of 1, 1.35 and 2g/kg during 3 month period increased transaminases. Changes in glucose and creatinine were not significant. No significant gross changes were found at necropsy. Histologic study showed liver degeneration and spongiform changes in the central nervous system (CNS) in rats treated with 2g/kg dose but not at the therapeutic dose of 1g/kg.

Paratuberculosis in sheep flocks in Morocco: a serological, microscopical and cultural survey.

In an attempt to estimate the importance of Johne's disease in sheep in Morocco, a diagnostic survey was made in three flocks suspected of being infected with Mycobacterium paratuberculosis. Blood and faeces samples collected randomly from 188 adult sheep were investigated using direct microscopy of fecal smears, fecal culture and the serum complement fixation test (CFT). Microscopical examination of faeces revealed acid-fast bacteria in 67 (35.6%) samples. However, Ziehl-Neelsen staining lacks specificity and furthermore, acid-fast bacteria could only be demonstrated in 34 (60%) animals found to be culturally positive. Fecal culture succeeded in the isolation of mycobactin dependent strains of M. paratuberculosis in 56 (29.8%) of the sheep examined, with three strains growing in yellow-pigmented colonies. The CFT was regarded as positive (titres of 1:10 and higher) in 55 (29.2%) sera of animals, demonstrating a sensitivity of 48.2% and a specificity of 74.5% in relation to fecal culture From the results, it can be concluded that the combination of CFT and fecal culture might be a practical and useful procedure for detecting infected sheep within flocks and for controlling Johne's disease. This study supports the suspicion that paratuberculosis may constitute a serious problem in Morocco, particularly in sheep flocks involved in cross-breeding programmes.

[Natural Cryptosporidium sp. infection in broiler chickens in Morocco]. / Infection naturelle à Cryptosporidium sp. chez le poulet de chair au Maroc.

The prevalence of cryptosporidium infection was assessed in 38 broiler flocks. Two-hundred-and-twenty-five broilers were subjected to clinical and post-mortem examinations. Analyses of impression smears and tissue samples from the intestine, bursa of Fabricius and trachea revealed Cryptosporidium sp. in 37% of broiler flocks investigated. The prevalence of infection within flocks varied from 14 to 100%. High incidence of Cryptosporidium infection occurred in 36 to 45-day-old broilers (52%), but Cryptosporidium was not found in chickens under 25 days of age. Cryptosporidium sp. was detected in 24% of bursa examined, intestine (15%) and trachea (2%). In the bursa of Fabricius, Cryptosporidium-induced epithelial lesions were associated in most cases (94%) with lymphoid atrophy and depletion.

Multifocal subacute necrotizing encephalomyelopathy in Simmental calves.

In 24 cases of multifocal necrotizing encephalopathy (MNE) in Simmental and Simmental-cross cattle, clinical features varied, consisting of mild rear limb ataxia, caudal paresis, and, less often, sudden death. Bilateral and symmetric malacic lesions were present in the brain stem (olivary nucleus) of all affected calves. Foci of malacia affecting thoracic spinal cord and additional brain stem sites were common. Neuronal cell bodies and hypertrophied capillaries were present within malacic foci. Rarefaction of neuropil, progressing to complete parenchymal loss, characterized advanced lesions. Pathologic features were similar to those of Leigh syndrome in humans, and a similar defect in aerobic metabolism is hypothesized. Occurrence of the syndrome within 1 breed over a wide geographic area suggests that hereditary factors contribute to development of MNE.

Toxigenic strains of Stachybotrys atra associated with poisonous straw in Morocco.

From 10 moldy straw samples collected in a Moroccan area with an apparent equine stachybotryotoxicosis outbreak in November 1991, 8 isolates of Stachybotrys atra were obtained. They all showed toxigenesis, however they were variable in nature and intensity. While 1 isolate had only mild toxicity when fed to mice as moldy barley, another revealed very high toxicity to Artemia saline larvae, or rat skin, and to mice. The toxicity of the other 6 isolates were between these 2 limits. This study indicates that the November 1991 outbreak was due to toxigenic strains of Stachybotrys atra.

Ultrastructural changes in Brown Swiss cattle affected with bovine progressive degenerative myeloencephalopathy (Weaver syndrome).

Thirty Brown Swiss cattle, 7 to 30 months old, clinically affected with the weaver syndrome and five clinically normal Brown Swiss were studied. Ultrastructural examination mainly of the thoracic spinal cord revealed axonal changes accompanied by degeneration of myelin sheaths that were fragmented and lamellae vesiculated. The degeneration was accompanied by moderate gliosis and phagocytosis of degenerated myelin. There were no inflammatory changes. The ultrastructural changes may represent a disturbance of axoplasmic transport and subsequent axonal degeneration.

Spinal muscular atrophy in Brown Swiss calves.

Nineteen Brown Swiss calves affected with spinal muscular atrophy were described. Weakness of the rear legs was the first sign observed at 3 to 4 weeks of age. Terminal stages were characterized by severe muscular atrophy, quadriparesis, and sternal recumbency. Bronchopneumonia was a frequent complicating disease. Microscopic changes consisted mainly of degeneration and loss of motor neurons in the ventral horns of the spinal cord. Neurogenic atrophy of muscles was a constant finding. Electron microscopy revealed accumulation of neurofilaments and mitochondria in affected neurons. The disease shares many features with Werdnig-Hoffmann disease in man and the spinal muscular atrophies of other animals.

Poisoning of sheep by Astragalus lusitanicus in Morocco: field and experimental studies.

This study demonstrated that Astragalus lusitanicus found in Morocco is toxic to sheep. The clinical syndrome shares some features with locoism. Poisoning may be either acute or chronic, depending on the total amount of the plant that has been ingested. Neurological disturbance was the main clinical manifestation of the syndrome. The signs persisted in poisoned animals after cessation of plant consumption. This suggests the occurrence of a persistent biochemical defect in the neuron. The relationship between vacuolation in neurons and the onset of the signs needs to be clarified. Future biochemical and electron microscopic studies should advance the knowledge of the pathogenesis of this toxic neuronal degeneration.