Toltrazuril and diclazuril: comparative evaluation of anti-coccidial drugs using a murine model

Intestinal coccidiosis caused by Eimeria protozoan species is an economically important disease, especially in poultry and cattle. Anti-coccidial drugs commonly used for controlling coccidiosis are toltrazuril (TTZ) and diclazuril (DCZ). In this study, the efficacies of TTZ and DCZ were compared using a murine model, and the effect of these treatments on the induction of acquired resistance was evaluated. Male C57BL/6J mice were inoculated with 1,000 sporulated E. vermiformis oocytes and treated with TTZ or DCZ. The recommended TTZ dose for cattle (15 mg/kg) completely prevented oocyte excretion. But, mice required 5 mg/kg of DCZ, which is five times the recommended dose for cattle, to reduce oocyte excretion. In E. vermiformis re-infection, TTZ (15 mg/kg) and DCZ (5 mg/kg) treatments did not interfere with the development of acquired resistance. Bodyweight gain was significantly higher in the TTZ-treated group than in the control (untreated/infected) group and the DCZ-treated group, and no significant difference in bodyweight gain was observed between the TTZ-treated group and the healthy (uninfected/untreated) group. Analysis of T lymphocyte subsets in the spleen and mesenteric lymph nodes indicated that the relative populations of CD4⁺ and CD8⁺ T cells were reduced in the DCZ-treated and control (untreated/infected) groups, suggesting there was immunosuppression during the infection. However, no reductions in T cell populations were observed in the TTZ-treated group. The results indicated that an optimal anti-coccidial drug is one that can completely break the parasite life cycle in the host animal.     

Studies on the immune status of calves with chronic inflammation and thymus atrophy

The thymus is a primary lymphoid organ where the primary T cell repertoire is generated. Thymus atrophy is induced by various conditions, including infectious diseases, glucocorticoid treatment, and poor breeding management. Cattle with thymus atrophy tend to exhibit weak calf syndrome, a condition in which approximately half of neonates die shortly after birth. Calves with thymus atrophy that survive the first month typically contract chronic inflammatory diseases. In this study, we analyzed the populations of the peripheral blood mononuclear cells and thymocytes in calves with thymus atrophy. In addition, we evaluated polarization of master gene and cytokine mRNA expression in peripheral blood CD4⁺ cells in the calves. The population of CD4⁺CD8⁺ cells in thymus of the calves with thymus atrophy was lower than that of control calves. IL10 mRNA expression in peripheral blood CD4⁺ cells of calves with thymus atrophy was significantly lower than that of control calves. TBX21 mRNA expression in peripheral CD4⁺ cells of thymus atrophy calves was tended to be higher than that of the control group. In addition, FOXP3 mRNA expression in peripheral CD4⁺ cells of the thymus atrophy calves was tended to be lower than that of the control calves. Thymus atrophy calves exhibited chronic inflammatory disease leading, in severe situations, to conditions such as pneumonia with caseous necrosis. These severe inflammatory responses likely are due to decreases in IL10 mRNA expression, impairing control of macrophages, one of the main cell fractions of natural immunity.     

Oestrus ovis larval myiasis among goats in northern Jordan

From December 1998 to December 1999, heads of 520 local goats slaughtered at the Irbid, Ramtha and Howarra Abattoirs (northern Jordan) were examined for the three larval instars (L(1)-L(3)) of Oestrus ovis. Of 520 heads, 126 (24%) were infested with O. ovis larvae. All three larval instars were observed in both sexes; all age groups were infested in each month of the year. The mean age of the goats sampled was 1.5 years. The numbers of parasites infesting hosts showed a significant (P<0.05) correlation with sheep age (r(sp)=0.31-0.42) for all three larval instars. The numbers of larvae in each host followed an overdispersed distribution, which fit a negative-binomial model (but not a Poisson distribution). There were more parasites recorded in the presence of purulent discharge or laryngitis, fewer in the presence of catarrhal discharge and no association with pharyngitis sinusitis, or rhinitis.     

Gross morphological,histological and scanning electron specifications of the oropharyngeal cavity of the hooded crow (Corvus cornix pallescens)

The present study was carried out on the oropharyngeal cavity of the hooded crow to investigate the gross and microscopic structures via gross anatomy, light microscopy and scanning electron microscopy (SEM). The gross anatomy clarified the elongated triangular shape of the oropharyngeal cavity with a non-protruding tongue with a bifid apex. The lingual body contained median groove rostrally and separated caudally from the root by a transverse papillary crest. The laryngeal mound located posterior to the lingual root, contained midline laryngeal cleft and bounded caudally by a transverse row of pharyngeal papillae. The palate contained choanal cleft rostrally and infundibular slit caudally in addition to five palatine ridges. By light microscopy, the dorsal lingual epithelium was highly keratinised stratified squamous with a lingual nail in the most rostral part of the apex. Then, the thickness of the keratin layer decreased caudally, while in the ventral surface, the lining epithelium became non-keratinised. The entoglossum supported the lingual body and root, but not extended to the apex. The lining epithelium of the palate was also keratinised stratified squamous and became none-keratinised at the oral side of the choanal cleft. There were numerous lobules of polystomatic salivary glands in the lingual root and the palate. SEM revealed the arrangement of different types of papillae covering both the floor and the roof of the oropharynx besides numerous openings of salivary glands in the lingual root, laryngeal mound and the palate. These findings reflect the functional relationship of the oropharyngeal cavity of the hooded crow during feeding.     

Effects of anti-ecdysteroid azole analogues of metyrapone on the larval development of the fleshfly,Neobellieria bullata

Based on our previous finding that PIM (phenyl-imidazolyl-metyra-pon; 2-(1-imidazolyl)-2-methyl-1-phenylpropan-1-one, 1) is a strong inhibitor of ecdysone 20-monooxygenase (IC₅₀ = 7.89 × 10^?7 M) from the fleshfly, Neobellieria bullata (Parker) and has also a good toxic action in vivo against this insect, 17 imidazole and 1,2,4-triazole analogues of metyrapone were synthesized and evaluated for their action against N. bullata larvae in terms of toxicity, length of larval development, weight of the puparium as well as special symptoms, i.e. malformations of the anterior and posterior spiracles, and of the mandibles. The introduction of p-methoxy (LC₅₀ = 49 mg kg^?1 in diet) or p-chloro (LC₅₀ = 97 mg kg^?1) substituents on the benzene ring of PIM resulted in a significant increase in toxicity compared to that of metyrapone (LC₅₀ = 561 mg kg^?1) and PIM (LC₅₀ = 148 mg kg^?1). The hybridization state of the carbon atom adjacent to the benzene ring was not an important factor for toxicity because the acetoxy derivative ( 13 ) was almost as toxic as PIM. At least one methyl group was required on the carbon atom adjacent to the azole ring to maintain activity, while an ethyl group ( 4 ) enhanced the toxic effect. At the applied doses some compounds including metyrapone itself, extended the duration of the larval development. Only metyrapone and PIM decreased the puparium weight. Several derivatives induced lethal malformations of mandibles as well as the anterior and posterior spiracles.     

Nutritional,chemical and molecular characterisation of Moringa oleifera Lam. and Moringa peregrina (Forssk.) Fiori genotypes

This work aimed to characterise Moringa oleifera (Mo) and Moringa peregrina (Mp), grown in Saudi Arabia, based on nutritional and molecular markers. Seven genotypes per species were evaluated using 1-year-old trees. The nutritional characterisation included chlorophyll, protein, macronutrients, micronutrients, and heavy metals. Simple sequence repeat (SSR) was applied using nine primers for genetic characterisation. Significant differences in nutritional content were found between the two species and among the genotypes of each species. Mp had more chlorophyll content, however Mo contained higher protein, Fe and Zn. Correlations among nutritional characteristics allowed representative classification of genotypes based on these pertinent indicators only. Cluster analysis separated the genotypes of each species in independent group, but three Mo genotypes and two Mp genotypes were distinguished for their variability in nutritional properties. Most Mo genotypes amplified the nine SSR primers, however 6/9 primers only produced bands in Mp genotypes. The number of amplified primers per Mp genotype varied from zero to six. A strong relationship was found between nutritional and molecular classifications of genotypes. The efficient classification based on four chemical characteristics could be beneficial for Moringa evaluation. The correlation between genetic and nutritional variability could serve in improving Moringa and identifying genetic criteria.     

Natural Ehrlichia ruminantium infection in two captive Arabian tahrs (Arabitragus jayakari) in Oman

This study was investigated the cause of death of two captive adult Arabian tahrs (Arabitragus jayakari) died within 2–3 days after onset of fever and neurologic signs in a private farm in northern Batinah Region of Oman. Blood counting revealed leukocytosis attributed to neutrophilia and serum chemistry showed hypoproteinemia, increased creatine kinase and BUN. Upon autopsy, the animals exhibited mild ascites and hydrothorax, prominent hydropericardium, with large pale-yellow clear fluid coagulum, prominent epicardial petechiation, as well as severe pulmonary edema associated with frothy fluid in airways. Brain edema with congestion of meningeal and parenchymal vessels was prominent. Histopathology revealed severe congestion and edema of both lung and brain as well as cardiac myopathy. Ehrlichia ruminantium colonies (the causative organism of cowdriosis; OIE-listed disease) were demonstrated in the capillary endothelium of fresh brain squash and lung macrophages. This is the first report of natural E. ruminantium infection in Arabian tahr, the highly endangered species, based on typical clinical signs of acute cowdriosis and demonstration of E. ruminantium colonies in the brain capillary endothelial cells.