Evidence of natural infections with Trypanosoma, Anaplasma and Babesia spp. in military livestock from Tunisia.

Livestock constitute habitual hosts and carriers for several infectious pathogens which may represent a serious public health concern affecting the readiness of military forces and lead to wide economic losses. The present report aimed to investigate the prevalence of some haemopathogens infecting military livestock, particularly, dromedaries, sheep and horses using Giemsa-stained blood smears. A total of 300 animals (100 from each species) were selected, clinically examined and sampled. Trypanosoma spp. (22.0%), Anaplasma spp. (17.0%) and Babesia spp. (1.0%) were identified in camels' blood. Six dromedaries were found to be co-infected by Trypanosoma and Anaplasma organisms (6.0%). Camels of female gender, infested by ticks and showing clinical signs were statistically more infected by Trypanosoma spp., compared to those of male gender, free of ticks and apparently healthy (P= 0.027, 0.000 and 0.004, respectively). Babesia spp. infection (1.0%) was identified, for the first time in Tunisia, in one adult female camel that presented abortion and anemia. Anaplasma spp. was the only haemopathogen identified in examined sheep (6.0%) and horses (17.0%). Horses infested by Hippobosca equina flies and sheep infested by Rhipicephalus turanicus ticks were more infected by Anaplasma spp. than other non-infested animals (P=0.046 and 0.042, respectively). Hyalomma dromedarii, H. impeltatum and H. excavatum were the most prevalent diagnosed ticks removed from camels with an intensity of infestation of 1.2 ticks per animal. However, in sheep, only R. turanicus was identified. H. equina and Tabanus spp. were the potential hematophagous flies found in dromedaries and horses herds. This useful data must be taken into consideration during animal treatment and vectors' control programs in Tunisian military farms which help to limit the diffusion of vector-borne diseases, keep our livestock healthy and reduce economic losses.

Evidence of natural infections with Trypanosoma, Anaplasma and Babesia spp. in military livestock from Tunisia

@#Livestock constitute habitual hosts and carriers for several infectious pathogens which may represent a serious public health concern affecting the readiness of military forces and lead to wide economic losses. The present report aimed to investigate the prevalence of some haemopathogens infecting military livestock, particularly, dromedaries, sheep and horses using Giemsa-stained blood smears. A total of 300 animals (100 from each species) were selected, clinically examined and sampled. Trypanosoma spp. (22.0%), Anaplasma spp. (17.0%) and Babesia spp. (1.0%) were identified in camels’ blood. Six dromedaries were found to be co-infected by Trypanosoma and Anaplasma organisms (6.0%). Camels of female gender, infested by ticks and showing clinical signs were statistically more infected by Trypanosoma spp., compared to those of male gender, free of ticks and apparently healthy (P= 0.027, 0.000 and 0.004, respectively). Babesia spp. infection (1.0%) was identified, for the first time in Tunisia, in one adult female camel that presented abortion and anemia. Anaplasma spp. was the only haemopathogen identified in examined sheep (6.0%) and horses (17.0%). Horses infested by Hippobosca equina flies and sheep infested by Rhipicephalus turanicus ticks were more infected by Anaplasma spp. than other non-infested animals (P=0.046 and 0.042, respectively). Hyalomma dromedarii, H. impeltatum and H. excavatum were the most prevalent diagnosed ticks removed from camels with an intensity of infestation of 1.2 ticks per animal. However, in sheep, only R. turanicus was identified. H. equina and Tabanus spp. were the potential hematophagous flies found in dromedaries and horses herds. This useful data must be taken into consideration during animal treatment and vectors’ control programs in Tunisian military farms which help to limit the diffusion of vector-borne diseases, keep our livestock healthy and reduce economic losses.

Lipids in predentine and dentine.

Using two histochemical methods, malachite green-aldehyde and iodoplatinate, phospholipids were visualized in the predentine of rat incisors in the spaces located between collagen fibers and in dentine as needle-like structures located along individual or groups of mineralizing collagen fibers. The same staining pattern was seen with phospholipase A2-gold. Autoradiographic investigation using 3H choline as labelled precursor, visualized the incorporation of membrane-associated and extracellular choline-containing phosphatidyl choline and sphingomyelin. The cell and membrane-associated labelling decreased gradually between 24 and 4 days, whereas incorporation of the labelled precursor as stable extracellular matrix component was seen in dentine. In addition to these investigations, pharmacologically induced (suramine) and genetically (Krabbe's disease) lysosomal storage pathology was investigated. Defects due to lipid metabolism alterations were seen in predentine and/or in dentine. The major differences visualized here between the non-mineralized and mineralized compartments and interactions between phospholipids and proteoglycans, support the view that phospholipids as matrix components play an important role in the mechanisms of dentine formation and mineralization.

Suramin-induced mucopolysaccharidosis in rat incisor.

Two weeks after a single injection of suramin, the secretory and post-secretory ameloblasts of the rat incisor were filled with large lysosome-like vacuoles. At the light-microscope level, these vacuoles were positively stained with Alcian blue when MgCl2 was used at a critical electrolyte concentration varying between 0.1 and 0.3 M, whereas no staining appeared when MgCl2 varied between 0.7 and 0.9 M. Hyaluronidase digestion markedly reduced but did not totally abolish the staining, indicating that glycosaminoglycans were accumulated inside these vacuoles. Examination of these cells with the electron microscope revealed a polymorphic population of large vesicles, filled to various degrees with cetylpyridinium chloride (CPC)-positive and malachite green aldehyde (MGA)-positive material. The same pattern was observed in secretory odontoblasts but to a lesser extent. In the extracellular matrix, suramin-induced alterations appeared as large defects occurring during enamel formation. In predentin and dentin, the number and/or size of electron-dense aggregates resulting from CPC and MGA fixation, were enhanced in the suramin-injected rats. These aggregates were largely reduced or suppressed respectively by hyaluronidase digestion and chloroform/methanol treatment of the sections. The accumulation of glycosaminoglycans and phospholipids reported here inside ameloblasts and odontoblasts and in predentin and dentin supports the occurrence of suramin-induced mucopolysaccharidosis and lipidosis in this experimental animal model.

[Lysosomal storage diseases, genetic or drug-induced? effect of glycosaminoglycan and sphingolipid disorders on dental tissues]. / Maladies de surcharge lysosomale, génétiques ou induites pharmacologiquement: effets de pathologies de glycosaminoglycanes et de sphingolipides sur les tissus dentaires.

In vivo studies were carried out on dental tissues of rat incisor after a single injection of suramin, a drug which induces mucopolysaccharidosis-like disease. Accumulation of lysosome-like structures was seen in secretory ameloblasts and odontoblasts. In vitro studies on embryonic tooth germ buds showed similar changes when they were cultured in presence of suramin. Anti-phospholipid immunolabelling revealed a developmentally regulated temporo-spatial pattern. Radiolabeling with 3H-suramin indicated cytosolic and nuclear incorporation. The drug acting as polyanion interacted directly with predentine. 35S sulphate incorporation was impaired by the drug. Another lysosomal storage disease, the sphingolipidosis, Krabbe's disease was also investigated in human. Changes were observed in pulp cells and as a consequence in dentin. Enamel also displayed many changes. Pharmacological or genetically acquired diseases constitute models providing insights on the role played by glycosaminoglycans and phospholipids in biomineralization.