Propagation du Lyssavirus chez les petits mammifères (Muridae et Soricidae) dans la Préfecture de Kindia, République de Guinée (Basse Guinée)

L’étude porte sur la propagation du Lyssavirus chez les petits mammifères dans la Préfecture de Kindia (Basse Guinée) a été réalisée entre avril 2015 et mars 2016 dans les différents biotopes (Maisons habitées, Forêts-Buissons, Champs agricoles, Entrepôts et Berges) et qui a pour objectif: Contribuée à l’amélioration de l’état de santé de la population. Pendant cette période d’étude, 412 rongeurs repartis en 12 espèces ont été capturées à savoir le rat d’herbe-Arvicanthis rufinus, les rats-Cricetomys gambianus, les rats-Crocidurinae spp., les souris rayées-Lemniscomys striatus, Lophuromys ansorgei, Lophuromys sikapusi, le rat à mamelles multiples-Mastomys spp., souris de maison-Mus musculus, Pelomys fallax, le rat de forêt-Praomys rostratus, le rat noir-Rattus rattus et le Malacomys edyardsi spp. Les plus répandus sont les Mastomys, Rattus rattus, Mus musculus et Cricetomys gambianus. En saison sèche, le nombre de rongeurs capturés dans la préfecture de Kindia a atteint 292 (71%) contre 120 (29%) rongeurs en saison pluvieuse. Pour des fins de recherches virologiques, le cerveau de 221 rongeurs a été prélevé et analysé parmi eux, 18 (8%) ont été trouvé porteurs de l’ARN de Lyssavirus. English title: Spread of Lyssavirus among small mammals (Muridae and Soricidae) in Kindia prefecture, Republic of Guinea (Lower Guinea) The study focuses on the spread of Lyssavirus among small mammals in the Prefecture of Kindia (Lower Guinea) was carried out between April 2015 and March 2016 in the different biotopes (inhabited houses, Forests-Bushes, Agricultural fields, Warehouses and Banks) and which has for objective: Contributed to the improvement of the state of health of the population. During this period, 412 rodents were caught in 12 species including the grass rat-Arvicanthis rufinus, the Cricetomys gambianus-rats, the Crocidurinae spp rats, striped mice Lemniscomys striatus, Lophuromys ansorgei, Lophuromys sikapusi, the multiple-teat rat-Mastomys spp., house mouse-Mus musculus, Pelomys fallax, forest rat-Praomys rostratus, black rat-Rattus rattus, and Malacomys edwardsi spp. The most common are: Mastomys spp., Rattus rattus, Mus musculus and Cricetomys gambianus. In the dry season, the number of rodents caught in the prefecture of Kindia reached 292 (71%) against 120 (29%) rodents caught during the rainy season. For virological research purposes, the brain of 221 rodents was collected and analyzed among them 18 rodents (8%) were found to carry Lyssavirus RNA.

Prevalence of Endo and Ecto Parasitic Infection of African Giant Rat (Cricetomys gambianus) in North Eastern Nigeria

Rodents are one of the most important groups of mammalian animal with more than 42%of the known mammalian species, with 1700 species which belongs to three different families include Muridae, microtidaie and sigmodontidae. The aim of this study is to examine endo and ecto parasitic infection of African Giant rat (Cricetomys Gambianus). Intestinal parasite were detected and identified from the stool samples using formalin ethyl-acetate concentration technique. A total of 18 African giant rats were captured, all of the captured rats were found infected with at least one or more endoparasites (100%). Whereas there’s no any ectoparasites identified from the rat. 16(89%) of the rats captured were found positive for haemoparasite. Therefore, the results of this study have shown that the rats are infected with parasite species that may play an important role in transmission of certain zoonotic diseases to humans. Keywords: African Giant rat, Cricetomys Gambianus, endo and ecto parasitic infection, Rodents, zoonotic disease.

Reproductive Hormones Imbalance, Germ Cell Apoptosis, Abnormal Sperm Morphophenotypes and Ultrastructural Changes in Testis of African Giant Rats (Cricetomys gambianus, Waterhouse, 1840) Exposed to Sodium Metavanadate Intoxication

Environmental exposure to vanadium has been on the increase in recent time. This metal is a known toxicant. The current study was conducted to investigate the reproductive toxicity of sodium metavanadate (SMV) in male African giant rats. Administration of SMV was done intraperitoneally daily for 14 consecutive days at a dosage of 3mg/kg body weight. Sterile water was administered to the control group. We analyzed serum reproductive hormones, sperm reserve and quality as well as testicular ultrastructural changes following SMV treatment. Our results showed SMV exposed AGR group had statistically increased progesterone but decreased testosterone, FSH and LH concentrations. Also, SMV treated group had statistically decreased sperm motility and mass activity with increased percentage of abnormal morphophenotypes of spermatozoa and upregulation of P53 immunopositive cell. Ultrastructural study revealed vocuolation of germ and Sertoli cells, cytoplasmic and nucleus; and mitochondrial swelling and vacuolations were also observed. There was severe disintegration of the seminiferous tubules, atrophy and degeneration of myeloid cells and apoptosis of the Leydig, Sertoli and germ cells. In conclusion, intraperitoneal SMV exposure exerts severe adverse effects on some serum reproductive hormones, reduction of sperm reserve and quality, apoptosis and degenerative changes of the Leydig, Sertoli and germ cells which can lead to infertility.

Occurrence and Prevalence of Macroparasites of African Giant Rats (Cricetomys Gambianus) in a Savanna Region of Nigeria

Rodents play an important role in the transmission of zoonotic diseases since they serve as reservoirs of these infections. A survey of ecto and intestinal parasites of the African giant rat (Cricetomys gambianus) was carried out between January and May, 2018 in Il-orin to access their potential as reservoirs of zoonoses. A total of 60 African giant rats were caught live using single catch rat traps which were set around bushes, near human habitation. The giant rats were euthanized with chloroform and thoroughly examined for ectoparasites. The giant rats were dissected and the alimentary canal removed. Direct smear floatation and sedimentation methods were used to detect endoparasites in the animals. The prevalence of different types of endoparasites were: Hymenolepis nana (33.3 %), Hymenolepis diminuta (25.0 %), Aspicularis tetraptera (29.2 %), and Acanthocephala spp. (12.5 %), while the ectoparasites were: Ixodes rasus (37.9 %), Xenopsylla cheopis (44.8 %) and Ornithonyssus bacoti (17.2 %). African giant rats harbour quite a number of infections that can be spread to humans especially in developing countries where most communities are economically disadvantaged, thus the need to properly enlighten the populace.

Ultrastructural Morphology of the Ependyma and Choroid Plexus in the African Giant Rat (Cricetomys gambianus)

Ependymal cells line the interface between the ventricular surfaces and the brain parenchyma. These cells, in addition to the choroid plexus, form the blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (BCSFB) and serve important functions in the protection and regulation of brain metabolism. The African giant rat (AGR) has been used as sentinels to detect potential neuropathology arising from ecotoxicological pollutions. This study examined the lateral ventricular lining by using histology, immunohistochemistry and electron microscopy. Marked variations were observed in some regions of the ventricles which showed multi-layering of ependymal cells that differed from the typical single layered ependymal cells at the apical surface, while subependymal structures revealed indistinctive neuropil and glia following histological examinations. The ependymal cells which form the epithelial lining of the ventricles were comprised of cuboidal or low columnar cells, with the plasmalemma of abutting cells forming intercellular bridge appearing links by: tight junctions (zonula occludens), intermediate junctions (zonula adherens), desmosomes (macula adherens) and infrequent gap junctions. The choroid plexus revealed cells of Kolmer with several cilia and microvilli. The possible functional components of the ependyma and choroid plexus morphology of the AGR are discussed and thus provide a baseline for further research on the AGR brain.