8 research outputs found
Morphological, genetical and ecological discrimination of sympatric Coastal Guinea Mastomys (Mammalia : Rodentia) species (West Africa) : implications for health and agriculture
Cytogenetic
and molecular tools have shown the existence of two sibling species of the multimammate rat in
Coastal Guinea : M. erythroleucus and M. huberti from Mankoutan locality. Here we present the study of
the unique population of M. huberti ever recorded in Guinea, distant from 350 km from the closest locality
in Senegal and representing the southernmost point of the speciesâ disjunct distribution. In order to clarify
its ecological preferences and define its degree of sympatry with M. erythroleucus, we have searched for
morphological and morphometric criteria allowing reliable identification of the species in Coastal Guinea.
Discriminant Factorial Analyses (DFA) were performed on external and skull measurements for respectively
108 and 106 previously genetically typed individuals. All discriminant analyses showed that the 100 % rate
of good classification is never attained. Misclassifications of 55.6 % of the specimens were obtained in the
field by using external fur colour and aspect whereas the error score ranged from 4.5 to 8 % by using DFA
on external measurements. Furthermore, DFA on skull measurements gave 100 % of correct classification
for M. huberti - which is characterized by a smaller size - against 96.97 % for M. erythroleucus. In the same
time, we were able to define the local specific habitat of each species. In Mankountan, M. huberti is never
found into houses but prefers wet rice fields, while M. erythroleucus is found both in houses and cultures as
well as in wet rice fields where it is found in syntopy with M. huberti at the end of the dry season. In Yerende,
a hundred kilometres from Mankoutan, we only caught M. erythroleucus both in houses and fields. This
study once again highlights the importance of a deep taxonomic knowledge of small mammalsâ diversity for
sanitary and agricultural risks evaluation but also confirms the problems of identification encountered with
rodent sibling species living in sympatryLes analyses cytogénétiques et moléculaires ont mis en évidence la présence de deux espÚces jumelles de Mastomys en Guinée Maritime: M. ervthroleucus et M. huberti dans la localité de Mankoutan. Il s'agit de la premiÚre étude de
la seule population de M. huberti rencontrée en Guinée située à 350 km de la population la plus proche du Sénégal, à l'extrémité Sud de l'aire de distribution disjointe de l'espÚce. Afin de définir ses préférences écologiques, nous avons recherché des critÚres morphologiques et
morphométriques pour identifier les deux espÚces de Mastomys afin de mieux définir leur degré de sympa-trie. Des Analyses Factorielles Discriminantes (AFD) effectuées sur les caractÚres externes et crùniens de 108 et 106 individus ayant fait l'objet d'analyses moléculaires (cyt.b) et /ou
cytogénétiques, provenant de deux localités proches, montrent que l'on ne peut jamais discriminer avec 100 % de certitude les spécimens en 'peau' et 'crùne'. Le taux d'erreur de détermination des deux espÚces atteint 55,6 % pour la coloration et l'aspect du pelage sur le terrain, il oscille
entre 4,5 et 8 % en AFD sur les mesures externes. Cependant avec les mesures crùniennes traitées par AFD, les M. huberti se distinguent à 100 % par une taille légÚrement plus faible, contre 96,97 % chez M. erythroleucus. ParallÚlement, nous avons pu préciser l'habitat spécifique aux deux
espĂšces dans la mĂȘme localitĂ©. Ainsi, Ă Mankountan, M. huberti n'est jamais rencontrĂ© dans les maisons et prĂ©fĂšre les champs de riz inondĂ©s. M. erythroleucus est prĂ©sent Ă la fois dans les maisons et dans les champs, quelquefois dans les riziĂšres inondĂ©s oĂč, Ă la fin de la saison sĂšche, il
se retrouve en syntopie avec M. huberti. La localité de Yerendé située à 100 km de Mankountan n'a livré que des M. erythroleucus, présents à la fois dans les maisons et les champs. Cette étude montre l'importance d'une connaissance approfondie de la systématique et de la diversité des petits
mammifÚres nuisibles pour l'évaluation des risques sanitaires et agricoles et confirme les difficultés d'identification morphologique des espÚces jumelles chez les rongeurs
Mastomys natalensis and Lassa Fever, West Africa
PCR screening of 1,482 murid rodents from 13 genera caught in 18 different localities of Guinea, West Africa, showed Lassa virus infection only in molecularly typed Mastomys natalensis. Distribution of this rodent and relative abundance compared with M. erythroleucus correlates geographically with Lassa virus seroprevalence in humans
Complete genome sequence of Ebrios, a novel T7virus isolated from the Ebrie Lagoon in Abidjan, CĂŽte dâIvoire
The lytic Escherichia coli phage Ebrios was isolated from a water sample collected in Ebrie Lagoon on the AdiopodoumĂ© River in Abidjan (Republic of CĂŽte dâIvoire, West Africa). The linear genome of this Podoviridae family member contains 39,752âbp, has a G+C content of 52.9%, is composed of 53 open reading frames, and is related to the Stenotrophomonas maltophilia phage IME15
Discrimination morphologique, gĂ©nĂ©tique et Ă©cologique de deux espĂšces sympatriques de Mastomys (Mammalia : Rodentia) en GuinĂ©e Maritime (Conakry) : implications pour la santĂ© et lâagriculture
Morphological, genetical and ecological discrimination of sympatric Coastal Guinea Mastomys (Mammalia : Rodentia) species (West Africa) : implications for health and agriculture.
Cytogenetic and molecular tools have shown the existence of two sibling species of the multimammate rat in Coastal Guinea : M. erythroleucus and M. huberti from Mankoutan locality. Here we present the study of the unique population of M. huberti ever recorded in Guinea, distant from 350 km from the closest locality in Senegal and representing the southernmost point of the speciesâ disjunct distribution. In order to clarify
its ecological preferences and define its degree of sympatry with M. erythroleucus, we have searched for
morphological and morphometric criteria allowing reliable identification of the species in Coastal Guinea.
Discriminant Factorial Analyses (DFA) were performed on external and skull measurements for respectively 108 and 106 previously genetically typed individuals. All discriminant analyses showed that the 100 % rate
of good classification is never attained. Misclassifications of 55.6 % of the specimens were obtained in the field by using external fur colour and aspect whereas the error score ranged from 4.5 to 8 % by using DFA on external measurements. Furthermore, DFA on skull measurements gave 100 % of correct classification
for M. huberti - which is characterized by a smaller size - against 96.97 % for M. erythroleucus. In the same time, we were able to define the local specific habitat of each species. In Mankountan, M. huberti is never found into houses but prefers wet rice fields, while M. erythroleucus is found both in houses and cultures as well as in wet rice fields where it is found in syntopy with M. huberti at the end of the dry season. In Yerende, a hundred kilometres from Mankoutan, we only caught M. erythroleucus both in houses and fields. This study once again highlights the importance of a deep taxonomic knowledge of small mammalsâ diversity for sanitary and agricultural risks evaluation but also confirms the problems of identification encountered with rodent sibling species living in sympatry.Les analyses cytogĂ©nĂ©tiques et molĂ©culaires ont mis en Ă©vidence la prĂ©sence de deux espĂšces jumelles de Mastomys en GuinĂ©e Maritime : M. erythroleucus et M. huberti dans la localitĂ© de Mankoutan. Il sâagit de la premiĂšre Ă©tude de la seule population de M. huberti rencontrĂ©e en GuinĂ©e situĂ©e Ă 350 km de la population la plus proche du SĂ©nĂ©gal, Ă lâextrĂ©mitĂ© Sud de lâaire de distribution disjointe de lâespĂšce. Afin de dĂ©finir ses prĂ©fĂ©rences Ă©cologiques, nous avons recherchĂ© des critĂšres morphologiques et morphomĂ©triques pour identifier les deux espĂšces de Mastomys afin de mieux dĂ©finir leur degrĂ© de sympatrie.
Des Analyses Factorielles Discriminantes (AFD) effectuĂ©es sur les caractĂšres externes et crĂąniens de 108 et 106 individus ayant fait lâobjet dâanalyses molĂ©culaires (cyt.b) et / ou cytogĂ©nĂ©tiques, provenant de deux localitĂ©s proches, montrent que lâon ne peut jamais discriminer avec 100 % de certitude les spĂ©cimens en âpeauâ et âcrĂąneâ. Le taux dâerreur de dĂ©termination des deux espĂšces atteint 55,6 % pour la coloration et lâaspect du pelage sur le terrain, il oscille entre 4,5 et 8 % en AFD sur les mesures externes. Cependant avec les mesures crĂąniennes traitĂ©es par AFD, les M. huberti se distinguent Ă 100 % par une taille lĂ©gĂšrement plus faible, contre 96,97 % chez M. erythroleucus. ParallĂšlement, nous avons pu prĂ©ciser lâhabitat spĂ©cifique aux deux espĂšces dans la mĂȘme localitĂ©. Ainsi, Ă Mankountan, M. huberti nâest jamais rencontrĂ© dans les maisons et prĂ©fĂšre les champs de riz inondĂ©s. M. erythroleucus est prĂ©sent Ă la fois dans les maisons et dans les champs, quelquefois dans les riziĂšres inondĂ©s oĂč, Ă la fin de la saison sĂšche, il se retrouve en syntopie avec M. huberti.
La localitĂ© de YerendĂ© situĂ©e Ă 100 km de Mankountan nâa livrĂ© que des M. erythroleucus, prĂ©sents Ă la fois dans les maisons et les champs. Cette Ă©tude montre lâimportance dâune connaissance approfondie de la systĂ©matique et de la diversitĂ© des petits mammifĂšres nuisibles pour lâĂ©valuation des risques sanitaires et agricoles et confirme les difficultĂ©s dâidentification morphologique des espĂšces jumelles chez les rongeurs.Denys Christiane, Lalis Aude, Kourouma FodĂ©, Kan Kouassi StĂ©phane, Nicolas Violaine, Aniskine Vladimir, Koivogui Lamine. Discrimination morphologique, gĂ©nĂ©tique et Ă©cologique de deux espĂšces sympatriques de Mastomys (Mammalia : Rodentia) en GuinĂ©e Maritime (Conakry) : implications pour la santĂ© et lâagriculture. In: Revue d'Ăcologie (La Terre et La Vie), tome 67, n°2, 2012. pp. 193-211
CaractĂ©risation molĂ©culaire des rongeurs rĂ©servoirs dâarĂ©navirus en CĂŽte dâIvoire : implications pour la santĂ©
International audienc
Taxonomy and biogeography of the African pygmy mice, subgenus Nannomys (Rodentia, Murinae, Mus) in Ivory Coast and Guinea (west Africa).
International audienceRecent investigations in Guinea and Ivory Coast showed that Mus (Nannomys) are hosts of new arenaviruses. However, the taxonomy and biogeography of the western pygmy mice are poorly known, as this genus contains many cryptic species. To improve our taxonomic knowledge on this subgenus and its distribution range in West Africa, we performed a molecular, cytogenetical and morphological study of all Mus (Nannomys) species in this part of Africa. This approach allowed us to detect five species in Guinea (Mus mattheyi, M. minutoides, M. setulosus, M. baoulei, M. musculoides) and four (M. minutoides, M. setulosus, M. baoulei, M. musculoides) in Ivory Coast. Our molecular results confirm the validity of M. baoulei and the extended distribution range of M. mattheyi. We also observed a high degree of genetic differentiation between and within these species, especially within the M. setulosus clade which may be a species complex. The canonical analyses on the craniometrical and external morphological features of the sequenced specimens are insufficient to perfectly separate the studied species. Nevertheless, our results confirm that M. setulosus and M. baoulei are the largest Mus species that occur in Guinea and Ivory Coast. M. baoulei can be distinguished by its short tail and M. setulosus by an enlarged and bilobated lower molar (M3). Among the smaller species, M. musculoides is difficult to identify using morphological data alone, but differences in tail length proportions, size of tympanic bullae, the length and shape of the upper dental row allow identification of this species with some confidence. Our results allow us to provide some conclusions about the distribution ranges of the studied Mus (Nannomys) spp. in both countries and to discuss their presence in relation to vegetation, habitat and human settlements
Fatal Case of Lassa Fever, Bangolo District, CĂŽte dâIvoire, 2015
International audienceLassa fever has not been reported in CĂŽte d'Ivoire. We performed a retrospective analysis of human serum samples collected in CĂŽte d'Ivoire in the dry seasons (January-April) during 2015-2018. We identified a fatal human case of Lassa fever in the Bangolo District of western CĂŽte d'Ivoire during 2015