Echinococcus multilocularis: identification of the parasite and echinococcosis diagnosis in animals

After a brief description of the parasite’s taxonomic status, the author reviews the diagnosis techniques of Echinococcosis in definitive (foxes, dogs, cats), intermediate (rodents) and aberrant hosts. Species identification is an essential prerequisite to the establishment of local control programmes (particularly in rodents). Current reliable methods, recognised by WHO, to diagnose the parasitosis at necropsy in definitive hosts include: i) the intestinal smear technique (IST) with a sensitivity and specificity of 100%; ii) the sedimentation and counting technique (SCT) with a sensitivity of 100% and a specificity of 78%. ELISA coproantigen detection in dog, cat and fox faecal samples is possible with a sensitivity of 80- 87% and a specificity of 70-99%. Furthermore, molecular biology techniques based on PCR (Polymerase Chain Reaction) are now available in specialized laboratories for the detection of E. multilocularis eggs or DNA, directly from faecal samples of carnivores. Special safety precautions must be implemented when handling definitive hosts infected with E. multilocularis and when using materials potentially contaminated with Echinococcus eggs. Two molecules (praziquantel and epsiprantel) are available for prophylaxis.Après un rappel sur la diagnose d'Echinococcus multilocularis, l'auteur rapporte les techniques de diagnostic de l'échinococcose chez les hôtes définitifs (renard, chien, chat), les intermédiaires (rongeurs), ainsi que chez les hôtes inhabituels. L'identification d'espèce est essentielle à l'établissement d'un programme local de contrôle (en particulier chez les rongeurs). Les méthodes actuelles, fiables pour le diagnostic chez les hôtes définitifs, réalisées à l'autopsie de l'animal, sont la technique de sédimentation (SCT), avec une spécificité et une sensibilité de 100 %, et celle du « grattage intestinal » (IST), avec une spécificité de 100 % et une sensibilité de 78 %. La détection de coproantigène par ELISA dans les fèces de chiens, de chats et de renards est possible avec une sensibilité de 80 à 87 % et une spécificité comprise entre 70 et 99 %. Des techniques de biologie moléculaire utilisant la PCR (Polymerase Chain Reaction) sont appliquées dans des laboratoires spécialisés, pour la détection d'oeufs d'E. multilocularis ou de l'ADN, directement à partir des échantillons fécaux de carnivores. La manipulation des hôtes définitifs infectés par E. multilocularis et l'utilisation du matériel potentiellement contaminé par les oeufs d'Echinococcus requièrent des précautions spéciales de sécurité. Deux molécules (praziquantel et epsiprantel) sont disponibles pour la prophylaxie

Wing morphology variations in Culicoides circumscriptus from France

The biting midge Culicoides circumscriptus Kieffer, 1918 is a European widespread vector of avian malaria throughout the continent and is a possible vector of Akabane virus and Bluetongue virus. This species populates a wide range of environments in contrasting ecological settings often exposed to strong seasonal fluctuations. The main goals of this study were to investigate C. circumscriptus phenotypic variation at three departments in France (Corsica Island, Moselle and Var) and to determine if its phenotypes vary with the environment. Culicoides circumscriptus wing phenotypes were analyzed using a geometric morphometric approach based on anatomical landmarks and outlines of the wing. Dendogram trees based on landmarks and the outlines-2 set (cell m4) showed similar topologies and separated populations of C. circumscriptus. In contrast, another set of outlines-1 (covering the r-m cross vein, M, radiale and arculus) presented a different hierarchical clustering tree. The phenotypic variation observed in C. circumscriptus indicated that these populations are exposed to environmental and ecological pressures. Our results suggest the presence of phenotypic plasticity in this species

An updated list of the Culicoides (Diptera, Ceratopogonidae) fauna from Ecuador

An updated list of biting midges of the genus Culicoides inhabiting Ecuador is provided. Entomological investigations were carried out from July 2010 to May 2019 using CDC light traps in three Ecuadorian regions (Amazon basin, Andean (foothills and highlands) and Pacific Coast). A total of 12,073 Culicoides specimens from seven subgenera and nine species groups were collected. More species and higher variation were found in the Amazon basin than in either of the Andes regions or coastal sites. A total of 53 species were identified. Of these, 15 are herein reported as new species records for Ecuador: Culicoides acotylus Lutz, C. aitkeni Wirth & Blanton, C. benarrochi Ortiz & Mirsa, C. carvalhoi Wirth & Blanton, C. freitasi Wirth & Blanton, C. ginesi Ortíz, C. lopesi Barretto, C. lyrinotatus Wirth & Blanton, C. profundus Santarém, Felippe-Bauer & Trindade, C. pseudoreticulatus Santarém, Felippe-Bauer & Castellón, C. quasiparaensis Clastrier, C. vernoni Wirth & Blanton, C. youngi Wirth & Barreto and two new species. Our results show that the updated list of the Ecuadorian Culicoides fauna comprises 70 species. This inventory highlights the presence of species that have been incriminated as vectors of disease elsewhere in animals and humans, mainly C. insignis and C. paraensis

Systématique moléculaire du genre Culicoides Latreille (Diptera, Ceratopogonidae) (étude pilote)

REIMS-BU Santé (514542104) / SudocSudocFranceF

Contribution à l'étude des Culicoides (Ceratopogonidae) sur l'exploitation de Montigny-la-cour (Aisne-02)

REIMS-BU Santé (514542104) / SudocSudocFranceF

Approche morphologique et morphométrique des Culicoides (Diptera : Ceratopogonidae) de la région Provence - Alpes Côte d'Azur

REIMS-BU Santé (514542104) / SudocSudocFranceF

Séroprévalence de la fièvre catarrhale ovine : enquête réalisée dans la faune sauvage du Nord-est de la France

REIMS-BU Santé (514542104) / SudocSudocFranceF

New data about Australophlebotomus notteghemae Léger & Pesson, 1993 (Diptera, Psychodidae)

International audienc

Wing morphometrics of biting midges (Diptera: Culicoides) of veterinary importance in Madagascar

International audienceBiting midges are vectors of arboviruses such as bluetongue virus, bovine ephemeral fever virus, Akabane virus, African horse sickness virus, epizootic haemorrhagic disease virus and Schmallenberg virus. Fast and accurate identification of biting midges is crucial in the study of Culicoides-borne diseases. Morphological identification of biting midges has revealed the presence of cryptic species. A total of 20 species are reported in Madagascar. In this study, we assessed wing morphometric analysis for identification of seven species namely C. dubitatus Kremer, Rebholtz-Hirtzel and Delécolle, C. enderleini Cornet and Brunhes, C. kibatiensis Goetghebuer, C. miombo Meiswinkel, C. moreli Clastrier, C. nevilli Cornet and Brunhes, and C. zuluensis de Meillon. Culicoides enderleini, C. miombo, C. moreli, C. nevilli and C. zuluensis are vectors diseases. A molecular approach, based on the cytochrome oxidase I gene (Cox1), was used for species delimitation. The molecular analysis presented seven different clades grouped two-by-two according to morphological characters. A total of 179 wing images were digitised. We found morphometric variation among seven species based on 11 landmarks and two outlines. Wing shape variation plots showed that species overlapped with species belonging to the same group. The cross-validation revealed a relatively high percentage of correct classification in most species, ranging from 91.3% to 100% for landmarks; 60% to 82.6% for outlines-1 and 77.1% to 91.3% for outlines-2. Our study suggests that wing geometric morphometric analysis is a robust tool for reliable "Moka Fohy" identification in Madagascar. This inexpensive and simple method is a precise supplement to morphological identification, with reaches the accuracy of Cox1 barcoding

Comprehensive characterisation of Culicoides clastrieri and C. festivipennis (Diptera: Ceratopogonidae) according to morphological and morphometric characters using a multivariate approach and DNA barcode

Abstract Biting midges are widespread around the world and play an essential role in the epidemiology of over 100 veterinary and medical diseases. For taxonomists, it is difficult to correctly identify species because of affinities among cryptic species and species complexes. In this study, species boundaries were examined for C. clastrieri and C. festivipennis and compared with six other Culicoides species. The classifiers are partial least squares discriminant analysis (PLS-DA) and sparse partial least squares discriminant analysis (sPLS-DA).The performance of the proposed method was evaluated using four models: (i) geometric morphometrics applied to wings; (ii) morphological wing characters, (iii) "Full wing" (landmarks and morphological characters) and (iv)  "Full model" (morphological characters—wing, head, abdomen, legs—and wing landmarks). Double cross-validation procedures were used to validate the predictive ability of PLS-DA and sPLS-DA models. The AUC (area under the ROC curve) and the balanced error rate showed that the sPLS-DA model performs better than the PLS-DA model. Our final sPLS-DA analysis on the full wing and full model, with nine and seven components respectively, managed to perfectly classify our specimens. The C. clastrieri and C. festivipennis sequences, containing both COI and 28S genes, revealed our markers’ weak discrimination power, with an intraspecific and interspecific divergence of 0.4% and 0.1% respectively. Moreover, C. clastrieri and C. festivipennis are grouped in the same clade. The morphology and wing patterns of C. clastrieri and C. festivipennis can be used to clearly distinguish them. Our study confirms C. clastrieri and C. festivipennis as two distinct species. Our results show that caution should be applied when relying solely on DNA barcodes for species identification or discovery