Rhabdias (Nematoda: Rhabdiasidae) from Chamaeleonidae (Sauria): two new species from Trioceros ellioti in East Africa and one from Brookesia superciliaris in Madagascar.

International audience; Rhabdias casiraghii n. sp. and R. kibiraensis n. sp. are described from Trioceros ellioti from Burundi and co-infection was observed in one of the host specimens. Distinctive characters between these species are, among others, the mouth and buccal capsule in front view, both of which are round in the former and laterally flattened in the latter species. Both species have a complete set of submedian head papillae (three in each submedian axis) as observed in the fourth stage larva of R. americanus from anurans. This primitive character opposes them to other species parasitic in Chamaeleonidae that have a single papilla per axis. The third species is the first described from the primitive chamaeleonid genus Brookesia; R. brygooi n. sp. from B. superciliaris from Madagascar can be distinguished from other Rhabdias in Chamaeleonidae by the small diameter of its mouth and buccal capsule. In this character, it resembles parasites from anurans. However, its infective larva has a rounded caudal extremity ornated with buds, as described in species of Rhabdias parasitic in Chamaeleonidae

Integrated taxonomy: traditional approach and DNA barcoding for the identification of filarioid worms and related parasites (Nematoda)

<p>Abstract</p> <p>Background</p> <p>We compared here the suitability and efficacy of traditional morphological approach and DNA barcoding to distinguish filarioid nematodes species (Nematoda, Spirurida). A reliable and rapid taxonomic identification of these parasites is the basis for a correct diagnosis of important and widespread parasitic diseases. The performance of DNA barcoding with different parameters was compared measuring the strength of correlation between morphological and molecular identification approaches. Molecular distance estimation was performed with two different mitochondrial markers (<it>coxI </it>and 12S rDNA) and different combinations of data handling were compared in order to provide a stronger tool for easy identification of filarioid worms.</p> <p>Results</p> <p>DNA barcoding and morphology based identification of filarioid nematodes revealed high coherence. Despite both <it>coxI </it>and 12S rDNA allow to reach high-quality performances, only <it>coxI </it>revealed to be manageable. Both alignment algorithm, gaps treatment, and the criteria used to define the threshold value were found to affect the performance of DNA barcoding with 12S rDNA marker. Using <it>coxI </it>and a defined level of nucleotide divergence to delimit species boundaries, DNA barcoding can also be used to infer potential new species.</p> <p>Conclusion</p> <p>An integrated approach allows to reach a higher discrimination power. The results clearly show where DNA-based and morphological identifications are consistent, and where they are not. The coherence between DNA-based and morphological identification for almost all the species examined in our work is very strong. We propose DNA barcoding as a reliable, consistent, and democratic tool for species discrimination in routine identification of parasitic nematodes.</p

First report of Rhabdias (Nematoda: Rhabdiasoidea) from lungs of montane chameleons in Cameroon: description of two new species and notes on biology.

Les nematodes pulmonaires parasites de cameleons du genre Rhabdias n'etaient connus qu'en Afrique orientale et a Madagascar. Deux especes sont decrites au Cameroun: il Rhabdias okuensis n. sp., hote-type Chamaeleo (Trioceros) quadricornis gracilior au Mont Oku est frequent; l'espece est proche de R. jarki, au Burundi, par la capsule buccale courte et l'oesophage long et mince, et en est distincte par la grande vesicule cervicale et des caracteres cephaliques (bouche, papilles). Les femelles parasites sont hermaphrodites (spermatozoides identifies); en outre, elles perforent la paroi pulmonaire et provoquent des lesions, comme R. jarki. C. (T.) w. wiedersheimi au Mont Oku heberge aussi R. okuensis, comme cela est demontre par les sequences des genes 12S rADN et coxl. ii) R. cristati n. sp., hote-type C. (T.) cristatus ou Mont Cameroun est decrit chez un specimen fortement parasite; l'espece est proche de R. chamaeleonis d'Afrique Orientale, et en est distinct par la grande taille de la capsule buccale et l'apex epais de l'intestin. La phase libre du cycle, etudiee chez R. okuensis, presente les caracteres des autres Rhobdias de cameleons: heterogonie, developpement des larves par endotokie matricide, stade infectant avec une extremite caudale epaisse et arrondie, exuvie transformee en gaine cuticulaire epaisse; chaque femelle libre produit une larve, comme chez les autres Rhabdias africains, alors que la femelle de R. gemellipara, parasite de cameleon malgache, en produit deux

Litomosa chiropterorum Ortlepp, 1932 (Nematoda: Filarioidea) from a South African miniopterid: redescription, Wolbachia screening and phylogenetic relationships with Litomosoides.

69 Miniopterus notalensis, type host of the onchocercid Litomosa chiropterorum, were collected in caves in the Western Province and Gauteng Province, South Africa. The prevalence of these filariae was about 50 %. The microfilaria is folded, as in other Litomosa and an area rugosa composed of cuticular bosses is present in the male posterior region. L. chiropterorum is close to the species parasitic in other Miniopterus spp. and some Rhinolophus spp. from Africa, Madagascar and Europe; it is unique with the expanded anterior extremity and the four cephalic submedian bosses. The molecular analysis of L. chiropterorum, the first done with Litomosa species from a bat, supports the hypothesis that Litomosa and Litomosoides, which have an exceptionally large buccal capsule in common, form a group in which Litomosa has a basal position. Interestingly, L. chiropterorum does not harbour Wolbachia, as proved with immunohistological staining and PCR screening using the 16S rDNA gene as target. This is contrary to L. westi from rodents and the majority of the Litomosoides species parasitic in bats or rodents. The absence of Wolbachia in a filarioid group considered ancient based on traditional and molecular approaches opens interesting scenarios on the evolution of the endosymbionts spread through filarial lineages

New Insights into the Evolution of Wolbachia Infections in Filarial Nematodes Inferred from a Large Range of Screened Species

Wolbachia are intriguing symbiotic endobacteria with a peculiar host range that includes arthropods and a single nematode family, the Onchocercidae encompassing agents of filariases. This raises the question of the origin of infection in filariae. Wolbachia infect the female germline and the hypodermis. Some evidences lead to the theory that Wolbachia act as mutualist and coevolved with filariae from one infection event: their removal sterilizes female filariae; all the specimens of a positive species are infected; Wolbachia are vertically inherited; a few species lost the symbiont. However, most data on Wolbachia and filaria relationships derive from studies on few species of Onchocercinae and Dirofilariinae, from mammals.We investigated the Wolbachia distribution testing 35 filarial species, including 28 species and 7 genera and/or subgenera newly screened, using PCR, immunohistochemical staining, whole mount fluorescent analysis, and cocladogenesis analysis. (i) Among the newly screened Onchocercinae from mammals eight species harbour Wolbachia but for some of them, bacteria are absent in the hypodermis, or in variable density. (ii) Wolbachia are not detected in the pathological model Monanema martini and in 8, upon 9, species of Cercopithifilaria. (iii) Supergroup F Wolbachia is identified in two newly screened Mansonella species and in Cercopithifilaria japonica. (iv) Type F Wolbachia infect the intestinal cells and somatic female genital tract. (v) Among Oswaldofilariinae, Waltonellinae and Splendidofilariinae, from saurian, anuran and bird respectively, Wolbachia are not detected.The absence of Wolbachia in 63% of onchocercids, notably in the ancestral Oswaldofilariinae estimated 140 mya old, the diverse tissues or specimens distribution, and a recent lateral transfer in supergroup F Wolbachia, modify the current view on the role and evolution of the endosymbiont and their hosts. Further genomic analyses on some of the newly sampled species are welcomed to decipher the open questions

The nematode community of two Italian rivers (Taro and Ticino)

Summary – The Taro and Ticino rivers were sampled (maximum 15 cm depth) for nematodes during 1 year at three sites for each river and some ecological parameters were measured. The yearly mean abundance of nematodes in the river Taro was 23 individuals/ 10 cm2 and in the river Ticino 79 individuals/10 cm2. In the two rivers five to 15 and three to ten species, respectively, were found. The highest station (Taro 1) of the river Taro was significantly different from all the other Taro and Ticino stations both for number and species composition: bacterial feeders were the dominant group in Taro 1 (mean Maturity Index (MI) was 2.25), whereas unicellular eukaryote feeders dominated the other Taro and Ticino sites (mean MI of 2.85). Chromadorina bioculata was the most common species in both rivers, except at Taro 1, where Eumonhystera dispar dominated. Significant correlations were found between conductivity and unicellular eukaryote feeders and bacterial feeders. For the first time the Distinctness Index + is used for freshwater nematodes. Comparing our communities with other Italian rivers (data taken from the literature), we detected significant differences between polluted and not polluted habitats

A new species of Litomosoides (Nematoda: Onchocercidae), parasite of Nectomys palmipes (Rodentia: Cricetidae: Sigmodontinae) from Venezuela: description, molecular evidence, Wolbachia pipientis screening

International audienc

New species of Rhabdias (Nematoda : Rhabdiasidae) from Afrotropical anurans, including molecular evidence and notes on biology

Despite the small sample size the diversity of Rhabdias Stiles et Hassall, 1905 from anurans in the Afrotropical region was found to be high. Four species were collected from four localities, one in South Africa, two on Cameroonese mountains and one in Madagascar: Rhabdias picardiae sp. n. from the bufonid Amietophrynus gutturalis (Power); Rhabdias ohlerae sp. n. and Rhabdias tanyai sp. n. from the arthroleptids Leptopelis brevirostris (Werner) and Astylosternus rheophilus Amiet, respectively; and Rhabdias vencesi sp. n. from the mantellid Boophis madagascariensis (Peters). Distinctive characters between these species are numerous and obvious, based on body size, shape and size of the buccal capsule, arrangement of head papillae, and shape and size of the oesophagus and intestinal apex. Molecular data based on 500 bp of 12S rDNA and 600 bp of coxI of three of the four species are presented. Rhabdias vencesi resembles Rhabdias madagascariensis Chabaud, Brygoo et Petter, 1961 from an African ptychadenid introduced on Madagascar, but differs in body size and head morphology. The remaining new species are clearly distinct from those previously known from Afrotropical anurans. Outside the Afrotropics, some Rhabdias species present characters similar to those observed in the new species, but they all differ in various other characters. No clear correlation was seen between Rhabdias species and families of anuran hosts in this region. However, the narrow buccal capsule seen in Rhabdias species from Afrotropical lissamphibians opposes them to the majority of Rhabdias parasitic in chamaeleonids. Furthermore, the infective larva of R. vencesi has a conical pointed tail, while those of Rhabdias from chameleons have a rounded tail tip ornated with a few buds