Molecular Characterization of Nippostrongylus brasiliensis (Nematoda: Heligmosomatidae) from Mus musculus in India.

Mus musculus (Rodentia: Muridae) has generally been infected with a rodent hookworm Nippostrongylus brasiliensis. In this report, we present morphological and molecular identification of N. brasiliensis by light and scanning electron microscopy and PCR amplification of mitochondrial cytochrome c oxidase subunit 1 (cox1) gene and the protein sequences encoded by cox1 gene, respectively. Despite the use of N. brasiliensis in many biochemistry studies from India, their taxonomic identification was not fully understood, especially at the species level, and no molecular data is available in GenBank from India. Sequence analysis of cox1 gene in this study revealed that the present specimen showed close identity with the same species available in GenBank, confirming that the species is N. brasiliensis. This study represents the first record of molecular identification of N. brasiliensis from India and the protein structure to better understand the comparative phylogenetic characteristics.

Description of two new species of Nippostrongylinae (Nematoda: Heligmonellidae) coparasites in three sympatric species of Mastomys spp. (Rodentia: Muridae) from Senegal.

Two new species of heligmosomoid Trichostrongylina nematodes belonging to the genera Neoheligmonella Durette-Desset, 1970 and Heligmonina Baylis, 1928 are described. They are parasitic in the small intestine of three species of Mastomys from Senegal living in sympatry: M. natalensis (Smith, 1834), M. erythroleucus (Temminck, 1853) and M. huberti (Wroughton, 1909). Neoheligmonella granjoni n. sp. is closely related to three species from Senegal. They concern: N. bai Diouf & Durette-Desset, 2002 and N. dielmensis Diouf, Bâ & Durette-Desset, 1998, both parasitic in Arvicanthis niloticus Geoffroy, 1903 and N. mastomysi Diouf et al., 1998, a parasite of M. erythroleucus. N. granjoni n. sp. differs from these species by having 15 cuticular ridges at mid-body versus 13, a large carene and spicules taking up 10-15% of body length versus 5.3-7.1%. Heligmonina kanei n. sp. differs from the most related species H. kotoensis Diouf, Daouda & Durette-Desset 2005, a parasite of M. natalensis from Benin in the following features: spicules taking up 11.6% of body length on average versus 16.8%; a female tail three times longer than the distance anus-vulva versus a tail of equivalent size to this distance. In N. granjoni n. sp., where the material is abundant in all three hosts, the infra-specific variations observed (morphological or morphometrical) were not related to the host species. This is the first report of the genera Neoheligmonella and Heligmonina in M. huberti. The relevance of the phenomenon of host capture concerning the evolution of these two genera is confirmed.

Phylogeny, host-parasite relationship and zoogeography.

Phylogeny is the evolutionary history of a group or the lineage of organisms and is reconstructed based on morphological, molecular and other characteristics. The genealogical relationship of a group of taxa is often expressed as a phylogenetic tree. The difficulty in categorizing the phylogeny is mainly due to the existence of frequent homoplasies that deceive observers. At the present time, cladistic analysis is believed to be one of the most effective methods of reconstructing a phylogenetic tree. Excellent computer program software for phylogenetic analysis is available. As an example, cladistic analysis was applied for nematode genera of the family Acuariidae, and the phylogenetic tree formed was compared with the system used currently. Nematodes in the genera Nippostrongylus and Heligmonoides were also analyzed, and the validity of the reconstructed phylogenetic trees was observed from a zoogeographical point of view. Some of the theories of parasite evolution were briefly reviewed as well. Coevolution of parasites and humans was discussed with special reference to the evolutionary relationship between Enterobius and primates.

Immunocytochemical localization of secretory acetylcholinesterase of the parasitic nematode Nippostrongylus brasiliensis.

Various parasitic nematodes secrete acetylcholinesterase (AChE). In this study, the localization of AChE in the nematode Nippostrongylus brasiliensis and the secretory forms of AChE in culture fluid were examined. A thiocholine method revealed that AChE activity was localized in the subventral glands, which have a secretory and excretory function via a duct connected to the excretory pore. By electron microscopy, AChE activity was found mainly in the matrix of secretory granules, and sometimes in the Golgi apparatus in the subventral gland cells. These results show that nematode AChE is produced and stored in the subventral glands. Monoclonal antibodies against AChE of human erythrocytes or electric rays also bound to the nematode subventral gland, suggesting immuno-cross-reactivity of AChE among these species. When AChE activity in the nematode excretory-secretory product was examined by SDS polyacrylamide gel electrophoresis combined with the thiocholine method, intense activity was demonstrated as a single band at 74 kDa. Immunoblot analysis showed specific recognition of this molecule by IgE and IgG1 antibodies, but not by IgG2a antibody, in nematode-infected rat sera. These results indicate that the nematode AChE molecule produced in and secreted from the subventral glands is antigenic for the production of IgE/IgG1 in host animals.

Levels of ecdysteroid-like material in adults of Nippostrongylus brasiliensis during the intestinal phase.

Total ecdysteroid-like immunoreactive material was assayed and quantified in adults of the parasitic nematode N. brasiliensis during the intestinal phase in the rat in order to detect possible physiological fluctuations in titre. Worms of the same sex isolated from one rat were pooled in order to quantify ecdysteroids using enzyme immunoassay (EIA). The concentration of ecdysteroids fluctuated during adult life according to the sex and the age of the parasite. Important differences of levels of ecdysteroid-like compounds between the two sexes of parasites were noted particularly at 128 and 168 h post-infection. The peak at 128 h, present in female, but not in male worms, corresponds to the time of egg-laying. Following HPLC-EIA analysis, the presence of ecdysone, 20-hydroxyecdysone and apolar ecdysteroid-like material was ascertained during this peak. The physiological role and the possible origin of ecdysteroids in this nematode are discussed.

Nematodes of the family Heligmonellidae (Trichostrongyloidea) collected from rodents of the Ryukyu archipelago and Taiwan.

Six species of the family Heligmonellidae (Nematoda: Trichostrongyloidea), including 3 new species, are recorded from rodents of the subfamily Murinae in the Ryukyu Archipelago and Taiwan. Heligmonoides ikeharai n. sp. from Tokudaia osimensis muenninki on Mt. Yonaha, Okinawa Island, is characterized by extremely long spicules and hypertrophied ridges in the prevulval region. Heligmonoides taiwanensis n. sp. from Apodemus draco on Mt. Alishan, Taiwan, is distinguished from other members of the genus in having a markedly asymmetrical bursa and stout bursal rays. Heligmonoides alishanensis n. sp. from Niviventer confucianus on Mt. Alishan differs from the allied forms in lacking hypertrophied ridges at the level of the middle of the spicules and in having longer spicules and a smaller body. Nippostrongylus sp. from N. confucianus on Mt. Alishan resembles Nippostrongylus brasiliensis but is distinguishable in that the externolateral ray is almost the same length as the lateroventral ray in the left lobe, and the fused tips of the spicules are thin and straight. Heligmonoides ryukyensis from Mus caroli and Orientostrongylus tenorai from Bandicota indica are first recorded from Taiwan. Heligmonellid nematodes parasitic in wild rodents in these areas are considered to have been introduced with their hosts from the mainlands of China and Japan through land connections in the Pleistocene.

[Helminths of birds and mammals from Israel. VI. The taxonomy and ecology of Trichostrongylid Nematodes (author's transl)]. / trichostrongyloides

Thirteen species of trichostronglyloid nematodes have so far been recorded from wild birds and mammals in Israel and surrounding territories. Three species were found in birds: Amidostomum fulicae (Rudolphi, 1819) in Fulica atra L., 1758, A. acutum (Lundahl, 1848) in Anas crecca L., 1758 AND Amidostomum sp. in Ceryle rudis L., 1758. Ten species, 3 of which are new, were found in small mammals: Trichostrongylus colubriformis (Giles, 1892) in Hystrix indica Kerr, 1792; Tenorastrongylus josephi n. sp. in Mus musculus L., 1758; Nippostrongylus brasiliensis (Travassos, 1914) in Rattus norvegicus Berk, 1796 and Rattus rattus L., 1758; Nippostrongylus witenbergi Greenberg, 1972, in Nesokia indica Gray et Hardw., 1832; Heligmonina nevoi n. sp. in Spalax ehrenbergi, Nehring, 1898; Boreostrongylus seurati (Travassos et Darriba, 1929) in Gerbillus allenbyi Thomas, 1918, G. pyramidum Geoffrey, 1825, G. (Dipodillus) dasyurus, Meriones sacramenti Thomas, 1922 and M. tristrami Thomas, 1892; Boreostrongylus minutus (Dujardin, 1845) in Microtus guentheri Danford et Alsen, 1880; Heligmosomoides polygyrus polygyrus (Dujardin, 1845) in Apodemus mystacinus Danf. et Alst., 1877 and A. sylvaticus L., 1758; Suncinema witenbergi n. sp. in Crocidura russula Herm., 1780. Ecologic and zoogeographic relationships are discussed.