Both asymmetric mitotic segregation and cell-to-cell invasion are required for stable germline transmission of Wolbachia in filarial nematodes.

Parasitic filarial nematodes that belong to the Onchocercidae family live in mutualism with Wolbachia endosymbionts. We developed whole-mount techniques to follow the segregation patterns of Wolbachia through the somatic and germline lineages of four filarial species. These studies reveal multiple evolutionarily conserved mechanisms that are required for Wolbachia localization to the germline. During the initial embryonic divisions, Wolbachia segregate asymmetrically such that they concentrate in the posteriorly localized P(2) blastomere, a precursor to the adult germline and hypodermal lineages. Surprisingly, in the next division they are excluded from the germline precursor lineage. Rather, they preferentially segregate to the C blastomere, a source of posterior hypodermal cells. Localization to the germline is accomplished by a distinct mechanism in which Wolbachia invade first the somatic gonadal cells close to the ovarian distal tip cell, the nematode stem cell niche, from the hypodermis. This tropism is associated with a cortical F-actin disruption, suggesting an active engulfment. Significantly, germline invasion occurs only in females, explaining the lack of Wolbachia in the male germline. Once in the syncytial environment of the ovaries, Wolbachia rely on the rachis to multiply and disperse into the germ cells. The utilization of cell-to-cell invasion for germline colonization may indicate an ancestral mode of horizontal transfer that preceded the acquisition of the mutualism

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

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

Whence river blindness? The domestication of mammals and host-parasite co-evolution in the nematode genus Onchocerca

The genus Onchocerca includes 34 described species and represents one of the largest genera of the filarial nematodes within the family Onchocercidae. Representative members of this genus are mainly parasites of ungulates, with some exceptions such as Onchocerca lupi and Onchocerca volvulus, infecting carnivores and/or humans. For a long time, the evolutionary relationships amongst onchocercids remained poorly studied, as the systematics of this genus was impaired by the high morphological variability of species included in the taxon. Although some molecular phylogenies were developed, these studies were mainly focused on bovine Onchocerca spp. and O. volvulus, including assessments of Wolbachia endosymbionts. In the present study, we analysed 13 Onchocerca spp. from a larger host spectrum using a panel of seven different genes. Analysis of the coxI marker supports its usefulness for the identification of species within the genus. The evolutionary history of the genus has been herein revised by multi-gene phylogenies, presenting three strongly supported clades of Onchocerca spp. Analyses of co-evolutionary scenarios between Onchocerca and their vertebrate hosts underline the effect of domestication on Onchocerca speciation. Our study indicates that a host switch event occurred between Bovidae, Canidae and humans. Cophylogenetic analyses between Onchocerca and the endosymbiotic bacterium Wolbachia indicate the strongest co-evolutionary pattern ever registered within the filarial nematodes. Finally, this dataset indicates that the clade composed by O. lupi, Onchocerca gutturosa, Onchocerca lienalis, Onchocerca ochengi and O. volvulus derived from recent speciation

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

マレーシアの看護教育：看護課程の発展と特徴

　近年，マレーシアの看護教育において，大学のカリキュラム構成に大きな変化が起きている．マレーシアにおける看護教育の進捗状況を研究するために，われわれは，高等教育省看護教育タスクフォースから出版されている「2020 年に向けたマレーシアの看護教育の発展」という論文を用いた．さらに，マラヤ大学看護学科の学士および修士課程のカリキュラムを分析した．2010 年では，看護師の大部分は単科大学や大学の3 年制の教育課程を受けたデイプロマ卒業生であった．看護実践の質を向上させるために，高等教育省は看護教育をデイプロマ課程から大学4 年制の学士課程に移行すべきことを提唱した．2020 年には，高等教育省は看護学士号を有する看護師の多くが臨床で働くことを目指した．高等教育省は専門看護師，看護師長，および看護管理者などの地位は修士課程を修了した看護師に提供されるべきであると提言している．マラヤ大学の看護学科において，学士課程および修士課程の看護教育が急速な進歩を見せていることが分かった．学士課程では，根拠のある看護を実践できる看護師を養成することが目的である．また，マラヤ大学の学部カリキュラムでは，イスラムおよびアジア文明論，民族関係論，および起業家精神文化論などの科目を含んでおり，それらはマレーシアの多民族社会を反映している．修士課程では，看護学研究が主要な構成要素である．また，大学院は看護の分野に関係する研究を行った院生に博士号（Ph.D）を授与している．問題解決型学習，学生中心の教育，根拠のある実践などはマレーシアの看護教育における核心的な論題である．また，看護の専門職性および自律性はマレーシアにおける専門的な看護実践のために大切な論点である

\u3ci\u3eEimeria\u3c/i\u3e Species from Serows (\u3ci\u3eCapricornis\u3c/i\u3e spp.) in Japan with Descriptions of Two New Species

Fresh fecal samples from 35 Japanese serows Capricornis crispus (Temminck, 1845), and 5 Formosan serows Capricornis swinhoei Gray, 1862, were collected between October 1998 and March 1999. Eimeriid coccidians were found in 12 (34%) Japanese serows and in 1 (20%) Formosan serow. Three Eimeria species were found, and 2 are described here as new. The third species is consistent with the description of Eimeria kamoshika Inoue, 1989. Sporulated oocysts of 1 new species are broadly ellipsoidal, 20.7 × 16.8 μm (18–23 × 14–19 μm) with a length (L):width (W) ratio of 1.2 (1.1–1.4); these lack a micropyle (M) and oocyst residuum (OR) but 1–2 polar granules (PGs) are sometimes present. Sporocysts are elongate-ellipsoidal, 10.5 × 5.9 μm (9–13 × 5–7 μm), with a L/W ratio of 1.8 (1.5–2.4), and have a Stieda body (SB) and sporocyst residuum (SR). Oocysts of the second new species are broadly ovoidal, 28.2 × 22.0 μm (25–33 × 19–23 μm), with a L/W of 1.3 (1.1–1.5), and have a M at the slightly pointed end, but lack an OR and PG. Sporocysts are ellipsoidal, 12.9 × 8.1 μm (11–15 × 7–10), with a L/W of 1.6 (1.3–1.9), and have a SB and SR

A combined human case of Dirofilaria ursi infection in dorsal subcutaneous tissue and Anisakis simplex sensu stricto (s.s.) infection in ventral subcutaneous tissue

Abstract Background Dirofilaria ursi is a filarial nematode that parasitizes the subcutaneous tissues of the American black bear (Ursus americanus) and Japanese black bear (Ursus thiabetanus japonicus). D. ursi that has parasitized black bears has the potential to subsequently infect humans. In addition, extra-gastrointestinal anisakiasis is less common in Japan. Case presentation We report a case of ventral subcutaneous anisakiasis and dorsal subcutaneous dirofilariasis that was acquired in Fukushima, in the northern part of Japan. The patient was an 83-year-old Japanese female, and subcutaneous parasitic granulomas were present on her left abdomen (near the navel) and left scapula. A pathological examination of the surgically dissected tissue sections from each region demonstrated eosinophilic granulomas containing different species of parasites. To enable the morphological and molecular identification of these parasites, DNA was extracted from paraffin-embedded sections using DEXPAT reagent, and the cytochrome oxidase 2 (COX2), internal transcribed spacer 1 (ITS1), 5.8S and ITS2 regions of the Anisakis larvae, and the 5S rRNA region of the male Dirofilaria were sequenced. The PCR products were examined and compared with DNA databases. Molecular analysis of the COX2 and 5S rRNA sequences of each worm revealed that the nematode found in the ventral region belonged to Anisakis simplex sensu stricto (s.s.) and the male Dirofilaria found in the dorsal region was classified as D. ursi. Conclusion The present case showed a combined human case of D. ursi and A. simplex s.s. infections in subcutaneous tissues. The results of this study will contribute to the identification of unknown parasites in histological sections