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Microbiology (Reading, England) Dec 2005Current phylogenies of the intracellular bacteria belonging to the genus Wolbachia identify six major clades (A-F), termed 'supergroups', but the branching order of...
Phylogeny of Wolbachia pipientis based on gltA, groEL and ftsZ gene sequences: clustering of arthropod and nematode symbionts in the F supergroup, and evidence for further diversity in the Wolbachia tree.
Current phylogenies of the intracellular bacteria belonging to the genus Wolbachia identify six major clades (A-F), termed 'supergroups', but the branching order of these supergroups remains unresolved. Supergroups A, B and E include most of the wolbachiae found thus far in arthropods, while supergroups C and D include most of those found in filarial nematodes. Members of supergroup F have been found in arthropods (i.e. termites), and have previously been detected in the nematode Mansonella ozzardi, a causative agent of human filariasis. To resolve the phylogenetic positions of Wolbachia from Mansonella spp., and other novel strains from the flea Ctenocephalides felis and the filarial nematode Dipetalonema gracile, the authors generated new DNA sequences of the Wolbachia genes encoding citrate synthase (gltA), heat-shock protein 60 (groEL), and the cell division protein ftsZ. Phylogenetic analysis confirmed the designation of Wolbachia from Mansonella spp. as a member of the F supergroup. In addition, it was found that divergent lineages from Dip. gracile and Cte. felis lack any clear affiliation with known supergroups, indicating further genetic diversity within the Wolbachia genus. Finally, although the data generated did not permit clear resolution of the root of the global Wolbachia tree, the results suggest that the transfer of Wolbachia spp. from arthropods to nematodes (or vice versa) probably occurred more than once.
Topics: Animals; Bacterial Proteins; Chaperonin 60; Cytoskeletal Proteins; DNA, Bacterial; Filarioidea; Genes, Bacterial; Insecta; Phylogeny; RNA, Ribosomal, 16S; Symbiosis; Wolbachia
PubMed: 16339946
DOI: 10.1099/mic.0.28313-0 -
Infection and Immunity Jun 1986Jirds with prepatent Dipetalonema viteae infections develop an acquired immunity to challenge infections. The objective of the present study was to observe...
Jirds with prepatent Dipetalonema viteae infections develop an acquired immunity to challenge infections. The objective of the present study was to observe parasite-specific and nonspecific cellular and humoral immune responses in immune jirds. Splenic hyperplasia was observed in infected jirds during the first 5 weeks of infection. Antigen-reactive spleen cells were observed in the lymphocyte transformation assay at 3 weeks postinfection. A depressed response to concanavalin A (ConA) was seen at 1 week postinfection through week 5. Mitomycin C-treated cells from infected jirds were capable of suppressing the response of normal cells to ConA. Sephadex G-10-nonadherent spleen cells from infected jirds showed elevated responses to D. viteae antigen at 1, 3, and 5 weeks and elevated responses to ConA at 3 and 5 weeks. Filaria-specific antibodies were seen at 1 week postinfection, and titers rose through week 5. Plaque-forming cell production to sheep erythrocytes was not depressed in infected jirds. It was concluded that jirds react immunologically with both cellular and humoral responses during the prepatent period of D. viteae infection. A concurrent immune depression was seen. Its effect on resistance and tolerance remains to be determined.
Topics: Animals; Antibody Formation; Antigens, Helminth; Dipetalonema; Dipetalonema Infections; Filariasis; Gerbillinae; Immunity, Cellular; Lymphocyte Activation; Male; Spleen; Splenomegaly
PubMed: 3710584
DOI: 10.1128/iai.52.3.742-747.1986 -
Revista Brasileira de Parasitologia... 2018Dipetalonema gracile (Rudolphi, 1809) (Filarioidea: Onchocercidae) is one of six species of cavities filarial parasites of Neotropical non-human primates. The present...
Dipetalonema gracile (Rudolphi, 1809) (Filarioidea: Onchocercidae) is one of six species of cavities filarial parasites of Neotropical non-human primates. The present study recorded the occurrence of D. gracile, provides morphological and morphometric data and extends the geographical distribution. Adult filariae were obtained from the thoracic and abdominal cavities of 38 specimens of woolly monkey, which were used for local human consumption, in the northeastern Peruvian Amazon. Male and female filarids were processed and analysed using light and scanning electron microscopy. Details of the cephalic papillae, post-cloacal bands and papillae, vulva, phasmid position and lateral appendages are showed by scanning electron microscopy and is recorded the occurrencce of Lagothrix poeppigii monkey as a new host of this filaria in the Yavari-Mirin river basin, Peruvian Amazon.
Topics: Animals; Atelinae; Dipetalonema; Female; Male; Microscopy, Electron, Scanning; Peru
PubMed: 29846443
DOI: 10.1590/s1984-296120180014 -
Journal of Immunology (Baltimore, Md. :... Nov 2010APC dysfunction has been postulated to mediate some of the parasite-specific T cell unresponsiveness seen in patent filarial infection. We have shown that live...
APC dysfunction has been postulated to mediate some of the parasite-specific T cell unresponsiveness seen in patent filarial infection. We have shown that live microfilariae of Brugia malayi induce caspase-dependent apoptosis in human monocyte-derived dendritic cells (DCs) in vitro. This study addresses whether apoptosis observed in vitro extends to patent filarial infections in humans and is reflected in the number of circulating myeloid DCs (mDCs; CD11c(-)CD123(lo)) in peripheral blood of infected microfilaremic individuals. Utilizing flow cytometry to identify DC subpopulations (mDCs and plasmacytoid DCs [pDCs]) based on expression of CD11c and CD123, we found a significant increase in numbers of circulating mDCs (CD11c(+)CD123(lo)) in filaria-infected individuals compared with uninfected controls from the same filaria-endemic region of Mali. Total numbers of pDCs, monocytes, and lymphocytes did not differ between the two groups. To investigate potential causes of differences in mDC numbers between the two groups, we assessed chemokine receptor expression on mDCs. Our data indicate that filaria-infected individuals had a lower percentage of circulating CCR1(+) mDCs and a higher percentage of circulating CCR5(+) mDCs and pDCs. Finally, live microfilariae of B. malayi were able to downregulate cell-surface expression of CCR1 on monocyte-derived DCs and diminish their calcium flux in response to stimulation by a CCR1 ligand. These findings suggest that microfilaria are capable of altering mDC migration through downregulation of expression of some chemokine receptors and their signaling functions. These observations have major implications for regulation of immune responses to these long-lived parasites.
Topics: Adult; Animals; Brugia malayi; Cell Separation; Chemotaxis, Leukocyte; Clinical Trials as Topic; Dendritic Cells; Dipetalonema Infections; Female; Filariasis; Flow Cytometry; Humans; Male; Mansonella; Mansonelliasis; Middle Aged; Myeloid Cells; Receptors, CCR1; Reverse Transcriptase Polymerase Chain Reaction; Wuchereria bancrofti
PubMed: 20956349
DOI: 10.4049/jimmunol.1001605 -
Iranian Journal of Parasitology Jan 2013The aim of the study was to determine the helminthic species occurring in great gerbil Rhombomys opimus collected from Maraveh Tappeh, Golestan Province, northeast Iran.
BACKGROUND
The aim of the study was to determine the helminthic species occurring in great gerbil Rhombomys opimus collected from Maraveh Tappeh, Golestan Province, northeast Iran.
METHODS
During 2010-2011, a total of 77 R. opimus were captured from rural areas of Maraveh Tappeh, Golestan Province, using Sherman live traps and examined for infectivity with any larva or adult stages of helminthic parasites.
RESULTS
Overall, 63 R. opimus (81.8%) were found infected with different helminthic species. The rate of infectivity with each species was as follows: Trichuris rhombomidis 31.2%, Trichuris muris 32.5%, Trichuris spp. 10.4%, Syphacia muris 2.6%, Dipetalonema viteae (Acanthocheilonema viteae) 37.7%, Skrjabinotaenia lobata 15.6%, Hymenolepis (=Rodentolepis) nana fraterna 5.2%, and Taenia endothoracicus larva 1.3%.
CONCLUSION
R. opimus is host for several species of cestodes and nematodes in the study area. The high rate of infectivity with D. viteae indicates the susceptibility of these gerbils to this filarial nematode. Synchronous infections occurred up to four species of helminthes in one host.
PubMed: 23682264
DOI: No ID Found -
Parasite (Paris, France) Mar 1998The development of the human filaria Loa loa (Dirofilariinae, Onchocercidae), previously studied in monkeys, was studied using the non permissive hosts-mice and jirds....
The development of the human filaria Loa loa (Dirofilariinae, Onchocercidae), previously studied in monkeys, was studied using the non permissive hosts-mice and jirds. The development proved to be rapid: moult 3 occurred on day 8 post-inoculation, the adult stage was reached on day 25 and measured at that time 3-3.5 mm in length. As in the other filarioids, the female genital apparatus developed during the fourth stage. A critical analysis of the studies on the development of Onchocercid species was made. The optimal duration of the stages (i.g. the shortest time) was chosen for the comparison. It appeared that the duration of the stage 3 was a constant character in a given species whatever the experimental conditions, whereas moult 4 might be retarded in a non susceptible host. Comparison between the 18 developmental cycles of Onchocercidae in the vertebrate host was made. Two biological types could be distinguished: either the moult 3 occurred on day 2-3 and was followed apparently by a late moult 4 (> or = 50 days), or the moult 3 occurred after about one week of development and it was associated with a less long stage 4 (20-40 days). The first group includes Dirofilaria and Onchocerca, the second group brings together mainly Loa and the Onchocercinae of the Dipetalonema line and related genera (Acanthocheilonema, Brugia, Litomosoides, etc.). The groups thus formed suggest real relationships as they fit with the morphology of the infective stage and the results of a recent molecular analysis of the 5S DNA.
Topics: Animals; Disease Models, Animal; Female; Gerbillinae; Humans; Larva; Loa; Loiasis; Male; Mice; Molting; Morphogenesis
PubMed: 9754295
DOI: 10.1051/parasite/1998051037 -
British Journal of Pharmacology Dec 19901. Isotonic contractions were recorded from the filarial nematode, Dipetalonema viteae (Acanthocheilonema viteae), in an isolated tissue chamber. 2. Nicotine (10(-6) M)...
1. Isotonic contractions were recorded from the filarial nematode, Dipetalonema viteae (Acanthocheilonema viteae), in an isolated tissue chamber. 2. Nicotine (10(-6) M) and pilocarpine (10(-5) M) increased the spontaneous contractions in the intact filariid, but acetylcholine (ACh, 10(-4) M) and muscarine (10(-5) M) were inactive. 3. When ACh was applied to an opened D. viteae, it was 10,000 times more potent. This indicates that the cuticle is an effective barrier to the penetration of ACh to the muscle cells. 4. The effects of ACh on the opened D. viteae were not affected by hexamethonium (10(-3) M) or atropine (10(-5) M) and were only partially reduced by (+)-tubocurarine (10(-4) M). 5. gamma-Aminobutyric acid (GABA, 10(-3) M) reduced the spontaneous activity of the intact D. viteae; however, the effect of GABA had a slow onset and recovery. Muscimol (10(-5) M) was more potent than GABA and had a more rapid onset and recovery. 6. GABA was 1,000 times more potent on the opened D. viteae than on the intact D. viteae. Baclofen (10(-3) M) was inactive on both preparations. 7. The effect of GABA was not antagonized by bicuculline (10(-4) M), picrotoxin (10(-5) M or penicillin G (10(-3) M). 8. It is concluded that the filariid cuticle acts like a lipid structure and blocks the penetration of polar substances, such as ACh and GABA. Also, due to the lack of efficacy of the ACh and GABA antagonists, it was concluded that the nematode receptors are somewhat different from the mammalian ACh and GABA receptors.
Topics: Acetylcholine; Action Potentials; Animals; Cholinergic Antagonists; Cricetinae; Dipetalonema; GABA-A Receptor Antagonists; Isotonic Contraction; Muscle Contraction; Muscles; Receptors, Cholinergic; Receptors, GABA-A; gamma-Aminobutyric Acid
PubMed: 1964825
DOI: 10.1111/j.1476-5381.1990.tb14190.x -
Bulletin of the World Health... 1969
[Evaluation of 2 immunological tests (skin test and complement fixation test) for the detection of filariasis in populations of Upper Volta where Wuchereria bancrofti, Onchocercă volvulus and Dipetalonema perstans occur together].
Topics: Antigens; Burkina Faso; Complement Fixation Tests; Dipetalonema; Filariasis; Humans; Onchocerca; Skin Tests; World Health Organization; Wuchereria
PubMed: 5307597
DOI: No ID Found -
Cadernos de Saude Publica 2001A survey on the prevalence of Dirofilaria immitis and Dipetalonema reconditum was conducted in 1,519 dogs from Maceió and two coastal areas in the State of Alagoas,...
A survey on the prevalence of Dirofilaria immitis and Dipetalonema reconditum was conducted in 1,519 dogs from Maceió and two coastal areas in the State of Alagoas, Northeast Brazil, from 1995 to 1999, by testing for microfilariae in blood. All blood samples were from exclusively domiciled dogs with a known history, showing that the infections were autochthonous, confirming transmission of canine filariasis in these areas. In Greater Metropolitan Maceió, 15 (1.3%) microfilaremic dogs were detected with D. immitis and 15 (1,3%) with D. reconditum. In the southern coastal area there was an estimated prevalence of 12.7% for D. immitis. D. immitis and D. reconditum microfilaria were 298.1 micrometer and 249.2 micrometer long and 7.3 micrometer and 4.4 micrometer wide, respectively. A Witness immunotest that detects D. immitis antigen was used to confirm parasitological results and reveal occult dirofilariasis cases. Of the total 6,579 females examined, 8 (0.1%) Culex quinquefasciatus were observed to be naturally infected with D. immitis larvae. These results proved dirofilariasis transmission in Maceió and demonstrated D. reconditum in the same geographic area.
Topics: Animals; Antigens, Helminth; Brazil; Dipetalonema; Dipetalonema Infections; Dirofilaria immitis; Dirofilariasis; Dog Diseases; Dogs; Female; Male; Prevalence
PubMed: 11784911
DOI: 10.1590/s0102-311x2001000600021 -
Infection and Immunity Dec 1999Ov20 is a structurally novel 20-kDa retinol binding protein secreted by Onchocerca volvulus. Immunological and biological investigation of this protein has been hampered... (Comparative Study)
Comparative Study
Ov20 is a structurally novel 20-kDa retinol binding protein secreted by Onchocerca volvulus. Immunological and biological investigation of this protein has been hampered by the inability to maintain O. volvulus in a laboratory setting. In an effort to find a system more amenable to laboratory investigation, we have cloned, sequenced, and expressed cDNA encoding homologues of Ov20 from two closely related filarial species, Brugia malayi (Bm20) and Acanthocheilonema viteae (Av20). Sequence comparisons have highlighted differences in glycosylation of the homologues. We present here an analysis of mouse immune responses to Ov20, Bm20, and Av20. The results suggest a strong genetic restriction in response to native Bm20 that is overcome when recombinant, nonnative material is used. Reactivity of human filarial sera to the three recombinant proteins confirmed previous specificity studies with Ov20 but highlighted important differences in the reactivity patterns of the O. volvulus and B. malayi homologues that may be due to differences in glycosylation patterns. Ov20 is a dominant antigen in infected individuals, while Bm20 is not. The availability of the B. malayi homologue enabled us to use defined murine reagents and inbred strains for genetic analysis of responsiveness in a way that is not possible for Ov20. However, the close sequence similarity between Ov20 and Av20 suggests that the A. viteae model may be more suited to the investigation of the biological functions of Ov20.
Topics: Amino Acid Sequence; Animals; Antibodies, Helminth; Antigens, Helminth; Brugia malayi; Cloning, Molecular; Dipetalonema; Filariasis; Glycosylation; Helminth Proteins; Humans; Immunization; Mice; Mice, Inbred Strains; Molecular Sequence Data; Onchocerca volvulus; Onchocerciasis; Recombinant Proteins; Retinol-Binding Proteins; Sequence Homology, Amino Acid; Wuchereria bancrofti
PubMed: 10569745
DOI: 10.1128/IAI.67.12.6329-6334.1999