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Veterinary Parasitology Aug 2004The present study determined the prevalence and geographical distribution of Dirofilaria immitis and other filariae, from dogs in littoral areas of Paraná state, in...
The present study determined the prevalence and geographical distribution of Dirofilaria immitis and other filariae, from dogs in littoral areas of Paraná state, in Brazil. This survey spanned eight months, between 1998 and 1999, and was also designed to compare the efficacy of different tests for diagnosis of heartworm infection in that area. Blood samples were collected from 256 native-owned dogs distributed along the Paraná coastal area. Five diagnostic procedures were used: direct smear examination, the Knott's modified test, filtration assay, and two heartworm antigen detection kits. A follow-up imaging exam was performed to support the heartworm diagnosis. The imaging diagnosis included radiographic and ultrasonographic exams of six dogs that had positive results for the heartworm antigen detection kits, but showed different microfilarial burdens. The presence and severity of radiographic and ultrasonographic signs were compared with the results obtained in microfilariae detection and antigen tests. Diagnostic parasitology results indicated that 31.25% of the dogs were microfilaremic. Three different microfilariae were recovered: D. immitis, Dipetalonema reconditum, and the third (mf3) was not identified. D. reconditum was the species with the highest prevalence: 22.6%. In general, D. immitis prevalence was 5.47% (28.57% occult infections), but it varied along the coast and the range was from 0 to 20%. No correlation could be established between the overall scores for microfilarial counts (small or large numbers) and the severity of radiographic results or the likelihood of detecting filariae in the pulmonary artery using echocardiography. The finding of a different type of microfilaria (mf) suggested the existence of a third species in Paraná state, whose prevalence was 4.68%. These results show that to obtain a reliable diagnosis of heartworm infection, antigen detection kits are indicated. Knott's test or filtration should be performed to confirm microfilaremia and not for diagnosis of heartworm infection. Imaging tests support parasitology exams and add more about severity of infection. The northern areas, specially Guaraqueçaba and Ilha das Peças, presented the highest number of heartworm-infected dogs.
Topics: Animals; Antigens, Helminth; Brazil; Dipetalonema; Dipetalonema Infections; Dirofilaria; Dirofilaria immitis; Dirofilariasis; Dog Diseases; Dogs; Female; Male; Prevalence; Radiography; Seroepidemiologic Studies; Ultrasonography
PubMed: 15262005
DOI: 10.1016/j.vetpar.2004.05.017 -
Parasitology Research Aug 2004The antifilarial activity of the marine red alga Botryocladia leptopoda against rodent and human lymphatic filarial parasites is described. The animal filarial species...
The antifilarial activity of the marine red alga Botryocladia leptopoda against rodent and human lymphatic filarial parasites is described. The animal filarial species included Litomosoides sigmodontis and Acanthocheilonema viteae maintained in cotton rats and Mastomys coucha, respectively, while a subperiodic strain of the human lymphatic filarial parasite Brugia malayi was maintained in M. coucha. The crude extract and its hexane fraction brought about a marked reduction in the peripheral microfilarial level in both of the rodent filarial parasites L. sigmodontis and A. viteae. The microfilaricidal effect began slowly from day 8 or 15 after initiation of treatment and increased with time with a very high efficacy at the end of the observation period against both rodent filariids. The microfilaricidal efficacy was, however, not as prominent in the case of B. malayi. The antifilarial activity, which occurred in the hexane fraction, exerted action at a much lower dose. The product killed a significant proportion of A. viteae and L. sigmodontis adult parasites. In the case of B. malayi, although the macrofilaricidal efficacy was much less than that of the rodent parasites, it (hexane fraction) caused sterilization of a significant proportion of the surviving female parasites. The present findings indicate the possibility of developing an adulticidal and female sterilizing agent against filarial parasites from a marine red alga.
Topics: Animals; Brugia malayi; Dipetalonema; Elephantiasis, Filarial; Female; Filaricides; Filarioidea; Humans; In Vitro Techniques; Male; Microfilariae; Muridae; Rhodophyta; Sigmodontinae
PubMed: 15243801
DOI: 10.1007/s00436-004-1159-8 -
The Veterinary Record Jun 2004
Topics: Animals; Dermatitis; Dipetalonema; Dipetalonema Infections; Dog Diseases; Dogs; Female; Male; Prevalence; Spain
PubMed: 15214517
DOI: 10.1136/vr.154.23.726 -
Parasitology Jun 2003Intracellular bacteria of the genus Wolbachia are found in most filarial nematodes, but are lacking in some species like Acanthocheilonema viteae. Due to their symbiotic...
Intracellular bacteria of the genus Wolbachia are found in most filarial nematodes, but are lacking in some species like Acanthocheilonema viteae. Due to their symbiotic nature and their role in the pathology of filarial infections they are considered to be potential targets for intervention against filarial infections in man. Infection of A. viteae (a species which does not naturally carry Wolbachia) with Wolbachia bacteria could allow comparative studies on the effect of the endobacterium on the parasite and on the host's immune systems. As a step towards such studies we microinjected adult female A. viteae with Wolbachia obtained from Litomosoides sigmodontis. The bacteria were isolated from L. sigmodontis by density-gradient centrifugation, microinjected into A. viteae worms and bacterial DNA detected by PCR with Wolbachia specific primers (ftsZ gene). Microinjected worms were cultured in vitro, and 81% survived for 10 days. Implantation of microinjected worms into Meriones unguiculatus, the rodent host of A. viteae resulted in 38% survival. The DNA of the microinjected worms recovered from jirds 8 weeks after implantation contained Wolbachia DNA as shown by PCR, suggesting that Wolbachia of L. sigmodontis can be horizontally transmitted to A. viteae.
Topics: Animals; DNA, Bacterial; DNA, Helminth; Dipetalonema; Filarioidea; Gerbillinae; Microinjections; Ornithodoros; Polymerase Chain Reaction; Symbiosis; Wolbachia
PubMed: 12866789
DOI: No ID Found -
Parasite (Paris, France) Jun 2003
Topics: Animals; Dipetalonema; Dipetalonema Infections; Dog Diseases; Dogs; Female; Italy; Male
PubMed: 12847930
DOI: No ID Found -
Parasite Immunology Jan 2003Filarial infections are characterized by high IgE antibody responses. So far, it is not clear whether IgE antibodies are involved in protection, pathology or both. We...
Filarial infections are characterized by high IgE antibody responses. So far, it is not clear whether IgE antibodies are involved in protection, pathology or both. We established a bioassay to detect reactive IgE antibodies in jirds infected with the filaria Acanthocheilonema viteae. Sera of A. viteae-infected jirds were used to sensitize rat basophil leukaemia (RBL) cells and degranulation was stimulated by addition of antigens of A. viteae. Reactive IgE responses were detected from 2 weeks post infection (p.i.) and throughout the A. viteae infection. Male antigen triggered the strongest mediator release, followed by female worms, infective larvae (L3) and microfilariae. Separation of male and female antigen indicated that several antigens of both genders are potent allergens. In particular, one male specific allergen of about 550 kDa induced strongest degranulation of RBL cells. In addition, mediator release stimulated by antigen fractions of about 15 kDa was due to filarial cystatin. In conclusion, we describe a convenient in vitro assay to examine IgE mediated responses in jirds. A sex specific filarial protein with high allergenic potential is identified and cystatin is established as a potent allergen of A. viteae.
Topics: Allergens; Animals; Antibodies, Helminth; Antigens, Helminth; Biological Assay; Cells, Cultured; Chromatography, High Pressure Liquid; Cystatins; Dipetalonema; Dipetalonema Infections; Female; Filariasis; Gerbillinae; Immunoglobulin E; Male; Rats
PubMed: 12753433
DOI: 10.1046/j.1365-3024.2003.00496.x -
Wiener Klinische Wochenschrift Feb 2003Host-seeking ixodid ticks were sampled in a floodplain forest ecosystem along the lower reaches of the Thaya (Dyje) river in South Moravia (Czech Republic) and Lower... (Comparative Study)
Comparative Study
Host-seeking ixodid ticks were sampled in a floodplain forest ecosystem along the lower reaches of the Thaya (Dyje) river in South Moravia (Czech Republic) and Lower Austria during the period 1989-2002. The ticks were examined by dark-field microscopy for borreliae (Borrelia burgdorferi sensu lato, the agent of Lyme borreliosis), and attempts were made to culture the spirochetes in BSK-H medium from preparations containing their high numbers. Isolated borreliae were identified by PCR-RFLP analysis using probes directed against ribosomal spacer genes. A total of 797 nymphal and 719 adult (391 female, 328 male) Ixodes ricinus were examined: 16.2% of nymphs, 28.6% of females and 29.0% of males were positive. Dermacentor reticulatus (70 females, 30 males) and Haemaphysalis concinna (12 nymphs, 8 females, 2 males) were negative for spirochetes. The overall prevalence rate of borreliae in I. ricinus from the floodplain forest is slightly higher than the mean European data (i.e., 14% for nymphs, 21% for adults). The difference in infection rate between nymphal and adult ticks was significant, including the proportion of heavily infected (with > 100 borreliae) nymphs (2.1%) vs. adults (7.6%). Prevalence of borreliae in I. ricinus showed a significant decrease during autumn in this ecosystem. Three strains of spirochetes, all of the Borrelia afzelii genomic group, were isolated from female I. ricinus. Moreover, Trypanosoma/Crithidia sp. protozoa and Dipetalonema rugosicauda nematodes were detected in 0.4% and 1.0%, respectively, of all I. ricinus.
Topics: Animals; Austria; Borrelia; Borrelia burgdorferi; Czech Republic; Ecosystem; Female; Genes, Bacterial; Ixodes; Lyme Disease; Male; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length; Trees
PubMed: 12674689
DOI: 10.1007/BF03040291 -
Biophysical Journal Jan 2003ES-62, a protein secreted by filarial nematodes, parasites of vertebrates including humans, has an unusual posttranslational covalent addition of phosphorylcholine to an... (Comparative Study)
Comparative Study
ES-62, a protein secreted by filarial nematodes, parasites of vertebrates including humans, has an unusual posttranslational covalent addition of phosphorylcholine to an N-type glycan. Studies on ES-62 from the rodent parasite Acanthocheilonema viteae ascribe it a dominant role in ensuring parasite survival by modulating the host immune system. Understanding this immunomodulation at the molecular level awaits full elucidation but distinct components of ES-62 may participate: the protein contributes aminopeptidase-like activity whereas the phosphorylcholine is thought to act as a signal transducer. We have used biophysical and bioinformatics-based structure prediction methods to define a low-resolution model of ES-62. Sedimentation equilibrium showed that ES-62 is a tightly bound tetramer. The sedimentation coefficient is consistent with this oligomer and the overall molecular shape revealed by small angle x-ray scattering. A 19 A model for ES-62 was restored from the small-angle x-ray scattering data using the program DAMMIN which uses simulated annealing to find a configuration of densely packed scattering elements consistent with the experimental scattering curve. Analysis of the primary sequence with the position-specific iterated basic local alignment search tool, PSI-BLAST, identified six closely homologous proteins, five of which are peptidases, consistent with observed aminopeptidase activity in ES-62. Differences between the secondary structure content of ES-62 predicted using the consensus output from the secondary structure prediction server JPRED and measured using circular dichroism are discussed in relation to multimeric glycosylated proteins. This study represents the first attempt to understand the multifunctional properties of this important parasite-derived molecule by studying its structure.
Topics: Amino Acid Sequence; Animals; Circular Dichroism; Dipetalonema; Helminth Proteins; Models, Molecular; Molecular Sequence Data; Protein Conformation; Protein Structure, Quaternary; Protein Structure, Secondary; Protein Structure, Tertiary; Sequence Alignment; Sequence Analysis, Protein; Sequence Homology, Amino Acid; Solutions
PubMed: 12524301
DOI: 10.1016/S0006-3495(03)74868-1 -
Veterinary Parasitology Jun 2002Both Dirofilaria immiti and Dipetalonema reconditum may be found in blood of infected dogs but it is not easy to distinguish D. immitis from D. reconditum in morphology....
Specific polymerase chain reaction for differential diagnosis of Dirofilaria immitis and Dipetalonema reconditum using primers derived from internal transcribed spacer region 2 (ITS2).
Both Dirofilaria immiti and Dipetalonema reconditum may be found in blood of infected dogs but it is not easy to distinguish D. immitis from D. reconditum in morphology. We cloned and sequenced the contiguous internal transcribed spacer (ITS) region, ITS1-5.8S-ITS2, of these two different parasites and published on GenBank as AF217800 for D. immiti and AF217801 for D. reconditum in this study. We designed two pairs of specific primers derived from ITS2 being used for polymerase chain reaction (PCR). The amplicons of ITS2 from D. immiti and D. reconditum are 302 and 348bp, respectively. Moreover, the limitation for amplifying ITS2 gene using this PCR demonstrated that 1 x 10(-2) microfilaria of each species of parasite smashed or even with mixed samples could be detected and the PCR products were predicted as the same as that described above. Thus, D. immiti and D. reconditum could be differentially diagnosed by this specific PCR. Seventeen clinical cases were evaluated and all of them were correctly identified. In this study, ITS1-5.8S-ITS2 of D. immiti or D. reconditum were the first time sequenced and analyzed. No significant similarity of ITS1 and ITS2 between D. immiti and D. reconditum could be observed.
Topics: Amino Acid Sequence; Animals; Base Sequence; Cloning, Molecular; DNA, Helminth; DNA, Ribosomal Spacer; Diagnosis, Differential; Dipetalonema; Dipetalonema Infections; Dirofilaria immitis; Dirofilariasis; Dog Diseases; Dogs; Molecular Sequence Data; Polymerase Chain Reaction; Sequence Alignment
PubMed: 12062512
DOI: 10.1016/s0304-4017(02)00032-8 -
The Journal of Parasitology Apr 2002Jirds (Meriones unguiculatus) were vaccinated with irradiated L3 third-stage larvae (L3) of Acanthocheilonema viteae, and the time required for killing of the challenge...
Jirds (Meriones unguiculatus) were vaccinated with irradiated L3 third-stage larvae (L3) of Acanthocheilonema viteae, and the time required for killing of the challenge L3 was determined. The number of parasites recovered from vaccinated jirds was reduced to about 10% of the control values on the second day after challenge infection and later on. Histological studies revealed an eosinophil-rich infiltrate containing macrophages, neutrophils, and mast cells in the vicinity of the L3 on day 2 after challenge and destruction of the worms by day 4 after challenge. Ultrastructural studies confirmed these data and showed that eosinophils, macrophages, and mast cells were close to the L3 on day 2 after challenge. Flattening of the eosinophils onto the surface of the worms, degranulation of electron-dense material, and rupture of the L3 surface was observed on day 4 after challenge, followed by invasion of the inner of the worms by phagocytic cells. These data show that immune attack against the challenge L3 in vaccinated jirds is initiated between the first and the second day after challenge and that killing occurs around the fourth day after challenge, before the worms undergo their first molt.
Topics: Animals; Dipetalonema; Dipetalonema Infections; Gerbillinae; Histocytochemistry; Immunization; Larva; Microscopy, Electron, Scanning Transmission; Skin
PubMed: 12053996
DOI: 10.1645/0022-3395(2002)088[0264:PIIBIT]2.0.CO;2