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P Deplazes

Publications and source records attributed to P Deplazes.

At least 73 records · Page 4Linked to original sources
PubMed1999

Detection of new Enterocytozoon genotypes in faecal samples of farm dogs and a cat.

The microsporidian species Enterocytozoon bieneusi had emerged as opportunistic pathogen in AIDS patients causing chronic diarrhoea and was found with high prevalences in faeces of asymptomatic pigs. Analysis of the ribosomal RNA gene internal transcribed spacer (rDNA ITS) had revealed that nine distinct but closely related genotypes occur in humans and in swine. Using primers that were designed to be specific for E. bieneusi, we obtained amplicons from the faecal samples of one from twelve cats and from three out of 36 farm dogs. Sequence analysis of the rDNA ITS, which is part of the diagnostic PCR product, revealed that the isolate from the cat is very closely related to the E. bieneusi genotypes of human or swine origin. The corresponding sequence of all three dog-derived isolates were identical among each other and had a sequence similarity to known sequences of only 47.6-48.2%. In addition, part of the small subunit rRNA gene was amplified and sequenced from one dog-derived isolate revealing a similarity to known sequences of human-derived E. bieneusi of 96-98%. Enterocytozoon-like spores could be detected by light microscopy in one canine sample. Together with recent reports of detection of Enterocytozoon in environmental samples, our findings suggest that microsporidia of the genus. Enterocytozoon seem to be ubiquitous and consist of many genotypes in various naturally infected animal species.

AIDS-Related Opportunistic Infections↗
PubMed1999

Development of a protective immunity against Ostertagia leptospicularis in trickle-infected sheep and parallel changes of serum gastrin, pepsinogen and antibody levels.

Nine lambs, approximately 9 months of age were allocated to three groups (A, B, C), with three animals in each. Sheep in Groups A and B were trickle-infected with doses of 1000 third-stage larvae (L3) of Ostertagia leptospicularis (five times per week) over periods of 7.5 and 10.5 weeks, respectively, and were subsequently treated with fenbendazole (7.5 mg/kg). Approximately 3 weeks after anthelmintic treatment, all sheep were challenged with a single dose of 100,000 L3, whereas sheep of Group C received the same dose as a primary infection. Sheep of Groups A and B were almost completely refractory against the challenge infection, as indicated by negative faecal egg counts and adult worm burdens. A relatively high infection level was present in the sheep of Group C. The results indicate that a comparatively short immunization period of 7.5 weeks is sufficient to protect lambs against subsequent larval challenge. During immunization, the pepsinogen-, gastrin- and IgA-responses were similar in the individual sheep. In contrast to parasite-specific IgG1 and IgG2 levels, IgA decreased rapidly after cessation of trickle infection and parallel anthelmintic treatment, and may therefore indicate current exposure to parasite antigen. After challenge, the majority of the immunized sheep exhibited immediate and short-term responses of pepsinogen, gastrin and IgA in the serum. The time course and the level of each of these responses were very similar in the individual sheep, suggesting that the release of pepsinogen, gastrin and IgA into the circulation was influenced by related mechanisms.

Animals↗
PubMed1999

Inter- and intra-species karyotype variations among microsporidia of the genus Encephalitozoon as determined by pulsed-field gel electrophoresis.

Disseminated infections due to microsporidia of the genus Encephalitozoon are detected increasingly, especially in patients with AIDS. Identification of microsporidia can be achieved by a variety of immunological and molecular methods. This study evaluates the feasibility of pulsed-field gel electrophoresis (PFGE) for the analysis of karyotypes of the 3 known species of this genus (Encephalitozoon cuniculi, Encephalitozoon hellem and Encephalitozoon intestinalis) and of 2 of the 3 known E. cuniculi strains (strains I and III). Eleven chromosomal DNA bands were resolved for E. cuniculi and 10 chromosomal DNA bands for E. hellem and E. intestinalis, with molecular sizes ranging from 231 to 320 kb, from 197 to 288 kb and from 195 to 285 kb, respectively, resulting in estimated genome sizes of about 3.0 Mb, 2.5 Mb and 2.4 Mb. Different PFGE chromosomal banding patterns indicate that not only E. cuniculi, as previously described, but also E. hellem, represent a heterogeneous entity. PFGE is a valuable method of evaluating inter- and intra-species variations among Encephalitozoon species that may enable the identification of environmental sources of infection and modes of transmission.

Animals↗
PubMed1999

Serological evidence of infection with Ehrlichia spp. in red foxes (Vulpes vulpes) in Switzerland.

Serum samples from 1,550 red foxes in Switzerland were tested for antibodies to the agents of canine granulocytic and monocytic ehrlichiosis by an indirect immunofluorescent technique. Forty-four (2.8%) of the samples were positive for Ehrlichia phagocytophila, which is an antigen marker for granulocytic ehrlichiosis. In contrast, none of the samples had antibodies specific to Ehrlichia canis, the agent of monocytic ehrlichiosis.

Animals↗
PubMed1999

Echinococcus multilocularis coproantigen detection by enzyme-linked immunosorbent assay in fox, dog, and cat populations.

A sandwich enzyme-linked immunosorbent assay (ELISA) for the detection of Echinococcus multilocularis coproantigens (EM-ELISA) was developed with polyclonal rabbit (solid phase) and chicken egg (catching) antibodies that were directed against E. multilocularis coproantigens and somatic worm antigens, respectively. In experimentally infected dogs and cats, coproantigens were first detectable 6-17 days postinfection (PI) in samples of 8 dogs (worm burdens at necropsy: 6,330-43,200) and from 11 days PI onward in samples of 5 cats infected with 20-6,833 worms. After anthelmintic treatment of 4 dogs and 5 cats at day 20 PI, coproantigen excretion disappeared within 3-5 days. The sensitivity of the ELISA was 83.6% in 55 foxes infected with 4-60,000 E. multilocularis, but reached 93.3% in the 45 foxes harboring more than 20 worms. The EM-ELISA was used in surveys of "normal" dog and cat populations in Switzerland. Among 660 dogs and 263 cats, 5 dogs and 2 cats exhibited a positive reaction. In 2 of these dogs (0.30%) and 1 cat (0.38%), intestinal E. multilocularis infections were confirmed by necropsy, polymerase chain reaction PCR, or both. The specificites of the ELISA in these groups were found to be 99.5% and 99.6%, respectively, if positive ELISA results that could not be confirmed by other methods were classified as "false positive" reactions.

Animals↗
PubMed1999

Phylogenetic analysis of Cryptosporidium isolates from captive reptiles using 18S rDNA sequence data and random amplified polymorphic DNA analysis.

Sequence alignment of a polymerase chain reaction-amplified 713-base pair region of the Cryptosporidium 18S rDNA gene was carried out on 15 captive reptile isolates from different geographic locations and compared to both Cryptosporidium parvum and Cryptosporidium muris isolates. Random amplified polymorphic DNA (RAPD) analysis was also performed on a smaller number of these samples. The data generated by both techniques were significantly correlated (P < 0.002), providing additional evidence to support the clonal population structure hypothesis for Cryptosporidium. Phylogenetic analysis of both 18S sequence information and RAPD analysis grouped the majority of reptile isolates together into 1 main group attributed to Cryptosporidium serpentis, which was genetically distinct but closely related to C. muris. A second genotype exhibited by 1 reptile isolate (S6) appeared to be intermediate between C. serpentis and C. muris but grouped most closely with C. muris, as it exhibited 99.15% similarity with C. muris and only 97.13% similarity with C. serpentis. The third genotype identified in 2 reptile isolates was a previously characterized 'mouse' genotype that grouped closely with bovine and human C. parvum isolates.

Animals↗
PubMed1999

Phylogenetic relationships among isolates of Cryptosporidium: evidence for several new species.

Isolates of Cryptosporidium were characterized using nucleotide sequence analysis of the 18S rRNA and dihydrofolate reductase genes and also random-amplified polymorphic DNA analysis. Phylogenetic analysis confirmed the validity of the species of Cryptosporidium examined in this study such as Cryptospordium muris and Cryptosporidium baileyi, and also reinforced evidence from numerous researchers worldwide suggesting that Cryptosporidium parvum is not a single uniform species. The data obtained provided strong support for the validity of Cryptosporidium felis. Evidence suggests that the newly identified marsupial and pig genotypes may also be distinct and valid species, but biological studies are required for confirmation.

Animals↗
PubMed1998

Canine leishmaniosis in Cyprus due to Leishmania infantum MON 1.

During a serological survey in 1996, a total of 601 dogs (group I) distributed all over the government controlled southern area of Cyprus was examined using an enzyme-linked immunosorbent assay (ELISA) for the presence of specific antibodies directed against soluble antigens of promastigote stages of Leishmania infantum. The overall seroprevalence rate in this group was 1.7%. A second group (group II) of dogs was selected from regions where seropositive dogs where determined within the first group. In group II specific anti-Leishmania antibodies could be detected in 30 of 301 dogs investigated (10%). The highest seroprevalence rates were found in the regions of Agios Georgios (26.2%) and Limnatis (12.2%). Ten parasite isolates from ten dogs (six with typical symptoms of canine leishmaniosis and four without symptoms) originating from five locations could be characterised by zymodeme analysis. All ten isolates were identified as L. infantum zymodeme MON 1.

Animals↗
PubMed1998

Molecular characterization of Cryptosporidium from various hosts.

A 298 bp region of the Cryptosporidium parvum 18S rDNA and a 390 bp region of the acetyl-CoA synthetase gene were sequenced for a range of human and animal isolates of Cryptosporidium from different geographical areas. A distinct genotype is common to isolates from cattle, sheep and goats and also an alpaca from Peru and is referred to here as the 'calf'-derived Cryptosporidium genotype. Another genotype of 'human'-derived isolates also appears to be conserved amongst human isolates although humans are also susceptible to infection with the 'calf' Cryptosporidium genotype. Mice and pigs carry genetically distinct genotypes of Cryptosporidium. Three snake isolates were also analysed, 2 of which exhibited C. muris genotypes and the third snake isolate carried a distinct 'mouse' genotype.

Acetate-CoA Ligase↗
PubMed1998

Dual microsporidial infection due to Vittaforma corneae and Encephalitozoon hellem in a patient with AIDS.

A 46-year-old human immunodeficiency virus-infected Swiss citizen living in Tanzania presented with respiratory, abdominal, and urogenital complaints. Microsporidial spores were isolated from urine and a sinunasal aspirate and were propagated in MRC-5 cell cultures. Western blot analysis and riboprinting identified the sinunasal isolate as Encephalitozoon hellem. Electron microscopic investigation of the urine isolate revealed spores with diplokaryotic nuclei and five to six isofilar coils of the polar tube and sporonts with two or three diplokarya. All stages were enveloped by two membranes, corresponding to a cisterna of host endoplasmic reticulum studded with ribosomes. These characteristics have been described for the genus Vittaforma. Western blot analysis of this isolate revealed a banding pattern identical to that of the Vittaforma corneae reference isolate. Part of the small subunit rRNA gene was amplified, sequenced (239 base pairs), and found to be identical to that of V. corneae. This is the second isolation of V. corneae and the first description of urinary tract infection due to V. corneae in a patient with AIDS.

AIDS-Related Opportunistic Infections↗
PubMed1998

Seroprevalence of Ehrlichia canis and of canine granulocytic Ehrlichia infection in dogs in Switzerland.

Serum samples from 996 dogs in Switzerland were examined for antibodies to Ehrlichia canis and to the agent causing canine granulocytic ehrlichiosis (CGE). Ehrlichiosis, borreliosis, and systemic illness not associated with ticks were suspected in 75, 122, and 157 of these dogs, respectively. The remainder of the serum samples were obtained from clinically healthy dogs which resided north (n = 235) or south (n = 407) of the Alps. The serum samples were tested by an indirect immunofluorescence technique for antibodies to the two agents incriminated, E. canis and Ehrlichia phagocytophila, a surrogate marker of the agent of CGE. Twenty-two of 996 (2.2%) serum samples had antibodies to E. canis and were distributed as follows: 20 of 75 (26.7%) samples from dogs suspected of having ehrlichiosis, 1 of 122 (0.8%) from dogs suspected of having borreliosis, and 1 of 407 (0.2%) from healthy dogs which resided south of the Alps. Of the 75 (7.5%) serum samples that had antibodies to E. phagocytophila, significantly more samples were from ill dogs than from healthy dogs. Among the sera from healthy dogs, antibodies to E. phagocytophila were significantly more prevalent in the north. Because seropositive dogs had a history of travel outside Switzerland and because Rhipicephalus sanguineus is found exclusively south of the Alps, it was presumed that, in contrast to the agent of CGE, E. canis is not indigenous to Switzerland.

Animals↗
PubMed1998

Blinded, externally controlled multicenter evaluation of light microscopy and PCR for detection of microsporidia in stool specimens. The Diagnostic Multicenter Study Group on Microsporidia.

The quality parameters for the detection of microsporidia in identical sets of 50 stool samples were determined for six laboratories where technicians used light microscopy and for six laboratories where technicians used PCR. The average overall sensitivities were 67% (89% for patient samples only) for the PCR laboratories and 54% (80% for patient samples only) for the light microscopy laboratories. Specificities were 98 and 95%, respectively. Differences in results were most apparent between the individual laboratories rather than between the two major methods used.

Animals↗
PubMed1998

[Is dirofilariasis in dogs spreading in south Switzerland?].

Microfilarial infections could be detected by the Difil Test in 11 (2.2%) of 479 blood samples of clinically asymptomatic dogs from the South of Switzerland. Dirofilaria repens and D. immitis were identified in 3 (0.6%) and 8 dogs (1.6%), respectively, by the acid phosphatase activity of the microfilariae. 10 dogs with microfilaremia had been abroad or a stay outside Switzerland could not be excluded. One dog diagnosed with D. immitis could have had acquired the infection in the canton Tessin according to information given by the owner. Dogs with microfilaremia are a potential source of infection for mosquitoes. An indigenous cycle of infection in the South of Switzerland is possible since the mean average temperature in summer is above 18 degrees C which is necessary for optimal parasite development in the vector. A strict control of imported dogs or animals exposed to the disease in endemic regions as well as the therapy of infected dogs in the South of Switzerland is advisable.

Acid Phosphatase↗
PubMed1998

[Imported hepatozoonosis in the dog: 3 cases].

Canine hepatozoonosis is presented with 3 cases. The most common signs are: fever, anorexia, weight loss, diarrhea and vomiting, muscle weakness, lymphadenopathy, anemia and purulent discharge from the nose and the eyes. Because an infection with H. canis in the dog is often associated with other infectious diseases such as leishmaniasis, ehrlichiosis and babesiosis, the clinical picture may be dominated by these diseases. The diagnosis is made with the typical inclusions in neutrophilic granulocytes and monocytes. Only short remissions may be obtained with the presently available medications.

Animals↗
PubMed1997

Echinococcus multilocularis metacestodes: immunological and immunocytochemical analysis of the relationships between alkaline phosphatase and the Em2 antigen.

Echinococcus multilocularis metacestodes possess an alkaline phosphatase (EmAP) which has been extensively characterized at the biochemical level in previous studies. The apparent molecular weight of the enzyme monomer and its isoelectric point matched those originally described for the Em2 antigen, a reference antigen currently used for the immunodiagnosis of E. multilocularis infection. These observations raised questions about the molecular relationship between the two molecules. In order to investigate the relations between EmAP and the Em2 antigen, immunoblotting and ELISA were carried out using polyclonal and monoclonal antibodies directed against EmAP and the Em2 antigen, respectively. In addition, the localization of EmAP and the Em2 antigen was compared by immunofluorescence and immunogold electron microscopy in in vitro-generated E. multilocularis metacestodes. The results show that common epitopes between EmAP and Em2 exist, which are predominantly of a peptidic nature. Both antigens are localized in an acellular parasite structure, the laminated layer, with additional locations for the EmAP on the glycocalyx and in the central region of invaginated protoscoleces. These results suggest a putative functional relationship between the two antigens and that Em2 could originate from EmAP.

Alkaline Phosphatase↗
PubMed1997

Comparison of polymerase chain reaction with light microscopy for detection of microsporidia in clinical specimens.

The detection of microsporidial DNA by the polymerase chain reaction (PCR) has been suggested as an alternative or supplement to conventional microscopic methods. However, the relative merits of these techniques remain uncertain. In the present study, clinical specimens of different origin (stool, urine, sputum, nasal discharge, and cerebrospinal fluid) containing four different microsporidial species were blinded after microscopic examination and analyzed by PCR and subsequent restriction fragment length polymorphism (RFLP) to determine the respective species. Thirty-four specimens from 31 patients were evaluated, 16 of which were positive and 18 negative by microscopic examination; PCR detection of microsporidia produced identical results in 82% (28/34) of these specimens. Four samples were microscopically negative, PCR-positive, and two were microscopically positive, PCR-negative. Species determination by RFLP analysis of the amplified product was accurate for all isolates containing Enterocytozoon bieneusi, Encephalitozoon intestinalis, Encephalitozoon hellem, and Encephalitozoon cuniculi compared with microscopic identification of the genus Enterocytozoon or molecular analysis of Encephalitozoon species after in vitro culture. Therefore, PCR-RFLP is useful for the rapid detection and differentiation of microsporidian spores in clinical specimens.

Animals↗
PubMed1997

Species-specific identification of microsporidia in stool and intestinal biopsy specimens by the polymerase chain reaction.

In view of the increasing number of cases of human microsporidiosis, simple and rapid methods for clear identification of microsporidian parasites to the species level are required. In the present study, the polymerase chain reaction (PCR) was used for species-specific detection of Encephalitozoon cuniculi. Encephalitozoon hellem, Encephalitozoon (Septata) intestinalis, and Enterocytozoon bieneusi in both tissue and stool. Using stool specimens and intestinal biopsies of patients infected with Enterocytozoon bieneusi (n = 9), Encephalitozoon spp. (n = 2), and Encephalitozoon intestinalis (n = 1) as well as stool spiked with spores of Encephalitozoon cuniculi and Encephalitozoon hellem and tissue cultures of Encephalitozoon cuniculi and Encephalitozoon hellem, three procedures were developed to produce PCR-ready DNA directly from the samples. Specific detection of microsporidian pathogens was achieved in the first PCR. The subsequent nested PCR permitted species determination and verified the first PCR products. Without exception, the PCR assay confirmed electron microscopic detection of Enterocytozoon bieneusi and Encephalitozoon intestinalis in stool specimens and their corresponding biopsies and in spiked stool samples and tissue cultures infected with Encephalitozoon cuniculi and Encephalitozoon hellem. Moreover, identification of Encephalitozoon spp. could be specified as Encephalitozoon intestinalis. Whereas standard methods such as light and transmission electron microscopy may lack sensitivity or require more time and special equipment, the PCR procedure described facilitates species-specific identification of microsporidian parasites in stool, biopsies, and, probably, other samples in about five hours.

AIDS-Related Opportunistic Infections↗