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At least 253 records · Page 14Linked to original sources
PubMed2006

Long-term feeding a high-fat diet causes histological and parasitological effects on murine schistosomiasis mansoni outcome.

This study investigated whether long-term feeding a high-fat diet (HFC) has an effect on schistosomiasis mansoni outcome compared to standard chow diet (SC). Swiss Webster female mice (3 wk old) fed each diet over 5 months, and then were infected with 50 Schistosoma mansoni cercariae. Their nutritional status was assessed by monitoring growth rates twice a week and measuring serum levels of lipoproteins. Mice were euthanised 63 days after infection. Parasitological and liver histological analyses were performed. The levels of TC, HDL-C and LDL-C, fecal and tissue schistosome eggs were statistically different (p<0.05) between groups. Livers from HFC mice showed exudative, exudative/exudative-productive, exudative-productive and productive granulomas, some degree of hepatic steatosis and focal necrosis. Mice fed normal-chow did not present productive granulomas and hepatic steatosis. The morphometric evaluation of hepatic granulomas did not reach statistical significance (p>0.05) between diets assayed. The high-fat diet for long-term produces effects on schistosomiasis mansoni outcome.

Animals↗
PubMed2005

New diagnostics in parasitology.

The long-overdue introduction of new technology into parasite diagnostics has produced important tests that are now finding a place in clinical laboratories. It is too early to consider abandoning microscopy; the novel technology will run alongside the more traditional techniques for some years to come. Well-trained microscopists, supported by regular continuing professional development and external quality assessment schemes, are still central to the provision of a reliable diagnostic parasitology service.

Feces↗
PubMed2004

Laser microdissection microscopy in parasitology: microscopes meet thermocyclers.

The new methods of laser microdissection microscopy have received wide acceptance in biology and have been applied in a small number of parasitology investigations. Here, the techniques and applications of laser microdissection microscopy are reviewed with suggestions of how the systems might be used to explore applied questions in parasite molecular biology and host-parasite interactions.

Animals↗
PubMed2006

Can spleen aspirations be safely used for the parasitological diagnosis of canine visceral leishmaniosis? A study on assymptomatic and polysymptomatic animals.

The purpose of this study was to evaluate the safety of spleen aspiration as a sampling technique for the parasitological detection by culture and microscopy of Leishmania (chagasi) infantum. Two hundred and nine domiciled dogs from an endemic area for visceral leishmaniasis in Bahia State, Brazil, were studied. Most dogs (87%) were seropositive for anti-L. chagasi antibodies by ELISA. Clinical signs of disease were recorded and the animals monitored during and after spleen puncture in order to detect possible complications associated with the procedure. From a total of 257 splenic punctures in the 209 animals, only three minor events occurred, with no significant consequence for the animals and no association with risk factors. Leishmania was isolated from 149/180 (83%) seropositive dogs, and from 6/26 (23%) seronegative animals. The procedure did not cause adverse side effects or unnecessary suffering and confirmed the diagnosis in a large percentage of dogs. We conclude that spleen aspiration can be considered an effective and safe procedure for the definitive diagnosis of canine visceral leishmaniosis.

Animals↗
PubMed2004

History of the World Association for the Advancement of Veterinary Parasitology (WAAVP).

Forty years ago the first meeting of the World Association for the Advancement of Veterinary Parasitiology (WAAVP) was held in Hannover, Germany. We now have a thriving, internationally recognized organization; the meetings attract hundreds of scientists, attendance is increasing with almost every meeting. It is a useful time to review our beginnings, our development and our future. Our history has been one of innovation and activity and contributed to by its members in important areas of veterinary parasitology.

Congresses as Topic↗
PubMed2004

A comparative evaluation of parasitological, serological and DNA amplification methods for diagnosis of natural Trypanosoma evansi infection in camels.

A representative number of 217 camels (Camelus dromedarius) from different areas of western Rajasthan State, India, were examined from July 2002 to May 2003 for Trypanosoma evansi infection. The tests used were parasitological (wet blood film, WBF; stained thin blood smear, TBS), immunodiagnostic (double antibody sandwich enzyme linked immunosorbent assay for antigen detection, Ag-ELISA), and DNA amplification by polymerase chain reaction (PCR). These techniques were compared and the best efficiency was found for the last named (PCR). A prevalence of T. evansi infection was detected in 17.05, 9.67, 4.60 and 4.14% by PCR, Ag-ELISA, TBS and WBF with a sensitivity of 100, 56.75, 27.02 and 24.32%, respectively. PCR revealed a specific 227bp band in positive samples. The intensity of PCR bands was variable in different test samples depending upon the level of infection in the test samples. The history of intermittent fever, emaciation, oedema, poor body condition significantly correlated with positive serological status in ELISA as well as trypanosome DNA detection by PCR.

Animals↗
PubMed2005

Evaluation of loop-mediated isothermal amplification (LAMP), PCR and parasitological tests for detection of Trypanosoma evansi in experimentally infected pigs.

Six surra negative piglets (6-week-old) were infected with Trypanosoma evansi and two uninfected piglets were used as negative controls. Detection performances of various diagnostic tests (LAMP, PCR and parasitological tests) were compared by analysing blood samples collected weekly over a period of 11 weeks. With a two by two analysis without a gold standard, all methods were 100% specific. MI had the highest sensitivity of 65%, while LAMP, PCR, MHCT and TBS had sensitivities of 45, 33, 38 and 24%, respectively. However, when the analysis was done using MI as a gold standard, the sensitivity of MHCT was the highest at 53% followed by LAMP, PCR and TBS at 49, 44 and 35%, respectively. All methods gave high specificity above 60%. This study validates LAMP as an alternative method for the diagnosis of surra.

Animals↗
PubMed2006

Parasitological and serological diagnosis of Strongyloides stercoralis in domesticated dogs from southeastern Brazil.

Canine strongyloidiasis is a parasitic infection caused by the nematode Strongyloides stercoralis and presents a great zoonotic potential. Its confirmation, using coproparasitological methods, is difficult. The detection of serum specific antibodies, however, may facilitate the diagnosis. The aims of this study were to determine the presence of S. stercoralis through the use of parasitological methods and to detect specific antibodies to the parasite in serum samples from domestic dogs by using the indirect fluorescent antibody test (IFAT) on slides and the enzyme-linked immunosorbent assay (ELISA). A total of 215 dogs of various breeds, from the cities of Uberlândia, Araxá and Campo Belo in the State of Minas Gerais, were examined and distributed according to age into the following groups: (I) 19 males and 20 females of 1-2 months old; (II) 11 males and 20 females of 2-month- to 1-year-old and (III) 41 males and 104 females, from 1 to 7 years old. Coproparasitological results showed that 63/215 (29.3%) of the dogs presented some kind of parasite, with two (0.9%) dogs (one from Araxá and the other from Uberlândia) passing S. stercoralis larvae in the feces. Serological results revealed antibodies to S. stercoralis in 45/215 (20.9%) of the dogs, with seropositivity rates of 0% (0/39) in Group I, 22.6% (7/31) in Group II, and 26.2% (38/145) in Group III. No serological cross-reactivity between S. stercoralis and hookworms or Ascaridae was found. Hookworm infections were seen in 31 dogs, but only one of these dogs (infected with both hookworm and Cystoisospora spp.) was S. stercoralis seropositive by IFAT. The present study demonstrated, for the first time, natural S. stercoralis infections in dogs diagnosed by coproparasitological and serological methods. It was concluded that the detection of specific antibodies to S. stercoralis by IFAT and ELISA may contribute to the diagnosis of canine strongyloidiasis.

Age Factors↗
PubMed2001

Post-genomic nematode parasitology.

The future direction of post-genomic nematode parasitology should focus on the function of the genes that are defined by large-scale expressed sequence tag sequencing and on broader questions about the genetic basis of parasitism. Functional characterisation will require the application of high throughput technologies that have been developed in other fields, including genome mapping strategies and DNA microarray analysis. These will be greatly aided by the development and application of appropriate model organisms. It is crucial that the field make the transition from a narrow focus on one or a few genes at a time to a focus on whole genomes in order to fully realise the potential of the expressed sequence tag and other genomic projects currently under way.

Animals↗
PubMed1999

The importance of systematics in parasitological research.

The discipline of systematics plays a central role in all branches of biology. In today's technology-orientated research world, it is important to realise the continuing value of systematics, the basic tenet of which is to combine diverse types of data to produce classifications that reflect the natural history of living organisms. Accurate classification systems are crucial in the field of parasitology, not only because they provide the means to identify species and strains of parasites, but also because they provide a framework around which a parasite's biology can be studied. The construction of such a classification system is often hampered by the parasite's biology, which may preclude the application of traditional techniques or concepts (such as morphological differentiation or the biological species concept) to delineate species. It is often the case that these difficulties can be overcome by the use of molecular systematic techniques. In this paper, it is proposed that a detailed understanding of the phylogeny of a group of organisms can be used as a basis to examine other aspects of their systematics. This is illustrated using the protozoan parasite Giardia intestinalis. Data gathered using the complementary techniques of allozyme electrophoresis and nucleotide sequencing have been used to infer the phylogenetic relationships of G. intestinalis isolated from various host species. The results, supported by biological data, suggest that G. intestinalis is a species-complex. As we move towards the year 2000, molecular systematics will play an increasingly important role in elucidating host-parasite relationships. However, its use as a taxonomic tool will require a general acceptance by parasitologists and the adoption of formal procedures to allow the description of new species by these methods. The aim of this approach is not to dismiss traditional methods, but to use them in combination with contemporary methods in the true spirit of the discipline of systematics.

Animals↗
PubMed2002

Parasitological and immunological follow-up of American tegumentary leishmaniasis patients.

A long-term evaluation of human American tegumentary leishmaniasis patients was conducted to detect immunological and/or parasitological indicators associated with cure or protection against leishmaniasis. Cutaneous leishmaniasis (CL) and mucosal leishmaniasis (ML) patients from endemic areas of Leishmania braziliensis infection in Brazil were studied during the active disease, at the end of therapy, and up to 10 years after the end of therapy. For immunological studies, lymphocyte proliferative responses, phenotypic characterization of CD4+ and CD8+ T cells reactive to L. braziliensis and cytokine production in vitro were assayed. In CL, with its tendency for healing lesions, at or shortly after the completion of therapy the ratio of CD4+ to CD8+ T cells was approximately one and production of interferon gamma (IFN gamma) remained roughly constant. In ML, these apparently beneficial CD4+/CD8+ ratios and cytokine patterns appeared later. The long-term memory T cell responses were associated with preferential induction of CD4+ subpopulations and IFN gamma production that probably led to protection against relapses or reinfection. Deoxyribonucleic acid (DNA) was isolated from peripheral blood and oligonucleotides that amplify the conserved region of the minicircle molecules of Leishmania were used in a 'hot-start' polymerase chain reaction (PCR). Leishmania DNA was found in about one-quarter of the patients with active disease as well as in individuals who had received chemotherapy. The PCR was also positive in one-third of the individuals with a positive skin test but no past or present history of leishmaniasis. The well-modulated T cell response leading to long-term protection observed in CL patients could result from a favourable host genetic background and/or a particular parasite genotype, leading to a beneficial T cell immune response even in the presence of parasite antigens. The possibility of parasite persistence after clinical cure suggests that the immune response can control, but not fully eliminate, the infection. It could prevent the parasite from causing disease, maintaining a leishmanial antigen-specific response and hampering reinfection.

Animals↗
PubMedDate not supplied

High plasma levels of nitrogen oxides are associated with severe disease and correlate with rapid parasitological and clinical cure in Plasmodium falciparum malaria.

Plasma levels of nitrogen oxide (NO), neopterin and C-reactive protein (CRP) were compared in 3 groups of Gabonese patients with Plasmodium falciparum malaria before and after therapy: adults with uncomplicated malaria, children with uncomplicated malaria, and children with severe malaria. Plasma levels of all 3 molecules were significantly higher in severe malaria than in uncomplicated malaria. High levels of neopterin and CRP during the acute phase of malaria significantly correlated with slow parasitological and clinical cure after therapy. In contrast, high NO plasma levels during the acute phase of malaria predicted accelerated cure. These findings provide further evidence for the protective role of NO in malaria. However, as NO levels were highest in severe disease, overproduction may be harmful for the patients.

Acute Disease↗
PubMed2001

Monitoring of bacterial and parasitological contamination during various treatment of sludge.

Wastewater treatment results in the production of large quantities of sludge. Agricultural use is an interesting alternative provided that the health risks are taken into account. In France, a decree (1998) defines "sanitized" sludge as sludge that has been treated so that pathogens (Salmonella, enteroviruses, viable nematode eggs) are no longer detectable. The aim of this study was to determine the impact of various sludge treatments on 2 types of pathogens (Salmonella and nematode eggs). We also assessed the levels of micro-organisms that indicate faecal contamination (E. coli, Enterococci, sulfite-reducing anaerobes spores). Various treatment processes were analyzed: 4 biological, 3 chemical, 1 heat, 2 storage and 4 sampling campaigns were carried out. Concerning the parasitological contamination of sludge at the entrance of all sites, concentrations of total nematode eggs and viable nematode eggs were highly heterogeneous (respectively, from 2 to 53 eggs/10 g DM and from 2 to 45 eggs/10 g DM) with viable eggs present in all samples. The total concentration of nematode eggs in the sludge was not greatly affected by treatment or storage, and was in the range < 1-66 eggs/10 g DM. However, the situation was different for mean viable egg counts. For four treatments, no viable eggs were detected. Mesophilic processes are inefficient at eliminating viable nematode eggs. Salmonella were systematically detected in all sludge samples at the entry to the station, except for limed sludge intended for storage. At the end of four treatments Salmonella had been totally eliminated. For the fecal contamination indicators, the largest decrease in E. coli contamination was observed following liming and after thermophilic treatment. The mesophilic treatments resulted in very small decreases in contamination. A similar pattern was observed with Enterococci. For the spores of sulfite-reducing anaerobe bacteria, with the exception of heat treatment, which reduced contamination by 3.2 log units, the maximum decrease in contamination was 1.7 log. For storage of sludge, E. coli and Enterococci levels had decreased at first but then increased between 6 and 8 months of storage.

Animals↗
PubMed2001

A comparative evaluation of parasitological tests and a PCR for Trypanosoma evansi diagnosis in experimentally infected water buffaloes.

In this study five parasitological methods and a polymerase chain reaction (PCR) were compared for the diagnostic sensitivity for Trypanosoma evansi in experimentally infected water buffaloes over a period of 15 weeks. The combined estimates of sensitivity (CE(se)) of the PCR proved to be highest at 78.2%, closely followed by the mouse inoculation (MI), the micro-haematocrite centrifugation technique (MHCT) and the mini-anion-exchange centrifugation technique (MAECT) with CE(se) of, respectively, 74.0, 69.6 and 62.4%. The CE(se) of the buffy-coat technique (BCT) at 38.6% and the sodium dodecyl sulfate (SDS) clarification technique at 25.1% were considerably lower. PCR detected consistently all buffaloes infected from week 3 post-infection (PI) onwards. For MI this occurred after 5 weeks PI while for MHCT and MAECT these sustainable high levels were reached in the 7th week PI. BCT and SDS never detected all buffaloes infected. The influence of time and temperature on the viability of T. evansi in heparinized blood from water buffalo was also studied. In general we observed that the survival time tends to be longer when blood is kept at 4 degrees C. In samples kept in direct sunlight parasites became undetectable with the MHCT after 30min. After treatment of the water buffaloes with diminazene aceturate, the PCR signal disappeared within 24h.

Animal Diseases↗
PubMed2001

Evaluation and improvement of parasitological tests for Trypanosoma evansi infection.

Research was undertaken to critically evaluate parasitological tests for the detection of Trypanosoma evansi in blood. The relative sensitivity of mouse inoculation (MI), the haematocrit centrifugation technique (HCT) and a modified miniature anion-exchange centrifugation technique (MAECT) were compared using blood and buffy coat. The effect that storage of blood prior to inoculation into mice has on the reliability of the MI test was also evaluated. The tests may be ranked in increasing order of sensitivity: HCT, MAECT with whole blood, MI with whole blood, MAECT with buffy coat and MI with buffy coat. The latter was able to detect 1.25 T. evansi per 4ml of blood. The reliability of the MI test was not reduced with storage of blood containing at least 25 T. evansi per ml for up to 21h prior to inoculation into mice. These results demonstrate that sensitivity of the MI and MAECT are increased approximately 10-fold through the use of buffy coat in place of whole blood. Although, the MI is marginally more sensitive MAECT is better suited to field use.

Animals↗
PubMed2002

Cooperia punctata trickle infections: parasitological parameters and evaluation of a Cooperia recombinant 14.2 kDa protein ELISA for estimating cumulative exposure of calves.

Three groups of four calves each were trickle infected with three different levels of Cooperia punctata: 310 (group A), 1250 (group B) and 5000 (group C) third stage infective larvae (L3) twice a week over a 17-week period. Group D was the non-infected control group. Parasitological parameters as faecal egg counts (epg), worm burdens, size of worms and number of eggs per female were collected and the differences between the groups compared. Serological analyses were also conducted to investigate the efficiency of a recombinant C. oncophora CoES 14.2kDa protein in an ELISA to detect C. punctata antibodies. Group C had higher faecal egg counts until week 9 when the values decreased to those in group B. Mean faecal egg counts in group A were always lower than in the two other infected groups. The worm burdens were highest in group C, and lowest in group A, although the number of worms as a percentage of total larval intake was higher for the lower group. The mean length of the worms was shorter and the number of eggs per female lower for group C than for both other groups. ELISA using the CoES 14.2kDa proved to be efficient in measuring C. punctata antibodies. For group C it took 4 weeks to get increased levels of antibodies and this was one and 2 months more for groups B and A, respectively. Overall, there was a congruent relation between C. punctata antibodies and the cumulative exposure to the three different levels of trickle infections.

Animals↗
PubMed2002

Variation in clinical and parasitological traits in Pietrain and Meishan pigs infected with Sarcocystis miescheriana.

Future prophylaxis needs new concepts, including natural disease resistance of hosts against infectious agents. Genomic approaches to detect and improve disease resistance in farm animals and the molecular mechanisms involved in host-parasite interactions depend to a high degree on the trait differences between founder breeds, i.e. on the animal model. The present study evaluates differences in susceptibility/resistance against Sarcocystis miescheriana in the European Pietrain (PI) and the Chinese Meishan (ME) pig breeds, based on 25 individuals, infected orally with 5x10(4) sporocysts of S. miescheriana. Significant differences appeared in clinical, serological, haematological and parasitological findings. The major discriminating period post infection (p.i.) was between days 42 and 45. Severity of signs was negatively correlated with specific immunoglobulin titres during the first 3 weeks p.i. and positively with the load of bradyzoites in muscle tissues of the pigs. Loads of bradyzoites in muscle tissues were 20 times higher in PI than in ME. Sarcocystis-specific differences between the two breeds were in the range of 1-2 standard deviations. The study lays the foundation for further experiments to analyse chromosomal regions, candidate genes, and thus the molecular basis of Sarcocystis susceptibility/resistance as a model for host-parasite interaction in protozoan infectious disease.

Animals↗