Avian coccidiosis: the basic pathology to control

Coccidiosis is a major intestinal parasitic disease of poultry that is associated with severe economic losses and welfare issues. This review brings together current knowledge about the disease and the pathological alterations involved at gross, microscopic and molecular level and how these aspects may be exploitable in the future to improve existing control measures. Particular attention was paid to the genotoxic and cytotoxic effects of Coccidia at the cellular level, and how these can be investigated using novel techniques, such as the single-gel electrophoresis [comet assay] on in vitro cultured cells

cross-sectional study of intestinal parasitic infections of the European badgers in Woodchester park, south west England

Tuberculosis and helminthiosis often coincide geographically. So, question arises whether helminthes can modulate the host immune response and affect tuberculosis. Knowledge of the specific interactions between both enables better understanding of pathogenesis and potential controls. The study evaluated the hypothesis that badgers with a high parasitosis exhibit more susceptibility to tuberculosis compared to those with low or no parasitic infection. Faecal specimens from 28 badgers were examined by using standardised protocols. Fourteen different parasitic species were recovered; nine helminth species and five protozoa species. This diversity indicates that parasites are abundant in UK badgers. Results were compared with regards to age and sex. Parasitic prevalence tended to be higher in males than females and in cubs than adults. Two significant findings were obtained; [1] males had heavier infections with Strongyle nematode L[1] larvae than females; [2] cubs showed both higher prevalence and intensity of infection with coccidian oocysts compared to adults. In the sampled population, no significant correlation was found between TB status and diversity or intensity of parasitic infection. This refutes the hypothesis that parasitism exacerbates TB status. Studies encompassing larger numbers of badgers are needed for confirmation of the present finding

Role of immune response in Toxoplasma gondii tachyzoite-bradyzote stage interconversion: a janus in determining disease outcome [short communication]

No doubt, Toxoplasma gondii and toxoplasmosis superimposed many zoonotic diseases from geographical and zoological distribution world wide

Kinetics of eosinophilia and IGE production in experimental murine toxocariasis

Eosinophilia and immunoglobulin E [IgE] antibody are considered the first and important elements in host responses to helminth infection. Toxocara canis, which elicits prominent eosinophilia and IgE production in normal mice, may be useful in understanding the Kinetics of circulating peripheral blood eosinophils and IgE antibody during infection. The onset, magnitude and duration of peripheral blood eosinophilia and total IgE production after primary T. canis infection in female outbred albino mice was investigated. Mice were either sham inoculated [controls] or were orally infected with 1000 embryonated eggs of T. canis. Patterns in leucocytic changes include significant increase in total WBC count between weeks 6 and 13 post infection [PI] with a peak on week 8 PI. Mice showed eosinophilia between weeks 2 to 17 PI with a peak on week 7. The development of eosinophilia in T. canis-infected mice was accompanied by the release of prominent level of serum IgE between weeks 2 to 21 with a peak at week 6 PI. These findings showed that eosinophilia in T. canis infected outbred mice can be T-cell dependent

Studies on Besnoitiosis bennetti in miniature donkeys

Besnoitia tissue cysts associated with the skin lesions recovered from the naturally-infected miniature donkeys [Equus asinus] during clinical examination were studied by the light and electron microscopy, as well as histochemically to elucidate the specific morphologic features of the cyst causing this disease. The cyst was differentiated phenotypically from those of other Besnoitia spp. The interpretation of results showed that morphometric attributes of the tissue cysts and the associated pathological changes in these donkeys were due to B. bennetti infection. The findings were confirmed by the phylogenetic analysis based on DNA sequences of the first internal transcribed spacer of nuclear rDNA. The cluster analysis showed that B. bennetti was distinct from all other Besnoitia spp. and positioned B. bennetti with parasites described from Besnoitia besnoiti of cattle and B. tarandi of reindeer. The genetic attributes complemented the morphological criteria and verified the accurate delimitation of the Besnoitia cysts isolated from these donkeys

Ultrastructure characteristics of Besnoitia darlingi tachyzoites brumpt, 1913 [protozoa: sarcocystidae] of the Michigan strain MIBD1

Tachyzoites of Besnoitia darlingi Brumpt, 1913 were redescribed based on new materials isolated from Virginia opossums [Dideiphis virginiana, Kerr] from Michigan, USA. Tachyzoites of the MIBD1 strain were propagated in bovine turbinate cell culture for more than two years. A comparison with previously described tachyzoites of the B. darlingi OP1 strain from Mississippi, USA revealed some morphological differences despite the remarkable genetic homogeneity between the two B. darlingi strains. MIBD1 tachyzoites were distinguished from OP1 tachyzoites by having more rhoptries, and fewer and haphazardly distributed micronemes at the conoidal end. This morphological heterogeneity between tachyzoites of the two strains suggests the role of geographical isolation in the Michigan strain. New morphological features of B. darlingi tachyzoites were described

Observations on besnoitiosis in virginia opossum [didelphis virginiana] from Michigan, USA

Besnoitia tissue cysts were found in five naturally-infected adult opossums [Didelphis virginiana] from Michigan. Details of the microscopy, histopathology, ultra-structure, and genetic features of the cysts were studied to identify their species-specific traits. The materials were differentiated phenotypically from cysts of other Besnoitia spp. by difference in size, pattern of tissue distribution, morphology of pellicle and nucleus, number of micronemes and rhoptries, amount of lipids and amylopectin, and presence of enigmatic bodies. Morphometric variations identified the tissue cysts and the pathologic changes in opossums host to be due to B. darlingi. The data were proved by phylogenetic analysis based on DNA sequences of the first internal transcribed spacer of nuclear rDNA. Cluster analysis showed that B. darlingi was distinct from all other Besnoitia spp. as two distinct phylogenetic clades: I- included Besnoitia spp. described from opossum [B. darlingi], sheep [B. jellisonf], rodent [B. akadoni] and rabbit [B. oryctofelisi] and clade II- encompassed parasites described from cattle [B. besnoiti], equids [B. bennetti] and reindeer [B. tarandi]. The genetic attributed particular to the genus Besnoitia complemented the morphological features and lead to accurate delimitation of Besnoitia species

Protozoal pollution of surface water sources in Dakahlia Governorate, Egypt

Water samples were collected different water sources and different districts of Dakahlia G., from September 2005 to August 2006, were investigated for pathogenic protozoa. Water specimens were examined by concentration technique followed by modified Ziehl-Neelsen [MZN] and Truant auramine-rhoda-mine [AR] stains for Giardia sp. cysts, Cryptosporidium sp. oocysts, and other protozoa species. In the 1[st] survey, 94/480 [19.6%] water samples had protozoa. Prevalence rates were in summer 38/120 [31.6%], autumn 27/ 120 [22.5%], spring 20/ 120 [16.6%] and lastly winter 9/120 [7.5%]. Protozoa were less common in treated potable water tanks 15/120 [12.5%], followed by River Nile [Demiatta branch] 22/120 [18.3%] and sub-branch Bahr-El-Saghear 24/120 [20%]. The highest prevalence was in water of the main local draining 33/120 [27.5%]. In the 2[nd] survey, 840 potable water samples from seven districts were examined. Prevalence in descending order was C. parvum [3.1%], G. intestinalis [2.1%], E. histolytica [1%], Blastocystis homi-nis [1%], lodamoeba sp, [0.5%], Isospora belli [0.47%], E. coli [0.36%], Cyclospora cayetanensis [0.24%], and Chilo-mastix mesnilli [0.12%]. Data suggested that C. parvum and G. intestinalis were the commonest disease-agent. The implementation of preventive measures to protect water system from protozoa contamination was given

Correlation of ELISA copro-antigen and oocysts count to the severity of cryptosporidiosis parvum in children

A total of one thousand and fifty [1050] young children from Mansoura Pediatric Hospital, July 2005 to July 2006 were examined for cryptosporidiosis. Detailed history was taken from each participant, stool examination by direct smear, Formalin-ether sedimentation, Sheather's floatation, modified Ziehl-Nelseen [MZN] stain, Cryptospordium oocysts count, coproantigen detection by ELISA. Other infections were excluded. Out of 1050 children examined, cryptosporidial oocysts were detected in 90 cases by modified Zeihl Nelseen [MZN] stain, and coproantigen ELISA added another 10 cases. There was a significant difference between age group [1-2 years], rural locality, nutrition status, and diarrhea regarding Cryptosporidium infection. There was highly significant difference in malnourished children regarding Cryptosporidium oocysts and ELISA-OD. There is a significant positive correlation between oocysts count, ELISA-OD and malnutrition. Only diarrhea had a highly significant difference in relation to other symptoms in both mean oocysts count and ELISA-OD. There was highly significant positive correlation between symptoms, oocysts count and ELISA-OD

Inference of molecular phylogeny of Sarcocystis felis [sarcocystidae] from cats based on nuclear-encoded ribosomal gene sequences

The phylogenetic position of four clinical isolates of Sarcocystis felis was assessed using ssurRNA and ITS 1 gene sequences in the context of a wide array of other Sarcocystis sp. Phylogenetic reconstructions using neighbour-joining and maximum parsimony methods generated identical tree topologies with strong support values at each node. High ssurRNA sequence similarity [>/= 99%] and the resulting phylogeny demonstrated that S. felis and S. neurona are significantly closely related to each other. The two Sarcocystis formed a monophyletic group distinct from the other Sarcocystis sp., irrespective of the alignment algorithms or tree-building method used. The absolute [100%] identity of ssurRNA sequences of sarcocysts and sporocysts obtained from one cat raised the question regarding the cat's role as a potential intermediate host besides its known role as a definitive host of S. felis. On the other hand, S. felis sarcocyst DNA sequence was found to be quite dissimilar over the ITS 1 region when compared to S. neurona. These findings indicated that using sequences from 'two different genetic loci provided a stronger comparative basis than would have been possible using either one

In vitro evaluation of bovine turbinate cells and Sarcocystis falcatula Proliferation in response to serum-free Medium and other media supplements

A serum-free medium [SFM] was evaluated for the growth of bovine turbinate [BT] cells used for the production of Sarcocystis falcatula merozoites. Serum free cultures used to propagate S. falcatula were compared to cultures maintained in media supplemented with fetal calf serum [FCS] or horse serum [HS]. Serum free cultures were more effective and very promising than the others in supporting the proliferation of S. falcatula merozoites. However, the serum free cultures were unable to adequately support BT cell proliferation compared to the serum-supplemented cultures. No significant differences were seen between cultures supplemented with HS or FCS used for the production of S. falcatula merozoites or BT cells. The rate of BT cell proliferation in response to SFM and different media supplements was assessed in a 96-well plate format using methylene blue staining assay. This technique was superior to manual counting method and allowed quick and accurate quantitative comparison between the response of proliferating BT cells to different growth conditions

Molecular and microscopic techniques for detection of Sarcocystis neurona sporocysts in fecal samples

Diagnosis of Sarcocystis sp. in the definitive host is generally by microscopic detection of the sporocysts in feces. This method is insensitive and cannot differentiate between species because sporocysts lack specific staining criteria. The hypothesis suggested that molecular techniques provide better alternatives to classical detection of Sarcocystis sporocysts. The sensitivity of two PCR assays was compared to one another and to microscopic examination by conventional fecal flotation and Diamant-Fuchsin staining procedures for detection of sporocysts spiked into mice feces. PCR1 assay using LSM1 and LSM2 primers that amplified 496 bp of the ssurRNA gene was more sensitive than the PCR2 method using JNB25 and JD396 primers that amplified 334 bp of a RAPD-derived marker. PCR1 gave positive results with 200 micro1 of fecal suspension spiked with as little as 5 sporocysts compared to 75 sporocysts detected by JNB25 and JD396 primers. PCR1 was more sensitive than conventional microscopy. PCR1 or PCR2 followed by sequencing or RFLP analysis not only detected Sarcocystis sporocysts in feces but also enabled to ascertain the genotype of the species as S. neurona

Sarcocystosis of sarcocystis felis in cats

The features of S. felis sarcocystosis in muscles of the domestic cats [Felis domesticus] were studied. A complete clinical history, post mortem, and histopathologic examinations were done for each cat. Multiple protozoan elliptical cysts were in the skeletal muscles, heart, and diaphragm muscles of 3/17 [17.6%] adult cats. Ultrastructural characteristics of the brady-zoites and cyst wall were consistent with those descried for S. felis in bobcat and domestic cat. Clinicopathological study in 3 cats showed hypertrophy cardiomyopathy and lymphosarcoma associated with S. felis. Tissue samples showed a spectrum of pathological changes such as multi-focal subacute myocarditis and multi-focal subarachnoid lymphocytic infiltration. DNA extracted from muscles diaphragm with cysts was tested by PCR and sequence analyses of ssurRNA gene. The phylogenetic reconstructions using neighbor-joining method showed that S. felis is closely related to S. neurona. The results were illustrated and photographed and peer discussed.