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A total of 100 Tilapia fish samples were collected from brackish water (n = 50) and fresh water (n = 50) resources, Northern Egypt, and examined for heterophyid encysted metacercariae (EMC) during the period from August 2007 to July 2008. The overall prevalence of infection was 32%; 22% for brackish water fish and 42% for fresh water fish. Significant differences in parasite occurrence among body regions were found, with muscles of the tail and caudal third being highly affected (93.4%) followed by middle third (84.3%) and anterior third (75%), while the head region had the lowest infection (21.9%). The prevalence was highest in summer season (46.4%) followed by spring (37.5%) and autumn (27.3%), and was lowest in winter (15.4%). The prevalence of infection decreased as fish size increased. Adult heterophyids, Heterophyes heterophyes, Heterophyes aequalis, Pygidiopsis genata, Haplorchis yokogawai, and Ascocotyle (Phagicola) ascolonga were recovered from EMC-feed puppies. Eggs of heterophyid type were detected in 10 (13.3%) out of 75 human stool specimens from local residents. An association exists between being a female (odd ratio [OR] 1.59 and 95% confidence interval [CI] 0.42-6.04), a fisherman (OR 1.39 [95% CI 0.26-7.48]), a housewife (OR 1.24 [95% CI 0.29-6.28]), 15-45 years old (OR 2.22 [95% CI 0.58-8.53]), or aged 5-14 years (OR 1.29 [95% CI 0.30-5.58]) and heterophyid infection. Measures should be implemented to reduce the risk of transmission of heterophyids to human and fish-eating animals.

Neuropathogenic protozoa have evolved strategies to breach the blood-brain barrier and invade the central nervous system. These include transcellular, paracellular and the Trojan horse routes but the associated molecular mechanisms remain incompletely understood. Here, we summarize the current understanding of protozoa penetration across the blood-brain barrier, focusing on Plasmodium, Babesia, Trypanosoma, Toxoplasma, Acanthamoeba and Balamuthia. Advances in understanding the molecular pathways will offer opportunities for the rational development of novel therapeutic interventions.

This retrospective study of sarcoptic mange in dogs aimed to identify risk factors for this disease and determine their influence on treatment outcome. Data regarding dog demographics, clinical presentation, diagnostic method, treatment, and outcome were analyzed. No statistical association was found between sex and incidence of sarcoptic mange. However, age of dogs was found to be a risk factor which could increase the chances of dogs contracting sarcoptic mange. The results indicate that the disease predominantly affects young dogs, of all breeds and both sexes, implicating age-related immunity. The most common clinical feature reported was pruritus, with the ear margins preferentially affected. Additionally, contact with other animals played an important role in occurrence of the disease indicating the highly transmissible nature of the disease.

Neosporiosis, a serious disease caused by the apicomplexan intracellular parasite Neospora caninum, is considered to be one of the most economically important diseases in cattle. It is associated with potentially serious complications such as abortion, stillbirth and maternal infertility. To survive in fluctuating physiological and immunological environments, N. caninum has evolved a diverse set of regulatory mechanisms that govern various adaptive responses. The most intriguing paradigm in N. caninum adaptive evolutionary biology is its ability to alternate between two phenotypically and functionally distinct stages within the host. Recent research has reinforced the notion that N. caninum tachyzoite-bradyzoite stage switching on and off is correlated with its ability to form dormant cysts. Knowledge of the specific mechanisms that govern the dynamics of N. caninum phenotype switching enables a better understanding of the pathogenesis of the disease and effective control measures to be identified. Herein we review the available knowledge relating to various aspects of stage interconversion in N. caninum, with particular focus on the stress-related hypothesis presumed to be involved in this event. Finally, we put forward the postulation that N. caninum uses stage interconversion as an adaptive process to cope with the hostile environment within the host and to ensure its continuity in nature.

The gross pathological and histopathological changes associated with parasitic infection in the European eel (Anguilla anguilla Linnaeus, 1758) was investigated. A total of 65 eels collected from three sampling localities in Eastern Delta, Egypt were examined over the period of January-May 2008. The fish were subjected to standard procedures for parasitological and pathological examinations. Overall, 22 (33.8%) of the 65 fish examined were found to have parasitic infections. The eels harbored a total of six parasite species; among them, the nematode Anguillicoloides crassus was the most prevalent species (10.7%), followed by the Monogenea Pseudodactylogyrus anguillae (7.7%) and Dactylogyrus species (6.1%), the ciliate Trichodinella epizootica (4.6%), the Myxozoa Myxidium giardi (3.1%), and the cestode Proteocephalus macrocephalus (1.5%). Affected fish showed varying levels of tissue damage and pathological alterations including mild to severe degenerative, necrotic, and inflammatory changes in the affected organs.

To investigate whether infection of Swiss outbred mice with the digenetic fluke Schistosoma mansoni is influenced by exposure to environmental pollutants, experimentally infected mice were exposed to 200 and 400 mg/kg of malathion. Pathology of liver and spleen, worm burden and levels of key hematological, biochemical and liver enzymes parameters of these mice were evaluated and were compared with data from infected, unexposed mice, uninfected, exposed mice as well as with data from uninfected, unexposed mice. Oral administration of malathion to mice infected with 20, 40 or 60 S. mansoni cercariae adversely affect architecture of liver and spleen and critically alter hematological, biochemical, histological and hepatic enzymes parameters significantly more than the controls. Alterations observed in infected, exposed mice included (i) higher mortality rate; (ii) severe pathologies in liver and spleen; (iii) increased serum level of bilirubin and alanine aminotransferase/aspartate aminotransferase (ALT/AST) enzymes; (iv) decreased serum level of albumin and total proteins; and (v) decreased red blood cell count (RBC), lymphocytes, leucocytic count, and hemoglobin content. The number of recovered adult worms of S. mansoni or their oviposition capacity did not seem to be affected with malathion treatment. Statistical analysis revealed that the increase alteration in hepatic functions is correlated with increasing the number of S. mansoni cercariae and malathion doses. Such alterations were more significant in mice treated with the higher dose of malathion or infected with the largest numbers of S. mansoni cercariae. These data indicate that schistosomiasis can be exacerbated by simultaneous malathion exposure, which in turn adversely impact the clinical and pathological outcome of the disease.

The infection status with heterophyids in the second intermediate host fish obtained from brackish and fresh water resources in Dakahlia governorate, northern Egypt was investigated. Encysted metacercariae (EMC) in the fish species Mugil cephalus, Mugil capito, Mugil auratus, Tilapia nilotica, and Tilapia zilli from brackish water and T. nilotica and T. zilli from fresh water were isolated by artificial digestion method and identified by microscopic examination. Morphometric analysis of EMC isolated from these fishes identified seven phenotypically distinct groups. No significant morphologic differences were detected between EMC of the same group obtained from different fish species. The adult flukes recovered from seven groups of puppies separately infected with distinct EMC groups were compatible with seven species belong to six genera of Heterophyidae namely Heterophyes heterophyes, Heterophyes aequalis, Pygidiopsis genata, Haplorchis yokogawi, Prohemostomum vivax, Phagicola ascolonga, and Stictodora tridactyla. EMC of these seven heterophyid species were detected in all examined brackish water fishes. On the other hand, only EMC of P. genata, H. yokogawi, and P. ascolonga were detected in fresh water fishes, T. nilotica and T. zilli. These results indicate that heterophyid infections occur in brackish and fresh water fishes in northern Egypt, where the parasites are indigenous.

3 Abstract: The focus of this report was to assess the role of passive immunization using immunoglobulins derived from chicken egg yolk in protection against M. gallisepticum infection in chickens. Immunoglobulins were produced by egg yolk technology. ELISA was used to evaluate their immunoreactivity and western immunoblotting demonstrated that chicken egg yolk immunoglobulins Y (IgY) were capable of recognizing M. gallisepticum immunoreactive antigens. Administration of IgY to experimentally infected broiler chickens afforded up to 70% protection rate as confirmed by culture analyses. Challenge of IgY - treated birds with M. gallisepticum virulent strain S6 revealed significantly (P< 0.05) lower isolation prevalence in comparison to control chickens treated with IgY from mock-immunized (control) hens that received the same bacterial challenge. Additionally, M. gallisepticum culture analysis from respiratory organs demonstrated that these antibodies protected chickens in a dose-dependent pattern against M. gallisepticum infection (i.e., increasing IgY titer resulted in decreased isolation rate). These findings demonstrate that IgY obtained from hens immunized by M. gallisepticum could provide an alternative approach for treatment of M. gallisepticu m infection in chickens.

We tested the hypothesis that brown-headed cowbirds ( Molothrus ater ) harbor Sarcocystis neurona , the agent of equine protozoal myeloencephalitis (EPM), and act as intermediate hosts for this parasite. In summer 1999, wild caught brown-headed cowbirds were collected and necropsied to determine infection rate with Sarcocystis spp. by macroscopic inspection. Seven of 381 (1.8%) birds had grossly visible sarcocysts in leg muscles with none in breast muscles. Histopathology revealed two classes of sarcocysts in leg muscles, thin-walled and thick-walled suggesting two species. Electron microscopy showed that thick-walled cysts had characteristics of S. falcatula and thin-walled cysts had characteristics of S. neurona . Thereafter, several experiments were conducted to confirm that cowbirds had viable S. neurona that could be transmitted to an intermediate host and cause disease. Specific-pathogen-free opossums fed cowbird leg muscle that was enriched for muscle either with or without visible sarcocysts all shed high numbers of sporocysts by 4 weeks after infection, while the control opossum fed cowbird breast muscle was negative. These sporocysts were apparently of two size classes, 11.4 ± 0.7 μm by 7.6 ± 0.4 μm ( n = 25) and 12.6 ± 0.6 μm by 8.0 ± 0 μm ( n = 25). When these sporocysts were excysted and introduced into equine dermal cell tissue culture, schizogony occurred, most merozoites survived and replicated long term and merozoites sampled from the cultures with long-term growth were indistinguishable from known S. neurona isolates. A cowbird Sarcocystis isolate, Michigan Cowbird 1 (MICB1), derived from thin-walled sarcocysts from cowbirds that was passaged in SPF opossums and tissue culture went on to produce neurological disease in IFNγ knockout mice indistinguishable from that of the positive control inoculated with S. neurona . This, together with the knowledge that S. falcatula does not cause lesions in IFNγ knockout mice, showed that cowbird leg muscles had a Sarcocystis that fulfills the first aim of Koch's postulates to produce disease similar to S. neurona . Two molecular assays provided further support that both S. neurona and S. falcatula were present in cowbird leg muscles. In a blinded study, PCR-RFLP of RAPD-derived DNA designed to discriminate between S. neurona and S. falcatula showed that fresh sporocysts from the opossum feeding trial had both Sarcocystis species. Visible, thick-walled sarcocysts from cowbird leg muscle were positive for S. falcatula but not S. neurona ; thin-walled sarcocysts typed as S. neurona . In 1999, DNA was extracted from leg muscles of 100 wild caught cowbirds and subjected to a PCR targeting an S. neurona specific sequence of the small subunit ribosomal RNA (SSU rRNA) gene. In control spiking experiments, this assay detected DNA from 10 S. neurona merozoites in 0.5 g of muscle. In the 1999 experiment, 23 of 79 (29.1%) individual cowbird leg muscle samples were positive by this S. neurona -specific PCR. Finally, in June of 2000, 265 cowbird leg muscle samples were tested by histopathology for the presence of thick- and thin-walled sarcocysts. Seven percent (18/265) had only thick-walled sarcocysts, 0.8% (2/265) had only thin-walled sarcocysts and 1.9% (5/265) had both. The other half of these leg muscles when tested by PCR-RFLP of RAPD-derived DNA and SSU rRNA PCR showed a good correlation with histopathological results and the two molecular typing methods concurred; 9.8% (26/265) of cowbirds had sarcocysts in muscle, 7.9% (21/265) had S. falcatula sarcocysts, 1.1% (3/265) had S. neurona sarcocysts, and 0.8% (2/265) had both. These results show that some cowbirds have S. neurona as well as S. falcatula in their leg muscles and can act as intermediate hosts for both parasites.

The higher intergenotypic polymorphism of the surface antigen genes 5 (SAG5)A, SAG5C, and SAG5E in Toxoplasma gondii was proposed to be the outcome of positive selection pressure favoring variation within these loci. However, the exact nature and magnitude of this selection is not completely known. To address this issue, the amino acids on which natural selection may operate were identified by comparing the ratios of nonsynonymous and synonymous substitutions (pN/pS) of homologous DNA sequences in strains belonging to the three major genotypes of T. gondii. Both positive and negative selections were detected and are likely to have contributed to shaping the patterns of nucleotide substitution and polymorphism in SAG5 genes. Several sites identified in SAG5 loci as likely to be under positive selection suggesting that diversifying selection may have promoted divergence in these genes. Also, it was noted that the SAG5 genetic loci contain many areas that exhibit signs of purifying selection; some of these areas might be the attractive candidates for drug targets. Phylogenetic analysis using the neighbor-joining and maximum parsimony methods grouped the SAG5 sequences of T. gondii strains into three distinct statistically well-supported evolutionary lineages. These findings carry important implications for human and veterinary toxoplasmosis epidemiology and may provide important insights into the pathways through which virulence has evolved in T. gondii.

The aim of this study was to compare the performance of three in-house diagnostic tests, i.e. counter current immunoelectrophoresis (CCIE), intradermal (ID) and indirect fluorescent immunoassay (IFI), for the diagnosis of Heterophyes infection. One hundred and twenty puppies were randomly divided into eight groups (n = 15/group). Heterophyes heterophyes infections were established in these puppies by administering a dose of 50 H. heterophyes encysted metacercariae/puppy by gavage. Forty puppies of similar age and sex were divided into eight groups, of five puppies each and were used as negative controls. Sera pooled from separate infected and uninfected groups were tested against H. heterophyes antigens, weekly for 8 weeks post-infection (PI). The ID assay detected infected puppies sooner than any of the serological tests. Sero-conversion was first detected 2 weeks PI by ID assay and 1 week later by CCIE and IFI assays. ID test performed well till the end of the experiment (sensitivity and specificity: 100% and 90%, respectively). Both IFI and CCIE assays had a sensitivity of 40% and 20%, respectively for early detection of antibody, which was less sensitive than ID but both assays were more specific (100%) than the ID assay. The lowest agreement was between ID and IFI tests (40.3%), whilst the highest was observed between CCIE and IFI tests (67.2%). Of the three evaluated methods, the ID test could be recommended for scientific and laboratory diagnosis of heterophyosis in naturally infected animals. However, since none of the investigated method are optimal (i.e, offers 100% specificity and sensitivity), the choice of test employed must depend on the aim of the study.

Sarcocystis neurona is an important protozoal pathogen because it causes the serious neurological disease equine protozoal myeloencephalitis (EPM). The capacity of this organism to cause a wide spectrum of neurological signs in horses and the broad geographic distribution of observed cases in the Americas drive the need for sensitive, reliable and rapid typing methods to characterize strains. Various molecular methods have been developed and used to diagnose EPM due to S. neurona, to identify S. neurona isolates and to determine the heterogeneity and evolutionary relatedness within this species and related Sarcocystis spp. These methods included sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), immuno-fluorescent assay (IFA), slide agglutination test (SAT), SnSAG-specific ELISA, random amplified polymorphic DNA (RAPD), PCR-based restriction fragment length polymorphism (RFLP), amplified fragment length polymorphism (AFLP) fingerprinting, and sequence analysis of surface protein genes, ribosomal genes, microsatellite alleles and other molecular markers. Here, the utility of these molecular methods is reviewed and evaluated with respect to the need for molecular approaches that utilize well-characterized polymorphic, simple, independent, and stable genetic markers. These tools have the potential to add to knowledge of the genetic population structure of S. neurona and to provide new insights into the pathogenesis of EPM and S. neurona epidemiology. In particular, these methods provide new tools to address the hypothesis that particular genetic variants are associated with adverse clinical outcomes (severe pathotypes). The ultimate goal is to utilize them in future studies to improve treatment and prevention strategies.

Malaria remains a serious health problem in many parts of the world. It causes high morbidity and claims many lives in developing countries each year. Humans are generally infected by four species of malaria parasites. However, malaria infection caused by Plasmodium malariae or P. falciparum is recognized as an important cause of acute renal failure (ARF) and other renal-related disorders (nephropathy) in infected patients. The increasing incidence of malarial ARF (MARF) and the emergence of clinical malarial infection after renal transplantation represent a serious challenge. Additionally, the impact of immunosuppressive therapies on malarial infection is intricate, complex, and not yet well defined. Pathogenesis of MARF is most likely to be due to immune complex-mediated glomerulonephritis caused by immune-complex deposition and endothelial damage, which may lead to fatal forms of quartan malarial nephropathies. Effects of mechanical, immunologic, cytokine, humoral, acute phase response, and hemodynamics factors in inducing malarial nephropathy have also been postulated. Development of preventive strategies aimed at combating MARF and other renal disorders associated with malaria infection requires (1) prevention of malarial infection, (2) early diagnosis, and (3) early referral to well-equipped centers to provide renal replacement therapy, if necessary, along with antimalarial therapy and support. These measures could significantly reduce mortality and enhance recovery of renal function.

The present study aimed to evaluate the association between the environmental tobacco smoke (ETS) and DNA damage in relation to oxidative stress (OS) in children. Sixty-four children of age 1-8 years, selected from the outpatient clinic of Mansoura University Children Hospital were divided into two groups (23 children/group) based on high (20 cigarettes/day) or low (20 cigarettes/day) exposure to ETS at home. Twenty symptom-free children with normal cotinine level and with no exposure to ETS were recruited as controls. The comet assay was used to quantify the level of DNA damage in lymphocytes isolated from all children. Spectrophotometric methods were used to assess the serum level of malondialdehyde (MDA) and activity of glutathione peroxidase (GSH-Px) in erythrocytes. Also, serum level of tocopherol fractions (alpha, gamma, delta) was assessed by high performance liquid chromatography (HPLC). Children exposed to ETS exhibited retarded growth, more chest problems, and gastroenteritis than the control. A significant increase in mean comet tail length indicating DNA damage was observed in ETS-exposed children (P0.001) compared to controls. ETS-exposed children had significantly (P0.001) higher MDA level paralleled with significant (P0.001) decrease in the level of GSH-Px and tocopherol fractions compared with controls. The GSH-Px activity and tocopherol levels were inversely correlated with the increase of ETS exposure. These results show that inhalation of ETS is associated with an increase in the level of oxidants and a simultaneous decrease in the level of antioxidants in the children's blood. This status of oxidant-antioxidant imbalance (OS) may be one of the mechanisms leading to DNA damage detected in lymphocytes of ETS-exposed children. In conclusion, the present study gives an indication of an association between DNA damage and ETS exposure in children.

© 2016 He et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Toxoplasma gondii remains a global public health problem. However, its pathophysiology is still not-completely understood particularly the impact of infection on host liver metabolism. We performed iTRAQ-based proteomic analysis to evaluate early liver protein responses in BALB/c mice following infection with T. gondii PYS strain (genotype ToxoDB#9) infection. Our data revealed modification of protein expression in key metabolic pathways, as indicated by the upregulation of immune response and downregulation of mitochondrial respiratory chain, and the metabolism of fatty acids, lipids and xenobiotics. T. gondii seems to hijack host PPAR signaling pathway to downregulate the metabolism of fatty acids, lipids and energy in the liver. The metabolism of over 400 substances was affected by the down regulation of genes involved in xenobiotic metabolism. The top 10 transcription factors used by upregulated genes were Stat2, Stat1, Irf2, Irf1, Sp2, Egr1, Stat3, Klf4, Elf1 and Gabpa, while the top 10 transcription factors of downregulated genes were Hnf4A, Ewsr1, Fli1, Hnf4g, Nr2f1, Pparg, Rxra, Hnf1A, Foxa1 and Foxo1. These findings indicate global reprogramming of the metabolism of the mouse liver after acute T. gondii infection. Functional characterization of the altered proteins may enhance understanding of the host responses to T. gondii infection and lead to the identification of new therapeutic targets.

This study investigates the temporal and spatial interchange of the aromatic amino acid phenylalanine (Phe) between human retinal pigment epithelial cell line (ARPE-19) and tachyzoites of the apicomplexan protozoan parasite Toxoplasma gondii (T. gondii). Stable isotope labelling by amino acids in cell culture (SILAC) is combined with Raman micro-spectroscopy to selectively monitor the incorporation of deuterium-labelled Phe into proteins in individual live tachyzoites. Our results show a very rapid uptake of l-Phe(D8) by the intracellular growing parasite. T. gondii tachyzoites are capable of extracting l-Phe(D8) from host cells as soon as it invades the cell. l-Phe(D8) from the host cell completely replaces the l-Phe within T. gondii tachyzoites 7-9 hours after infection. A quantitative model based on Raman spectra allowed an estimation of the exchange rate of Phe as 0.5-1.6 × 10(4) molecules/s. On the other hand, extracellular tachyzoites were not able to consume l-Phe(D8) after 24 hours of infection. These findings further our understanding of the amino acid trafficking between host cells and this strictly intracellular parasite. In particular, this study highlights new aspects of the metabolism of amino acid Phe operative during the interaction between T. gondii and its host cell.

© 2015 Zhou et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The interplay between the Apicomplexan parasite Toxoplasma gondii and its host has been largely studied. However, molecular changes at the metabolic level in the host central nervous system and pathogenesis-associated metabolites during brain infection are largely unexplored. We used a global metabolomics strategy to identify differentially regulated metabolites and affected metabolic pathways in BALB/c mice during infection with T. gondii Pru strain at 7, 14 and 21 days post-infection (DPI). The non-targeted Liquid Chromatography- Mass Spectrometry (LC-MS) metabolomics analysis detected approximately 2,755 retention time-exact mass pairs, of which more than 60 had significantly differential profiles at different stages of infection. These include amino acids, organic acids, carbohydrates, fatty acids, and vitamins. The biological significance of these metabolites is discussed. Principal Component Analysis and Orthogonal Partial Least Square-Discriminant Analysis showed the metabolites' profile to change over time with the most significant changes occurring at 14 DPI. Correlated metabolic pathway imbalances were observed in carbohydrate metabolism, lipid metabolism, energetic metabolism and fatty acid oxidation. Eight metabolites correlated with the physical recovery from infection-caused illness were identified. These findings indicate that global metabolomics adopted in this study is a sensitive approach for detecting metabolic alterations in T. gondii-infected mice and generated a comparative metabolic profile of brain tissue distinguishing infected from non-infected host.

The objective of this study was to evaluate the utility of a simple, efficient, and rapid method for the isolation of Sarcocystis neurona merozoites and Besnoitia darlingi tachyzoites from cultured cells. The efficacy of this purification method was assessed by microscopy, SDS-PAGE, Western blotting, immuno-fluorescence, and three novel quantitative PCR assays. Culture medium containing host cell debris and parasites was eluted through PD-10 desalting columns. This purification method was compared to alternatives employing filtration through a cellulose filter pad or filter paper. The estimated recovery of S. neurona merozoites purified by the column method was 82% (+/-3.7) of the original merozoites with 97.5% purity. In contrast, estimated recovery of S. neurona merozoites purified by filter pad and filter paper was 40% and 30% with 76% and 83% purity, respectively. The same procedures were applied to purify B. darlingi tachyzoites from cultured cells. Of the original cultured B. darlingi tachyzoites, 94% (+/-2.5) were recovered from the PD-10 column with 96.5%, purity whereas percentage recovery of B. darlingi tachyzoites purified by filter pad and filter paper were 51% and 35% with 84% and 88% purity, respectively. All described methods maintained sterility so that purified parasites could be subsequently cultured in vitro. However, purification using a PD-10 column minimized parasite loss and the loss of viability as determined by the trypan blue dye exclusion assay, the rate of parasite production, and plaque forming efficiency in cell culture. Moreover, column-purified parasites improved the sensitivity of an immuno-fluorescent (IFA) analysis and real-time quantitative PCR assays targeted to parasite 18S ribosomal DNA and hsp70 genes. This technique appears generally applicable for purifying coccidia grown in cell cultures.

Fourteen miniature donkeys (Equus asinus) in a mid-Michigan herd of 38 animals presented with clinical signs of besnoitiosis, including the presence of typical tissue cysts in the ocular sclera, the buccal and nasal mucosa, together with characteristic dermatitis in specific areas of the body. The common histopathological change seen was the presence of many 100-200-microm diameter, thick walled, typical Besnoitia sp. tissue cysts together with a chronic cellular response associated with degenerating cysts. Microscopy of isolated scleral cysts and skin biopsies showed the presence of protozoal organisms consistent in morphology with that of Besnoitia bennetti bradyzoites. Molecular analysis of these parasites indicates that they differ from previously described coccidia, including Besnoitia sp., from rabbits and opossums. Isolated cases of infection with this agent have been reported infrequently in equids; however, this is the first report of an outbreak in a herd of donkeys in the United States.

The Sarcocystidae comprise a diverse, monophyletic apicomplexan parasite family, most of whose members form intracellular cysts in their intermediate hosts. The extent of pathology associated with such cyst formation can range widely. We currently lack experimental animal models for many of these infections. Here we explored dexamethasone treatment as a means to render outbred mice susceptible to Besnoitia darlingi infection and demonstrated that this approach allows viable parasites to be subsequently isolated from these mice and maintained in tissue culture. Besnoitia bradyzoites recovered from crushed cysts derived from naturally infected opossums (Didelphis virginiana) replicated and reproduced the development of besnoitiosis in mice treated with dexamethasone (0.5 mg/ml drinking water) daily for 12 days post infection (DPI). Isolates recovered from the peritoneal exudates of these mice were viable and were maintained in long-term tissue cultures. In contrast, control mice given saline without dexamethasone and challenged with similar bradyzoites remained clinically normal for up to 70 DPI. An additional group of mice challenged with the same inoculum of bradyzoites and given dexamethasone at the same concentration and treated with sulfadiazine (1 mg/ml drinking water) daily for 12 DPI also remained normal for up to 70 DPI. Severe disease developed more rapidly in dexamethasone-treated mice inoculated with culture-derived B. darlingi tachyzoites than in those inoculated with cyst-derived bradyzoites. B. darlingi tachyzoite-infected, untreated control mice developed signs of illness at 18 DPI. In contrast, mice treated with sulfadiazine showed no clinical signs up to 50 DPI. Although dexamethasone treatment was required to establish B. darlingi infection in outbred mice inoculated with opossum-derived B. darlingi bradyzoites, no such treatment was required for mice inoculated with culture-derived B. darlingi tachyzoites. Finally, sulfadiazine was highly effective in protecting mice from infection with the tachyzoite stage of B. darlingi.

From April 1996 to December 2002 the prevalence of Sarcocystis neurona sporocysts in North American opossum (Didelphis virginiana) in Southern Michigan was estimated. Sporocysts of S. neurona were found in intestinal scrapings from 31 (15%) of 206 examined opossum. The frequency of infection was higher in adult animals (26/206; 12.6%) and females (19/206; 9.2%) than in juveniles (5/206; 2.4%) and males (12/206; 5.8%). Also, prevalence of S. neurona sporocysts in opossums in relation to factors such as age, sex, season, body condition, presence of concomitant infection, and presence of young in the pouch of females was studied in detail over the course of the year, 2002. Univariate analyses identified the following factors as being associated with the presence of S. neurona sporocysts in opossums: (i) for age, adult (odd ratio [OR] = 2.074, P = 0.0005); (ii) for sex, female (OR = 7.016, P = 0.0119); (iii) for season, summer (OR = 7.917, P = 0.0032) and spring (OR = 4.071, P = 0.1063); (iv) for body condition, poor (OR = 3.50, P = 0.1200) and good (OR = 1.167, P = 0.8637); (v) for the presence of concomitant infection (OR = 23.056, P = 0001), and (vi) for the presence of young in the pouch of females (OR = 40.083, P = 0.0001). Multivariate logistic-regression analyses selected the following factors as being significantly associated with presence of S. neurona sporocysts in opossums: (i) for the presence of concomitant infection (OR = 8.722, P = 0.0160) and (ii) for the presence of young in the pouch of females (OR = 31.915, P = 0.0065). The prevalence of S. neurona sporocysts in D. virginiana suggests that this opossum may constitute an ample reservoir of infection to other animals in the northern United States.

Sarcocystis neurona has become recognized as the major causative agent of equine protozoal myeloencephalitis (EPM) in the Americas. At least 3 pathogenic species of Sarcocystis, including S. neurona, can be isolated from opossums. Methods are needed to ascertain whether these isolates are viable and capable of causing infections. In this study, the nuclear stain propidium iodide (PI) was used to differentiate between live (viable) and heat-killed (nonviable) S. neurona sporocysts. PI was excluded by live sporocysts but penetrated compromised sporocyst membrane and stained sporozoite nuclei of dead sporocysts. After live and dead sporocysts were mixed at various ratios, the number of unstained sporocysts detected after the staining procedure correlated significantly (r2 = 0.9978) with the expected numbers of live sporocysts. Sporocyst mixtures were also assayed for in vitro excystation and development in tissue cultures. The correlation between the percentage of plaques formed in tissue cultures and the percentage of expected infectious (live) sporocysts in each mixture was r2 = 0.6712. By analysis of variance, no statistically significant difference was measured between the percentage of viable sporocysts and the percentage of infectious sporocysts (P = 0.3902) in each mixture. In addition, there was evidence of a relation between PI impermeability of sporocysts and animal infectivity. These results suggest that the PI dye-exclusion technique can be a useful tool in identifying viability and potential infectivity of S. neurona sporocysts and in differentiating between viable and nonviable sporocysts.

Opossums (Didelphis virginiana) are exposed to a wide range of coccidia through feeding on a variety of foods, including, but not limited to, carrion, insects, and nestling birds. Abundant D. virginiana populations in urban and suburban areas can be important reservoirs of parasitic infection because of their profuse and prolonged excretion of the sporocysts of several species of Sarcocystis, their omnivorous diet, and their relatively long life span. This report describes 2 adult female opossums found to be simultaneously infected with the tissue cysts of Besnoitia darlingi, sarcocysts of Sarcocystis inghami, as well as with the intestinal sporocysts of S. neurona. Cysts typical of B. darlingi based on gross, histological, and ultrastructural charac- teristics were disseminated throughout the visceral organs, musculature, ears, and skin. The S. neurona and B. darlingi infections were confirmed by comparative sequence analysis of polymerase chain reaction-amplified diagnostic genetic loci. Sarcocysts of S. inghami are also described. Such examples of multiple parasitic infec- tions show that concurrent infections occur naturally. The propensity for species to coexist should be considered in the differential diagnosis of tissue cyst-forming coccidian protozoa and may have important epidemiological and evolutionary implications. The role of the North American Virginia opossums (Di- delphis virginiana) in the epidemiology of coccidian para- sites is not fully understood. Heteroxenous apicomplexans of the family Sarcocystidae generally require a herbivorous or omnivorous intermediate host and a carnivorous definitive host. 14 How extensive a role opossums play in disseminating specific coccidians has yet to be fully defined. Because opos- sums consume a wide variety of foods, they would appear vulnerable to ingesting tissue cysts of many coccidian spe- cies. In addition, opossums ingesting sporocysts excreted by other carnivores risk becoming intermediate hosts of other coccidian species. 15 Such is the case for Besnoitia darlingi, for which cats serve as definitive hosts and shed oocysts that are ingested by opossums, which serve as intermediate hosts. Because opossums have few marsupial relatives in the New World, and none throughout much of their North American range, they represent an interesting model to understand the capacity of phylogenetically unrelated hosts to exchange par- asites as a consequence of shared feeding behavior. Although most experimental studies to elucidate the life history of par- asites are restricted to inoculation with a single species, wildlife often simultaneously harbor multiple parasitic infec- tions. Besnoitia darlingi infections are prevalent in opos- sums (D. virginiana) of the United States. 5 Also, opossums

This report describes a new, inexpensive procedure for the rapid and efficient purification of Sarcocystis neurona sporocysts from opossum small intestine. S. neurona sporocysts were purified using a discontinuous potassium bromide density gradient. The procedure provides a source of sporocyst wall and sporozoites required for reliable biochemical characterization and for immunological studies directed at characterizing antigens responsible for immunological responses by the host. The examined isolates were identified as S. neurona using random amplified polymorphic DNA primers and restriction endonuclease digestion assays. This method allows the collection of large numbers of highly purified S. neurona sporocysts without loss of sporocyst viability as indicated by propidium iodide permeability and cell culture infectivity assays. In addition, this technique might also be used for sporocyst purification of other Sarcocystis spp.

Multiresistant Shiga toxin-producing Escherichia coli (STEC) O118:H16 and O118 nonmotile strains (designated O118:[H16]) were detected by examination of 171 STEC isolates for their antimicrobial sensitivity. Of 48 STEC O118:[H16] strains, 98% were resistant to sulfonamide, 96% were resistant to streptomycin, 79% were resistant to kanamycin, 75% were resistant to tetracycline, 67% were resistant to ampicillin, 60% were resistant to chloramphenicol, 48% were resistant to trimethoprim, and 10% each were resistant to gentamicin and nalidixic acid. Nalidixic acid resistance and reduced susceptibility to ciprofloxacin were associated with the mutation gyrA LEU-83 . The STEC O118:[H16] strains were found to belong to a single genetic clone as investigated by multilocus enzyme electrophoresis and by multilocus sequence analysis of E. coli housekeeping genes. The STEC O118:[H16] strains originated from humans and cattle and were isolated in seven different countries of Europe between 1986 and 1999. Strains showing multiresistance to up to eight different antimicrobials predominated among the more recent STEC O118:[H16] strains. The genes in parentheses were associated with resistance to kanamycin ( aphA1-Ia ), chloramphenicol ( catA1 ), tetracycline [ tet (A)], and ampicillin ( bla TEM-1 ). Class 1 integrons containing sulI (sulfonamide resistance), aadA1a (streptomycin resistance), or dfrA1 (trimethoprim resistance) -aadA1a gene cassettes were detected in 28 strains. The bla TEM-1b gene was present in 18 of 21 strains that were examined by nucleotide sequencing. Class 1 integrons and bla TEM genes were localized on plasmids and/or on the chromosome in different STEC O118:[H16] strains. Hybridization of Xba I-digested chromosomal DNA separated by pulsed-field gel electrophoresis revealed that bla TEM genes were integrated at different positions in the chromosome of STEC O118:[H16] strains that could have occurred by Tn 2 insertion. Our data suggest that strains belonging to the STEC O118:[H16] clonal group have a characteristic propensity for acquisition and maintenance of resistance determinants, thus contrasting to STEC belonging to other serotypes.

International audience; The aim of this review is to provide a comprehensive update on the biology, epidemiology, clinical features, diagnosis, treatment, and prevention of canine cardio-pulmonary angiostrongylosis. This cardiopulmonary disease is caused by infection by the metastrongyloid nematode Angiostrongylus vasorum. The parasite has an indirect life cycle that involves at least two different hosts, gastropod molluscs (intermediate host) and canids (definitive host). A. vasorum represents a common and serious problem for dogs in areas of endemicity, and because of the expansion of its geographical boundaries to many areas where it was absent or uncommon; its global burden is escalating. A. vasorum infection in dogs can result in serious disorders with potentially fatal consequences. Diagnosis in the live patient depends on faecal analysis, PCR or blood testing for parasite antigens or anti-parasite antibodies. Identification of parasites in fluids and tissues is rarely possible except post mortem, while diagnostic imaging and clinical examinations do not lead to a definitive diagnosis. Treatment normally requires the administration of anthelmintic drugs, and sometimes supportive therapy for complications resulting from infection.

The aim of this study was to determine the prevalence of amoebic infection in non-human primates (NHPs) from six Zoological gardens in the United Kingdom. Initially, 126 faecal samples were collected from 37 individually identified NHPs at Twycross Zoo, UK, and were subjected to microscopic examination. A subsequent, nationwide experiment included 350 faecal samples from 89 individually identified NHPs and 73 unidentified NHPs from a number of UK captive wildlife facilities: Twycross Zoo (n = 60), Colchester Zoo (n = 3), Edinburgh Zoo (n = 6), Port Lympne Wild Animal Park (n = 58), Howletts Wild Animal Park (n = 31), and Cotswold Wildlife Park (n = 4). Samples were examined by PCR and sequencing using four specific primer sets designed to differentiate between the pathogenic E. histolytica, the non-pathogenic E. dispar, and non-pathogenic uninucleate cyst-producing Entamoeba species. In the first experiment, Entamoeba was detected in 30 primates (81.1%). Six (16.2%) primates were infected with E. histolytica species complex. The highest carriage of Entamoeba species was found in Old World Colobinae primates. In the nationwide experiment, molecular analysis of faecal samples revealed notable rates of Entamoeba infection (101 samples, 28.9%), including one sample infected with E. histolytica, 14 samples with E. dispar, and 86 samples with uninucleated-cyst producing Entamoeba species. Sequences of positive uninucleated-cyst producing Entamoeba samples from Twycross Zoo clustered with the E. polecki reference sequences ST4 reported in Homo sapiens, and are widely separated from other Entamoeba species. These findings suggest a low prevalence of the pathogenic Entamoeba infection, but notable prevalence of non-pathogenic E. polecki infection in NHPs in the UK.

Background The survival of the intracellular protozoan parasite Neospora caninum depends on its ability to adapt to changing metabolic conditions of the host cell. Thus, defining cellular and metabolic changes in affected target tissues may aid in delineating pathogenetic mechanism. We undertook this study to assess the metabolic response of human brain microvascular endothelial cells (HBMECs) to N. caninum infection in vitro. Methods HBMECs were exposed to N. caninum infection and the cytotoxic effects of infection were analyzed by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazoliumbromidin (MTT) assay and lactate dehydrogenase (LDH) release assay. Metabolic footprinting of the extracellular metabolites of parasite-infected and non-infected culture supernatant was determined by using targeted (Randox RX Imola clinical chemistry analyser) and unbiased RS (Raman microspectroscopy) approaches. Results The MTT assay did not reveal any cytotoxic effect of N. caninum challenge on host cell viability. Measurement of LDH activity showed that N. caninum significantly induced loss of cell membrane integrity in a time-dependent and dose-dependent manner compared to control cells. Targeted biochemical analysis revealed that beta hydroxybutyrate, pyruvate, ATP, total protein, non-esterified fatty acids, and triglycerides are significantly different in infected cells compared to controls. RS-based footprinting with principal component analysis (PCA) were able to correctly distinguish extracellular metabolites obtained from infected and control cultures, and revealed infection-related spectral signatures at 865 cm−1, 984 cm−1, 1046 cm−1, and 1420 cm−1, which are attributed to variations in the content of lipids and nucleic acids in infected cultures. Conclusions The changing pattern of extracellular metabolites suggests that HBMECs are target of metabolic alterations in N. caninum infection, which seem to reflect the changing metabolic state of infected cells and constitute a level of information exchange that host and parasite use to coordinate activities.

A 10-year-old horse developed ataxia and incoordination and was submitted for necropsy after euthanasia. The main gross postmortem finding was of bilateral renal masses, and a renal carcinoma had been suspected. Also, nematodes were present in histological sections of the cervical spinal cord. The microscopic feature was marked granulomatous inflammation, in both kidneys and local lymph nodes, and the clinical and morphologic features of this case resemble those observed in other reports of Halicephalobus gingivalis infection in horses. Aspects of the pathogenesis and pathology are discussed. Infection with H gingivalis should be included in the differential diagnosis of horses with acute neurological disease. However, lesions of H gingivalis are likely to be present in other organs that may be clinically inapparent. Owing to the widespread geographic distribution of H gingivalis and its zoonotic potential, this parasite poses a risk to animal and human health.

To the Editor Helicobacter pylori is a major gastroduodenal pathogen affecting about half of the world population (Taylor and Blaser 1991). It causes persistent gastritis and peptic ulceration and is directly linked to the development of various gastric malignant diseases (Huang et al. 1998; Uemura et al. 2001). Prevalence of H. pylori infection (Rowland et al. 2006) and the annual “true” reinfection rates (Zhang et al. 2009) are higher in developing countries than in developed countries and can vary by ethnicity, host genetics, place of birth, and socioeconomic factors. Differences in the incidence and severity of H. pylori infection can be attributed to differences in H. pylori strain virulence or the host’s capacity to control H. pylori infection due to altered immune responses caused by concurrent infection and/or environmental factors (Kusters et al. 2006). Helminth infections are estimated to infect three billion people worldwide (Crompton and Nesheim 2002). Schistosomiasis is helminth infection caused by the blood flukes of the genus Schistosoma. Despite intensive control efforts, disease caused by these worms remains a major public health concern in Egypt and +74 developing countries (Savioli et al. 1997). Although schistosomiasis is endemic in Egypt where H. pylori is a widespread problem and coinfections are frequent, limited data exist on the effects of schistosomiasis on the severity of H. pylori infection (Elshal et al. 2004). For the correct clinical management of H. pylori disease, obtaining thorough information on the other concurrent infections is essential. Here, we thought to compare the gastric pathologies in H. pylori-infected mice with concurrent Schistosoma mansoni infection with those infected with H. pylori alone. Eight-week-old CD1 age-matched female outbred albino mice (n=20) were obtained from Theodor Bilharz Research Institute, Cairo, Egypt. Mice were divided into four groups, each of five mice. Group (i) includes mice infected with S. mansoni and challenged with H. pylori 5 weeks after parasite infection, group (ii) includes mice challenged with H. pylori alone, group (iii) includes mice infected with S. mansoni alone, and group (iv) includes healthy noninfected control mice. Mice were infected with 60 S. mansoni cercariae of an Egyptian strain as described (Elsheikha et al. 2008). For challenge with H. pylori, mice were inoculated intragastrically with a single dose of 0.1 ml of Helicobacter suspension (10 bacteria) and then observed for an additional 2 weeks. All mice were euthanized at 7 weeks post-S. mansoni infection (i.e., 2 weeks after bacterial infection). Animal infection was conducted according to protocols approved by the Animal Care and Ethics Committee at Mansoura University, Egypt. Parasitol Res (2009) 105:297–299 DOI 10.1007/s00436-009-1486-x

Background The brain is the most commonly affected organ during Neospora caninum infection but the mechanisms utilized by this protozoan parasite for traversal of the blood–brain barrier (BBB) are not yet understood. Herein, we investigate the cellular pathogenicity of N. caninum infection on bioenergetics of human brain microvascular endothelial cells (HBMECs), a fundamental component of the BBB. Methods We tracked the growth kinetics of N. caninum in HBMECs. Focusing on cell bioenergetics, oxygen consumption rate (OCR) was determined using Clark electrode system and mitochondrial membrane potential (ΔΨm) was evaluated using DePsipher staining by fluorescence microscopy in the presence and absence of infection. Results HBMECs provided a receptive environment for parasite proliferation. N. caninum tachyzoites were able to invade and replicate within HBMECs without significantly altering cell proliferation rate, as measured with the MTT assay, up to 24 hr post infection (pi). The oxygen consumption rate (OCR) was significantly inhibited (p 6 cell min-1 and from −0.29±0.09 to −0.16±0.1 nmol 106 cell min-1 for uninfected HBMECs and free N. Caninum tachyzoites, respectively]. After normalization for DNA content the basal OCR did not differ between two host cell types: HBMECs and K562. The OCR of HBMECs was significantly elevated 24 hr pi in the absence of substrate, in 10 mM glucose and in the presence of a tetramethyl-p-phenylenediamine (TMPD)/ascorbate redox shuttle. Although quantitatively similar results were observed for uninfected K562 cells, there was no effect on their OCR 24 hr pi with N. caninum under any of the above substrate conditions. 6mM azide abolished OCR in all situations. Mitochondrial staining with DePsipher indicated no change in their membrane potential (Δψm) up to 24 hr pi. Conclusions N. caninum is able to grow in HBMECs without markedly disrupting their normal proliferation or mitochondrial integrity. However, it is associated with an increase in infected cell respiration. Whether this increase reflects numeric addition of the parasites own respiration or results from an additional energy demand upon the host cell remains to be elucidated.

Chemotherapy remains the foremost available tool for the control of nematode parasites. However, the substantial use of anthelmintics, combined with a scarcity of new anthelmintic classes, has led to a gradual increase in the resistance of nematode parasites to these compounds. Multi-Drug Resistance (MDR) in economically important livestock nematodes, such as

AS colleagues will be aware, from January 1, 2012, the regulations under the Pet Travel Scheme (PETS) for dogs and cats entering the UK will change. While it is anticipated that tapeworm treatment before entry into the UK will be retained with the agreement of the European Parliament, tick treatment will no longer be required. Every effort needs to be made to ensure that the European Parliament approves the retention of tapeworm treatment, as the risk of Echinococcus multilocularis being introduced into the UK is considerably diminished by a tapeworm treatment (Torgerson and Craig 2009). It is our concern that removal of the requirement to treat animals with an approved acaricide before they enter the UK is likely to result in …

Despite the increasing knowledge of the immunobiology and epidemiology of parasitic helminths of the gastrointestinal system and the cardiorespiratory system, complications arising from infections of animals and humans with these parasites are a major clinical and economic problem. This has been attributed to the high incidence of these parasites, the widespread emergence of multi-drug resistant parasite strains and the lack of effective vaccines. Efforts to develop and produce vaccines against virtually all helminths (with the exception of Dictyocaulus viviparus and some cestode species) have been hindered by the complexity of the host-parasite relationship, and incomplete understanding of the molecular and immune regulatory pathways associated with the development of protective immunity against helminths. Novel genomic and proteomic technologies have provided opportunities for the discovery and characterisation of effector mechanisms and molecules that govern the host-parasite interactions in these two body systems. Such knowledge provided clues on how appropriate and protective responses are elicited against helminths and, thus, may lead to the development of effective therapeutic strategies. Here, we review advances in the immune response to selected helminths of animal health significance, and subsequent vaccine potential. The topics addressed are important for understanding how helminths interact with host immune defences and also are relevant for understanding the pathogenesis of diseases caused by helminths.

Liver flukes belonging to the genus Fasciola are among the causes of foodborne diseases of parasitic etiology. These parasites cause significant public health problems and substantial economic losses to the livestock industry. Therefore, it is important to definitively characterize the Fasciola species. Current phenotypic techniques fail to reflect the full extent of the diversity of Fasciola spp. In this respect, the use of molecular techniques to identify and differentiate Fasciola spp. offer considerable advantages. The advent of a variety of molecular genetic techniques also provides a powerful method to elucidate many aspects of Fasciola biology, epidemiology, and genetics. However, the discriminatory power of these molecular methods varies, as does the speed and ease of performance and cost. There is a need for the development of new methods to identify the mechanisms underpinning the origin and maintenance of genetic variation within and among Fasciola populations. The increasing application of the current and new methods will yield a much improved understanding of Fasciola epidemiology and evolution as well as more effective means of parasite control. Herein, we provide an overview of the molecular techniques that are being used for the genetic characterization, detection and genotyping of Fasciola spp.., This work was supported, in part, by the National S & T Major Program (Grant No. 2008ZX10004-011, 2009ZX10004-302, 2009ZX10004-201), the National Key Technology R & D Program (Grant No. 2008BAI56B03), the State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, the Yunnan Provincial Program for Introducing High-level Scientists (Grant No. 2009CI125) and the Program for Changjiang Scholars and Innovative Research Team in University (Grant No. IRT0723).

Acanthamoeba granulomatous encephalitis generally develops as a result of haematogenous spread, but it is unclear how circulating amoebae enter the central nervous system (CNS) and cause inflammation. At present, the mechanisms which Acanthamoeba use to invade this incredibly well-protected area of the CNS and produce infection are not well understood. In this paper, we propose two key virulence factors: mannose-binding protein and extracellular serine proteases as key players in Acanthamoeba traversal of the blood–brain barrier leading to neuronal injury. Both molecules should provide excellent opportunities as potential targets in the rational development of therapeutic interventions against Acanthamoeba encephalitis.

The helminth parasite Fasciola hepatica is responsible for major economic losses in agriculture throughout temperate regions of the globe. Control measures are heavily reliant on chemotherapy resulting in the emergence of drug resistant parasite populations. Novel control strategies based on vaccination ultimately require a deeper knowledge of host-parasite interactions. Herein we discuss recent advances in the understanding of the immune response to F. hepatica placing them in context with previous knowledge and developments from other model systems. Advances in RNAi and proteomics in the context of helminth research should make target identification and characterisation more rapid. In parallel, integration of these technologies with better immunological understanding will be crucial for future research into F. hepatica control measures.

Facilitated clinical relevance (FCR) at the University of Nottingham School of Veterinary Medicine and Science is a small-group educational model that promotes student-centered learning. The objectives of this study were: (1) to examine students’ opinions of FCR as a learning approach compared with other teaching methods; and (2) to establish if gender, year of study, or prior exposure to FCR were predictors of attitude. Questionnaires were distributed to undergraduate veterinary students (N = 185) in the first and second year of study. Students’ opinions were assessed by noting their degree of agreement with seven statements using a seven-point Likert-type scale. A total of 162 students (87.6%) completed the survey instrument. The findings indicate that FCR is highly valued among the students. The majority of students regarded FCR as directly relevant for clinical preparation because it helps them to integrate pre-clinical and clinical knowledge and skills in veterinary medicine. However, commonly identified challenges were peer dominance, less cooperative facilitators, and coping with the ambiguity of knowledge and reasoning. No significant differences were detected in attitude between students in the tested variables (p > 0.05). However, being in the first year of study, being male, and having prior exposure to FCR was found to predict a negative attitude (p < 0.006). To increase students’ satisfaction, effective strategies must be designed and implemented to provide support for struggling individuals.

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

The sero-markers of Toxoplasma gondii and oxidative stress (OS) were determined in a group of 260 blood donors attending blood banks in Greater Cairo. Twenty-four blood donors with the highest anti-T. gondii IgG titre were tested for IgG avidity. Of whom 4 (16.6%) had low IgG avidity antibodies, documenting recent infection, 6 (25%) had borderline avidity and 14 (58.3%) showed high avidity, ruling out recent infection. The plasma level of malondialdehyde (MDA) was significantly higher and activity of glutathione peroxidase (GSH-Px) and level of tocopherol (alpha, gamma,lambda) fractions (P0.001) were lower in T. gondii-seropositive than in seronegative blood donors. This significant alteration in redox status between seropositive and seronegative donors suggested a degradation of their antioxidant enzymes caused by OS induced by increased free radicals attributable to toxoplasmosis infection. T. gondii infection also had a prominent influence on the association between OS biomarkers and immune-suppression status in seropositive donors.

Parasitic diseases at the wildlife/primate/human interface are of particular importance in zoological gardens. Better understanding of the types of wildlife parasites that do persist in zoological gardens, and drives that lead to increases in prevalence or impacts, can point to new strategies for limiting the risk of human and captive primates' exposure in zoo centres. Also, it improves our understanding of the underlying mechanisms that influence the emergence of parasitic diseases. As wild animals and humans come into greater contact with each other, the risk posed by multi-host parasites for humans, captive primates, and wildlife populations increases. Despite strong public awareness of the fact that wildlife constitutes a large and often unknown reservoir of most emerging infectious diseases, animal-human interaction has not been addressed. Herein, the potential for cross-species parasite transmission between the wild rodents, captive primates and humans is considered using the current literature and medical records. Additionally, some aspects of the interface among wildlife, captive primates and humans and its impacts on human health are discussed. Finally, priorities for future research are identified, including identifying those parasites for which multi-host interaction is likely to have the greatest impact.

A cross-sectional study was conducted to evaluate the prevalence and risk factors of Toxoplasma gondii antibodies in 260 blood donors seen at blood banks, Mansoura University Hospital, Egypt. Blood donors were interviewed about sociodemographic characteristics and risk factors for T. gondii infection. A blood sample was taken to document the T. gondii antibody status by using ELISA. Overall, 155 (59.6%) of 260 blood donors were positive for anti-T. gondii IgG antibodies. Multivariate logistic regression analysis showed a significant association between T. gondii positivity and eating processed meat as luncheon and/or shawerma (adjusted odds ratio [OR] 80.82 [95% CI 18.62-350.81], P0.0001) or being non-educated (adjusted OR 32.25 [95% CI 7.46-139.44], P0.0001). These findings highlight the prevalent T. gondii among blood donors and focused on the risk factors.

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 L1 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.

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.

A cross-sectional survey was conducted to monitor and compare the prevalence of helminthes in rodents from Dakahlia and Menoufia governorates. The domestic rodents (271) were Rattus norvegicus, Rattus rattus frugivorous, Rattus r. alexandrinus,Mus musculus. The overall prevalence of helminthes was 52.8%. In Dakahlia, 72/145 rats (49.6%) were infected. The highest prevalence of infection was in R. r. frugivorous 43 (60.4%), then R. r. alexandrinus 44 (47.7%), R. norvegicus 38 (44.7%), and the lowest was M. musculus 20 (40%). In Menoufia, 71/126 rats (56.3%) were infected. The highest prevalence of infection was in R. r. frugivorous 36 (77.7%), then M. musculus 27 (48.1%), R. norvegicus 23 (47.8%), and the lowest was in R. r. alexandrinus 40 (47.5%). A total of 24 species of helminthes (11 trematodes, 4 cestodes10 nematodes) were identified among the 271 rodents. The commonest trematode was Mesostephanus aegypticus followed by Stictodora tridactyla. The commonest cestode was Hymenolepis diminuta followed by Taenia taeniaformis. The commonest nematode was Capillaria hepatica followed by Trichurus muris. Given the zoonotic potential of rodents' parasites and since several residential, commercial, and agricultural sites exist in the examined geographic areas, the potential health risk should not be ignored.

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.

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.