Prevalence of intestinal parasite infections in stray and farm dogs from Spain.

Dogs play a potential role as reservoirs for zoonotic parasites, being especially problematic uncontrolled dog populations such as stray and farm dogs with access to populated areas. In order to investigate the prevalence of canine intestinal parasites in at-risk dog populations, we tested a total of 233 faecal samples shed by stray and dairy farm dogs from northern Spain. Telemann method was used to detect the presence of eggs and (oo)cysts of common dog intestinal parasites and Cryptosporidium was detected by PCR. One hundred and forty eight out of 233 samples (63.5%) were positive for at least one intestinal parasite, being Ancylostomidae (35.6%; 83/233) and Trichuris (35.2%; 82/233) the parasites most frequently identified. Cryptosporidium DNA was not detected in any of the faecal samples analysed. The overall prevalence was significantly higher in stray dogs than in farm dogs (72.5% vs 58.8%). Specifically, stray dogs had a significantly higher prevalence of Ancylostomatidae, Toxocara, Toxascaris and Taenidae. These dog populations are an important source of environmental contamination with intestinal parasite forms, which could be of significance to animal and human health.

Prevalence of intestinal parasite infections in stray and farm dogs from Spain / Prevalência de infecções por parasitos intestinais em cães errantes e de fazenda na Espanha

Abstract Dogs play a potential role as reservoirs for zoonotic parasites, being especially problematic uncontrolled dog populations such as stray and farm dogs with access to populated areas. In order to investigate the prevalence of canine intestinal parasites in at-risk dog populations, we tested a total of 233 faecal samples shed by stray and dairy farm dogs from northern Spain. Telemann method was used to detect the presence of eggs and (oo)cysts of common dog intestinal parasites and Cryptosporidium was detected by PCR. One hundred and forty eight out of 233 samples (63.5%) were positive for at least one intestinal parasite, being Ancylostomidae (35.6%; 83/233) and Trichuris (35.2%; 82/233) the parasites most frequently identified. Cryptosporidium DNA was not detected in any of the faecal samples analysed. The overall prevalence was significantly higher in stray dogs than in farm dogs (72.5% vs 58.8%). Specifically, stray dogs had a significantly higher prevalence of Ancylostomatidae, Toxocara, Toxascaris and Taenidae. These dog populations are an important source of environmental contamination with intestinal parasite forms, which could be of significance to animal and human health.

Resumo Os cães desempenham um importante papel como reservatório de parasitos zoonóticos, sendo especialmente problemáticas as populações descontroladas, como a de cães errantes e de fazenda, com acesso às áreas povoadas. Para investigar a prevalência de parasitos intestinais em populações caninas de risco, foram analisadas 233 amostras fecais provenientes de cães de fazendas leiteiras e errantes do norte da Espanha. O método Telemann foi utilizado para detectar ovos, cistos e oocistos dos parasitos caninos mais comuns e para a detecção de Cryptosporidium foi utilizada a técnica da PCR. Cento e quarenta e oito de 233 amostras analisadas (63,5%) foram positivas para pelo menos um parasito intestinal, sendo Ancyostomatidae (35,6%; 83/233) e Trichuris sp. (35,2%; 82/233) os parasitos identificados com maior frequência. O DNA de Cryptosporidium sp. não foi detectado em nenhuma das amostras fecais analisadas. A prevalência geral foi significativamente maior em cães errantes do que em cães de fazenda (72,5% vs 58,8%). Especificamente, os cães errantes tiveram prevalência maior para Ancylostomatidae, Toxocara, Toxascaris e Taenidae. Essas populações de cães são importantes fontes de contaminação ambiental, pois eliminam formas de vida desses parasitos, que podem ter impacto na saúde animal e humana.

Immune response profile of caruncular and trophoblast cell lines infected by high- (Nc-Spain7) and low-virulence (Nc-Spain1H) isolates of Neospora caninum.

BACKGROUND: Bovine neosporosis, one of the main causes of reproductive failure in cattle worldwide, poses a challenge for the immune system of pregnant cows. Changes in the Th-1/Th-2 balance in the placenta during gestation have been associated with abortion. Cotyledon and caruncle cell layers form the maternal-foetal interface in the placenta and are able to recognize and induce immune responses against Neospora caninum among other pathogens. The objective of the present work was to elucidate the immunomodulation produced by high- (Nc-Spain7) and low-virulence (Nc-Spain1H) isolates of N. caninum in bovine trophoblast (F3) and caruncular cells (BCEC-1) at early and late points after infection. Variations in the mRNA expression levels of toll-like receptor-2 (TLR-2), Th1 and Th2 cytokines (IL-4, IL-10, IL-8, IL-6, IL-12p40, IL-17, IFN-γ, TGF-ß1, TNF-α), and endothelial adhesion molecules (ICAM-1 and VCAM-1) were investigated by RT-qPCR, and protein variations in culture supernatants were investigated by ELISA. RESULTS: A similar pattern of modulation was found in both cell lines. The most upregulated cytokines in infected cells were pro-inflammatory TNF-α (P < 0.05-0.0001) and IL-8 (P < 0.05-0.001) whereas regulatory IL-6 (P < 0.05-0.001) and TGF-ß1 (P < 0.05-0.001) were downregulated in both cell lines. The measurement of secreted IL-6, IL-8 and TNF-α confirmed the mRNA expression level results. Differences between isolates were found in the mRNA expression levels of TLR-2 (P < 0.05) in both cell lines and in the mRNA expression levels (P < 0.05) and protein secretion of TNF-α (P < 0.05), which were higher in the trophoblast cell line (F3) infected with the low-virulence isolate Nc-Spain1H. CONCLUSIONS: Neospora caninum infection is shown to favor a pro-inflammatory response in placental target cells in vitro. In addition, significant immunomodulation differences were observed between high- and low-virulence isolates, which would partially explain the differences in virulence.

Differential susceptibility of bovine caruncular and trophoblast cell lines to infection with high and low virulence isolates of Neospora caninum.

BACKGROUND: Neospora caninum, one of the main causes of abortion in cattle, is very effective at crossing the placental barrier and placental damage is crucial in the pathogenesis of abortion. Bovine trophoblast and caruncular cell layers are key cellular components in the maternal-foetal interface in placentomes, playing a fundamental role in placental functionality. METHODS: We studied tachyzoite adhesion, invasion, proliferation and egress of high- (Nc-Spain7) and low- (Nc-Spain1H) virulence N. caninum isolates in established cultures of bovine caruncular epithelial (BCEC-1) and trophoblast (F3) cells. The parasite invasion rate (pInvR) and the cell infection rate (cInfR) were determined by immunostaining plaque assay at different time points and multiplicities of infection (MOIs), respectively. In addition, tachyzoite growth kinetics were investigated using real-time PCR (qPCR) analysis and immunostaining plaque assay at different times. RESULTS: Neospora caninum invaded and proliferated in both cell lines. The pInvR was higher in F3 compared to BCEC-1 cells for the Nc-Spain7 isolate (P < 0.05), and higher for the Nc-Spain7 than the Nc-Spain1H in F3 cells (P < 0.01). The cInfR was also higher in F3 cells than in BCEC-1 cells for both isolates (P < 0.0001), and the cInfR for the Nc-Spain7 isolate was higher than for the Nc-Spain1H isolate in both cell lines (P < 0.05). Tachyzoite growth kinetics showed tachyzoite exponential growth until egress at 58 hpi for both isolates in F3, whereas Nc-Spain1H showed a non-exponential growth pattern in BCEC-1. Asynchronous egress of both isolates was observed from 22 h post-infection onwards in BCEC-1. In addition, the tachyzoite yield (TY58h) was higher in F3 than in BCEC-1 infected by both isolates (P < 0.0001), highlighting better replication abilities of both parasites in F3. Nc-Spain7 showed shorter doubling times and higher TY58h compared to Nc-Spain1H in F3 cells; adhesion, invasion and proliferation mechanisms were very similar for both isolates in BCEC-1. CONCLUSIONS: Our results indicate a highly similar behavior of high- and low-virulence isolates in their interactions with maternal caruncular cells and suggest an important role of foetal trophoblasts in the pathogenesis of N. caninum infection.

EFFECT OF DIFFERENT ECOSYSTEMS AND MANAGEMENT PRACTICES ON TOXOPLASMA GONDII AND NEOSPORA CANINUM INFECTIONS IN WILD RUMINANTS IN SPAIN.

Toxoplasma gondii and Neospora caninum are two major abortifacient protozoans in domestic small ruminants and cattle, respectively, and they also parasitize a wide range of wildlife. Numerous serosurveys have been conducted in wild ruminants worldwide. However, the potential effect of different ecosystems and management practices on these infections has not been investigated. We studied the prevalence of antibodies to T. gondii and N. caninum in wild ruminants between 2007 and 2012 from four national wildlife reserves: three open space reserves in northwest Spain (Ancares, Mampodre, and Riaño) and a fenced reserve in central Spain (Quintos de Mora). Sera from roe deer ( Capreolus capreolus ) and chamois ( Rupicapra rupicapra ) were collected in Ancares (roe deer), Mampodre (both species), and Riaño (both species), whereas red deer ( Cervus elaphus ) sera were collected only in Quintos de Mora. The results of immunofluorescence antibody tests showed a T. gondii antibody prevalence significantly higher in red deer (13%; 17/131) than in roe deer (2%; 5/228) and chamois (4%; 6/149) (P<0.05, Fisher's exact test). Moreover, N. caninum -specific antibodies were only detected in 1% of animals (2/131 red deer, 2/228 roe deer, and 2/149 chamois). Management measures were implemented in the Quintos de Mora reserve and T. gondii antibody prevalence in red deer decreased from 13% to 2% after 5 yr. In contrast, N. caninum antibody prevalences were very low (<2%) over the years. The results suggest a low frequency of sylvatic life cycles in the hunting reservations studied, so interconnection between sylvatic and domestic life cycles is unlikely. Regardless, a sustainable exploitation of natural resources in wildlife reserves may help to reduce the prevalence of T. gondii infection.

Neospora caninum tachyzoite immunome study reveals differences among three biologically different isolates.

Pathogenesis of bovine neosporosis is determined by different host- and parasite-dependent factors, including isolate virulence. A previous study identified that several Neospora caninum tachyzoite proteins were more abundant in virulent isolates, Nc-Liv and Nc-Spain7, compared with the low-virulent isolate Nc-Spain1H. Herein, we explored differences in the immunomes of these three isolates. Protein extracts from the Nc-Liv, Nc-Spain1H and Nc-Spain7 isolates were analysed in a 3×3 design by 2-DE immunoblot using sera from experimentally infected mice with these same three isolates. All isolates displayed a highly similar antigenic pattern when they were assessed using the same serum. Most of the reactive spots were located in the acidic region (pH 3-7) and grouped in 3 antigenic areas (250-70, 45-37 and 35-15 KDa). Differences found in the immunome depended on the sera used, regardless of the extract employed. In this sense, sera from Nc-Liv and Nc-Spain7 infected mice recognized the highest number of antigens, followed by Nc-Spain1H infected mice sera. In fact, 4 proteins identified by MS were not consistently detected in each isolate extract by sera from low-virulent Nc-Spain1H-infected mice: serine-threonine phosphatase 2C and superoxide dismutase (related to metabolism), gliding associated protein GAP45 (related to tachyzoites invasion), and NcGRA1 (located on dense granules). Similarly, 4 non-identified spots and another 2 spots chains located in 45-37 kDa area were not detected by this pooled sera. Variations between virulent Nc-Spain7 and Nc-Liv were limited to the absence of recognition by sera from Nc-Spain7-infected mice of GAP45 and the spot chains located in the 45-37 kDa area. These results suggest that variations in the immunome profiles rely on the immune response induced by each isolate and that these differentially recognized antigens could be investigated as putative virulence markers of neosporosis.

Neospora caninum infection during early pregnancy in cattle: how the isolate influences infection dynamics, clinical outcome and peripheral and local immune responses.

This work studies the influence of Neospora caninum intra-species diversity on abortion outcome, infection dynamics in terms of parasite dissemination and peripheral-local immune responses in pregnant cattle. Animals were intravenously inoculated at day 70 of pregnancy with 107 tachyzoites of two isolates showing marked differences in virulence in vitro and in pregnant mouse models: Nc-Spain7, a high virulence isolate, and Nc-Spain8, a low-to-moderate virulence isolate. After inoculation, pregnancy was monitored, and dams were culled when foetal death was detected. Foetal mortality occurred in all infected heifers between days 24 and 49 post-infection (pi), however, it was detected sooner in Nc-Spain7-infected animals (median day = 34) than those inoculated with Nc-Spain8 (median day = 41) with a trend towards significance (P < 0.11). Similar histological lesions were observed in placentomes and in most of the foetuses from the two infected groups. However, parasites were more frequently detected in the placenta and foetuses by PCR and in the foetal brain by immunohistochemistry in Nc-Spain7-infected animals. Specific antibodies were detected starting at day 13 post-infection in all infected cattle, with higher IgG levels in Nc-Spain7-infected group. IFN-γ and IL-4 profiles also varied between infected groups in PBMC stimulation assays. Infected animals showed significant increases in their cytokine mRNA levels (IFN-γ, IL-4, IL-10, IL-12p40 and TNF-α) in the caruncle at time of foetal death. Differences between the infected groups were also observed for cytokine profiles. These results demonstrate the influence of the N. caninum isolate on foetal death outcome, infection dynamics and immune responses in cattle.

The first report of Cryptosporidium bovis, C. ryanae and Giardia duodenalis sub-assemblage A-II in roe deer (Capreolus capreolus) in Spain.

The aim of the present study was to identify the species and/or genotypes of Cryptosporidium and Giardia duodenalis infecting roe deer (Capreolus capreolus) in Galicia (NW Spain). The presence of both enteropathogens was investigated in 212 faecal samples from roe deer shot in diverse game preserves in three different areas of Galicia. The samples were analyzed by immunofluorescence microscopy and PCR amplification, and fragments of the 18S SSU rRNA gene of Cryptosporidium and the ß-giardin gene of G. duodenalis were sequenced. In total, 9 samples (4.2%) were positive for Cryptosporidium and 19 samples (8.9%) for G. duodenalis. These samples tested positive with both techniques. However, gene sequencing was only possible for Cryptosporidium in 6 of the samples and for G. duodenalis in 7 of the samples. Cryptosporidium bovis was identified in 3 samples and C. ryanae oocysts were detected in another 3 samples. Sequencing of the amplicons identified G. duodenalis sub-assemblage A-II in 7 samples. Both Cryptosporidium and G. duodenalis infections were more prevalent in juvenile than in adult animals, although the differences were not significant. G. duodenalis was more prevalent than Cryptosporidium in both age groups, although again the differences were not statistically significant. The mean intensity of infection by Cryptosporidium and G. duodenalis was similar in both age groups and ranged between 5 and 225 oocysts/g and 5 and 320 cysts/g of faeces, respectively. This study represents the first molecular characterization of these parasites in Spanish roe deer. Identification of C. bovis and G. duodenalis sub-assemblage A-II indicates that zoonotic transmission of these enteropathogens between roe deer and humans is possible and that cross transmission of some Cryptosporidium species and G. duodenalis (sub-assemblage A-II) may occur between related animal species sharing the same habitats.

Presence of Cryptosporidium scrofarum, C. suis and C. parvum subtypes IIaA16G2R1 and IIaA13G1R1 in Eurasian wild boars (Sus scrofa).

The aim of the present study was to identify the species of Cryptosporidium infecting Eurasian wild boars (Sus scrofa) in Galicia (NW, Spain). A sampling of 209 wild boars shot in different game preserves was carried out during the hunting season in 2009-2010. All samples were examined for Cryptosporidium infection, using both immunological and molecular tools. Cryptosporidium oocysts in faecal samples were identified using a direct immunofluorescence technique with monoclonal antibodies (DFA). The presence of Cryptosporidium DNA was determined using nested PCR involving amplification of a fragment of the small-subunit (SSU) ribosomal RNA gene (SSU rRNA). A total of 35 (16.7%) samples tested positive with both techniques. However, sequencing was only possible in 27 samples. Cryptosporidium scrofarum, Cryptosporidium suis and Cryptosporidium parvum oocysts were identified in 19, 5 and 3 of the samples, respectively. Moreover, C. scrofarum was detected as a dominant species infecting all age groups (juveniles, sub adults and adults). Sequence analyses of the glycoprotein (GP60) gene revealed the presence of C. parvum subtypes IIaA16G2R1 in 2 juveniles and IIaA13G1R1 in 1 sub adult wild boar. These species and subtypes have previously been described in human patients, indicating that isolates from asymptomatic wild boars might have zoonotic potential. This is the first report of the presence of C. scrofarum, C. suis and C. parvum subtypes IIaA16G2R1 and IIaA13G1R1 in wild boars (S. scrofa) in Spain.

Detection of a novel genotype of Cryptosporidium in Antarctic pinnipeds.

A study was conducted to investigate the presence of Cryptosporidium and Giardia in Antarctic marine mammals. A total of 270 faecal samples from different species of pinnipeds from different locations in the South Shetland Islands and Antarctic Peninsula were analysed by immunofluorescence microscopy and PCR. Cryptosporidium was detected by PCR in three samples from Southern elephant seals (Mirounga leonina) and 2 Weddell seals (Leptonychotes weddellii). However, no oocysts were observed in any of the samples by immunofluorescence microscopy. Molecular characterisation of the isolates, using the 18S rDNA, the HSP70 and the COWP loci, revealed the presence of a Cryptosporidium sp., previously reported from an Antarctic Southern elephant seal, in the elephant seals and a novel genotype in Weddell seals. Giardia could not be detected in any of the samples analysed.

Detection of Toxoplasma gondii antibodies in Antarctic pinnipeds.

The presence of Toxoplasma gondii antibodies was investigated in Antarctic marine mammals. Two hundred and eleven sera from different species of pinnipeds collected in years 2007, 2010 and 2011 from different locations in the South Shetland Islands and Antarctic Peninsula were analysed using a commercially available agglutination test kit. The presence of antibodies (titres ≥ 1:25) against T. gondii was detected in a total of 28 animals (13.3%). Amongst animal species, percentages of detection were higher in Southern elephant seals (Mirounga leonina) (76.9%; 10/13) followed by Weddell seals (Leptonychotes weddellii) (41.9%; 13/31). Antibodies were also found in 4 of 165 (2.4%) Antarctic fur seals (Arctocephalus gazella) and 1 of 2 Crabeater seals (Lobodon carcinophaga). Highest titres (1:100-1:800) were also observed in Southern elephant seals and Weddell seals. To the best of our knowledge this is the first report on the detection of antibodies against T. gondii in Antarctic marine mammals.

Proteome expression changes among virulent and attenuated Neospora caninum isolates.

Neospora caninum is a cyst-forming parasite that has been recognised worldwide as a cause of cattle abortion and neuromuscular disease in dogs. Variations in genetic profiles, behaviour in vitro, and pathogenicity have been established among N. caninum isolates. However, it is unclear which parasite factors are implicated in this intra-specific diversity. Comparative analysis of protein expression patterns may define the determinants of biological diversity in N. caninum. Using DIGE and MALDI-TOF MS techniques, we quantified and identified differentially expressed proteins in the tachyzoite stage across three N. caninum isolates: the virulent Nc-Liv and Nc-Spain 7 isolates, and the attenuated Nc-Spain 1H isolate. Comparison between Nc-Spain 7 and Nc-Spain 1H extracts revealed 39 protein spots that were more abundant in Nc-Spain 7 and 21 in Nc-Spain 1H. Twenty-four spots were also increased in Nc-Spain 7 and 12 in Nc-Liv. Three protein spots were more abundant in the Nc-Liv extracts than in the Nc-Spain 1H extracts. MS analysis identified 11 proteins differentially expressed that are potentially involved in gliding motility and the lytic cycle of the parasite, and oxidative stress. These differences could help to explain variations in behaviour between isolates and provide a better knowledge of mechanisms associated with virulence.

In vitro invasion efficiency and intracellular proliferation rate comprise virulence-related phenotypic traits of Neospora caninum.

In this study, we examined the in vitro invasion and proliferation capacities of the Nc-Liv and ten Spanish Neospora caninum isolates (Nc-Spain 1 H - Nc-Spain 10). The invasion rate was determined as the number of tachyzoites that completed their internalisation into MARC-145 cells at 2, 4, and 6 h post-inoculation (pi). The proliferation rate was evaluated by determining the doubling time during the exponential proliferation period. Significant differences in the invasion rates of these isolates were detected at 2 and 4 h pi (P < 0.0001, Kruskal-Wallis test). At 4 h pi, the Nc-Spain 4 H and Nc-Liv isolates displayed the highest, while the Nc-Spain 3 H and Nc-Spain 1 H isolates had the lowest invasion rates (by Dunn's test). Variations in the proliferation kinetics of these isolates were also observed. Between different isolates, the lag phase, which occurs before the exponential growth phase, ranged from 8 to 44 h, and the doubling time ranged from 9.8 to 14.1 h (P = 0.0016, ANOVA test). Tachyzoite yield, which combines invasion and proliferation data, was also assessed and confirmed marked differences between the highly and less prolific isolates. Interestingly, a direct correlation between the invasion rates and tachyzoite yields, and the severity of the disease that was exhibited by infected pregnant mice in previous works could be established for the isolates in this study (Spearman's coefficient > 0.62, P < 0.05). The results of this study may help us to explain the differences in the pathogenicity that are displayed by different isolates.

Influence of adjuvant and antigen dose on protection induced by an inactivated whole vaccine against Neospora caninum infection in mice.

In this study, the protection afforded by a Neospora caninum inactivated vaccine formulated with three different adjuvants (water-in-oil emulsion, aluminum hydroxide with CpG oligodeoxynucleotides and aluminum hydroxide with ginseng extract) and three different parasite doses (10(5), 5 × 10(5) or 10(6) inactivated whole tachyzoites) was evaluated using a mouse model. Mice were immunized subcutaneously twice at three-week intervals with inactivated Nc-Spain 1H tachyzoites and challenged by intraperitoneal inoculation with 10(6) live Nc-1 tachyzoites. The efficacy of the immunization was evaluated in non-pregnant BALB/c mice on days 1 and 5 (acute infection phase) and days 14 and 30 (chronic infection phase) post-challenge. The results showed the ability of water-in-oil emulsion combined with inactivated 5 × 10(5) tachyzoites to induce protection against neosporosis during the chronic stage, limiting parasite multiplication in the brain. Aluminum hydroxide-ginseng extract and inactivated tachyzoites reduced the number of parasites circulating in the blood during acute phase but failed to limit the establishment of chronic infection. On the other hand, a dose-effect was observed in groups vaccinated with aluminum hydroxide-ginseng extract in which the lesion severity increased as the inactivated tachyzoite dose. This study demonstrates that efficacy can significantly vary depending on the adjuvant, the dose of antigen and the phase of N. caninum infection in which the vaccine is tested.

Influence of Neospora caninum intra-specific variability in the outcome of infection in a pregnant BALB/c mouse model.

Previous assays in pregnant animals have demonstrated the effect of different host factors and timing of infection on the outcome of neosporosis during pregnancy. However, the influence of Neospora caninum isolate itself has been poorly investigated. Here, we compared the effects on clinical outcome and vertical transmission observed in a pregnant mouse model following infection with 10 different N. caninum isolates. The isolates in our study included the Nc-Liv isolate and nine N. caninum isolates obtained from calves. Female BALB/c mice were inoculated with 2x10(6) tachyzoites at day 7 of pregnancy. Morbidity and mortality, in both dams and offspring during the course of infection, and transmission to progeny at day 30 postpartum were evaluated. The serum IgG1 and IgG2a production in dams were also examined. All dams showed elevated IgG1 and IgG2a responses, confirming N. caninum infection, although signs of disease were only exhibited in dams infected with 4 of the 10 isolates (Nc-Spain 4H, Nc-Spain 5H, Nc-Spain 7 and Nc-Liv). In neonates, clinical signs were observed in all N. caninum-infected groups, and neonatal mortality rates varied from greater than 95% with the isolates mentioned above to less than 32.5% with the other isolates. Vertical transmission rates, as assessed by parasite PCR-detection in neonate brains, also varied from 50% to 100% according to the isolate implicated. These results confirm the wide pathogenic and transmission variability of N. caninum. The intra-specific variability observed herein could help us explain the differences in the outcome of the infection in the natural host.

Microsatellite markers for the molecular characterization of Neospora caninum: application to clinical samples.

We report here on the development of a nested PCR procedure for the application of Neospora caninum microsatellite markers to clinical samples. Genotyping technology by fluorescently labelled DNA fragment analysis was used in combination with DNA sequencing for those markers which show additional SNPs or complex repetitive sequences. Twenty-nine DNA samples from naturally infected bovine aborted foetuses from two regions of Spain where N. caninum had been detected by nested PCR of the ITS1 rRNA region were analysed using these microsatellites. Complete, or almost complete allele profiles were obtained from 18 samples. Two pairs of DNA samples showed identical profiles, these originated from twins and foetuses from the same herd, respectively. The multilocus analysis performed showed sub clustering of isolates according to their geographical origin. These results highlight the usefulness of these markers for the molecular characterization of isolates of N. caninum and for isolate tracking in live vaccine development.

Molecular characterisation of Cryptosporidium isolates from pet reptiles.

In this study, we investigated the presence of Cryptosporidium in 171 faecal samples from reptiles commonly used as pet animals. These include lizards belonging to the genera Eublepharis, Pogona, Chlamydosaurus, Hemiteconyx, Teratoscincus, Tiliqua, Iguana, and Chamaeleo, snakes of the genera Lampropeltis, Elaphe, Python, Boa and Corallus, and tortoises belonging to the genera Testudo and Kinixys. Cryptosporidium oocysts were detected by immunofluorescence using a commercially available kit and cryptosporidial DNA by amplification of a polymorphic fragment of the 18S rDNA and the HSP70 locus. Cryptosporidium was detected in 38.6% and 25.1% of the samples analysed by immunofluorescence and PCR, respectively. Molecular characterisation of the isolates confirmed that C. serpentis and C. varanii (syn. C. saurophilum) are the main species involved in infection in pet reptiles but also showed the presence of C. parvum and C. muris, as well as other species or genotypes of this parasite including the Cryptosporidium mouse genotype and Cryptosporidium tortoise genotype previously described in reptiles. In addition, a Cryptosporidium sp. was isolated from a chameleon and a python.

Molecular approaches to diversity of populations of apicomplexan parasites.

Apicomplexan parasites include many parasites of importance either for livestock or as causative agents of human diseases. The importance of these parasites has been recognised by the European Commission and resulted in support of the COST (Cooperation in Science and Technology) Action 857 'Apicomplexan Biology in the Post-Genomic Era'. In this review we discuss the current understanding in 'Biodiversity and Population Genetics' of the major apicomplexan parasites, namely the Eimeria spp., Cryptosporidium spp., Toxoplasma gondii, Neospora caninum, Theileria spp. and Plasmodium spp. During the past decade molecular tools for characterizing and monitoring parasite populations have been firmly established as an integral part of field studies and intervention trials. Analyses have been conducted for most apicomplexan pathogens to describe the extent of genetic diversity, infection dynamics or population structure. The underlying key question for all parasites is to understand how genetic diversity influences epidemiology and pathogenicity and its implication in therapeutic and vaccination strategies as well as disease control. Similarities in the basic biology and disease or transmission patterns among this order of parasites promote multifaceted discussions and comparison of epidemiological approaches and methodological tools. This fosters mutual learning and has the potential for cross-fertilisation of ideas and technical approaches.

Use of an immunodominant P17 antigenic fraction of Neospora caninum in detection of antibody response in cattle.

A Neospora caninum 17 kDa protein fraction (p17) has been described as an immunodominant antigen (IDA) under reducing and non-reducing conditions. The aim of the present study was to investigate the diagnostic utility of p17 in cattle. In order to achieve this, p17 was purified by electroelution from whole N. caninum tachyzoite soluble extract and a p17-based Western blot (WB-p17) was developed. The p17 recognition was measured by densitometry and expressed as OD values to check the validity of the WB-p17. A total of 131 sera including sequential samples from naturally- and experimentally-infected calves and breeding cattle were analysed by WB-p17 and compared with IFAT using whole formalin-fixed tachyzoites as a reference test. The results obtained highlight the feasibility of using the N. caninum p17 in a diagnostic test in cattle. Firstly, the assay based on the p-17 antigen discriminated between known positive and negative sera from different cattle populations, breeding cattle and calves. Secondly, the p17 antigen detected fluctuations in the antibody levels and seroconversion in naturally- and experimentally-infected cattle. Significant differences in p-17 antigen recognition were observed between naturally infected aborting and non-aborting cattle, as well as significant antibody fluctuations over time in experimentally infected cattle, which varied between groups. Furthermore, the results obtained with WB-p17 are in accordance with the results obtained with the IFAT as high agreement values were obtained when all bovine subpopulations were included (kappa = 0.86).

Multilocus microsatellite analysis reveals extensive genetic diversity in Neospora caninum.

Neospora caninum is a world-wide parasite that causes neuromuscular disorders in dogs and bovine abortion. Biological diversity among isolates has been proved in both in vivo and in vitro studies. In contrast, little is known about the genetic diversity of this parasite. Microsatellite sequence analysis constitutes a suitable tool that has been used for the genetic analysis of other apicomplexan parasites. In this report, we describe the identification and analysis of 13 microsatellite loci from N. caninum DNA sequences deposited in public databases, which were evaluated with the use of 9 isolates grown in vitro. One microsatellite was monomorphic, and the remaining 12 loci exhibited 3 to 9 separate alleles. Multilocus analysis showed that each of the 9 isolates investigated here displayed a unique profile and revealed no association between the genetic similarity and host or geographic origin. The multilocus analysis approach described here might nevertheless provide the powerful tool needed to study the genetic complexity of N. caninum and the molecular epidemiology of neosporosis.