Cystoisospora suis infection in suckling piglets in Brazil: Prevalence and associated factors.

Piglet coccidiosis is a parasitic disease caused by the protozoan Cystoisospora suis, which is regarded as the most prevalent gastrointestinal parasite in intensive pig farms. Despite the availability of highly effective chemo-metaphylaxis (toltrazuril), coccidiosis is still prevalent in European and other countries. We conducted a cross-sectional study on swine farms in Brazil, to assess the prevalence of Cystoisospora suis in fecal samples and determined the associated factors. In total, 666 litters from 50 farms were sampled twice within one week between samplings (mean age at sampling: 10.75 and 17.7 days). Of 666 litters, 225 (33.8%) were positive at least once, and the expected within farm prevalence of C. suis oocysts was 32.9% (25.4-41.3%; 95% confidence interval). Oocysts were more prevalent in fecal samples collected from farms with diarrhea (odds ratio = 6.75). The room temperature was also positively associated with oocyst detection; a one-degree increase in room temperature increased the chance of a litter being positive by 23.2%. Up-to-date, this is the most comprehensive technical evidence of factors associated with C. suis infection in Brazilian industrial piglet farms.

Gestation and breastfeeding in schistosomotic mice differentially alters the expression of histone deacetylases (HDACs) in adult offspring.

BACKGROUND: Breastfeeding or gestation in schistosomotic mothers can cause long-term alterations in the immune response of offspring. OBJECTIVES: Evaluate the expression of histone deacetylases (HDACs) (all classes), the production of cytokines by T and B lymphocytes and macrophages, and the frequency of CD4+CD25+FoxP3+-cells in adult offspring born and/or suckled by schistosomotic mothers. METHODS: We harvested splenocytes from offspring born to (BIM), suckled by (SIM), or born to/suckled by (BSIM) schistosomotic mothers and animals from noninfected mothers (Control) at seven-weeks old and cultured them with/without Concanavalin A. HDAC expression was evaluated by real-time quantitative polymerase chain reaction (qPCR), and cytokines and membrane markers were evaluated by fluorescence-activated cell sorting (FACS). FINDINGS: Compared to Control, BIM mice showed increased expression of HDAC9 and frequency of CD4+IL-10+-cells. The SIM group had increased expression of HDAC1, HDAC2, HDAC6, HDAC7, HDAC10, Sirt2, Sirt5, Sirt6, and Sirt7. The BSIM group only had increased HDAC10 expression. The SIM and BSIM groups exhibited decreased frequencies of CD4+IL-4+-cells and CD4+CD25+FoxP3+-cells, along with a higher frequency of CD14+IL-10+-cells and an increase in CD45R/B220+IL-10+-cells. The BSIM group also showed a high frequency of CD4+IL10+-cells. MAIN CONCLUSIONS: Breastfeeding induced the expression of HDACs from various classes involved in reducing inflammatory responses. However, gestation enhanced the expression of a single HDAC and breastfeeding or gestation appears to favour multiple IL-10-dependent pathways, but not cells with a regulatory phenotype.

The dynamics of ovine gastrointestinal nematode infections within ewe and lamb cohorts on three Scottish sheep farms.

Gastrointestinal nematodes (GIN) are a serious concern for sheep producers worldwide. However, there is a paucity of evidence describing the epidemiology of GIN on modern UK sheep farms. The aim of this paper was to understand whether expected seasonal variations of infection are still found in ewes and lambs under varying management strategies in temperate climates. Faecal egg counts (FEC) were conducted on freshly voided samples collected from groups of ewes and lambs every third week for twelve months on three farms in southeast Scotland. The patterns of egg output have been described here in relation to management practices undertaken on the farms. Despite changes in farming practice and climatic conditions, the findings complement historical studies detailing the epidemiology of GIN. Findings include a periparturient rise in ewe FEC on two of the farms, while lambing time treatment appeared to suppress this on the third farm. On the same two farms lamb FEC increased during the summer, reaching a peak in the autumn. The work also highlights how the ad hoc use of anthelmintics does little to impact these patterns.

Gestation and breastfeeding in schistosomotic mice differentially alters the expression of histone deacetylases (HDACs) in adult offspring

BACKGROUND Breastfeeding or gestation in schistosomotic mothers can cause long-term alterations in the immune response of offspring. OBJECTIVES Evaluate the expression of histone deacetylases (HDACs) (all classes), the production of cytokines by T and B lymphocytes and macrophages, and the frequency of CD4+CD25+FoxP3+-cells in adult offspring born and/or suckled by schistosomotic mothers. METHODS We harvested splenocytes from offspring born to (BIM), suckled by (SIM), or born to/suckled by (BSIM) schistosomotic mothers and animals from noninfected mothers (Control) at seven-weeks old and cultured them with/without Concanavalin A. HDAC expression was evaluated by real-time quantitative polymerase chain reaction (qPCR), and cytokines and membrane markers were evaluated by fluorescence-activated cell sorting (FACS). FINDINGS Compared to Control, BIM mice showed increased expression of HDAC9 and frequency of CD4+IL-10+-cells. The SIM group had increased expression of HDAC1, HDAC2, HDAC6, HDAC7, HDAC10, Sirt2, Sirt5, Sirt6, and Sirt7. The BSIM group only had increased HDAC10 expression. The SIM and BSIM groups exhibited decreased frequencies of CD4+IL-4+-cells and CD4+CD25+FoxP3+-cells, along with a higher frequency of CD14+IL-10+-cells and an increase in CD45R/B220+IL-10+-cells. The BSIM group also showed a high frequency of CD4+IL10+-cells. MAIN CONCLUSIONS Breastfeeding induced the expression of HDACs from various classes involved in reducing inflammatory responses. However, gestation enhanced the expression of a single HDAC and breastfeeding or gestation appears to favour multiple IL-10-dependent pathways, but not cells with a regulatory phenotype.

Maternal schistosomiasis: IL-2, IL-10 and regulatory T lymphocytes to unrelated antigen in adult offspring mice.

INTRODUCTION: We evaluated IL-10, IL-2 and regulatory T cells (Treg), in response to ovalbumin (OA), in offspring from schistosomotic mouse mothers. METHODS: We used animals born (BIM) or suckled (SIM) from infected mothers; and mice born/suckled from infected (BSIM) or non-infected mothers (CONTROL). After OA+adjuvant immunization, spleen cells were cultured, with or without OA, and doubly marked for cytometry. RESULTS: BIM showed fewer CD4+/IL-2+ and more B220+/IL-10+ cells, whereas the SIM group showed increased Treg frequency. BSIM had fewer B220+/IL-10+ and Treg cells. CONCLUSIONS: Separately, gestation or nursing induced immunosuppressive cells in infected mothers, but improved anti-OA immunity when combined.

Maternal schistosomiasis: IL-2, IL-10 and regulatory T lymphocytes to unrelated antigen in adult offspring mice

Abstract INTRODUCTION: We evaluated IL-10, IL-2 and regulatory T cells (Treg), in response to ovalbumin (OA), in offspring from schistosomotic mouse mothers. METHODS: We used animals born (BIM) or suckled (SIM) from infected mothers; and mice born/suckled from infected (BSIM) or non-infected mothers (CONTROL). After OA+adjuvant immunization, spleen cells were cultured, with or without OA, and doubly marked for cytometry. RESULTS: BIM showed fewer CD4+/IL-2+ and more B220+/IL-10+ cells, whereas the SIM group showed increased Treg frequency. BSIM had fewer B220+/IL-10+ and Treg cells. CONCLUSIONS: Separately, gestation or nursing induced immunosuppressive cells in infected mothers, but improved anti-OA immunity when combined.

Gestation and breastfeeding in schistosomotic mothers differently modulate the immune response of adult offspring to postnatal Schistosoma mansoni infection.

Schistosoma mansoni antigens in the early life alter homologous and heterologous immunity during postnatal infections. We evaluate the immunity to parasite antigens and ovalbumin (OA) in adult mice born/suckled by schistosomotic mothers. Newborns were divided into: born (BIM), suckled (SIM) or born/suckled (BSIM) in schistosomotic mothers, and animals from noninfected mothers (control). When adults, the mice were infected and compared the hepatic granuloma size and cellularity. Some animals were OA + adjuvant immunised. We evaluated hypersensitivity reactions (HR), antibodies levels (IgG1/IgG2a) anti-soluble egg antigen and anti-soluble worm antigen preparation, and anti-OA, cytokine production, and CD4+FoxP3+T-cells by splenocytes. Compared to control group, BIM mice showed a greater quantity of granulomas and collagen deposition, whereas SIM and BSIM presented smaller granulomas. BSIM group exhibited the lowest levels of anti-parasite antibodies. For anti-OA immunity, immediate HR was suppressed in all groups, with greater intensity in SIM mice accompanied of the remarkable level of basal CD4+FoxP3+T-cells. BIM and SIM groups produced less interleukin (IL)-4 and interferon (IFN)-g. In BSIM, there was higher production of IL-10 and IFN-g, but lower levels of IL-4 and CD4+FoxP3+T-cells. Thus, pregnancy in schistosomotic mothers intensified hepatic fibrosis, whereas breastfeeding diminished granulomas in descendants. Separately, pregnancy and breastfeeding could suppress heterologous immunity; however, when combined, the responses could be partially restored in infected descendants.

Gestation and breastfeeding in schistosomotic mothers differently modulate the immune response of adult offspring to postnatal Schistosoma mansoni infection

Schistosoma mansoni antigens in the early life alter homologous and heterologous immunity during postnatal infections. We evaluate the immunity to parasite antigens and ovalbumin (OA) in adult mice born/suckled by schistosomotic mothers. Newborns were divided into: born (BIM), suckled (SIM) or born/suckled (BSIM) in schistosomotic mothers, and animals from noninfected mothers (control). When adults, the mice were infected and compared the hepatic granuloma size and cellularity. Some animals were OA + adjuvant immunised. We evaluated hypersensitivity reactions (HR), antibodies levels (IgG1/IgG2a) anti-soluble egg antigen and anti-soluble worm antigen preparation, and anti-OA, cytokine production, and CD4+FoxP3+T-cells by splenocytes. Compared to control group, BIM mice showed a greater quantity of granulomas and collagen deposition, whereas SIM and BSIM presented smaller granulomas. BSIM group exhibited the lowest levels of anti-parasite antibodies. For anti-OA immunity, immediate HR was suppressed in all groups, with greater intensity in SIM mice accompanied of the remarkable level of basal CD4+FoxP3+T-cells. BIM and SIM groups produced less interleukin (IL)-4 and interferon (IFN)-g. In BSIM, there was higher production of IL-10 and IFN-g, but lower levels of IL-4 and CD4+FoxP3+T-cells. Thus, pregnancy in schistosomotic mothers intensified hepatic fibrosis, whereas breastfeeding diminished granulomas in descendants. Separately, pregnancy and breastfeeding could suppress heterologous immunity; however, when combined, the responses could be partially restored in infected descendants.

Selection for anthelmintic resistant Teladorsagia circumcincta in pre-weaned lambs by treating their dams with long-acting moxidectin injection.

Administration of long-acting anthelmintics to pregnant ewes prior to lambing is a common practice in New Zealand. Today, most of these products contain macrocyclic lactone (ML) actives, which because of their lipophilic nature, are detectable in the milk of treated animals and in the plasma of their suckling offspring. This study was conducted to confirm the transfer of ML actives to lambs in the ewe's milk, and to assess whether this could result in selection for ML resistant nematodes in the lamb. Ninety, twin bearing Romney ewes were treated before lambing with a long-acting injectable formulation of moxidectin, a 100-day controlled release capsule (CRC) containing abamectin and albendazole, or remained untreated. After lambing, seven ewes from each treatment group were selected for uniformity of lambing date and, along with their twin lambs, relocated indoors. At intervals, all ewes and lambs were bled, and samples of ewe's milk were collected, for determination of drug concentrations. Commencing 4 weeks after birth all lambs were dosed weekly with 250 infective larvae (L3) of either an ML-susceptible or -resistant isolate of Teladorsagia circumcinta. At 12 weeks of age all lambs were slaughtered and their abomasa recovered for worm counts. Moxidectin was detected in the plasma of moxidectin-treated ewes until about 50 days after treatment and in their lambs until about day 60. Abamectin was detected in the plasma of CRC-treated ewes until the last sample on day 80 and in the plasma of their lambs until about day 60. Both actives were detectable in milk of treated ewes until day 80 after treatment. Establishment of resistant L3 was not different between the treatment groups but treatment of ewes with moxidectin reduced establishment of susceptible L3 by 70%, confirming the potential of drug transfer in milk to screen for ML-resistance in the suckling lamb.

Calving season is a stronger determinant of worm burdens in pasture-based beef production than the level of residual larval contamination at turnout.

The combined influence of (1) calving period (early or late) and (2) overwintering contamination by residual infective larvae (high or low) on subsequent exposure of suckler calves to gastrointestinal nematodes was investigated. We found that the effect of calving date was greater than the level of residual contamination. This was because the adult cows produced large quantities of manure containing small amounts of nematode eggs from turnout, which significantly contaminated the pasture, and thereby, reduced the effect of prior high-low contamination. Early born calves were found to be more heavily exposed to parasites, most likely due to ingesting more herbage than those born later. Late-born calves also had relatively high antibody levels at turnout, which first decreased and then increased again. We suggest that the high antibody levels at turnout reflect passive transfer of maternal antibodies through the milk. There was also a significant difference in animal performance, with the more heavily exposed early born calves having significantly lower daily weight gain than the late-born calves. However, this might not be entirely due to increased parasitism.

Toxocara vitulorum in suckling calves in The Netherlands.

A Dutch farmer with beef cattle and suckling calves noticed one of the calves suffering from diarrhoea and observed large white worms near the perineum. In the faeces of this calf, eggs of Toxocara vitulorum were found. The majority of the cows in the herd were of the Piemontese breed previously imported from southern France. Treatment with albendazole was successful. Two other calves had positive faecal egg counts. One month after treatment of these calves with doramectin, no eggs were found. To prevent further infections on the farm and dissemination of this uncommon infection to other farms, the farmer decided to have all his cattle slaughtered.

Influence of toltrazuril treatment on parasitological parameters and health performance of piglets in the field--an Austrian experience.

Porcine coccidiosis caused by Isospora suis is one of the leading causes of neonatal diarrhea in suckling piglets. Currently the only registered drug for metaphylaxis is toltrazuril. To evaluate the effect of treatment on piglets from 7 Austrian farms without and 8 Austrian farms with toltrazuril application we examined oocyst excretion (including determination of oocysts per gram of feces; OPG), diarrhea (fecal score FS 1-4 with 3 and 4 being diarrhea), and general health (health score HS 1-4 with 3 and 4 describing poor health). Both groups included farms with different levels of hygiene. Samples from 265 litters without treatment, comprising 1588 individual samples, and 1548 samples from 258 treated litters were taken twice (around the 14th and the 21st day of life, respectively), examined by autofluorescence and, if positive, by McMaster counting. In both groups animals had less diarrhea and lower health scores during the second sampling but the treated piglets were always significantly healthier and had less diarrhea. The percentage of weaned piglets was higher in treated animals although this was not significant (p=0.052). In the first round of sampling 17.8% of the individual samples from untreated piglets were positive for oocysts (with a maximum prevalence on the 12-15th day of life) while in the treated piglets only 0.4% shed oocysts p<0.001). At the second sampling only 2.1% of the untreated animals and none of treated piglets excreted I. suis (p=0.083). Positive animals shed up to 8 × 10(3)OPG. There was an increased risk for infected piglets to develop diarrhea (odds ratio, OR 4.73) and poor health (OR 5.05) in untreated piglets, and poor hygiene without disinfection was identified as a risk factor for poor health (OR 1.90), diarrhea (OR 1.42) and oocyst excretion (OR 1.73). The risk of poor health (OR 2.89) and diarrhea (OR 1.44) was also increased for piglets under poor hygienic conditions receiving toltrazuril, so both metaphylaxis of coccidiosis and good hygiene are necessary to effectively control neonatal diarrhea. The costs of treatment are considerably lower than the estimated financial production losses. Therefore, treatment is recommended for farms where clinical coccidiosis is diagnosed.

The impact of daily Duddingtonia flagrans application to lactating ewes on gastrointestinal nematodes infections in their lambs in the Netherlands.

Two experiments were performed in 2002 and 2003 to evaluate the effect of biological control of gastrointestinal nematodes in sheep through the daily feeding of 500,000 chlamydospores of Duddingtonia flagrans/kg bodyweight to lactating ewes during the first 9 weeks with their young lambs on pasture. In both experiments four groups of eight ewes and their April-borne lambs were used. They were turned out on four separate plots (plots A) at the beginning of May, moved to similar separate plots after 3 (plots B) and 6 weeks (plots C), respectively, and weaning occurred after 9 weeks. In both experiments, two groups were fed spores daily while the two other groups served as controls. The effect of D. flagrans application was evaluated through faecal egg counts of ewes and lambs, the yield of faecal cultures in ewes, pasture larval counts and worm counts of lambs and tracer lambs. The results demonstrated no effect of D. flagrans application during the first 5 (2002) or 4 (2003) weeks. Subsequently, fungus application strongly reduced the yield in faecal cultures of the ewes. This was, however, not reflected in the pasture larval counts, but lower worm burdens were observed in tracer lambs of 'treated' plots C in 2002 than on those of 'control' plots. In 2003 worm burdens in 'treated' lambs returned to plots B were lower than those of 'control' lambs and a tendency for the same was observed for plots C. However, in all groups, lambs and tracer lambs developed severe haemonchosis.

Resistance of Santa Inês and Ile de France suckling lambs to gastrointestinal nematode infections.

A trial was carried out to determine the resistance to natural infection by gastrointestinal nematodes in 12 Santa Inês and nine Ile de France lambs before weaning. Faecal samples were obtained for faecal nematode egg counts (FEC). Blood samples were collected to determine packed cell volume (PCV), total plasma protein levels and peripheral eosinophil counts. Most Ile de France lambs (77.8%) were treated with an anthelmintic at 43 days of age, while 50% off Santa Inês lambs were treated at weaning, 57 days of age. The mean PCV values were normal in Santa Inês lambs, while in Ile de France lambs showed lower values reaching 22.3% at 43 days of age. The lowest mean plasma protein values were observed in Ile de France lambs (4.13 g/dl) at 43 days of age and in Santa Inês lambs (5.0 g/dl) at 57 days of age. Before weaning, Santa Inês lambs were susceptible to natural infections by gastrointestinal nematodes but with a greater capacity to stand the adverse effects of parasitism compared to Ile de France lambs.

Parasites of domestic and wild animals in South Africa. XLII. Helminths of sheep on four farms in the Eastern Cape Province.

At monthly intervals for periods ranging from 9 to 25 consecutive months between three and four Merino yearling-sheep and two Merino lambs on three farms in Eastern Cape Thornveld, and two Dorper yearling-sheep on a farm in Valley Bushveld were slaughtered and examined for helminths. The Merino sheep were infected with 15 nematode species, of which Haemonchus contortus, Nematodirus spathiger and Trichostrongylus spp. were the most numerous, and with four cestode species. The Dorper sheep were infected with 17 nematode species, of which Trichostrongylus rugafus and N. spathiger were the most numerous, and with two cestode species. Haemonchus contortus was most numerous in older sheep during the summer months and exhibited no tendency to over-winter as arrested fourth stage larvae. The largest numbers of N. spathiger were present in sheep on the most coastally located of the farms during autumn and winter; on a farm further inland during spring; and on an inland farm in Valley Bushveld during spring and summer. As Merino lambs progressed from birth to 9 months of age a larger proportion of their dwindling burdens of N. spathiger was present as fourth stage larvae. Dorper sheep in Valley Bushveld harboured most Teladorsagia circumcincta in May and from October to January. Trichostrongylus rugatus was most numerous in Merino sheep on one of the Thornveld farms during September, whereas all Trichostrongylus spp., including T. rugatus, were most numerous in Dorper sheep on the Valley Bushveld farm during January.

The role of the 19-kDa region of merozoite surface protein 1 and whole-parasite-specific maternal antibodies in directing neonatal pups' responses to rodent malaria infection.

Maternal Abs generated as a result of prior exposure to infectious agents such as the malaria parasite are transferred from the mother through the placenta to the fetus. Numerous studies have attributed the resistance to malaria infection observed in neonates and infants up to 6 mo of age to the presence of maternally derived Abs. However, recent studies have produced conflicting results suggesting that alternative protective mechanisms may be responsible. Although the presence of maternally derived Abs in the infant is not disputed, their exact role in the infant is unknown. Even less clear is the effect that maternally derived Abs, if generated in response to vaccination, may have on the infant's ability to respond to malaria infection. Studies on mouse pups were performed to determine the role of the 19-kDa region of merozoite surface protein 1 (MSP1(19)) and Plasmodium yoelii-specific Abs in neonatal malaria infection and to examine their effect on the development of a specific immune response in the pup. It was shown that P. yoelii- and MSP1(19)-specific Abs transferred to the pup from the mother act to suppress the growth of the parasite in the pup. However, the maternally derived Abs interfered with the development of the pups' own Ab response to the parasite by altering the fine specificity of the response. These results suggest that immunizing women of child-bearing age with a malaria vaccine candidate such as MSP1(19) would not prevent the infant from producing Abs in response to malaria infection, but it may affect the region of the Ag to which it responds.

Health evaluation of arctic fox (Alopex lagopus) cubs in Sweden.

Hematologic, serum biochemistry, and serum cortisol reference ranges were established and tonsil/rectal bacterial and fecal parasite examinations were performed on 21 wild arctic fox (Alopex lagopus) cubs during July 1996. Several of the hematologic and serum biochemistry values fell within normal ranges for other wild canids or domestic dogs of the same age class. Serum alanine transaminase and creatine phosphokinase values were significantly higher in the youngest cubs. Proteus vulgaris and Escherichia coli were isolated from both tonsilar and rectal swabs of several cubs in all dens. The most common gastrointestinal parasite ova were Toxascaris leonina (59%), Isospora spp. (52%), Uncinaria stenocephala (33%), and Capillaria spp. (26%). Prevalence of T. leonina differed significantly between dens and between age groups. Hematologic and serum biochemistry values and degree of parasitism may be indicators of health, stress, and nutritional status of arctic foxes.