Blastocystis is an obligately anaerobic protist, commonly found in intestinal tract of numerous animals and humans across whole world. It is genetically very variable and rather enigmatic organism. Many aspects of its biology need to be further studied and clarified. On a chosen farm were during the year 2010 collected samples of pig faeces for parasitological survey. A total number of 40 samples was collected and cultivated by the method of Dobel-Leidlaw (1926). Of them, 19 was positive for Blastocystis. Other samples were checked by molecular methods (PCR). Using them, five Blastocystis sequences were obtained, which clearly belong to subtypes 1 and 5.

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No description available.

Hubble Space Telescope images of the Orion nebula taken with the Wide-Field Camera have revealed subarcsecond structure in several dozen objects which are apparently ionized externally from nearby stars. We have obtained near-IR images and IR polarimetry of the Orion region to search for correlations with the WFC objects. We find that all of the ultracompact WFC objects are associated with IR features of some sort, and that some are associated with strongly polarized IR emission. The object with strongest polarization also shows small IR "lobes". In addition, we find some previously unreported sources, showing polarized IR emission, outside the field of the HST images, which we believe may be the same sorts of object. We note that the object with strongest polarization has a double-lobed appearance in the K band image.

No description available.

Six experiments were conducted to determine the mechanism of action of exogenous PGF2alpha on the clearance of uterine infections in sheep and pigs. The first two experiments were designed to characterize the uterine immune response to bacterial infection under progesterone dominance in pigs. The uterine immune response to infections seems to change with parity. This is probably an artifact of increased number of bacterial exposures; therefore, the third experiment was designed to evaluate the uterine immune response to multiple intrauterine bacterial inoculations. Experiments 4, 5, and 6 were designed to evaluate the effects of endogenous and exogenous PGF2alpha on the uterine immune response to uterine infections in sheep and pigs. Injections with Lutalyse (PGF2alpha analogue) during the luteal phase in sheep causes luteolysis; therefore, it impossible to evaluate the effects of Lutalyse independently of luteolysis. In order to cause an endogenous release of PGF2alpha without causing luteolysis in sheep a PGF2alpha secretagogue (oxytocin) was used in Exp. 5. And in Exp. 6, we were able to evaluate the effects of Lutalyse independently of luteolysis using pigs as a model. From these six experiments we concluded that during periods of estrogen dominance, the uterine immune system is up-regulated, and therefore, infections do not develop after intrauterine inoculation with bacteria, during periods of progesterone dominance, the uterine immune system is down-regulated, and, therefore, infections develop after intrauterine inoculation with bacteria, and stimulation of the uterus with PGF2alpha or oxytocin independently of luteolysis up-regulates the uterine immune. / Ph. D.

Enteric microbiota influences enteric viral infections, and host response to these pathogens and vaccines. Using gnotobiotic (Gn) pigs transplanted with human gut microbiota (HGM), we studied the effects of HGM on the immune response to oral rotavirus vaccination and rotaviral disease. We also used HGM transplanted Gn pigs to determine the effects of HGM on human norovirus infection. Despite commercially available vaccines, human rotavirus is a leading acute gastroenteritis in children, especially those in developing countries. Human norovirus (HuNoV) is a leading cause of acute gastroenteritis in all age groups worldwide, and no vaccines are commercially available. Further understanding of how enteric microbiota influences these viral diseases may identify therapeutic targets. In our rotavirus study, pigs were colonized with HGM from an infant with low fecal concentrations of enteropathy biomarkers and responded well to their first dose of oral rotavirus vaccine (healthy human gut microbiota "HHGM"); or pigs were colonized with HGM from an infant with high fecal concentrations of enteropathy biomarkers and a poor response to the first dose of oral rotavirus vaccine (unhealthy human gut microbiota "UHGM"). HHGM colonized pigs had stronger cell-mediated and mucosal immune response to oral rotavirus vaccine compared to UHGM pigs based on the number of rotavirus-specific IFN-γ producing T cells in the ileum, spleen, and blood, and trends towards higher rotavirus specific antibody titers in intestinal contents, respectively. Significant correlations between multiple Operational Taxonomic Units (OTUs) of bacteria and frequencies of IFN-γ producing T cells at the time of human rotavirus challenge existed, suggesting that certain members of the microbiota influenced the immune response to the vaccine. After the vaccinated pigs were challenged with human rotavirus, HHGM pigs had less severe and shorter duration of viral shedding and diarrhea compared to UHGM pigs, suggesting that HHGM facilitated development of stronger protective immunity. These results demonstrated that composition of the enteric microbiota influenced host immune response to oral vaccination. In the norovirus study, Gn pigs were colonized with HHGM to determine the effects of microbiota on HuNoV infection. Colonized pigs shed more virus for a longer duration than non-colonized pigs, and also had higher viral titers in the duodenum and distal ileum. Diarrhea was more severe 4-10 days post-infection and lasted longer in colonized compared to non-colonized pigs. Twenty-seven genes related to the immune system were highly upregulated in HuNoV infected, colonized pigs compared to non-colonized controls. These result showed that HHGM influenced infectivity of HuNoV in the Gn pig model and altered host gene expression related to the immune system. These studies showed that HHGM can improve the host immune response and efficacy of rotavirus vaccine, but it can also enhance infection and clinical disease in HuNoV infected Gn pigs. Depending on the virus, gut microbiota may be beneficial or detrimental to the host. Those developing future treatments aimed at altering microbiota to prevent or ameliorate one viral pathogen need to consider the potential for enhancing a different pathogen. These studies demonstrated the usefulness of HGM transplanted Gn pigs for evaluation of microbiota influence on infection and immunity of enteric viral pathogens. / Ph. D. / Gut microbiota influences intestinal viral infections, and host response to these pathogens and vaccines. Using gnotobiotic (Gn) pigs transplanted with human gut microbiota (HGM), we studied the effects of HGM on the immune response to oral rotavirus vaccination and rotaviral disease. We also used HGM transplanted Gn pigs to determine the effect of HGM on human norovirus infection. Despite commercially available vaccines, human rotavirus is a leading acute gastroenteritis in children, especially those in developing countries. Human norovirus (HuNoV) is a leading cause of vomiting and diarrhea in all age groups worldwide, and no vaccines are commercially available. Further understanding of how gut microbiota influences these viral diseases may identify therapeutic targets. In our rotavirus study, pigs were colonized with HGM from an infant without evidence of intestinal disease based on fecal analysis, and who responded well to the first dose of oral rotavirus vaccine (healthy human gut microbiota “HHGM”); or pigs were colonized with HGM from an infant with evidence of potential intestinal dysfunction and a poor response to the first dose of oral rotavirus vaccine (unhealthy human gut microbiota “UHGM”). HHGM colonized pigs had a stronger immune response to the oral rotavirus vaccine compared to UHGM pigs. Significant correlations between multiple Operational Taxonomic Units (OTUs) of bacteria and frequencies of rotavirus-specific immune cells at the time of human rotavirus challenge existed, suggesting that certain members of the microbiota influenced the immune response to the vaccine. After the vaccinated pigs were challenged with human rotavirus, HHGM pigs had less severe and shorter duration of viral shedding and diarrhea compared to UHGM pigs, suggesting that HHGM enhanced vaccine efficacy. These results demonstrated that composition of the gut microbiota influenced host immune response to oral vaccination. In the norovirus study, GN pigs were colonized with HHGM to determine the effects of microbiota on HuNoV infection. Colonized pigs shed more virus for a longer duration than non-colonized pigs, and also had higher viral titers in sections of small intestine. Diarrhea was more severe 4-10 days after infection and lasted longer in colonized compared to non-colonized pigs. Twenty-seven genes related to the immune system were highly upregulated in HuNoV infected, colonized pigs compared to controls. These result showed that HHGM influenced infectivity of HuNoV in the Gn pig model and altered host gene expression related to the immune system. These studies showed how HHGM improved the host immune response and efficacy of rotavirus vaccine, but conversely enhanced infection and clinical disease in HuNoV infected pigs. Depending on the virus, gut microbiota may be beneficial or detrimental to the host. Those developing future treatments aimed at altering microbiota to prevent or ameliorate one viral pathogen need to consider the potential for enhancing a different pathogen. These studies showed the usefulness of HGM transplanted Gn pigs for evaluation of microbiota influence on infection and immunity of intestinal viruses.

Thesis (MScAgric)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The objective of this study was to determine the effect of the inclusion of Acid Buf™ at 4g.k–1 g to a maize-soya bean diet in both pelleted and meal form, on the occurrence of stomach ulcers, performance parameters, carcass characteristics and histological parameters of the small intestine of growing finisher pigs. The trail was done on 320 growing finisher pigs fed for 8 weeks. The four treatments (Tr) were as follows: Tr1 – pelleted, Tr2 – meal, Tr3- pelleted with Acid Buf™ at 4g.kg-1, Tr4 –meal with Acid Buf™ at 4g.kg-1. No significant differences (P>0.05) were observed for cumulative feed intake between the different treatments. The feed conversion ratio (FCR) showed significant differences with the pigs on the meal diet faring significantly (P<0.05) worse than those the pelleted diet containing Acid Buf™. The average daily gain (ADG) on Tr3 was significantly better (P<0.05) than those on the meal diets. Overall the performance parameters showed a positive response to the inclusion of Acid Buf™. With regards to changes in the intestinal pH, significant differences (P<0.05) were observed between the different treatments for pH in the stomach, duodenum and colon. The pH in the stomach was closest to optimal with Tr3m and Tr4. The pH in the duodenum was highest and closest to optimum with Tr4. Scoring of stomachs revealed that the highest percentage of normal stomachs was found in pigs on Tr4, with 64.1% of the stomachs being normal,57.1% was the second highest percentage of normal stomachs and was found with Tr3, pelleted with AB. Carcass scoring showed no significant differences (P>0.05) between the different treatments. The mean villi height to crypt depth ratio (VH: CD) in the jejunum showed a significant difference (P<0.05) between Tr1 and Tr3. The pigs on the pelleted diet had VH: CD of 0.89 while those on the pelleted diet with AB a VH: CD of 1.28. The average villi height measured in both the duodenum and the jejunum was higher in both of the pelleted diets compared to the meal diet and the meal with AB diet. The results of the different experiments conducted to evaluate the effect of AB all showed improved results with the inclusion of AB to the diet. / AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om die effek van die insluiting van Acid Buf™(AB) teen 4g.kg-1 in 'n mielie-sojaboondieët in beide verpilde- en meelvorm, op die voorkoms van maagsere, groei parameters, karkaseienskappe en histologiese parameters van die dunderm in groeivarke te bepaal. Die studie is vir agt weke op 320 groei varke uitgevoeroor. Die vier behandelings (Tr) was soosvolg: Tr1 - verpil, Tr2 - meel, tr3- verpil met Acid Buf™ teen 0,4% ingesluit, Tr4 – meel metAcid Buf™ teen 0,4% ingesluit. Daar was geen beduidende verskille (P> 0.05) in die kumulatiewe voerinname tussen die verskillende behandelings waargeneem nie. Voeromsetverhouding (VOV) op die meel diet (Tr4) het beduidend swakker gevaar (P<0.05) as die varke op Tr3. Die gemiddelde daaglikse toename (GDT) van die varke op Tr3 was aansienlik beter (P<0.05) as die van die varke op Tr2. Met betrekking tot die pH van die spysverteringskanaal was daar beduidende verskille (P>0.05) opgemerk tussen die verskillende behandelings vir pH in die maag, duodenum en kolon. Die pH in die maag was die laagste en naaste aanoptimaal vir die AB dïete . Die pH in die duodenum was die hoogste en naaste aan optimaal met Tr4. Gradering van die mae toon die hoogste persentasie van normale, met 64.1 % van die mae met Tr4 normaal. Die tweede hoogste persentasie was 57.1 % normale mae en was gevind met Tr3, verpil met AB. Karkasgradering het geen beduidende verskille (P>0.05) tussen die verskillende behandlinge getoon nie. Die gemiddelde villi hoogte kryptdiepte verhouding (VH: KD) in die jejenum het beduidende verskille (P<0.05) getoon tussen Tr1 en Tr3. Die verpilde diet (Tr1) het n (VH: KD) van 0.89 getoon en Tr3, die varke op die verpilde diët met AB 1.28. Die gemiddeldie villi hoogte gemeet in beide die duodenum en jejenum was hoër in die beide die verpilde diëte as in die meel diëte. Die resultate van die verskillende eksperimente uitgevoerom die effek van AB teevalueer, toon verbetering met die insluiting van AB in die diët.

Call number: LD2668 .T4 1949 G61 / Master of Science

Call number: LD2668 .T4 1961 D43