Made available in DSpace on 2016-05-02T13:54:44Z (GMT). No. of bitstreams: 1 Dissertacao completa Silvia Cristina Lopes Fernandez.pdf: 309786 bytes, checksum: 0998ae4c9bd35208a4394152308f7622 (MD5) Previous issue date: 2006-11-24 / Coordenacao de Aperfeicoamento de Pessoal de Nïvel Superior / Intestinal parasitoses are diseases closely related to sanitary conditions and a serious problem of public health in underdeveloped countries Many studies have shown that children are more susceptible to parasitic infections due to poor hygienic habits and therefore the effects of parasitism are more significant in them In face of the growth of cities and a higher participation of women in the work market mothers have to take their small children to day-care centers where they are exposed to a potentially contaminated environment In Brazil more than half the population of pre-school and school children have parasitoses In the present study epidemiological variables were surveyed by means of a questionnaire applied to 200 children at their homes who were cared for in microareas of Basic Heathcare Units (Unidades Basics de Saudi) and Family Health Program (Programa de Saúde da Família) of the city of Poços de Caldas State of Minas Gerais Brazil Parasitologic examinations were conducted by the spontaneous sedimentation Technique Results showed that Entamoeba coli and E hystolitica were the most prevalent Parasites The socieconomical conditions of the city are indicative of the population s Good quality of life The most marked risk factors for parasitic infection were the permanent presence of vectors such pets flies mosquitoes cockroaches and/or rats in the house The preventive measures proposed to the Vigilância Sanitária e Epidemiológica (Service of Sanitary and Epidemiological Vigilance) are the implementation of basic sanitation and continuous programs of sanitary education routine follow-up of parasitic infections and checking the effectiveness of the treatment prescribed / Parasitoses intestinais são doenças que estão intimamente relacionadas às condições sanitárias e representam um importante problema de saúde pública nos países subdesenvolvidos Estudos mostram a criança como alvo da infecção parasitária devido a hábitos de higiene e saúde não suficientemente consolidados sendo que nela repercussões das parasitoses tornam-se mais significativas Em função da maior urbanização e maior participação feminina no mercado de trabalho as creches passaram a ser o primeiro ambiente externo ao doméstico que a criança freqüenta tornando-se potenciais ambientes de contaminação No Brasil mais da metade de pré-escolares e escolares encontram-se parasitadas No presente estudo analisaram-se variáveis epidemiológicas através de um inquérito domiciliar de 200 crianças assistidas por micro-áreas de Unidades Básicas de Saúde e Programa de Saúde da família (PSF) do município de Poços de Caldas-MG e exames parasitológicos através da técnica de Sedimentação Espontânea para possível diagnóstico de parasitoses intestinais Os resultados evidenciaram que no município de Poços de Caldas foi predominante o diagnóstico de protozooses intestinais entre crianças na faixa escolar destacando-se a Entamoeba coli e a E histolytica como as parasitoses mais prevalentes o quadro socioeconômico do município é favorável ou indicativo de uma boa qualidade de vida da população os fatores de risco para as infecções parasitárias com maiores destaques foram a presença permanente de possíveis vetores como animais domésticos e o aparecimento também freqüente de vetores como moscas mosquitos baratas e/ou ratos na casa as atividades preventivas propostas à vigilância sanitária e epidemiológica são a implementação de medidas de saneamento básico e programas contínuos concomitantemente visando a educação sanitária acompanhamento rotineiro das infecções parasitárias bem como participação e verificação da eficácia do tratamento preconizado

Thesis (M. Dev.) -- University of Limpopo, 2016. / In South Africa, particularly in the Limpopo Province, the handling of human excreta and the use of human excreta for food production are still not valued and generally not acceptable. The issue of social acceptance is one of the several issues that must be tackled in order to successfully institute the practice of human waste reuse in agriculture. As such, this study explored the attitudes and perceptions towards the utilisation of urine and faeces as the alternative to chemical fertilizer in a rural agriculture in Ga-Mothapo, Polokwane Local Municipality in Limpopo. The study adopted a qualitative approach using a case study design. Data was collected using face to face interviews. A majority of the households indicated that they are not comfortable with the idea of using human excreta for agricultural purpose. According to them, it was against their cultural beliefs and it is a taboo to use the waste of human as they prefer to use animal waste instead. The health risk and environmental contamination were also highlighted by the households as weighing against the use of human excreta. Even though some respondents mentioned that using human excreta has the potential to enrich their depleted agricultural soils, and that it had the effect of reducing the cost of buying commercial fertilizers, they still felt uncomfortable using it. This study concludes by recommending that there is a need for constant intervention and awareness to address the issue of food security through ecological sanitation which will promote sustainable agriculture by providing soil with nutrients. Keywords: Ecological Sanitation, Human Excreta, Perceptions, Attitudes, Food Security

Sewage pollution of surface waters is a pressing issue of global concern, even in regions with extensive wastewater and sewage treatment infrastructure. Contaminants, like harmful bacteria that can cause gastrointestinal disease and hinder economic growth and development, enter natural waters through a variety of point and non-point source discharges that range from treated to untreated. With increasing urbanization, aging infrastructure, and changing precipitation patterns due to climate change, it is increasingly important to understand and predict the persistence and transport of sewage-derived bacterial pollution in surface waters. To effectively monitor and predict these contaminants, it is critical to understand sewage-derived bacteria’s extra-enteric ecology, or the ecological dynamics they experience after transitioning from a primary habitat (like the human gastrointestinal system) to a secondary habitat (like natural waters). Dynamics of fecal bacteria are assumed to be driven by loss, as commonly observed for the fecal indicator bacteria (FIB), Enterococcus sp., with sunlight exposure as the dominant driver (i.e., greatest impact on population dynamics). However, particle association of FIB may alter their persistence and transport in natural waters, though this aspect of extra-enteric ecology is rarely included in predictive models. Models predicting persistence and transport of fecal bacteria and pathogens could be improved by incorporating information on the impacts of particle association on dominant loss rates of FIB and the population dynamics of various indicated pathogenic groups. Further, it is important to understand the variation in and drivers of surface water optical properties, like water transparency, due to the likely importance of light penetration to fecal bacteria environmental persistence. This dissertation aims to address the critical knowledge gaps of how particle association influences the extra-enteric ecology of various sewage-derived bacteria and how optical properties relevant to the light-dependent mortality of FIB vary spatially and temporally in an urban-influenced water body. To do so, I employ a combination of empirical, modeling, and observational techniques. The Hudson River Estuary (HRE) is an ideal field site for this research because of its consistent problems with sewage pollution, especially following precipitation events, despite significant improvements following the Clean Water Act in 1972. Managing human health risks associated with sewage pollution is especially important for this water body that runs through the NY/NJ metropolitan area with its 19 million stakeholders. Further, previous research quantifying FIB dynamics has predominantly been conducted in clear, low turbidity water columns. Experiments constraining the dynamics of FIB in water with low clarity, like in the HRE, would fill this important knowledge gap in the field of sewage pollution monitoring and modeling. Chapter 1 assesses the impact of particle association on dominant growth rates and persistence of the brackish fecal indicator bacteria, Enterococcus sp. (also called enterococci). In this chapter, I conducted a series of natural water microcosm laboratory experiments to quantify dominant growth rates of enterococci. I then used these growth rates to parameterize a 1-dimensional advection-diffusion-decay model to simulate enterococci persistence in waters ranging from clear, quiescent lakes to turbid, turbulent waters. This combined empirical and mathematical modeling approach led to four major conclusions related to the persistence and transport of enterococci in natural waters: 1) particle association increases dominant growth rates (light-induced and dark, temperature-dependent growth) and induces sinking of enterococci, 2) particle association increases simulated enterococci persistence, 3) simulated enterococci persist longer in more turbid and/or more turbulent waters, and 4) discharge timing later in a diel cycle increases simulated Enterococcus sp. persistence. Results from this chapter demonstrate the importance of distinguishing free-living and particle-associated Enterococcus sp. in models of their persistence and transport and provide empirical data for independently constraining their population dynamics. Further, the simulated persistence indicates that sewage-derived fecal bacteria discharged into water bodies like the HRE will last longer than discharges in clear, calm waters (e.g. Lake Tahoe) and even clear, turbulent waters (e.g. coastal ocean in California). This information is broadly applicable to water quality management and indicates how variability in turbidity or turbulence within a water body could alter sewage discharge persistence and exposure risk for the public. Model sensitivity testing confirmed the consistent impact of particle association on enterococci persistence and reaffirms the need for FIB models to include particle association. An adapted version of Chapter 1 was published in Water Research (Myers and Juhl 2020). Because particle association increases enterococci persistence and growth rates, it is important to determine if particle association similarly affects co-occurring pathogenic bacteria and if particle association prevalence is similar. Chapter 2 is a valuable complement to Chapter 1 and addresses key knowledge gaps related to ambient pathogen abundance, particle association, and correlation with FIB in surface waters, in addition to the effect of particle association on dominant pathogen growth rates. In this chapter, I report multi-year observations of abundance and particle association proportions in the HRE for four bacterial genera: the fecal indicator Enterococcus sp., two enteric pathogens (Salmonella sp. and Shigella sp.) and a naturally-occurring, marine pathogen (Vibrio sp.). I found that mean particle association ranged from 34% to 49% and that overall abundances were significantly positively correlated across all genera. The second major goal of this chapter was to determine if particle association impacted dominant growth rates of pathogens similarly to the effect observed for enterococci (Chapter 1). In experiments similar to those in Chapter 1, I quantified the fraction-specific (free-living, particle-associated, and total) temperature and light-dependent growth of the three pathogenic genera. Overall, particle association consistently increased temperature- and light-dependent growth rates across genera, similarly to Chapter 1, though particle association did not benefit Vibrio sp. as much as the enteric genera. I found that Salmonella sp. had similar temperature- and light-dependent growth rates to enterococci. By contrast, Shigella sp. growth rates were greater than those of enterococci. As expected due to its different origin, Vibrio sp. also had dissimilar growth rates to enterococci. Interestingly, Shigella sp. behaved more similarly to Vibrio sp., with increasing dark period growth with temperature, which is opposite of the trend observed for the other two enteric organisms (Salmonella sp. and enterococci). The disparities and similarities of dominant growth rates between enterococci and 2 co-occurring fecal pathogens, together with the finding that abundances were positively correlated across all genera, suggests that enterococci are good indicators of recent sewage pollution, but have limitations in their use for assessing extended water column persistence of some co-occurring pathogenic bacteria. Information in this chapter is important for our understanding of FIB use to monitor sewage pollution persistence and for water quality management to minimize human exposure risk, especially in water bodies where environmental persistence is likely longer, like in turbid and turbulent waters (as shown in Chapter 1). Persistence simulations in Chapter 1 demonstrated that water transparency (modeled as diffuse attenuation of light, 3), was critical for determining the persistence of enterococci. It is then important to understand how water transparency varies throughout a water body to eventually predict how sewage bacteria persistence timescales vary. Chapter 3 examines the spatial and temporal variability of water transparency and its primary drivers (suspended particulate matter (SPM), chlorophyll, and colored dissolved organic matter (CDOM)) throughout the terrestrially- and marine-influenced HRE using observational and laboratory techniques. Data in this chapter indicate that water transparency in the HRE is predominantly controlled by SPM (measured as turbidity) and, to a lesser degree, chlorophyll. Despite some dramatic changes in inputs affecting the primary drivers (e.g. decreased sewage pollution - NYCDEP 2012, decreased chlorophyll concentrations - Caraco et al. 1997; Smith et al. 1998, and increased dissolved organic carbon transport - Findlay 2005) in the HRE, the dominance of turbidity in determining water transparency found in this study was consistent with work in the 1980s (Stross and Sokol 1989). Together, the findings by Stross and Sokol 1989 and in this chapter suggest that future work on understanding water transparency variability and its impact on sewage bacteria persistence in the HRE should focus on quantifying the variability in SPM. In contrast to other estuarine systems, CDOM absorption in this chapter minimally impacted water transparency (measured here via KdPAR). This chapter also documents spatial and temporal variability of water transparency and its primary drivers in the HRE. Turbidity and chlorophyll fluorescence varied seasonally, generally consistent with trends in other estuarine systems. Turbidity, chlorophyll, and CDOM absorption were all elevated after increased river flow from Tropical Storm Isaias. All three primary drivers of water transparency were also commonly higher for nearshore and tributary sites, as opposed to mid-channel sites, possibly due to increased shallow bed resuspension and terrestrial runoff. In the upper, freshwater portions of the estuary, CDOM absorption was highest, indicating a greater relative importance of CDOM on water transparency in this region. Data in this chapter also demonstrated that Wastewater Treatment Plant (WTP) outfalls commonly had elevated optical brighteners and (Sl(275-295), a CDOM slope ratio that indicates excess smaller CDOM molecules at a treated discharge, and a contrasting influence on CDOM absorption. This information could then allow CDOM absorption and optical brightener fluorescence to be used as indicators of treated or untreated discharges that could be measured on a faster timescale than current bacteria monitoring via culture-based techniques. Appended to this dissertation are results from experiments examining bacterial community composition for free-living and total populations in the HRE, which provide additional context for the research presented in this dissertation. The free-living and and total bacteria communities were not found to be significantly different, which indicates that there are not distinct communities in free-living and particle-associated fractions. Together with results from Chapters 1 and 2, this indicates that particle association may increase growth rates for bacteria that become particle-associated, instead of particles supporting the development of a unique and more resistant bacteria community. Four of the five fecal core families (bacteria commonly found in human fecal samples) were also identified in samples for these experiments, though relative abundance of these groups for free-living and total fractions were largely uncorrelated with each other over time. This finding demonstrates a notable influence of sewage inputs on the bacterial community in the HRE. Finally, these observations demonstrate that bacteria community composition varied seasonally, as noted by the significant influence of temperature and salinity on bacterial community composition. A wide variety of genera were strongly associated with colder (<12°C) water temperatures and samples from colder water generally exhibited higher alpha diversity. The findings from this dissertation have significantly contributed to our understanding of the extra-enteric ecology of the fecal indicator bacteria Enterococcus sp. and multiple co-occurring potential pathogens. This dissertation demonstrates that particle association must be considered in models of sewage-derived bacteria persistence. This dissertation also deepens our current understanding of water transparency drivers and their spatial and temporal heterogeneity in the turbid and turbulent system of the HRE. The results from this dissertation are useful for improving predictions of sewage pollution persistence and, by extension, minimizing human exposure risk to potentially harmful bacteria. These findings are broadly applicable beyond the HRE, to water bodies of varying turbidity and turbulence conditions.

Two trials were designed to study the relationships of dietary fiber (ADF) and protein level and source to fecal consistency in lactating cattle. In Experiment 1, 30 cows (12 multiparous, 18 primiparous) were randomly assigned to one of six total mixed diet treatments through four 21 d periods. For Experiment 2, six primiparous cows were used in two 6 x 6 Latin squares to evaluate water consumption, apparent digestibilities of DM, AOF, NOF, and starch, and to quantitate whole corn kernel passage. Total mixed diets for both trials were formulated to contain 17% (LF) or 25% AOF (HF) with CP levels of: 15% (S15) and 22% (S22) with soybean meal (SBM) supplementation, or 22% (G22) with combination of 50% corn gluten meal (eGM) and 50% SBM. Two forage sources were evaluated: corn silage (e) and alfalfa/corn silage (Ae) (50:50 on OM basis). Fecal consistency was evaluated using a 4 point scale (l-most fluid to 4-least fluid). Experiment 1 demonstrated that lower dietary fiber reduced fecal pH (LF=6.65, HF=7.11) and fecal score (LF=2.18, HF=2.41), but increased fecal DM (LF=16.1%, HF=13.2%). Supplementing SBM (S22) decreased fecal DM (S22=14.1%, G22=15.5%) and fecal score (S22=2.01, G22=2.48). Forage source affected fecal DM (C=14%,AC=15.3%), but not pH or score. HF=13.2%). Supplementing SBM (S22) decreased fecal DM (S22=14.1%, G22=15.5%) and fecal score (S22=2.01, G22=2.48). Forage source affected fecal DM (C=14%,AC=15.3%), but not pH or score. Results of Experiment 2 support major conclusions of Experiment 1. High supplementation of SBM increased daily water consumption (S22=80.2 kg, G22=74.5 kg), and reduced fecal score (S22=1.9, G22=2.4). Forage source affected apparent corn kernel (C=21.1% ,AC=33.9%) and starch (C=96%, AC=93%) digestibilities. High protein diets resulted in greater apparent DM digestibility (S15=68.2%, S22=71.8%, G22=71%). In prediction of fecal score from dietary components and animal parameters, dietary DM percent and 4% fat corrected milk (r²=.09, Experiment 1), and DM intake (r²=.12, Experiment 2) were variables most related to fecal score. Dietary effects on fecal consistency were primarily due to ADF level and type of protein supplement. Accurate prediction of fecal consistency score from the dietary and animal parameters identified was not possible. Further study is suggested to evaluate different protein sources, the contribution of water consumption, and to clarify interactions of protein, forage source and fiber level in relation to fecal consistency. / Master of Science

This dissertation documents efforts to evaluate metabolic variables and the fecal microbiome in adult horses fed grass hay. In the first study, eight Arabian geldings limit-fed an 18% vs. 12% non-structural carbohydrate (NSC) hays in a cross-over design during two 28-day periods were included to evaluate the influence of grass hay NSC on serum insulin and plasma glucose concentrations. Serum insulin concentrations was higher in geldings fed the 18% NSC hay; however, this difference was only detected on day 7 and none of the geldings developed hyperinsulinemia. Blood glucose concentrations did not differ between hay groups. The second and third studies were extensions of the first and were conducted to use denaturing gradient gel electrophoresis (DGGE) and real-time PCR in evaluating the effect of forage carbohydrates on equine fecal bacteria diversity and abundance, respectively. Fecal microbiomes were similar (80.5-87.9%) between geldings. The abundance of bacteria belonging to the Firmicutes phylum increased (p = 0.02) in the feces of geldings fed 12% NSC hay (mean 8.06 range [8.03-8.11] log10 copies/g feces) compared to the feces of the same geldings when fed the 18% NSC hay (7.97 [7.97-7.98] log₁₀ copies/g feces). The Firmicutes (43.7%), Verrucomicrobia (4.1%), Proteobacteria (3.8%), and Bacteroidetes (3.7%) phyla dominated the fecal microbiomes. This work was the first to report the presence of the Actinobacteria, Cyanobacteria, and TM7 phyla in the equine fecal or gut microbiome. There was a high abundance (38%) of unclassified bacterial sequences in the gelding fecal microbiome. In the fourth study, 5 overweight adult mixed-breed mares and 5 adult mixed-breed mares in moderate condition, limit-fed a grass hay, were used to evaluate the effect of body condition on diet digestibility, plasma and fecal volatile fatty acid (VFA) concentrations, and fecal bacterial abundance. Hay, fecal, and blood samples were taken daily for 4 days after a 10 day adaptation period. A difference in hay digestibility, fecal VFA concentration, or bacterial abundance was not detected between overweight mares and mares in moderate condition. Plasma acetate, a product of microbial fermentation of fiber, was higher in the overweight mare group. / Ph. D.

A bench study was conducted to compare two membrane filter techniques for their efficiency in recovering fecal coliforms exposed to selected heavy metals. The effects on recovery by increasing time and metal concentration were also examined. The recovery methods employed included the standard membrane filter technique (S-MF) and a modified membrane filter technique (M-MF)~ which consisted of a lactose agar overlay and a five-hour preincubation at 35 C. The heavy metals Cd, Cr, Pb, and Zn were examined, each at two concentrations, to evaluate their effect on the recovery of the I. coli test organism, after exposure for 6, 24, and 48 hours. A statistical analysis of the data found the recoveries obtained by the M-MF to be significantly greater (.0001 level) than those of the S-MF, in all cases. Time was also found to significantly effect recovery, with recoveries decreasing as time increased. A significant difference was also found between the effects of the heavy metals tested and the concentrations of metals was likewise found to significantly effect recovery, with decreased recoveries being obtained at the high concentration of each metal. / Master of Science

Wastewater samples were collected from both the secondary settling and the chlorine contact tanks at a secondary sewage treatment plant (trickling filter) in Blacksburg, Virginia and analyzed for fecal coliforms using three procedures. Physical parameters including total suspended solids, DO, pH, turbidity, temperature and total chlorine residual were measured in effort to ascertain their effect on fecal coliform recoveries. The three procedures employed included the multiple-tube fermentation technique that yields the most probable number (MPN), the standard MF technique (SF-MF), and a modified MF technique (IF-MF) which consisted of a lactose overlay and a 5-hour incubation period at 44.5°C. A statistical analysis of the data showed that the means of the recoveries by the IF-MF technique were significantly greater (0.01 level) than those by the SF-MF technique in both the secondary settling tank and the chlorine contact tank samples. Recoveries by the IF-MF technique were comparable to those by the MPN technique when samples from the secondary settling basin were analyzed, but not in samples from the chlorine contact tank. However, the means of the IF-MF recovery procedure were within the 95 percent confidence interval associated with the MPN. No relationships could be established between the observed variations in the physical and chemical characteristics of the treated sewage samples and the fecal coliform densities. / Master of Science

Identification of pollen in fecal pellets is a potential technique for describing an animals diet and in turn the vegetation of an area. Mule deer and Bighorn Sheep pellets representing both summer and winter browsing and a variety of habitats were examined using relative percentages and the absolute pollen frequencies. In addition, fossil pellets from Stanton's Cave, Grand Canyon, Arizona, were examined and compared with modern pellets. Absolute pollen frequencies of individual pellets showed higher values and greater variation for summer pellets than for winter pellets. Relative pollen percentages for a specific vegetation type showed more variation in fecal pellets than in soil surface samples. Unless specifically being eaten, arboreal pollen types such as Pinus are less abundant in fecal pellets than in soil samples. Unlike soil surface samples, arboreal pollen types in fecal pellets are frequently limited to the immediate source area.

O desempenho de seis métodos de extração de DNA de oocistos de Cryptosporidium spp. em fezes foram avaliados pela nested PCR do gene SSU rRNA. Os métodos consistem na combinação com pequenas variações de duas técnicas para a liberação de esporozoítos (indução de excistamento/E ou choque térmico/C) e três técnicas de purificação de DNA (fenol-clorofórmio/F, GuSCN-sílica/S ou kit QIAmp DNA Stool Mini/K). Para a avaliação da sensibilidade analítica, os testes foram realizados a partir de diluições seriadas de oocistos purificados, na ausência e na presença de 100 &mu;l de fezes bovinas. A sensibilidade diagnóstica foi avaliada pela comparação com o método microscópico de centrífugo-flutuação em sacarose (padrão-ouro) em 15 amostras fecais de diferentes hospedeiros naturalmente infectados. Na ausência de fezes, foram avaliados apenas os métodos EF, ES, CF e CS, sendo que EF apresentou sensibilidade analítica superior, possibilitando a detecção de até 1 oocisto. Na presença de fezes, os métodos EF, EK e CK apresentaram desempenhos equivalentes, com sensibilidade de 104 oocistos. As maiores sensibilidades diagnósticas foram obtidas pelos métodos EK e CK, que possibilitaram a detecção de 13 (86,7%) das 15 amostras. Devido à alta sensibilidade analítica de EF em amostras purificadas, avaliou-se sua sensibilidade diagnóstica em amostras de oocistos purificados pelo método de centrífugo-flutuacão em sacarose, obtendo-se 100% de detecção. A presença de inibidores nas amostras fecais reduziu fortemente a sensibilidade das reações de PCR a partir de DNA extraído pelos métodos avaliados, sendo recomendável o emprego de técnicas de purificação de oocistos previamente à extração de DNA. Os resultados apontam para uma melhor eficiência dos métodos de indução de excistamento e kit QIAmp DNA Stool Mini. / The performance of six methods for DNA extraction from Cryptosporidium spp. oocysts in feces were evaluated by nested PCR of SSU rRNA gene. The methods are the combination with small variations of two techniques for the release of sporozoites (induction of excystation/E or thermal shock/C) and three techniques for DNA purification (phenol-chloroform/F, GuSCN-silica/S or QIAmp DNA Stool Mini kit/K). For the evaluation of analytical sensitivity, tests were made from serial dilutions of purified oocysts, in absence and in presence of 100 &mu;l of cattle feces. The diagnostic sensitivity was assessed by comparison with the microscopic method of centrifugalflotation in sucrose (gold standard) in 15 fecal samples from different naturally infected hosts. In the absence of feces, only methods EF, ES, FC, and CS were tested. EF had the highest analytical sensitivity, enabling the detection of up to 1 oocyst. In the presence of feces, methods EF, EK, and CK showed similar performance, with sensitivity of 104 oocysts. The highest sensitivities were obtained by methods EK and CK, which enabled the detection of 13 (86.7%) of 15 samples. Due to the high analytical sensitivity of EF in purified samples, its diagnostic sensitivity was evaluated in samples of purified oocysts by the method of centrifugal-flotation in sucrose, resulting in 100% detection. The presence of inhibitors in fecal samples greatly reduced the sensitivity of the PCR reactions from DNA extraction methods evaluated, and the use of techniques for purification of oocysts prior to DNA extraction is recommended. The results show a better performance of the methods of induction of excystation and QIAmp DNA Stool Mini kit.

Made available in DSpace on 2016-08-10T10:31:01Z (GMT). No. of bitstreams: 1 NATALINA GOMES DE ALMEIDA MENEZES.pdf: 750865 bytes, checksum: fa2bc830f9ad70862b5c87b5a6bbfe3b (MD5) Previous issue date: 2012-02-07 / The evaluation of foods is one of the necessary prerequisites for the construction of a database used in the development of economically viable and that have diets low environmental impact. Digestibility is one of the ways to determine the nutritional value of food, however the choice of method of collecting appropriate stool is directly related to the accuracy of the data produced. Thus, the present study aimed to evaluate the effect of feces collects method, on the rate of leaching of nutrients in the water, so as to determine the best time for collects feces s Tambaqui (Colossoma macropomum) digestibility was estimated by indirect method in Guelph system using modified chromium oxide as inert marker, the concentration of 0.2%. The ranges correspond to collects to 60 min, 120 min, 240min, and 480 min. 64 juvenile tambaqui were used with an average weight of 300 g randomly distributed in eight power tanks with a capacity of 310L of water. The collects were made during four weeks, where each week was considered one repetition. And the determination of the chromium concentration and rations of feces were held at the Department of Animal Production (DPA/EV/UFG). After determination of the concentrations of chromium and phosphorus in animal feed and feces, MS CDAs and P were determined. The experimental design was entirely chance, with four treatments and four repetitions. Stool collection interval for the tambaqui digestibility values influence of dry matter and phosphorus. However, higher digestibility values were observed for the match after 240 and 480 min., while the smallest value of CDA was noted for the range of 120 min. one can conclude that in Guelph s collects method modified the collects intervals of feces for determination of the CDA of P and MS are different, being necessary the realization of collects an hour after the elimination of feces in order to reduce leaching of P in water bodies While for the smallest variation in CDA values of MS recommends that collects are performed in two to eight hours after the start of the release of stool. / A avaliação de alimentos é um dos pré-requisitos necessários para a construção de uma base de dados utilizados na formulação de dietas economicamente viáveis e que tenham baixo impacto ambiental. A digestibilidade é uma das formas de se determinar o valor nutritivo dos alimentos, entretanto a escolha do método de coleta de fezes mais adequado está diretamente relacionada com a acurácia dos dados produzidos. Desta forma, o presente trabalho objetivou avaliar o efeito do método de coleta de fezes, sobre a taxa de lixiviação de nutrientes na água, assim como determinar o melhor horário para coleta de fezes de Tambaqui (Colossoma macropomum) A digestibilidade foi estimada pelo método indireto, no sistema de Guelph modificado, utilizando-se óxido de cromo III, como marcador inerte, na concentração de 0,2%. Os intervalos corresponderam às coletas aos 60min, 120min, 240min, e 480 min. Foram utilizados 64 juvenis de tambaqui com peso médio inicial de 300g distribuídos aleatoriamente em oito aquários de alimentação com capacidade para 310L de água. As coletas foram realizadas durante quatro semanas, onde cada semana foi considerada uma repetição. E a determinação da concentração de cromo das rações e das fezes foram realizadas no Departamento de Produção Animal (DPA/EV/UFG). Após determinação das concentrações de cromo e fósforo nas rações e nas fezes, os CDAs da MS e do P foram determinados. O delineamento experimental foi inteiramente casualizado com quatro tratamentos e quatro repetições. O intervalo de coleta de fezes para o tambaqui influenciou nos valores de digestibilidade do fósforo e da matéria seca. Entretanto, maiores valores de digestibilidade foram observados para o fósforo após 240 e 480 min., enquanto o menor valor de CDA foi observado para o intervalo de 120 min. Pode-se concluir que no método de coleta de Guelph modificado os intervalos de coleta de fezes para determinação do CDA do P e da MS são diferentes, sendo necessária a realização da coleta uma hora após a eliminação das fezes de modo a reduzir a lixiviação do P nos corpos d água, enquanto para a menor variação nos valores de CDA da MS recomenda-se que as coletas sejam realizadas de duas a oito horas após o início da liberação das fezes.