Development of an ex vivo organ culture model using human gastro-intestinal tissue and Campylobacter jejuni.

Campylobacter jejuni is an important food-borne pathogen. However, relatively little is understood regarding its pathogenesis, and research is hampered by the lack of a suitable model. Recently, a number of groups have developed assays to study the pathogenic mechanisms of C. jejuni using cell culture models. Here, we report the development of an ex vivo organ culture model, allowing for the maintenance of intestinal mucosal tissue, to permit more complex host-bacterium interactions to be studied. Ex vivo organ culture highlights the propensity for C. jejuni to adhere to mucosal tissue via the flagellum, either as discrete colonies or as multicellular units.

A unique homologue of the eukaryotic protein-modifier ubiquitin present in the bacterium Bacteroides fragilis, a predominant resident of the human gastro-intestinal tract

In the complete genome sequences of Bacteroides fragilis NCTC9343 and 638R, we have discovered a gene, ubb, the product of which has 63% identity to human ubiquitin and cross-reacts with antibodies raised against bovine ubiquitin. The sequence of ubb is closest in identity (76%) to the ubiquitin gene from a Migratory Grasshopper entomopoxvirus, suggesting acquisition by inter-kingdom horizontal gene transfer. We have screened clinical isolates of B. fragilis from diverse geographical regions and found that ubb is present in some, but not all strains. The gene is transcribed and the mRNA translated in B. fragilis, but deletion of ubb did not have a detrimental effect on growth. BfUbb has a predicted signal sequence; both full length and processed forms were detected in whole cell extracts, while the processed form was found in concentrated culture supernatants. Purified recombinant BfUbb inhibited in vitro ubiquitination and was able to covalently bind the human E1 activating enzyme, suggesting it could act as a suicide substrate in vivo. B. fragilis is one of the predominant members of the normal human resident gastro-intestinal microbiota with estimates up to >1011 cells g-1 of faeces by culture. These data indicate that the gastro-intestinal tract of some individuals could contain a significant amount of aberrant ubiquitin with the potential to inappropriately activate the host immune system and/or interfere with eukaryotic ubiquitin activity. This discovery could have profound implications in relation to our understanding of human diseases such as inflammatory bowel and autoimmune diseases.

La texture et la granulométrie de la moulée influencent les concentrations d’acide propionique et butyrique de même que la prévalence d’Escherichia coli dans le tractus gastro-intestinal du porc d’engraissement

Certaines stratégies alimentaires sont actuellement considérées pour remplacer l’usage des antimicrobiens dans les fermes porcines. Les objectifs de cette étude étaient d'évaluer l'effet de la granulométrie et de la texture des aliments sur les concentrations d'acides gras volatils intestinaux, la composition des populations pathogènes et commensales d’E. coli et sur les performances de croissance des porcs. Des porcs d'engraissement (n= 840) ont reçu l'une des six diètes suivantes: moulée texturée 500, 750 et 1250 µm et moulée cubée 500, 750 et 1250 µm. Le gain de poids a été mesuré à chaque changement de formulation de moulée. À l'abattoir, les contenus du caecum et du côlon de 165 porcs ont été échantillonnés pour le dénombrement des E. coli par PCR quantitatif (qPCR) et pour la quantification des AGV. Le gène yccT a été utilisé pour dénombrer les E. coli totaux. Une diminution du taux de conversion alimentaire a été associée avec la moulée cubée et/ou la moulée de 500 µm. Les concentrations d’acide propionique et butyrique, et ce tant au niveau du caecum que du côlon, étaient plus élevées chez les porcs recevant de la moulée texturée que chez ceux recevant de la moulée cubée. Du point de vue de la granulométrie, les concentrations caecales et du côlon d’acide butyrique étaient plus élevées chez les porcs alimentés avec de la moulée de 1250 µm que chez ceux recevant de la moulée de 500 µm. D'autre part, les niveaux intestinaux d’E. coli totaux étaient plus élevés pour les porcs nourris avec de la moulée cubée que pour ceux ayant reçu de la moulée texturée. Les résultats ont montré que la moulée texturée est associée à des performances de croissance plus faibles mais à des changements intestinaux favorables.

Parent-reported gastro-intestinal symptoms in children with autism spectrum disorders

The objective of this study is to investigate whether parentally-reported gastro-intestinal (GI) symptoms are increased in a population-derived sample of children with autism spectrum disorders (ASD) compared to controls. Participants included 132 children with ASD and 81 with special educational needs (SEN) but no ASD, aged 10-14 years plus 82 typically developing (TD) children. Data were collected on GI symptoms, diet, cognitive abilities, and developmental histories. Nearly half (weighted rate 46.5 %) of children with ASD had at least one individual lifetime GI symptom compared with 21.8 % of TD children and 29.2 % of those with SEN. Children with ASD had more past and current GI symptoms than TD or SEN groups although fewer current symptoms were reported in all groups compared with the past. The ASD group had significantly increased past vomiting and diarrhoea compared with the TD group and more abdominal pain than the SEN group. The ASD group had more current constipation (when defined as bowel movement less than three times per week) and soiling than either the TD or SEN groups. No association was found between GI symptoms and intellectual ability, ASD severity, ASD regression or limited or faddy diet. Parents report more GI symptoms in children with ASD than children with either SEN or TD children but the frequency of reported symptoms is greater in the past than currently in all groups.

Interactions between nutrition and infections with Haemonchus contortus and related gastro-intestinal nematodes in small ruminants

Interactions between host nutrition and feeding behaviour are central to understanding the pathophysiological consequences of infections of the digestive tract with parasitic nematodes. The manipulation of host nutrition provides useful options to control gastrointestinal nematodes as a component of an integrated strategy. Focused mainly on the Hameonchus contortus infection model in small ruminants, this chapter (i) illustrates the relationship between quantitative (macro- and micro-nutrients) and qualitative (plant secondary metabolites) aspects of host nutrition and nematode infection, and (ii) shows how basic studies aimed at addressing some generic questions can help provide solutions, despite the considerable diversity of epidemiological situations and breeding systems.

Relationship between alcohol abuse upper gastro-intestinal haemorrhage and nutritional status during acute hospital admission

This thesis is concerned with the effect of alcohol consumption on the pathogenesis of bleeding from the upper gastrointestinal tract via nutritional pathways. Altered nutritional status is a frequently recognised clinical accompaniement of heavy alcohol consumption in hospitalized patients. Similarly, upper gastrointestinal bleeding is frequently accompanied by the presence of heavy alcohol consumption. Nevertheless, the clinical quantification of alcohol intake is often descriptive, so that a link between alcohol use and upper gastrointestinal haemorrhage via nutritional mechanisms has been only generally defined. In the literature review, the methods of defining alcohol use and abuse, using interview, biochemical and haematological techniques are noted. The relationship between alcohol abuse and nutrient imbalances is reviewed, especially in relation to possible effects on the gastrointestinal tract, appetite and eating habits. A further section reviews the relationship between alcohol use and anatomical lesions of the upper gastrointestinal tract likely to lead to bleeding. Following the chapter in which the methods used in this thesis are described. Chapter 4 seeks to describe the study population and its subgroups in this thesis in relation to interview, biochemical and haematological methods. Alcohol use is defined in relation to (1) a clinical classification of heavy or light drinking, based on a questionnaire administered in Casualty, (2) a quantified method of determining alcohol consumption during a subsequent ward dietetic assessment, (3) in relation to a biochemical definition (recent drinking and non-drinking), and a classification of (1) and (2) called, for the purposes of this thesis, 'alcohol abusers' and 'nonabusers'. Heavy, regular and recent drinkers and alcohol abusers tend to be male and younger than light, infrequent and nonrecent drinkers and nonabusers. Chapter 5 relates the nutritional status of those patients admitted acutely to hospital in relation to the groups defined in Chapter 4, Nutritional status is defined in terms of food intake, anthropometry, biochemical and haematological parameters. Different methods of defining alcohol use give rise to different patterns of nutritional impairment. Chapter 6 relates the nutritional status of those patients admitted acutely to hospital in relation to the presence or absence of an endoscopically defined site of upper gastrointestinal bleeding. A difference is seen between those bleeding from a Mailory-weiss tear and other sites of bleeding, similarly, biochemical differences in nutritional status emerge between those patients who presented in shock, and those who did not. Chapter 7 explores the relationships between biochemical markers of nutritional status and haemostatic variables in the groups of abusers/non-abusers, the various sites of primary bleeding/controls, and shock/non-shock. Serum copper appears to be related to altered haemostasis in a manner not apparently described elsewhere.

Gastro-intestinal transit time in South American deer

The study of diet and physiological peculiarities of the digestive system of neotropical deer is not well known and the literature shows inconsistencies. To better understand the digestive system of these mammals the difference in the gastro-intestinal transit time of four species of neotropical deer (Mazama americana, Mazama gouazoubira, Mazama nana, Blastocerus dichotomus), kept ill captivity, was evaluated. Four plants (Neonotonia wightii, Morus albans, Medicago sativa, Leucaena leucocephala) were utilized and two variables were measured, mean time of the beginning of the elimination (BE) and mean time of permanence (TP). The results obtained for BE indicated similarity among the deer species, with significant differences between M. gouazoubira (mean = 13.62 hr) and M. Americana (mean = 19.25 hr). For the plants, the BE was faster with N. wightii and L. leucocephala, and slower for M. sativa. The TP results for B. dichotomus showed longer time when compared to the other species, whereas M. gouazoubira had a lower permanence. Overall, N. wightii had the highest retention time in the digestive tract of all the deer species studied. Associated with this observation, N. wightii had the highest quantity of plant fiber of the plants tested. In a similar fashion M. sativa showed the lowest TP in the digestive tract of the deer and had the lowest quantity of acid detergent fiber. The data from this study showed that, within species, the shape of the excretion curve of the plants was similar when the animals consumed N. wightii or M. sativa. Blastocerus dichotomus and M. gouazoubira had the highest and the lowest gastro-intestinal transit time, respectively. This suggests that these species characterize different abilities to digest high fiber food, and consequently, represent the two extremities in the morphophysiological adaptation within the deer species evaluated. This information is vital because it is important to know the digestive physiology to define the diet of captive animals, particularly regarding the quantity and quality of fiber. Zoo Biol 25:47-57, 2006. (C) 2005 Wiley-Liss, Inc.

Parasitismo natural de bufalinos em Botucatu, SP, Brasil: III. Dinâmica do parasitismo gastro-intestinal em vacas e suas crias

Gastro-intestinal parasitism of 24 buffalo cows before parturition, and post-parturition, their infection and that of their respective calves during the following 30 weeks were studied. Willis, Hoffmann and whenever possible, the modified Gordon & Whitlock techniques were used for fecal examinations. Toxocara vitulorum eggs were the earliest forms encountered in calves feces, as follows: during the 1st week after birth, 58.33% of the calves were positive, and in the 4th week, 100% of these animals were positive. Eggs of Strongyloides sp were in the 1st week after birth in two of the calves and in the 5th week, all for them were positive. The next parasites to appear were the Coccidia of which oocysts were detected in the feces of two calves in the 2nd week after birth, and 58.33% of the calves were positive for these in the 3rd week, and in the 6th week, all calves shed oocysts in their feces. on the other hand, eggs of Strongylids were the last forms to appear in calves feces. However, despite their sporadic appearance in the feces, eggs of these parasites were observed continuously from the 11th week onwards, and at this point, the percentage of positive samples began to increase to reach its peak. Relatively to adult animals, eggs of T. vitulorum were observed in the feces of 11 cows, one or twice at most; eggs of Strongyloides sp were seen only once in the feces of four buffalo cows and eggs of Strongylids in 21 out of 24 cows. Oocysts of Coccidia were observed in 16 cows. Mechanisms of infestation of calves with these parasites are discussed.

Supplementation with protected fat to manage gastro-intestinal nematode infections in Santa Ines sheep

This experiment aimed to determine the influence of supplementation with protected fat on nematode infections in periparturient sheep or sheep in their final stage of pregnancy. Fifty Santa Ines ewes received 200 g of concentrate/animal/day, mineral salt and water and were grouped according to their weight, hematocrit and the number of eggs per gram of feces (EPG). Two diets were used: a control treatment and a treatment consisting of supplementation with 30 g/animal/day of protected fat in the concentrate. Three monthly evaluations were performed over a total of 84 days of testing. The variables analyzed were weight, body condition, EPG and coprocultures; blood tests were performed for the determination of packed cell volume, hemoglobin concentration and total plasma protein, and leukograms and eosinophil counts were performed. For weight and hemoglobin concentrations, interactions were observed between diet and collection date (P<0.05); body condition, total plasma protein, packed cell volume and total leukocytes did not differ statistically among treatments (P> 0. 05) but did differ by collection day (P <0.05). The EPG and eosinophil counts did not differ statistically by either diet or collection date (P>0.05). The genus Haemonchus was predominant, followed by the genera Cooperia, Trichostrongylus and Oesophagostomum. The protected fat did not decrease EPG and did not improve the blood parameters of infected sheep.

Supplementation with protected fat to manage gastro-intestinal nematode infection in Santa Ines sheep

This experiment aimed to determine the influence of supplementation with protected fat on nematode infections in periparturient sheep or sheep in their final stage of pregnancy. Fifty Santa Ines ewes received 200 g of concentrate/animal/day, mineral salt and water and were grouped according to their weight, hematocrit and the number of eggs per gram of feces (EPG). Two diets were used: a control treatment and a treatment consisting of supplementation with 30 g/animal/day of protected fat in the concentrate. Three monthly evaluations were performed over a total of 84 days of testing. The variables analyzed were weight, body condition, EPG and coprocultures; blood tests were performed for the determination of packed cell volume, hemoglobin concentration and total plasma protein, and leukograms and eosinophil counts were performed. For weight and hemoglobin concentrations, interactions were observed between diet and collection date (P<0.05); body condition, total plasma protein, packed cell volume and total leukocytes did not differ statistically among treatments (P> 0. 05) but did differ by collection day (P <0.05). The EPG and eosinophil counts did not differ statistically by either diet or collection date (P>0.05). The genus Haemonchus was predominant, followed by the genera Cooperia, Trichostrongylus and Oesophagostomum. The protected fat did not decrease EPG and did not improve the blood parameters of infected sheep.