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PubMed2006

Fractionation of the reference inoculum of epizootic rabbit enteropathy in discontinuous sucrose gradient identifies aetiological agents in high density fractions.

Epizootic rabbit enteropathy (ERE) is a major cause of economic loss in intensive rabbit production. Since its first recognition in 1997, much work has been done to determine the pathogenic mechanisms of the disease and to identify the aetiological agent(s). Unfortunately, the quest for aetiology has only met with limited success despite the ability to reproduce the syndrome by inoculation of intestinal contents from field cases. These intestinal inocula contain a huge number of microorganisms which could all be involved in the aetiology of ERE. To decrease the number of putative agents, the French reference inoculum TEC3 was fractionated on a discontinuous sucrose gradient so that seven fractions (supernatant, 10%, 20%, 30%, 40%, 50% and pellet) were obtained. Specific-pathogen-free rabbits were inoculated with three out of these seven fractions (supernatant, 30%, and pellet). The objectives were: (1) to characterise the seven fractions by bacteriological examination; (2) to verify whether the aetiological agent was present in the fractions by inoculation of rabbits; (3) to assign the aetiological agent of ERE to a morphological group of pathogens; (4) to identify a fraction which could replace the reference inoculum TEC3 in applications such as cell cultures or egg inoculation. The results strongly suggest that ERE is a bacterial disease and does not have a viral or parasitic aetiology.

Animals↗
PubMed1981

[Enterotoxic activity of the pseudotuberculosis microbe].

For the first time the activity of Y. pseudotuberculosis, its extracellular, surface antigen and Westphal's lipolysaccharide has been studied with the use of biological models (the ligated loop of the small intestine of a rabbit, the pulmonary model, the intradermal tests). This microorganism has been found capable of inducing the accumulation of exudate in the ligated loop of the small intestine of a rabbit and interfering with the permeability of the vascular walls. The toxic action of Y. pseudotuberculosis is neutralized by immunization.

Animals↗
PubMed1989

Novel cellular interactions and networks involving the intestinal immune system and its microenvironment.

The interactions we have described enable the intestine to respond appropriately to antigenic challenge in an effective and coordinated way. This is of vital importance when one considers the dual role of the intestine as a first line of defence against harmful microorganisms and as the route by which the animal obtains nutrition. Under normal circumstances, these interactions select for an appropriate cell phenotype by providing a network of interactions that contribute to intestinal homeostasis. If there is dysfunction of any component, then other cells will be affected. For example, if down-regulation of the mucosal immune response is not effective, damage to the epithelium, nerves and muscle may occur during an inflammatory response. Similarly, if the integrity of the epithelium is disrupted, damage to the elements of the mucosal immune system may occur. This model would suggest that these interactions must be considered if one wishes to adequately explain diseases such as IBD and design innovative therapeutic regimens. Future interdisciplinary research will shed light on the web of interactions occurring in the intestinal environment and provide a novel view of the respective contributions of the immune system and its local environment to cell differentiation, function and regulation.

Animals↗
PubMed2004

Microflora of the gastrointestinal tract: a review.

The mucosal surface of the human gastrointestinal (GI) tract is about 200-300 m2 and is colonized by 1013-14 bacteria of 400 different species and subspecies. Savage has defined and categorized the gastrointestinal microflora into two types, autochthonous flora (indigenous flora) and allochthonous flora (transient flora). Autochthonous microorganisms colonize particular habitats, i.e., physical spaces in the GI tract, whereas allochthonous microorganisms cannot colonize particular habitats except under abnormal conditions. Most pathogens are allochthonous microorganisms; nevertheless, some pathogens can be autochthonous to the ecosystem and normally live in harmony with the host, except when the system is disturbed. The prevalence of bacteria in different parts of the GI tract appears to be dependent on several factors, such as pH, peristalsis, redox potential, bacterial adhesion, bacterial cooperation, mucin secretion, nutrient availability, diet, and bacterial antagonism. Because of the low pH of the stomach and the relatively swift peristalsis through the stomach and the small bowel, the stomach and the upper two-thirds of the small intestine (duodenum and jejunum) contain only low numbers of microorganisms, which range from 103 to 104 bacteria/mL of the gastric or intestinal contents, mainly acid-tolerant lactobacilli and streptococci. In the distal small intestine (ileum), the microflora begin to resemble those of the colon, with around 107-108 bacteria/mL of the intestinal contents. With decreased peristalsis, acidity, and lower oxidation-reduction potentials, the ileum maintains a more diverse microflora and a higher bacterial population. Probably because of slow intestinal motility and very low oxidation-reduction potentials, the colon is the primary site of microbial colonization in humans. The colon harbors tremendous numbers and species of bacteria. However, 99.9% of colonic microflora are obligate anaerobes.

Animals↗
PubMed1989

Increased concentrations of liver cholesterol in rats fed lactulose.

The disaccharide lactulose (beta-D-galactopyranosyl-(1-4)-D-fructofuranose) is thought to be poorly hydrolized by intestinal enzymes but is broken down by microorganisms in the colon. Thus lactulose shares with pectin similar characteristics. Lactulose is used in the food industry and in the treatment of constipation. There is preliminary evidence that dietary lactulose (5%, w/w) causes increased concentrations of serum and liver cholesterol in rats when compared with pectin. This paper describes dose-response relationships between dietary lactulose and cholesterol in either serum or liver.

Animals↗
PubMed1989

Immunological and bacteriological aspects of reactive arthritis.

It is apparent that in the development of reactive arthritis the patient fails in his first line of defence against the invading microorganism. This results in persistence of the microorganism probably in or close to the intestinal epithelium. Microbial antigens may appear also in the circulation, perhaps as part of the immune complexes, or within cellular elements. Through these transportation mechanisms they enter the synovium, triggering an inflammatory process that leads to reactive arthritis.

Antibodies, Bacterial↗
PubMed2006

The F1F0-ATPase of Bifidobacterium animalis is involved in bile tolerance.

Adaptation and tolerance to bile stress are important factors for the survival of bifidobacteria in the intestinal tract. Bifidobacterium animalis is a probiotic microorganism which has been largely applied in fermented dairy foods due to its technological properties and its health-promoting effects for humans. The effect of the presence of bile on the activity and expression of F(1)F(0)-ATPase, the pool of ATP and the intracellular pH of B. animalis IPLA 4549 and its mutant with acquired resistance to bile B. animalis 4549dOx was determined. The bile-resistant mutant tolerated the acid pH better than its parent strain. Bile induced the expression of the F(1)F(0)-ATPase and increased the membrane-bound H(+)-ATPase activity, in both parent and mutant strains. In acidic conditions (pH 5.0), the expression and the activity of this enzyme were higher in the mutant than in the parent strain when cells were grown in the absence of bile. Total ATP content was higher for the mutant in the absence of bile, whereas the presence of bile induced a decrease of intracellular ATP levels, which was much more pronounced for the parent strain. At pH 4.0, and independently on the presence or absence of bile, the mutant showed a higher intracellular pH than its parent strain. These findings suggest that the bile-adapted B. animalis strain is able to tolerate bile by increasing the intracellular ATP reserve, and by inducing proton pumping by the F(1)F(0)-ATPase, therefore tightly regulating the internal pH, and provide a link between the physiological state of the cell and the response to bile.

Adenosine Triphosphate↗
PubMed1980

Effect of anthraquinone derivatives on canine and rat intestinal motility.

The effects on gastrointestinal motility of 3 senna preparations containing 18% oxidized Ca-sennosides, 60% Ca-sennosides, or pure sennosides A + B were tested in dogs and rats as measured by electromyography. Oral administration of the oxidized products in the fasted animal increased the activity of the small intestine within 2 h and reduced both caecal and colonic contractions for 24 h. Severe diarrhoea was present 4-6 h after administration and lasted for at least 1 day. Ca-sennosides had a similar, but weaker effect while pure sennosides affected motility only 6-10 h after oral administration. The intracolonic administration of the oxidized products resulted in an immediate reduction of colon motility for 7-8 h and diarrhoea was present within 40 min. Intracolonic Ca-sennosides and sennosides A + B induced only small changes in the intestinal motility, but diarrhoea also appeared. The results confirm that pure sennosides act predominantly on large intestine motility after their degradation by colonic microorganisms. Oxidized products are already effective in the upper gastrointestinal tract. The early action of Ca-sennosides requires further investigation. Side effects after oral senna treatment such as griping or nausea may be caused by motility changes induced by the presence of small amounts of oxidized products in the drug.

Animals↗
PubMed1987

Influence of dietary fiber on xylanolytic and cellulolytic bacteria of adult pigs.

Xylanolytic and cellulolytic bacteria were enumerated over an 86-day period from fecal samples of 10 8-month-old gilts that were fed either a control or a 40% alfalfa meal (high-fiber) diet. Fecal samples were collected from all pigs on days 0, 3, 5, 12, 25, 37, 58, and 86. Overall, the numbers of xylanolytic bacteria producing greater than 5-mm-diameter zones of clearing on 0.24% xylan roll tube medium after 24 to 36 h of incubation were 1.6 X 10(8) and 4.2 X 10(8)/g (dry weight) of feces for the control pigs and those fed the high-fiber diet, respectively. After 1 week of incubation, a large number of smaller zones of clearing (1 to 2 mm) appeared. Besides Bacteroides succinogenes and Ruminococcus flavefaciens, which produced faint zones of clearing in xylan roll tubes, three strains which closely resembled B. ruminicola hydrolyzed and used xylan for growth. The overall numbers of cellulolytic bacteria producing zones of clearing in 0.5% agar roll tube medium were 0.36 X 10(8) and 4.1 X 10(8)/g for the control pigs and those fed the high-fiber diet, respectively. B. succinogenes was the predominant cellulolytic isolate from both groups of pigs, and R. flavefaciens was found in a ratio of approximately 1 to 15 with B. succinogenes. Degradation of xylan and cellulose, measured by in vitro dry matter disappearance after inoculation with fecal samples, was significantly greater for pigs fed the high-fiber diet than that for the controls. These data suggest that the number of fibrolytic microorganisms and their activity in the large intestine of the adult pig can be increased by feeding pigs high-alfalfa-fiber diets and that these organisms are similar to those found in the rumen.

Animal Feed↗
PubMed2001

Viability of Giardia intestinalis cysts and viability and sporulation state of Cyclospora cayetanensis oocysts determined by electrorotation.

Electrorotation is a noninvasive technique that is capable of detecting changes in the morphology and physicochemical properties of microorganisms. Electrorotation studies are reported for two intestinal parasites, Giardia intestinalis and Cyclospora cayetanensis. It is concluded that viable and nonviable G. intestinalis cysts can be differentiated by this technique, and support for this conclusion was obtained using a fluorogenic vital dye assay and morphological indicators. The viability of C. cayetanensis oocysts (for which no vital dye assay is currently available) can also be determined by electrorotation, as can their sporulation state. Modeling of the electrorotational response of these organisms was used to determine their dielectric properties and to gain an insight into the changes occurring within them. Electrorotation offers a new, simple, and rapid method for determining the viability of parasites in potable water and food products and as such has important healthcare implications.

Animals↗
PubMed2005

The host response to the probiotic Escherichia coli strain Nissle 1917: specific up-regulation of the proinflammatory chemokine MCP-1.

BACKGROUND: The use of live microorganisms to influence positively the course of intestinal disorders such as infectious diarrhea or chronic inflammatory conditions has recently gained increasing interest as a therapeutic alternative. In vitro and in vivo investigations have demonstrated that probiotic-host eukaryotic cell interactions evoke a large number of responses potentially responsible for the effects of probiotics. The aim of this study was to improve our understanding of the E. coli Nissle 1917-host interaction by analyzing the gene expression pattern initiated by this probiotic in human intestinal epithelial cells. METHODS: Gene expression profiles of Caco-2 cells treated with E. coli Nissle 1917 were analyzed with microarrays. A second human intestinal cell line and also pieces of small intestine from BALB/c mice were used to confirm regulatory data of selected genes by real-time RT-PCR and cytometric bead array (CBA) to detect secretion of corresponding proteins. RESULTS: Whole genome expression analysis revealed 126 genes specifically regulated after treatment of confluent Caco-2 cells with E. coli Nissle 1917. Among others, expression of genes encoding the proinflammatory molecules monocyte chemoattractant protein-1 ligand 2 (MCP-1), macrophage inflammatory protein-2 alpha (MIP-2alpha) and macrophage inflammatory protein-2 beta (MIP-2beta) was increased up to 10 fold. Caco-2 cells cocultured with E. coli Nissle 1917 also secreted high amounts of MCP-1 protein. Elevated levels of MCP-1 and MIP-2alpha mRNA could be confirmed with Lovo cells. MCP-1 gene expression was also up-regulated in mouse intestinal tissue. CONCLUSION: Thus, probiotic E. coli Nissle 1917 specifically upregulates expression of proinflammatory genes and proteins in human and mouse intestinal epithelial cells.

Biological Therapy↗
PubMedDate not supplied

[The role of the carbohydrate composition of the glycocalyx in some species of lactobacilli in the manifestation of their adhesive properties].

Availability of certain monosaccharides in the composition of glycocalyx of lactic acid bacteria (Lactobacillus plantarum--strains 337D and 11/16; Streptococcus thermophilus--strains S1 (nonmucous race) and S5 (mucous race), Enterococcus faecium (K-50) has been investigated with the help of plant lectins with certain carbohydrate specificity labelled by colloid gold. All the microorganisms under investigation were characterized by the presence of N-acetyl-D-galactosamine and N-acetyl-D-glucosamine in rather insignificant amounts. Glycocalyx of lactic acid bacteria was also characterized by availability of essential amount of L-fructose and low amount of sialic acid (except for S. thermophilus S5 (mucous race). Presence of alpha-N-acetyl-D-galactosamine, alpha-D, beta-D-galactose, alpha-D-glucose, alpha-D-mannose in the composition of the lactic acid bacteria glycocalyx composition evidences for the additional role of these monosaccharides in the process of the microorganism adhesion on the human and animal intestine mucosa. It has been confirmed that availability of certain monosaccharides in the composition of surface glycopolymers of lactic acid bacteria was connected with adhesive properties of cells and their existence conditions.

Bacterial Adhesion↗
PubMed2001

Selective decontamination of the digestive tract as infection prevention in the critically ill. Does it lead to resistance?

Several meta-analysis showed the efficacy of selective decontamination of the digestive tract (SDD) in the reduction of infections in critically ill patients, particularly for ventilator associated pneumonia and bloodstream infections, thereby reducing mortality and morbidity. The principle of SDD is that by means of application of non-absorbable antibiotics in the intestinal canal and oropharyngeal cavity, potentially pathogenic microorganisms are eliminated, thereby reducing the incidence of organ site infections. The endogenous anaerobic flora is preserved as a factor contributing to defence against colonization. The potential induction of antibiotic resistance (AR) due to SDD is a major concern in ICU. This review evaluates the onset of clinically relevant AR after SDD. The results of a recent meta-analysis and of several studies, which confirmed the virtual absence of any reported AR with SDD and that did not find AR after stopping SDD, are presented. The eradication of the reservoir of abnormal bacteria located in the gut by topical non-absorbable antibiotics appears to significantly reduce morbidity, mortality and resistance. Using only systemic antibiotics in ICU may contribute to maintain an abnormal population of bacteria among which AR is encouraged.

Acute Disease↗
PubMed1980

[Teeth and nutrition (basic questions)].

Recognized methods used in the science of nutrition are only applicable to a limited extent for nutrition aspects of dental health; the necessity of using more highly differentiated methods of measurement was substantiated. The consumption trends for the most important groups of foodstuffs in recent years was discussed, based on data from the 1980 report on nutrition; nutrient supply and an evaluation of consumption statistics were considered and possibilities for necessary improvements were mentioned. Using the example of theoretical and recent test results for sugar exchange substances, it was shown how many different ways must be considered for symbiosis between man and microorganisms (namely, including lower sections of the intestine) in evaluating foodstuff safety for sugar exchange substances. Those aspects of nutrition control, particularly in regard to dentistry, arising from this study were discussed in a separate section which promote a further development in the relationship between dentistry and the science of nutrition.

Colon↗
PubMed1983

Chronic nonspecific diarrhea in children: investigation of the surface morphology of small bowel mucosa utilizing the scanning electron microscope.

Investigations by scanning electron microscopy into changes of surface morphology of small bowel mucosa in children with chronic nonspecific diarrhea are reported. The study population comprised 56 patients, ranging in age from 5 months to 7 years; 65% were between 10 and 28 months old, and 64% of the patients were boys. The major findings were: microorganisms on the mucosal surface; excessive extrusion of cell cytoplasm and of enterocytes (cell shedding); presence of excessive mucus on the mucosal surface; damage to the brush border; and partial villous atrophy. The latter lesion was found in only four patients. All these changes are considered pathologic and, for the most part, are presumed to be due to the presence of antigens, in particular, microorganisms. A depression of disaccharidase activities was encountered in 64% of the patients, but prevalence was without regard to age. Most common was a combined depression of lactase, sucrase, and maltase, as well as an isolated depression of lactase. The possibility has to be considered that enteroadherent microorganisms which are usually not considered pathogenic, and microorganisms such as Mycoplasma, may emerge as intestinal pathogens in susceptible children. It is feasible that genetic traits of the host and environmental factors facilitate adherence and colonization of the small bowel mucosa which, in turn, produces chronic diarrhea. Further studies are needed to confirm the preliminary information contained in this report.

Atrophy↗
PubMed1994

The use of Bacillus subtilis as an antidiarrhoeal microorganism.

This review describes the therapeutic activity of Bacillus subtilis spores (Enterogermina) in the treatment of intestinal disorders associated with alterations in the qualitative and quantitative composition of the normal human intestinal flora. On the basis of the present knowledge of gastrointestinal microbiology and of the physiology fo this antidiarrhoeal microorganism, a mechanism of action of oral bacteriotherapy with B. subtilis is proposed. Advantages of the use of B. subtilis as an antidiarrhoeal microorganism are also discussed.

Bacillus subtilis↗
PubMedDate not supplied

[The antagonistic properties of bacteria isolated from the digestive tract of female mink housed in the area of the Chernobyl Atomic Electric Power Station].

Differences in species composition, number and level of antagonistic activity of bacteria isolated from the digestive tract of Chernobyl female minks of various age and with different immunological state have been established. Prevalence of anaerobes (bifidobacteria) and microaerophils (lactic acid bacteria) with the increase of microorganisms concentration along the channel: stomach, small and large intestine (10(7)-10(10)/g) was found in all the departments of digestive tract of minks. Among the identified lactic-acid bacteria Lactobacillus helveticus (10(7)-10(8)/g) prevailed in the stomach of the studied female minks, L. coryniformis (10(9)-10(10)/g) in the small intestine, L. casei (10(10)/g) in the large one. Antagonistic activity was most expressed in the strains of L. helveticus and L. casei, isolated from the younger (1.5 year-old) minks. Enterococcus faecalis isolated from the stomach of 1.5 year-old female minks was distinguished by the greatest antagonistic activity among identified enterococci. Strains of E. faecium isolated from the thin intestine of the young female minks (1.5 year-old) and from the large intestine of more nature animals (2.5 years) who received thymogen were characterized by the most expressed antibiosis among enterococci isolated bacteria a conclusion was made that the mechanisms of inhibitory effect of the studied microorganisms are underlied by not only their capacity to form organic acids but also by the capacity to produce antibiotic products.

Animals↗
PubMed2005

Selective stimulation of the growth of anaerobic microflora in the human intestinal tract by electrolyzed reducing water.

96-99% of the "friendly" or residential microflora of intestinal tract of humans consists of strict anaerobes and only 1-4% of aerobes. Many diseases of the intestine are due to a disturbance in the balance of the microorganisms inhabiting the gut. The treatment of such diseases involves the restoration of the quantity and/or balance of residential microflora in the intestinal tract. It is known that aerobes and anaerobes grow at different oxidation-reduction potentials (ORP). The former require positive E(h) values up to +400 mV. Anaerobes do not grow unless the E(h) value is negative between -300 and -400 mV. In this work, it is suggested that prerequisite for the recovery and maintenance of obligatory anaerobic microflora in the intestinal tract is a negative ORP value of the intestinal milieu. Electrolyzed reducing water with E(h) values between 0 and -300 mV produced in electrolysis devices possesses this property. Drinking such water favours the growth of residential microflora in the gut. A sufficient array of data confirms this idea. However, most researchers explain the mechanism of its action by an antioxidant properties destined to detox the oxidants in the gut and other host tissues. Evidence is presented in favour of the hypothesis that the primary target for electrolyzed reducing water is the residential microflora in the gut.

Bacteria, Anaerobic↗