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At least 1,099 records · Page 61Linked to original sources
PubMed1996

Helicobacter pylori serology in chronic gastritis with antral atrophy and negative histology for Helicobacter-like organisms.

It has been suggested that there may be a correlation between Helicobacter pylori (Hp) infection and precancerous lesions of the stomach. However, histological evaluation of bacterial colonization in chronic atrophic gastritis shows a relatively low prevalence of the microorganism, which does not support the hypothesis. The aim of our study was to investigate the Hp serology in 95 patients with chronic gastritis with antral atrophy, with (27 cases) and without (68 cases) intestinal metaplasia, and without Helicobacter-like organisms in antral and corpus biopsy specimens. For all subjects, serum anti-Hp immunoglobulin IgG was identified by a fluorescent immunoenzymatic method (Helori-test; Eurospital), and mucosal atrophy and activity were graded histologically (Sydney System score). The serum Hp-antibody status documented the presence of current bacterial infections in 64 of 95 (67.4%) patients and previous infections in another 17 subjects. In only 14.7% of cases was there no evidence of current or previous infection. These subjects had less severe mucosal atrophy and lower inflammatory scores. In addition, there were no cases of intestinal metaplasia in such subjects. The high prevalence of Hp infection confirms the primary role of the microorganism in the pathogenesis of chronic gastritis with antral atrophy, although the bacterium is no longer present in the advanced stages of such disease. The histological evaluation of Hp colonization following the criteria of the Sydney System appears from our study to underestimate the true prevalence of the infection in the stomach when there is mucosal atrophy.

Adult↗
PubMed2003

IgG antibodies against microorganisms and atopic disease in Danish adults: the Copenhagen Allergy Study.

BACKGROUND: Seropositivity to food-borne and orofecal microorganisms (hepatitis A virus, Helicobacter pylori, and Toxoplasma gondii ), which are considered to be markers of poor hygiene, has been reported to be associated with a lower prevalence of atopy. In contrast, colonization of the gut with Clostridium difficile, a potential intestinal bacterial pathogen, in early childhood may be associated with a higher prevalence of atopy. OBJECTIVE: The objective of this study was to investigate the association between atopy and exposure to 2 groups of food-borne and orofecal microorganisms: (1) markers of a poor hygiene and (2) intestinal bacterial pathogens. METHODS: A cross-sectional population-based study of 15- to 69-year-olds living in Copenhagen, Denmark, was carried out in 1990 to 1991. Atopy was defined as a positive test result for specific IgE to at least 1 of 6 inhalant allergens. Exposure to microorganisms was assessed as IgG seropositivity to microorganisms. RESULTS: Seropositivity to 2 or 3 markers of poor hygiene (hepatitis A virus, H pylori, and T gondii ) was associated with a lower prevalence of atopy (adjusted odds ratio, 0.5; 95% CI, 0.3 to 0.8). In contrast, seropositivity to 2 or 3 intestinal bacterial pathogens (C difficile, Campylobacter jejuni, and Yersinia enterocolitica ) was associated with a higher prevalence of atopy (adjusted odds ratio, 1.7; 95% CI, 1.2 to 2.6). CONCLUSION: Exposure to markers of poor hygiene was associated with a lower prevalence of atopy, whereas exposure to intestinal bacterial pathogens was associated with a higher prevalence of atopy. These findings raise the hypothesis that different groups of food-borne and orofecal microorganisms may have different effects on the risk of atopy.

Adolescent↗
PubMed1993

Microorganisms in the gastrointestinal tract of the rat prevent absorption of the mutagen-carcinogen 3-amino-1,4-dimethyl-5H-pyrido(4,3-b)indole.

The extent to which lactic acid bacteria, intestinal bacteria, and yeast from the gastrointestinal tract of rats suppress the absorption of 3-amino-1,4-dimethyl-5H-pyrido(4,3-b)indole (Trp-P-1) was investigated. Trp-P-1 was absorbed from the small intestine very rapidly, but in the stomach it was slowly absorbed, requiring 1 or 2 h after administration. When mixtures of Trp-P-1 and freeze-dried microorganisms were administered to rats for 1 h, the amounts of Trp-P-1 absorbed from the small intestine were significantly reduced, and the levels of Trp-P-1 in blood decreased by 40.4-64.7% compared with a control in which only Trp-P-1 was administered. There were no significant differences between the organisms used. In vitro, freeze-dried cells of the strains tested bound 51-97% of Trp-P-1. The Trp-P-1 bound to cells was effectively extracted by aqueous methanol, ethanol, ammonia (50 g/L), and solutions of MgCl2 and CaCl2 (100 mM/mL), but little was extracted by water and solutions of KCl, NaCl, and buffers at various pH values.

Administration, Oral↗
PubMed1990

Effect of lomefloxacin on the normal oral and intestinal microflora.

Ten healthy volunteers received 400 mg of lomefloxacin orally once daily for seven days. Saliva and faecal samples were collected on days 0, 2, 4, 7, 9, 11, 14 and 21 to investigate the effect of lomefloxacin on the normal oral and intestinal microflora. The mean concentration of lomefloxacin in faeces on day 7 was 203 mg/kg, while saliva levels were low, less than 0.6 mg/l in nine of ten volunteers. Aerobic gram-negative microorganisms were almost completely eradicated, while aerobic gram-positive and anaerobic microorganisms were virtually unaffected by the lomefloxacin administration. Two weeks after lomefloxacin was discontinued, the oral and intestinal microflora had returned to normal levels.

4-Quinolones↗
PubMedDate not supplied

[Organic pathomorphological changes in animals with dietary infection by food products contaminated by Bacillus cereus].

The authors noticed marked vascular disorders in the capillary system, focal hemorrhages, and inflammatory, largely proliferative reactions in the stroma coupled with dystrophic and necrotic changes in parenchymal elements. The changes were found to be the most pronounced in the intestine, liver, myocardium, and in brain tissue. The degree of the lesions depended on the microorganism dosage. Provided the food contained 10(9)/g Bac. cereus, the injuring action was recorded to be more powerful, which manifested in the increased extent of vascular disorders with the hemorrhagic manifestations, thrombus formation in the vessels of the brain, heart, lungs, stomach and intestine, augmentation of dystrophic changes in organ parenchymal elements.

Animals↗
PubMedDate not supplied

[The effect of subinhibitory concentrations of antibiotics on the adhesion of enterobacteria].

It is impossible to determine rigidly a net result of the influence of antibiotics on the interaction between parasite and host cells, as many factors participating in this process are not studied. Adhesion of microorganisms is one of the essential mechanisms of the above interaction. Antibiotics with a different mechanism of action in the subinhibitory concentrations affecting viability of microbes either slightly or nowise have been studied for their effect on adhesion on a model of the intestine section of human embryos and experimental animals. Most of antibiotics influenced differently adhesion of the microorganisms, that also depended on the species attribution of the latter. The accelerated selection of resistance during a successive passage via the suggested adhesion system was observed. The data obtained elucidated certain mechanisms of the effect of antibiotics on the microbial populations at the initial phase of the infectious process and under the primary contamination of mucosa.

Animals↗
PubMedDate not supplied

[Microfloral makeup of the feces of infants on various types of feeding].

Dissimilarity in the fecal microflora of infants fed with breast milk and the ones receiving in the neonatal period the mixture "Malyutka" and experimental samples of the dry acidopilic mixture "Malyutka" because of their mothers' state of hypolactation. Features specific for intestinal biocenosis in the breast-nursed infants is the prevalence of bifidobacteria, low abundance of microorganisms accomplishing proteolysis and also a high percentage of colicinogenic cultures of colibacillus. In further preparations of adapted milk mixtures it appears expedient to go on with investigations oriented toward incorporation in their composition of factors contributing to bringing the intestinal microflora composition closer to that in natural feeding.

Breast Feeding↗
PubMed1991

[The autologous intestinal microflora in the postresuscitation period after acute blood loss in rats].

In this work the data obtained in the study of intestinal microbiocenosis in rats on the third day of the postresuscitation period after acute blood loss are presented. The quantitative and qualitative shifts of microflora at different biotopes, such as the wall of the small intestine, the parietal microflora of Peyer's patches, the contents and wall of the large intestine, have been characterized. Some specific features of dysbiotic changes have been revealed in comparison with the shifts of intestinal microflora in cases of dysbacteriosis caused by other reasons. The translocation of different microorganisms, including Bacterium bifidum and lactobacilli, into mesenteric lymph nodes, the liver, the spleen and the blood has been observed.

Acute Disease↗
PubMed1999

Protective nutrients and bacterial colonization in the immature human gut.

The normal human microflora is a complex ecosystem that is in part dependent on enteric nutrients for establishing colonization. The gut microbiota are important to the host with regard to metabolic functions and resistance to bacterial infections. At birth, bacterial colonization of a previously germ-free human gut begins. Diet and environmental conditions can influence this ecosystem. A breast-fed, full-term infant has a preferred intestine microbiota in which bifidobacteria predominate over potentially harmful bacteria, whereas in formula-fed infants, coliforms, enterococci, and bacteroides predominate. The pattern of bacterial colonization in the premature neonatal gut is different from that in the healthy, full-term infant gut. Those infants requiring intensive care acquire intestinal organisms slowly, and the establishment of bifidobacterial flora is retarded. A delayed bacterial colonization of the gut with a limited number of bacterial species tends to be virulent. Bacterial overgrowth is one of the major factors that promote bacterial translocation. The aberrant colonization of the premature infant may contribute to the development of necrotizing enterocolitis. Breast-feeding protects infants against infection. Oligo-saccharides and glycoconjugates, natural components in human milk, may prevent intestinal attachment of enteropathogens by acting as receptor homologues. Probiotics and prebiotics modulate the composition of the human intestinal microflora to the benefit of the host. These beneficial effects may result in the suppression of harmful microorganisms, the stimulation of bifidobacterial growth, or both. In the future, control and manipulation of the bacterial colonization in the neonatal gut may be a new approach to the prevention and treatment of intestinal infectious diseases of various etiologies.

Bacteria↗
PubMed2006

Lactoferrin downregulates pro-inflammatory cytokines upexpressed in intestinal epithelial cells infected with invasive or noninvasive Escherichia coli strains.

Intestinal epithelial cells are able to differentially interact with commensal or pathogenic microorganisms, triggering a physiological or destructive inflammation, respectively. To mimic commensal-enteroinvasive bacteria-host cell interaction, we infected Caco-2 cells with noninvasive Escherichia coli HB101 and with recombinant invasive E. coli HB101(pRI203). Using DNA microarray mRNA profiling and ELISA assays, we studied the expression of several cytokine and cytokine-related genes in infected Caco-2 cells in the absence or presence of bovine lactoferrin (bLf). Infection of Caco-2 cells with the noninvasive strain induced a slight increase in the expression of interleukin 8 (IL-8), whereas infection with invasive E. coli HB101(pRI203) induced a significant increase in the expression of IL-8 as well as other pro-inflammatory cytokines. The addition of bLf, in native- or holo-form, did not influence expression of cytokine genes by uninfected Caco-2 cells, but it decreased expression of IL-8 by cells infected with E.coli HB101. Moreover, except for IL-8, bLfs dramatically downregulated pro-inflammatory cytokines upexpressed by Caco-2 cells infected with the invasive strain. Although IL-8 was decreased by bLfs, it remained upregulated, suggesting that it could be a signal of persistence of intracellular bacteria. The bLf ability to reduce expression of some pro-inflammatory cytokines, which appears independent of its iron saturation, might represent an important natural mechanism in regulating epithelial cell responses to pathogenic bacteria and in limiting cell damage and the spread of infections.

Animals↗
PubMed2006

Intestinal versus external growth conditions change the surficial properties in a collection of environmental Escherichia coli isolates.

Predicting the fate of microorganisms in the environment is increasingly warranted, especially for pathogenic strains. A major habitat of Escherichia coli, which encompasses commensal as well as pathogenic strains, is the gastrointestinal tract with conditions very different from the environment it encounters after shedding from the host or during cultivation in the laboratory. We developed two relevant growth conditions representative of intestinal (host-associated) and external (postshedding) environments to investigate the surficial properties and behaviors of a diverse subset of E. coli feedlot isolates. Surficial properties may determine an isolate's physical fate. A pronounced increase in cell hydrophobicity and concomitant biofilm mass formation was observed for isolates grown under external conditions. Isolates that exhibited the highest surface hydrophobicity also formed visible suspended aggregates under external conditions. Other than hydrophobicity, flagella-mediated motility was determinant in affecting E. coli biofilm formation under external conditions, with all four nonmotile E. coli isolates characterized as thin-biofilm formers. The majority (88%) of Ag43+ (outer membrane protein, antigen 43) isolates formed thick biofilms, whereas the majority (75%) of Ag43- isolates formed thin biofilms. The tested E. coli O157:H7 strain behaved differently from the environmental E. coli isolates: it displayed a low electrostatic charge, a small decrease in hydrophobicity upon shifts to external conditions, and very little biofilm formation. On the other hand, the commonly used laboratory strain E. coli K-12 displayed low hydrophobicity both intestinally and externally, but it formed significant biofilm mass under external conditions. Clearly, various E. coli strains manifest significant variability in surficial behavior. This variability is further modulated by growth conditions. The interacting strain-inherent and cultivation-dependent effects on surficial behavior may have broad consequences for the fate and ecology of pathogenic and commensal E. coli strains.

Bacterial Adhesion↗
PubMed1997

[Role of dysbacteriosis in the development of surgical infection].

The intestinal microflora was examined in 230 patients operated on for abdominal abnormalities and injuries. There were profound intestinal microbiocenotic impairments as appeared as lower bifidobacteria, intensive growth of opportunistic (coccal) microorganisms. A direct relationship was established between the severity of dysbacteriosis and the incidence of pyoinflammatory complications in the postoperative period. The use of live bacterial preparations in the complex therapy of patients with expected and emergency abdominal diseases or injuries reduced the number of pyoinflammatory complications and improved the therapeutic outcomes of patients with peritonitis.

Anti-Bacterial Agents↗
PubMed1989

Hemagglutination and intestinal adherence properties of clinical and environmental isolates of non-O1 Vibrio cholerae.

Hemagglutination and intestinal adherence properties of non-O1 Vibrio cholerae were studied in vitro. No definite correlation between the cell-associated hemagglutinin titers and the intestinal adhesion indices was noted. Sugar- and glycoprotein-mediated inhibition data also indicated differences between the hemagglutination and adherence processes in respect to the receptor structures. Intestinal adherence of most V. cholerae strains could be inhibited to various extents by N-acetyl D-glucosamine. This observation provides a likely explanation for the ecological behavior of these organisms, which are known to associate themselves with chitinous (chitin:homopolymer of N-acetyl D-glucosamine) surfaces of zooplankton. The absence of any significant difference between the intestinal adherence indices of clinical and environmental isolates suggests that intestinal adhesion may be an essential but not sufficient prerequisite for colonization by and subsequent expression of pathogenicity of these microorganisms.

Animals↗
PubMed1991

Does patient age or intestinal pathology influence the bacteria found in cases of necrotizing enterocolitis?

To evaluate the relationship between bacterial colonization in neonatal peritonitis and patient age or intestinal pathology, we retrospectively reviewed peritoneal culture results from 96 infants having surgery for necrotizing enterocolitis. Microorganisms recovered mirrored those usually found as fecal flora within the neonatal intensive care unit. These reflect, in turn, the abnormal colonization intrinsic to care in the intensive care nursery. Analysis revealed no significant correlation between the disease and either age of the infant or intestinal site of disease.

Age Factors↗
PubMed1989

Simple intestinal obstruction causes bacterial translocation in man.

Indirect clinical evidence has accumulated indicating that the gut may be a reservoir for microorganisms causing systemic infection in man. Our experimental results, in a variety of animal models, demonstrate that bacteria can translocate across the mucosal barrier and cause systemic infections. To determine directly whether bacterial translocation occurs in man, we cultured mesenteric lymph nodes (MLNs) obtained at laparotomy from 42 patients, none of whom were clinically infected. Ten (59%) of 17 patients with intestinal obstruction (none of whom had necrotic bowel) had bacteria in their MLNs, in contrast to one (4%) of 25 patients operated on for other reasons. The most common bacteria cultured from the MLNs was Escherichia coli. Thus, it appeared that simple intestinal obstruction of the colon or small bowel in the absence of necrotic bowel was associated with bacterial translocation.

Adult↗
PubMed2003

Application of prebiotics and probiotics in poultry production.

The intestinal microbiota, epithelium, and immune system provide resistance to enteric pathogens. Recent data suggest that resistance is not solely due to the sum of the components, but that cross-talk between these components is also involved in modulating this resistance. Inhibition of pathogens by the intestinal microbiota has been called bacterial antagonism, bacterial interference, barrier effect, colonization resistance, and competitive exclusion. Mechanisms by which the indigenous intestinal bacteria inhibit pathogens include competition for colonization sites, competition for nutrients, production of toxic compounds, or stimulation of the immune system. These mechanisms are not mutually exclusive, and inhibition may comprise one, several, or all of these mechanisms. Consumption of fermented foods has been associated with improved health, and lactic acid bacteria (lactobacilli and bifidobacteria) have been implicated as the causative agents for this improved health. Research over the last century has shown that lactic acid bacteria and certain other microorganisms can increase resistance to disease and that lactic acid bacteria can be enriched in the intestinal tract by feeding specific carbohydrates. Increased bacterial resistance to antibiotics in humans has caused an increase in public and governmental interest in eliminating sub-therapeutic use of antibiotics in livestock. An alternative approach to sub-therapeutic antibiotics in livestock is the use of probiotic microorganisms, prebiotic substrates that enrich certain bacterial populations, or synbiotic combinations of prebiotics and probiotics. Research is focused on identifying beneficial bacterial strains and substrates along with the conditions under which they are effective.

Animals↗
PubMed1996

[Yogurt as source of lactose autodigestion].

Microorganisms in yogurt have the capacity of quantitatively digest in vivo in the small intestine the lactose from yogurt. The process of autodigestion of lactose in yogurt reduces both lactose maldigestion and lactose intolerance in lactase deficient individuals. Enzyme activity in yogurt depends upon the buffer capacity of the yogurt, microbial cells resistance to acid and enzymatic activity and to the effect of bile in the microbial cell that release beta-galactosidase activity. Lactose autodigestion capacity of yogurt is significantly reduced in pasteurized yogurt and it is also affected by the type and amount of microorganism that is added to milk and by the presence of fat. Yogurt intake represents an important food alternative for lactase deficient individuals.

Digestion↗
PubMed2003

Honor thy symbionts.

Our intestine is the site of an extraordinarily complex and dynamic environmentally transmitted consortial symbiosis. The molecular foundations of beneficial symbiotic host-bacterial relationships in the gut are being revealed in part from studies of simplified models of this ecosystem, where germ-free mice are colonized with specified members of the microbial community, and in part from comparisons of the genomes of members of the intestinal microbiota. The results emphasize the contributions of symbionts to postnatal gut development and host physiology, as well as the remarkable strategies these microorganisms have evolved to sustain their alliances. These points are illustrated by the human-Bacteroides thetaiotaomicron symbiosis. Interdisciplinary studies of the effects of the intestinal environment on genome structure and function should provide important new insights about how microbes and humans have coevolved mutually beneficial relationships and new perspectives about the foundations of our health.

Animals↗