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PubMed1996

Antimicrobial treatment of periodontal diseases disturbs the human ecology: a review.

Periodontal diseases are associated with specific pathogenic microorganisms and therefore antimicrobial agents are often used in the treatment of patients with periodontitis refractory to conventional mechanical therapy. Perorally administered antimicrobial agents often lead to ecological disturbances in the normal oral and intestinal microflora with overgrowth of potentially pathogenic microorganisms, which may spread within the host or from patient to patient, causing infections. The use of antimicrobial agents also promotes the emergence of bacterial drug resistance, both in the periodontal pocket and in the normal oral and intestinal microflora. Topical administration of antimicrobial agents in the periodontal pockets causes restricted disturbances in the intestinal microflora, although there is a substantial risk of development of resistance at the site of application. A number of clinical studies imply that correct use of antimicrobial agents might be beneficial for a subset of patients with adult or juvenile periodontitis. The choice of antimicrobial agent should always be based on accurate microbial analyses of the subgingival microflora and in vitro antimicrobial susceptibility tests of the most important periodontal pathogens. Preferably, agents with low potential of causing ecological disturbances should be used.

Anti-Bacterial Agents↗
PubMed1990

A tubular bioreactor for high density cultivation of microorganisms.

By simulating the functions of the animal intestine, the authors have developed a novel tubular bioreactor (TBR) which is capable of containing both the reaction and separation of products in a single system. This reactor consisted of inorganic ultra filtration membrane modules in the primary part of the system, a heat exchanger and a recycling pump. The operation characteristics of the TBR were studied by cultivating Lactobacillus casei at a laboratory scale. The cell density obtained was up to 10 times higher than the density obtained by using the conventional jar fermentor. Furthermore, 40 g l-1 of cell mass was obtained in only 14 hours with 20 l of fresh medium when the dilution rate was increased according to the cellular growth. Afterwards, the cultivation time and the volume of fresh medium were reduced to 44% and 74%, respectively, of the values in the cultivation operation at constant dilution rate.

Bacteriological Techniques↗
PubMed1992

[Intestinal microflora in young children with rotavirus infection].

A total of 270 children with rotavirus diarrhea were examined. The quantitative and qualitative composition of their intestinal microflora was studied. Most frequently microorganisms of the genus Enterobacter and most seldom, Serratia were isolated. A decrease in the amount of bifidobacteria, normal Escherichia coli and an increase in the amount of lactose-negative Escherichia were noted. In cases of pronounced dysbiosis in young children the clinical course of rotavirus infection is aggravated and the period of rotavirus excretion is prolonged.

Enterobacter↗
PubMed1998

Cryptosporidium parvum initiates inflammatory bowel disease in germfree T cell receptor-alpha-deficient mice.

Flora-bearing mice with targeted disruption of T cell receptor (TCR)-alpha or -beta genes spontaneously develop intestinal inflammation with features similar to ulcerative colitis in humans. TCR-alpha-deficient mice maintained germfree or colonized with a limited number of intestinal bacteria failed to develop inflammatory bowel disease (IBD)-like lesions. Evidently, inflammation in these mice does not develop spontaneously or result from a generalized antigenic stimulation, but rather requires induction by a heretofore unidentified specific stimulus. We describe the development of IBD-like lesions in germfree TCR-alpha-deficient mice monoassociated with the protozoan Cryptosporidium parvum. Lesions were seen in distal ileum, cecum, and colon and were most severe in the cecum. A prominent leukocytic infiltrate within the lamina propria was a common characteristic of the lesions observed in the C. parvum-infected germfree TCR-alpha-deficient mice. The leukocytic infiltrate was composed of aggregates of B220+ cells, the majority of which expressed surface IgD (ie, conventional B lymphocytes). It has been proposed that antigenic stimulation by a microorganism(s) is needed to initiate intestinal inflammation in TCR-alpha-deficient mice. Our results indicate that a single microbial species, C. parvum, is capable of triggering the development of IBD-like lesions in germfree TCR-alpha-deficient mice.

Animals↗
PubMed2003

Stimulatory effect of a dietary casein phosphopeptide preparation on the mucosal IgA response of mice to orally ingested lipopolysaccharide from Salmonella typhimurium.

The effect on immunoglobulin production of a commercially available casein phosphopeptide preparation (CPP-III) consisting mainly of bovine alpha s2-casein (1-32) and beta-casein (1-28) in mice that had orally ingested lipopolysaccharide (LPS) from Salmonella typhimurium was investigated. No significant difference in body weight gain was observed between the mice fed on the CPP-III-added diet and those fed on the control diet. The mice fed on the CPP-III-added diet exhibited similar serum and intestinal IgG, IgM, and IgE responses towards LPS to those fed on the control diet. In contrast, fecal and intestinal anti-LPS IgA and total IgA in mice fed on the CPP-III-added diet were significantly higher than in those fed on the control diet. Spleen cells from mice fed on the CPP-III-added diet produced larger amounts of IgA, IL-5, and IL-6 than cells from mice fed on the control diet. These results suggest that dietary casein phosphopeptide may protect a host from invasion of the intestinal mucosa by food-born pathogenic microorganisms.

Adjuvants, Immunologic↗
PubMed1981

[Interaction between Bifidobacterium bifidum, Proteus vulgaris, and Klebsiella pneumoniae 204 in the gastrointestinal tract of gnotobiotic chicks].

Experiments on gnotobiont chickens indicated that the strains B. bifidum 1/85 phi, P. vulgaris F-30 and K. pneumoniae 204, when introduced simultaneously into the gastrointestinal tract in a single administration, proliferate there with the pronounced predominance of bifidobacteria. 6 additional administrations of B. bifidum 1/85 phi culture resulted in the complete suppression of microorganisms belonging to the genera Rroteus and Klebsiella as early as 10 days after the introduction of bifidobacteria. These data suggest that it is necessary to use B. bifidum 1/85 phi in cases of intestinal dysbacteriosis characterized by the predominance of microorganisms belonging to the genera Proteus and Klebsiella.

Actinomycetaceae↗
PubMedDate not supplied

Comparative effects of cefadroxil and phenoxymethylpenicillin on the normal oropharyngeal and intestinal microflora.

The ecological effects on the commensal microflora in saliva and stool samples were studied during administration of two commonly used antibiotics: cefadroxil 500 mg b.i.d. for 10 days and phenoxymethylpenicillin 1 g b.i.d. for 10 days. Twenty healthy volunteers participated in the study. In the oropharyngeal microflora the aerobic microflora was significantly suppressed during administration of cefadroxil while no significant changes were noticed in the anaerobic microflora. Administration of phenoxymethylpenicillin caused a strong decrease in the number of viridans streptococci and an overgrowth of Neisseria cocci. The total numbers of anaerobic oropharyngeal microorganisms were suppressed during phenoxymethylpenicillin administration. In the intestinal microflora the variation in numbers of aerobic and anaerobic microorganisms was minor in both groups. The microflora became normalised 2 weeks after withdrawal of the drugs. It was concluded that peroral administration of cefadroxil to healthy volunteers resulted in minor ecological disturbances in the oropharyngeal and intestinal microflora, which were in the same range as for phenoxymethylpenicillin.

Adult↗
PubMed2002

Adhesion of dairy propionibacteria to intestinal epithelial tissue in vitro and in vivo.

Adhesion to the intestinal mucosa is a desirable property for probiotic microorganisms and has been related to many of their health benefits. In the present study, 24 dairy Propionibacterium strains were assessed with regard to their hydrophobic characteristics and their autoaggregation and hemagglutination abilities, since these traits have been shown to be indicative of adherence in other microorganisms. Six strains were further tested for their capacity to adhere to ileal epithelial cells in vitro and in vivo. The results of the study showed that propionibacteria were highly hydrophilic, and hemagglutination and autoaggregation were properties not commonly found among these microorganisms. No relationship was found between surface characteristics and adhesion ability, since hemagglutinating, autoaggregating, and nonautoaggregating bacteria were able to adhere to intestinal cells both in vitro and in vivo. Microscopic examination revealed that autoaggregating cells adhered in clusters, with adhesion being mediated by only a few bacteria, whereas the hemagglutinating and nonautoaggregating strains adhered individually or in small groups making contact with each epithelial cell with the entire bacterial surface. The in vitro assessment of adhesion was a good indication of the in vivo association of propionibacteria with the intestinal epithelium. Therefore, the in vitro method presented here should be valuable in screening routinely adhesive properties of propionibacteria for probiotic purposes. The adhesion ability of dairy propionibacteria would prolong their maintenance in the gut and increase the duration of their provision of beneficial effects in the host, supporting the potential of Propionibacterium in the development of new probiotic products.

Bacterial Adhesion↗
PubMed2002

Bacterial translocation as a cause for septic complications in obstructive colonic ileus.

Failure of intestinal barrier function and subsequent translocation of microorganisms and their degradation products play a decisive role in development of systemic septic complications for many systemic and intra-abdominal pathologies, for example, following obstructive colonic ileus (OCI). This study was aimed at the evaluation of the intestinal barrier state in OCI. Sixty albino Wistar rats weighting 250 to 300 g (mean 265 g) were divided into four groups (15 animals in each). Acute colonic ileus (ACI) was modeled as follows except a control group (Group 1). Our objective was to examine changes in bacterial flora in the abdomen, mesenteric lymphatic nodes (MLN), liver, spleen, and lungs during the model of OCI after 72 hours following the beginning of experiment. The composition of parietal mucus in normal and in OCI 48 hours following the beginning of experiment examined. Interleukin (IL-VI) levels were determined in both portal and peripheral blood. The right-hand half of colon was ligated at the level of ileocaecal junction in animals of Group 2 (n = 15), whereas in animals of Group 3 (n = 15) it was ligated at the level of sigmoid colon. With the same purpose, a portion of the suspended caecal content was administered into lumen of the jejunum at a concentration of 10(6) colony-forming units (CFU) in animals of Group 4 (n = 15). Experimentally--induced OCI causes significant bacterial translocation (BT) in rats. The process of colonization of the proximal small intestine with colonic flora takes place under the conditions of ileus. The conditions favorable for the development of BT are generated with colonization of 10(6) CFU in volume. As a result, intestinal flora penetrates into the abdominal organs and lungs. Its highest concentrations are noted in the lymph nodes, lungs and liver. The modeling of the small intestine colonization with colonic flora (Group 4) demonstrates critical parameters of microbial semination.

Acute Disease↗
PubMedDate not supplied

[Characteristics of immune response in acute intestinal enterobacterial infections].

Update literature on the problem of microorganism--host interactions with pathogenic enterobacteria as a model is reviewed. The activation of lymphoid cells and their protective role is shown to be due to the stimulating action of bacterial antigens. The role of cytokines and stimulation of their expression are discussed. Some phenomena of immunosuppression, phases of enteric mucosal immune response are described.

Animals↗
PubMed1995

Entry of microbes into the host: using M cells to break the mucosal barrier.

Enteric microbial pathogens interact with the gut epithelium to establish infection. Recently, it has become clear that many microorganisms that colonize or traverse the intestinal mucosa do so via the specialized M cells. Recent work has shown that Shigella flexneri and Salmonella typhimurium specifically target M cells to initiate infection of the host.

Animals↗
PubMed2002

The place of probiotics in human intestinal infections.

A number of studies have been carried out on the effect of several probiotic species on treatment and prevention of intestinal infections. The most commonly used microorganisms are lactic-acid producing bacteria such as lactobacilli and bifidobacteria belonging to the human normal microflora. In vitro and animal studies have shown that probiotic microorganisms interfere with the colonisation of Helicobacter pylori and of enteropathogenic microorganisms. In humans the significance is more uncertain. Clinically significant benefits of probiotics have been demonstrated in the treatment of rotavirus induced diarrhoea and of Saccharomyces boulardii in the prevention of antibiotic-associated diarrhoea (AAD). In patients suffering from inflammatory bowel disease, several probiotic strains have been shown to be as effective as traditional medication in preventing relapses. Standardised and well performed studies are needed to elucidate further the mechanisms of action and the clinical significance of probiotics.

Digestive System↗
PubMed2002

Mucosal flora in inflammatory bowel disease.

BACKGROUND & AIMS: Microorganisms that directly interact with the intestinal mucosa are obscured by fecal flora and poorly characterized. METHODS: We investigated the mucosal flora of washed colonoscopic biopsies of 305 patients with bowel inflammation and 40 controls. The microbial cultures were validated by quantitative polymerase chain reaction with subsequent cloning and sequencing, fluorescence in-situ hybridization, and electron microscopy. RESULTS: We found high concentrations of mucosal bacteria in patients with bowel inflammation, but not in controls. The concentrations of mucosal bacteria increased progressively with the severity of disease, both in inflamed and non-inflamed colon. In patients with >10,000 cfu/microL, a thick bacterial band was attached to the intact mucosa without signs of translocation. Patients with inflammatory bowel disease (IBD) and concentrations of mucosal bacteria >50,000 cfu/microL had characteristic inclusions of multiple polymorphic bacteria within solitary enterocytes located next to the lamina propria, without or having no contact with the fecal stream. The identified bacteria were of fecal origin. CONCLUSIONS: Our findings suggest that the changes in the mucosal flora in IBD are not secondary to inflammation, but a result of a specific host response. We hypothesize that the healthy mucosa is capable of holding back fecal bacteria and that this function is profoundly disturbed in patients with IBD.

Adolescent↗
PubMed2006

Probiotics and their use in diverticulitis.

Probiotics are live microorganisms that when ingested affect the intestinal microbial flora and benefit the health of the host. Probiotics have been shown to have a positive effect on various gastrointestinal and other conditions; however, the beneficial effect of probiotics on treating diverticulitis and diverticular disease has not yet been clearly demonstrated. In this paper, the theoretical framework for using probiotics to prevent or treat diverticular disease is reviewed, and two preliminary studies on the use of probiotics for maintenance of remission of uncomplicated diverticular disease are briefly summarized.

Disease Progression↗
PubMed2006

Probiotics in primary care pediatrics.

Probiotics are live microorganisms that help stabilize and balance intestinal microflora. Although these organisms are ubiquitous and have been used in the production of foods, probiotics have been used more frequently for therapeutic purposes, including the treatment and prevention of pediatric diseases. This article reviews the proposed mechanisms of the beneficial effects of probiotics, potential uses of these organisms in pediatric care, and promising future directions for their application.

Bifidobacterium↗
PubMedDate not supplied

[Spontaneous bacterial peritonitis].

Spontaneous bacterial peritonitis occurs in 30% of patients with ascites due to cirrhosis leading to high morbidity and mortality rates. The pathogenesis of spontaneous bacterial peritonitis is related to altered host defenses observed in end-stage liver disease, overgrowth of microorganisms, and bacterial translocation from the intestinal lumen to mesenteric lymph nodes. Clinical manifestations vary from severe to slight or absent, demanding analysis of the ascitic fluid. The diagnosis is confirmed by a number of neutrophils over 250/mm3 associated or not to bacterial growth in culture of an ascites sample. Enterobacteriae prevail and Escherichia coli has been the most frequent bacterium reported. Mortality rates decreased markedly in the last two decades due to early diagnosis and prompt antibiotic treatment. Third generation intravenous cephalosporins are effective in 70% to 95% of the cases. Recurrence of spontaneous bacterial peritonitis is common and can be prevented by the continuous use of oral norfloxacin. The development of bacterial resistance demands the search for new options in the prophylaxis of spontaneous bacterial peritonitis; probiotics are a promising new approach, but deserve further evaluation. Short-term antibiotic prophylaxis is recommended for patients with cirrhosis and ascites shortly after an acute episode of gastrointestinal bleeding.

Ascites↗
PubMed2006

[The protective activity of a new variant of the probiotic Acilact in exposure to ionizing radiation and anticancer chemotherapy under experimental conditions].

The aim of the study was to investigate the protective activity of a new variant of the probiotic Acilact in exposure to ionizing radiation and anticancer chemotherapy under experimental conditions. The study revealed protective effects of the preparation after combined exposure of mice to radiation and temperature. The preparation increased 30-day survival of the mice, inhibited intestinal colonization with gram-negative microorganisms, and increased resistance to LPS. A multidirectional protective effect of the probiotic was observed after the use of sublethal doses of radiation; this effect was manifested by quicker normalization of hematological parameters and bone marrow cellularity, as well as elevation of blood concentration of the hemoragulatory cytokines IL-3 and IL-6.

Animals↗