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PubMed1999

The effect of synbiotics on colon carcinogenesis in rats.

Evidence indicates that consumption of probiotic microorganisms such as bifidobacteria reduces the risk of colon cancer in animal models. Feeding certain fructans such as oligofructose and inulin, which are thought to selectively increase the growth of intestinal bifidobacteria (i.e., a prebiotic effect), also has been shown to reduce colon cancer risk. The objective of our study was twofold, i. e., to determine whether the combination of bifidobacteria and oligofructose would have an additive effect (i.e., synbiotic) in reducing colon cancer risk in rats, and to determine whether other oligosaccharides would also be effective as part of a synbiotic combination. The development of colonic preneoplastic lesions (aberrant crypts) was used as an index of colon cancer risk. In one series of experiments, rats were given the carcinogen 1, 2-dimethylhydrazine (DMH) and administered one of the following treatments: skim milk (control), bifidobacteria (bifido), oligofructose (OF) or bifido + OF. Neither bifido nor OF alone significantly reduced aberrant crypt number. Bifido + OF reduced aberrant crypt number in five of six experiments, although the reduction was significant in only one. However, a paired comparison of the six experiments indicated a significant overall reduction in aberrant crypts by bifido + OF (P = 0.039). Soybean oligosaccharide (SBO) and wheat bran oligosaccharide (WBO) were also fed in combination with bifidobacteria. In two other experiments, SBO did not alter the number of aberrant crypts compared with the control, whereas WBO reduced aberrant crypt number in one experiment but not in another. Of OF, SBO and WBO, only SBO reduced the colonic mucosa proliferation compared with the control. These results suggest that the combination of bifidobacteria and oligofructose reduces colon cancer risk in carcinogen-treated rats, but the effect of other oligosaccharides is uncertain.

1,2-Dimethylhydrazine↗
PubMed2024

Interactions between microbiota and uterine corpus endometrial cancer: A bioinformatic investigation of potential immunotherapy.

Microorganisms in the gut and other niches may contribute to carcinogenesis while also altering cancer immune surveillance and therapeutic response. However, determining the impact of genetic variations and interplay with intestinal microbes' environment is difficult and unanswered. Here, we examined the frequency of thirteen mutant genes that caused aberrant gut in thirty different types of cancer using The Cancer Genomic Atlas (TCGA) database. Substantially, our findings show that all these mutated genes are quite frequent in uterine corpus endometrial cancer (UCEC). Further, these mutant genes are implicated in the infiltration of different subset of immune cells within the Tumor Microenvironment (TME) of UCEC patients. The top-ranking mutant genes that promote immune cell invasion into the TME of UCEC patients were PGLYRP2, OLFM4, and TLR5. In this regard, we used the same deconvolution of the TCGA database to analyze the microbiome that have a strong association with immune cells invasion with TME of UCEC patients. Several bacteria and viruses have been linked to the invasion of immune cells, such as B cell memory and T cell regulatory (Tregs), into the TME of UCEC patients. As a result, our findings pave the way for future research into generating novel immunizations against bacteria or viruses as immunotherapy for UCEC patients.

Humans↗
PubMedDate not supplied

[Hafnia alvei in a rare case of severe pneumonia in a postanesthesia recovery unit].

An 85-year-old man with a history of moderate chronic obstructive pulmonary disease in treatment with anticholinergic drugs was admitted to the recovery unit for postoperative monitoring after right inguinal herniorrhaphy surgery and removal of a strangulated intestinal section. On the third day after surgery the patient developed radiographic signs consistent with pneumonia and required mechanical ventilation. Two blood cultures and a respiratory secretion sample grew a microorganism identified as Hafnia alvei. H. alvei is a gram-negative bacillus that colonizes the digestive tract of humans and animals and in immunodepressed patients it can colonize the mouth and pharynx. Isolation of H. alvei is described in the literature on pediatric patients and those with a history of immune deficiency or chronic disease. Infection has a severe impact on general health. We report a rare and interesting case of pneumonia and bacteremia from H. alvei infection acquired by an immunocompetent patient soon after arrival in the postoperative recovery unit. The patient died of the infection.

Aged↗
PubMedDate not supplied

[Experimental basis of principles for creating microbiologic standards for food products for children during the 1st year of life].

Standard media were designed simulating the gastro-intestinal contents of infants during the first year of life. These media were used in the in vitro tests to study the viability of a number of potentially-pathogenic microorganisms. It was shown that S. aureus, E. coli O-III, S. liquefaciens not only survived but also multiplied in the media with pH values similar to those of gastric juice in infants of the first year of life, in the presence of the mixture for child nutrition "Malysh". The results obtained necessitate strict requirements for the absence of potentially-pathogenic microorganisms in definite volumes of dry milk mixtures and their components intended for child nutrition.

Animals↗
PubMed1981

Comparison of selective staining of fungi in paraffin sections by light microscopy, SEM and BEI.

Paraffin-embedded sections from human tissues with fungi or organisms classified with fungi were studied by light microscopy (LM), scanning electron microscopy (SEM), and the backscatter electron imaging (BEI) mode of the SEM. The fungal organisms selected for study were those familiar to the pathologist on the basis of their appearance in paraffin-embedded material stained with the Gomori-Grocott Chromic Acid Methenamine Silver Stain (GMS). The organisms were Actinomyces, Rhizopus, Cryptococcus, Histoplasma capsulatum, and Coccidia imitis. Sections were stained with the GMS Stain and/or the Becker modification of the GMS Stain (BGMS) and examined in the secondary electron imaging mode (SEI) and BEI mode with an annular backscatter electron detector. This silver staining technique accentuated the wall of fungal organisms, in the backscatter mode. Depending on the fungal organism and type of silver stain employed, the GMS seemed the preferable stain. The advantages of SEM over LM were greater depth of focus and potential range of magnifications. BEI may also be used in conjunction with LM stain for microorganisms to establish their presence.

Actinomyces↗
PubMed1997

[Meropenem in the treatment of surgical intra-abdominal infections].

Intraabdominal infections are severe with a high morbidity and mortality which may be produced by multiple causes: perforation of the empty viscera, intestinal inflammatory processes, vascular pictures, abdominal traumatisms as a consequence of surgery. From a microbiologic point of view, different types of gram positive and gram negative aerobes such as anaerobe microorganisms or fungi may be isolated as causes. Polymicrobial infections are usually observed. The main treatment policy is to correctly eliminate the causing foci of the bacterial contamination whether surgically of by percutaneous drainage. Parallelly, it is essential for the surgeon to use appropriate antibiotic treatment. Meropenem, a carbapenem, has a wide spectrum antibacterial activity which cover gram positive and gram negative aerobes in addition to anaerobes leading to scarce adverse reactions. All the above leads meropenem to be a very effective alternative in both the treatment of these infections as monotherapy and for initiating empiric therapy.

Abdomen↗
PubMed1992

Bacteriocin-like activity of Bacteroides fragilis group isolated from marmosets.

The ability of strains of the B. fragilis group, isolated from the oral cavity and intestine of marmosets, to produce bacteriorin-like substances in solid medium, in terms of auto-, iso- and heteroantagonism, was evaluated. Antagonistic activity was exhibited by 52% of the intestinal strains, 3 of which showed autoantagonistic activity. Three out of 9 oral strains isolated, tested against themselves, showed simultaneous isoantagonism to 4 indicator strains; but not autoantagonism. The same 9 oral strains, when tested against 16 reference strains, revealed interspecific activity only against 2 Gram-positive microorganisms. Higher activity, evaluated by the size of the inhibition halo, was observed in BHI-S agar, and greatest inhibition was obtained after 72 h of incubation.

Animals↗
PubMed1986

[Ammonia and glutamine metabolism of the intestine. The effect of lactulose and neomycin].

The present work is directed to distinguish between ammonia production by the mucosa and by the intestinal flora, as well as to evaluate the influence of neomycin and lactulose. In vitro studies using rat intestine show that mucosa cells produce ammonia alanine and glutamic acid when incubated with glutamine, whose process can be impaired by neomycin or lactulose. Since the release of the above solutes is virtually the same in germ-free rats, the influence of the bacterial flora might be negligible under the experimental conditions used. Elimination of the aerobic microorganisms results in a minute decrease of ammonia concentration in portal blood in contrast to elimination of the anaerobic flora, which leads to an excessive reduction of ammonia formation. In germ-free rats colonisation with anaerobic microorganisms results in an increment in portal ammonia concentration, whose value, however, is still below levels observed in normal animals. Colonisation with aerobic bacteria has no effect on portal ammonia concentration. Neomycin and lactulose affect ammonia production in the gut by interfering with glutamine uptake in the mucosa cell, thus the influence upon ammonia formation apparently can not be exclusively explained by alterations of the intestinal flora. Possible reasons for the considerable increase in arterial glutamine levels in normal rats are discussed.

Ammonia↗
PubMed1997

Recovery of Bilophila wadsworthiafrom Clinical Specimens in Italy.

This report is the first survey in Italy to evaluate the incidence of recovery of Bilophila wadsworthia in clinical situations. The survey was carried out at the departments of Microbiology in two Northern Italian hospitals over a one-year period. Tests for B. wadsworthia were carried out on a range of specimens from different body sites, when etiology by anaerobes was suspected. Out of a total of 350 samples examined, 67% were positive in bacteriological tests. Mixed anaerobic infections were detected in 53 specimens, corresponding to 23% of all cases. Strains of B. wadsworthia were isolated from 12 samples, equivalent to 5% and 22% of total and mixed/anaerobic infections, respectively. Bilophila wadsworthia was always isolated in mixed infections, mainly from the large intestine (67% of cases). The infectious process of B. wadsworthia was often complicated by abscess formation, regardless of body site. Interestingly, a strain was isolated from one case of bacteremia. The microorganisms most frequently isolated with B. wadsworthia were Escherichia coli for facultative species (38%), and Bacteroides fragilis, from anaerobic isolates (25%). Production of beta-lactamases by B. wadsworthia isolates was found in ten strains (83%), which appeared to be penicillin G resistant at concentration equal to or greater than the break-point (4 microg/mL). Epidemiological and clinical data from this and previous studies point to the involvement of B. wadsworthia in mixed infections. To assess the specific contribution of the species to the disease, studies of pathogenetic factors are to be considered in parallel. Nonetheless, production of beta-lactamases by most B. wadsworthia isolates could easily interfere with the therapeutical approach to infections involving the new species. The addition of a selective medium to culture specimens from the abdominal cavity should be considered in order to detect the presence of B. wadsworthia.

Journal Article↗
PubMed1981

Whipple's disease: morphologic and immunofluorescence characterization of bacterial antigens.

The bacterial etiology of Whipple's disease is generally accepted. However, the exact identity of the "Whipple bug" has remained elusive. Indeed, the isolation of several types of bacteria from different patients with Whipple's disease has caused some to speculate that Whipple's disease may have polymicrobial etiology. Our light and electron microscopic studies document the presence of bacilliform organisms lying free in the lamina propria of the duodenal mucosa. Intact and partially degraded bacterial organisms were seen in the phagosomes of macrophages. Indirect immunofluorescence studies demonstrated the presence of multiple bacterial antigens in the lamina propria as well as the macrophage granules. This profile of antigens is similar to the profile demonstrated in four other patients in two previous studies. The occurrence of similar profiles of bacterial antigens in the tissues of different patients with Whipple's disease suggests a single microorganism in the etiology of Whipple's disease. Because of the overlapping features of muciphages and Whipple's cells in the rectal biopsy material, the superiority and reliability of proximal small intestinal biopsy in preference to rectal biopsy are re-emphasized.

Adult↗
PubMed2005

Gastrointestinal complications in renal transplant recipients.

Gastrointestinal complications are frequent in renal transplant recipients and can include oral lesions, esophagitis, peptic ulcer, diarrhea, colon disorders and malignancy. Oral lesions may be caused by drugs such as cyclosporine and sirolimus, by virus or fungal infections. Leukoplakia may develop in patients with Epstein-Barr virus (EBV) infection. The commonest esophageal disorder is represented by fungal esophagitis usually caused by candida. A number of patients may suffer from nausea, vomiting and gastric discomfort. These disorders are more frequent in patients treated with mycophenolate mofetil (MMF). Peptic ulcer is more rare than in the past. Patients with a history of peptic ulcer are particularly prone to this complication. Other gastroduodenal disorders are caused by cytomegalovirus (CMV) and herpes simplex infection. Diarrhea is a frequent disorder which may be caused by pathogen microorganisms or by immunosuppressive agents. The differential diagnosis may be difficult. Colon disorders mainly consist of hemorrhage, usually sustained by CMV infection, or perforation which may be caused by diverticulitis or intestinal ischemia. Colon cancer, anal carcinoma, and EBV-associated lymphoproliferative disorders are particularly frequent in transplant recipients. A particular gastric lymphoma called mucosa-associated lymphoid tissue (MALT) lymphoma may develop in renal transplant patients. It usually responds to the eradication of Helicobacter pylori.

Colonic Diseases↗
PubMed2006

TLR engagement prevents transplantation tolerance.

In many experimental models, heart, pancreas and kidney allografts are accepted long-term following costimulation-targeting therapies, whereas skin, lung and intestine resist the induction of tolerance under the same regimens. We noted that a common feature of the resistant organs is their constant exposure to commensal microbes and hypothesized that these microorganisms may stimulate Toll-like receptors (TLRs), promote alloresponses and prevent tolerance induction. This hypothesis prompts the predictions that TLR engagement at the time of transplantation should avert tolerance to heart allografts in animals treated with costimulation-targeting therapies, whereas inhibition of TLR signaling should promote tolerance to skin allografts under the same conditions. Indeed, engagement of a single TLR was sufficient to prevent anti-CD154-mediated long-term cardiac allograft acceptance and correlated with abolished intragraft recruitment of CD4+/FoxP3+ regulatory T cells and the development of linked-suppression. Conversely, a lack of donor and recipient MyD88-dependent signaling led to successful skin allograft acceptance in anti-CD154-treated animals. Thus, the status of TLR signaling contributes to the resistance versus susceptibility of organs to transplantation tolerance.

Animals↗
PubMed1987

Spirochaetosis of the human rectum associated with an intraepithelial mast cell and IgE plasma cell response.

In two patients presenting with mild intestinal symptoms, rectal spirochaetosis was the only morphological abnormality diagnosed by light microscopy. A re-evaluation of the morphological changes using electron microscopy and immunohistochemistry showed certain unusual features: the microorganisms were observed within epithelial cells and in subepithelial macrophages; there were numerous partially degranulated intraepithelial mast cells; and there was a marked increase in the proportion of IgE plasma cells within the lamina propria. Mucosal penetration by the organisms may be responsible for the unusual immune response. In one patient, treatment with antibiotics eliminated the spirochaetes and resulted in a clinical improvement. Spirochaetes should not always be considered as harmless commensals in the colon.

Adult↗
PubMed1984

Jejunal microflora in patients with chronic alcohol abuse.

The types and numbers of bacteria were examined in aspirates from the jejunums of 27 chronic alcoholics and 13 hospitalized control patients of comparable age distribution without alcohol abuse or diseases of the liver. Samples of jejunal juice were aspirated in the fasting state. The mean number of microorganisms obtained during anaerobic incubation was distinctly higher in the alcoholics (log10, mean +/- SD: alcoholics 4.9 +/- 2.2, controls 3.2 +/- 1.5, p less than 0.025). A similar difference was found for the number of aerobic bacteria (alcoholics 4.7 +/- 1.9, controls 3.3 +/- 2.1, p less than 0.05). Significant counts (greater than 10(5)/ml) of bacteria obtained during anaerobic incubation were more frequent in the alcoholics (48.1%) than in the controls (7.6%, p less than 0.001). Coliform microorganisms were cultured much more frequently from the jejunal fluid of the alcoholics (alcoholics 55.6%, controls 15.4%, p less than 0.025). In addition the incidence of Gram-negative anaerobic bacteria and endospore-forming rods was higher in the aspirates from alcoholics (p less than 0.05). In both groups the number of microorganisms in jejunal fluid correlated closely with the pH found in the gastric juice. No correlation was found between the numbers or types of microorganisms in the jejunum and the type or degree of liver disease in the alcoholics. It is concluded that bacterial overgrowth might contribute to functional and/or morphological abnormalities of the small intestine commonly found in patients with chronic alcohol abuse.

Actinomyces↗