Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “BACTEROIDES INFECTIONS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 577 records · Page 32Linked to original sources
PubMed1988

Bacteroides fragilis endocarditis.

We recently diagnosed and treated an unusual case of primary endocarditis due to Bacteroides fragilis, for which no underlying etiology was found. Antibiotic treatment involved multiple parenteral and oral antibiotics, and sensitivity studies allowed choice of antibiotics. Despite complications, the patient was cured. Few cases of Bacteroides fragilis endocarditis have been reported, and therapy has changed with newer antibiotics.

Aged↗
PubMed2005

Induction of colonic transmural inflammation by Bacteroides fragilis: implication of matrix metalloproteinases.

BACKGROUND: Commensal bacteria are implicated in the pathophysiology of intestinal inflammation, but the precise pathogenetic mechanisms are not known. We hypothesized that Bacteroides fragilis-produced metalloproteinases (MMPs) are responsible for bacterial migration through the intestinal wall and transmural inflammation. AIM: To investigate the role of bacterial-MMP activity in an experimental model of colitis induced by the intramural injection of bacteria. METHODS: Suspensions of viable B. fragilis or Escherichia coli were injected into the colonic wall, and the effect of the MMP inhibitor (phenantroline) on histologic lesion scores was tested. MMP activity in bacterial suspensions was measured by azocoll assay. RESULTS: The inoculation with B. fragilis induced chronic inflammatory lesions that were preferentially located in the subserosa, whereas inoculation with E. coli induced acute-type inflammatory reactions, evenly distributed in both the submucosa and subserosa. Treatment with phenantroline significantly decreased subserosal lesion scores in rats inoculated with B. fragilis, but not in rats inoculated with E. coli. Bacterial suspensions of B. fragilis showed MMP activity, but E. coli suspensions did not. Sonication of B. fragilis reduced MMP activity and virulence to induce serosal lesions. CONCLUSION: Our data suggest that bacterial MMPs may be implicated in the serosal migration of B. fragilis and in the induction of transmural inflammation.

Animals↗
PubMed1985

Characterisation of cryptic plasmids in clinical isolates of Bacteroides fragilis.

A screening method for plasmids in the fragilis group of Bacteroides spp. was developed, taking account of the lysozyme resistance of these species; 26 strains, 24 of them B. fragilis, were investigated by this method. Eleven strains contained plasmids and up to three different plasmids were found in individual strains. The plasmids belonged to five different size classes of mol. wt (10(6] 2.8, 3.5, 3.6, 4.2 and 19. Plasmids of equal size showed homology; no homology was found between plasmids of different sizes. Plasmids of equal size showed identical restriction patterns with 17 restriction endonucleases. Restriction maps were constructed for the five classes of plasmid.

Anti-Bacterial Agents↗
PubMed1986

Bacteroides fragilis is a silent pathogen in acute appendicitis.

The role of Bacteroides fragilis in the pathogenesis of acute appendicitis was studied in 135 patients in four patient groups: normal (17); phlegmonous appendicitis (17); gangrenous appendicitis (75); and septic complications of appendicitis (26). Aerobic and anaerobic bacteria were isolated from all groups and members of the 'B. fragilis group' were the most common anaerobic isolates. The rate of isolation of B. fragilis was similar from normal and inflamed appendices but was significantly higher from those with septic complications (p less than 0.01). Antibodies against B. fragilis were demonstrated in patients of all groups and occurred with similar frequencies in patients with normal and inflamed appendices but at a significantly higher rate in those with septic complications (p less than 0.01). Whereas patients in this latter group showed IgM-antibody responses to B. fragilis only, those with acute appendicitis had IgM antibodies against a wide range of organisms of the 'B. fragilis group' which suggests that B. fragilis does not play a significant role in acute appendicitis but may be a major cause of its septic complications.

Acute Disease↗
PubMed2004

Molecular characterization of imipenem-resistant, cfiA-positive Bacteroides fragilis isolates from the USA, Hungary and Kuwait.

Fifteen Bacteroides fragilis isolates from the USA, Hungary and Kuwait were examined for carbapenem resistance, for carbapenemase activity and, with the use of various PCR-based methods and nucleotide sequencing, for cfiA genes and activating insertion sequence (IS) elements. All the B. fragilis isolates were cfiA-positive, 10 of the cfiA genes being upregulated by IS elements that are already known. Of these 10, one was of a novel type (designated IS943) and two further ones (IS614B and IS614C) were suspected hybrids of IS612, IS614 and IS942. There were five cfiA-positive imipenem-resistant B. fragilis isolates with elevated imipenem MICs (minimal inhibitory concentration) that harboured no IS insertion upstream of the cfiA gene, but produced carbapenemase; these isolates might possess a novel activation mechanism. On the basis of the available phenotypic and genotypic evidence, the present data suggest that there are at least two cfiA activation mechanisms among B. fragilis isolates.

Amino Acid Sequence↗
PubMed1992

Pathogenicity of Bacteroides fragilis group in rat intra-abdominal abscesses.

Attempts were made to study the pathogenicity of some strains of Bacteroides fragilis group in the rat intra-abdominal abscess model. Multiple intraabdominal abscesses were produced in 50 to 70% of animals when an inoculum containing 10(9) CFU/ml of any of the five species of Bacteroides fragilis group was injected. Rising homologous antibody titers determined by indirect fluorescent antibody test were observed till the 3rd week when tested last, indirectly confirming the multiplication of the organisms as also evident by viable count of bacteria in the abscesses. In some cases in addition to inoculated organisms some intestinal bacteria like Escherichia coli, Proteus mirabilis and Streptococcus spp. were also recovered from the abscess pus. Studies with the electron microscope showed presence of capsular polysaccharide only in Bacteroides fragilis and Bacteroides thetaiotaomicron. It was doubtful in Bacteroides distasonis and absent in Bacteroides ovatus and Bacteroides vulgatus, suggesting that virulence factor beside the capsular polysaccharide may be playing a role. Further studies are required to investigate the virulence factor responsible for the pathogenicity of noncapsulated species.

Abdomen↗
PubMed1994

Effect of Escherichia coli lipopolysaccharide on Bacteroides fragilis abscess formation and mortality in mice.

To study the mechanism of synergism between Bacteroides fragilis and Escherichia coli, the effect of sublethal dose of E. coli lipopolysaccharide (LPS) (25 micrograms/mouse) was checked on B. fragilis abscess formation. LPS was administered prior or after inoculum injection. No significant difference in the abscess size was observed at necropsy on day 6. However, all the groups receiving LPS showed higher incidence of recovery of additional intestinal bacteria (23.5-45.5%) from the abscess pus. When LPS was given 4 hr prior to inoculum administration, 83-100% mortality was observed. Detailed investigation showed autoclaved cecal contents alone could also cause similar mortality. Studies with stimulation of endogenous cytokines by E. coli LPS demonstrated induction of all of them within 3 hr in the blood stream with TNF-alpha demonstrating peak at 1 hr, IL-1 alpha and IL-6 at 4 hr and IFN-gamma between 6-9 hr with moderately high levels at 4 hr. This E. coli LPS-triggered cytokine cascade possibly gets further stimulated by injection of autoclaved cecal contents containing high concentration of endotoxins (1.6 x 10(5) EU/ml) contributed by dead bacteria and lead to the mortality of animals.

Abscess↗
PubMed1978

A case of atypical polyagglutinability due to Tk-transformation.

A case of acquired transient polyagglutinability in a group O, Rh(D) positive female patient, Wa, is described. An unusual finding in the preliminary serological investigation was the non-reaction of the cells with peanut (Arachis hypogaea) extract. The patient's red cells were strongly agglutinated by normal human and rabbit sera from which anti-T had been removed. Electrophoretic mobility studies and tests with polybrene indicated that their sialic acid content was normal. The use of a specific antiserum raised in a rabbit to Wa cells and cross-absorption tests showed that the patient's erythrocytes shared similar antigenic determinants to red cells treated with supernatants from pure cultures of Bacteroides fragilis. The in vitro-modified red cells reacted strongly with BS II lectin prepared from Bandeiraea simplicifolia seeds thus providing confirmatory evidence for Tk transformation on Wa cells. It is concluded that the Tk receptor is probably a more frequent feature of acquired transient polyagglutinability than has hitherto been recognized.

Animals↗
PubMed2006

Occurrence of bacterial indicators and bacteriophages infecting enteric bacteria in groundwater in different geographical areas.

AIMS: The aim of this research was to determine the suitability of coliphages (bacteriophages) for assessing the microbial quality of groundwater. METHODS AND RESULTS: The number of several bacterial indicators (faecal coliforms, Escherichia coli, enterococci and spores of sulfite-reducing clostridia) and bacteriophages (somatic coliphages, F-specific RNA bacteriophages and bacteriophages infecting Bacteroides fragilis) were determined in groundwater of aquifers in various geographical areas. Results show that the relative abundance, determined as percentages of positive detections, of the bacterial indicators and bacteriophages varies depending on the aquifer. CONCLUSIONS: A single bacterial indicator may not be enough to assess microbiological quality in certain aquifers. One bacterial indicator and a bacteriophage parameter provide more information than two bacterial indicators. SIGNIFICANCE AND IMPACT OF THE STUDY: Coliphages (CPH) provide different information from that provided by bacterial indicators on the microbial quality of groundwater in different geographical areas. Easy, fast and inexpensive methods for the detection of CPH are feasible in both industrialized and developing countries.

Argentina↗
PubMed2005

Detection of bacteria in endodontic samples by polymerase chain reaction assays and association with defined clinical signs in Italian patients.

BACKGROUND/AIMS: The presence of selected bacteria (Enterococcus faecalis, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythensis, Treponema denticola) in infected root canals was studied using polymerase chain reaction (PCR) assays, and the association of bacteria with clinical signs of endodontic disease was assessed. The null hypothesis, that no difference could be observed between clinical signs of apical periodontitis and a specific bacterial strain, was tested. METHODS: Microbial samples were obtained from 62 teeth in 54 patients with endodontic disease. For each tooth, clinical data including patient symptoms were collected. Teeth were categorized by diagnosis as having acute apical periodontitis (AAP, teeth with clinical symptoms but no periapical radiolucency, n=22), chronic apical periodontitis (CAP, teeth with radiolucency but no clinical symptoms, n=15) or exacerbated apical periodontitis (EAP, teeth with symptoms and radiolucency, n=25). Seventy-one percent of cases were primary endodontic infections, and 29% were recurrent ('secondary') endodontic infections (failing cases). PCR assays were used to detect the presence of the selected bacteria. RESULTS: T. denticola and E. faecalis were each detected in 15 of 62 samples (24%), P. gingivalis in 8 samples (13%), P. intermedia in 5 samples (8%), and T. forsythensis in 4 samples (7%). T. denticola was detected in 56% of teeth with EAP. E. faecalis was found in 60% of teeth with CAP and in 72% of teeth with secondary infection. Statistical analysis demonstrated an association of CAP and secondary endodontic infection with the presence of E. faecalis. (P<0.01). EAP was associated with the presence of T. denticola (P<0.01). CONCLUSION: T. denticola was associated with symptomatic endodontic disease in the presence of apical bone resorption. E. faecalis was associated with treatment failures. We suggest that these species may play critical roles in endodontic pathology.

Adult↗
PubMed2000

A new subtype of the metalloprotease toxin gene and the incidence of the three bft subtypes among Bacteroides fragilis isolates in Japan.

The bft gene encoding Bacteroides fragilis toxin (BFT) has been devided into two subtypes, bft-1 and bft-2. We found a novel subtype by sequencing a segment of the bft gene from 64 enterotoxigenic B. fragilis (ETBF) strains isolated in Japan. The 1548-bp nucleotide sequences of the new bft, the bft-1, and bft-2 genes were determined for five, four, and four ETBF strains, respectively; the nucleotide sequence was identical among each bft subtype and the degree of identity between each subtype was between 89 and 94%. Most of the variations between the three subtypes were detected in the region encoding mature toxin. A multiplex PCR was developed with a four-primer mix to subtype the bft sequences. The subtyping of 143 ETBF isolates from extraintestinal and stool specimens of humans and cows showed that the bft-1 was the most prevalent subtype, followed by bft-2 and a new bft subtype. No other subtype was found among the strains tested.

Adolescent↗