Outer membrane permeation of Bacteroides fragilis by cephalosporins was examined by a previously described method. The permeation parameters of cephalosporins in B. fragilis were close to 10(-5) cm3/min per microgram of cell dry weight. These values were about an order of magnitude lower than those in Escherichia coli. In B. fragilis, the permeation was not directly proportional to the hydrophi...

The two investigated algae had almost identical sterol composition, but there were significant differences in the composition of the polar components and especially in the composition of the volatiles. P. denudata f. fragilis extracts possessed a stronger biological activity (antibacterial, antifungal and toxicity against Artemia salina). Despite the minute morphological differences between the...

Escherichia coli and Bacteroides fragilis are common copathogens in clinical intra-abdominal sepsis, yet it is unclear how they interact synergistically in vivo. We sought to determine whether E. coli and B. fragilis, in combination but not alone, could exert a detrimental effect on the peritoneal host defenses of translymphatic absorption and bacterial phagocytosis. Our data indicated that non...

Incubation of normal human erythrocytes with the supernatant of centrifuged culture of some strains of Bacteroides fragilis results in the exposure of Tk polyagglutination determinants on the erythrocyte membrane. These determinants are present on non papain-labile structures and are probably exposed by an enzyme mechanism. Other strains of B. fragilis were found to produce neuraminidase, haemo...

In order to determine the therapeutic value of penicillins in the management of anaerobic infections caused by Bacteroides fragilis, the antibacterial activity of penicillin G, ampicillin, and carbenicillin against 10 strains of B. fragilis subsp. fragilis, isolated from clinical material, was studied. This was undertaken by using a triple-layer technique, enzymatic inactivation of the antibiot...

Radioimmunoassay methods were evaluated for immunoglobulin G and immunoglobulin M antibodies against Bacteroides fragilis antigen. Of 12 serum samples from patients with B fragilis infections, 9 had higher concentrations of immunoglobulin G antibodies than any from 11 control subjects. Of 9 serum samples from infected patients, 6 had higher concentrations of immunoglobulin M than any from contr...

Bacteroides fragilis colonizes dog guts both as a commensal and as an opportunistic pathogen. This study aims to evaluate virulence factors of 13 B. fragilis strains isolated from dog intestinal tracts and their ability for biofilm formation. Capsules were detected in all the evaluated strains. A total of 61.5% of all strains were biofilm producers. These attributes most likely play an importan...

Dientamoeba fragilis is a commonly encountered trichomonad which has been implicated as a cause of gastrointestinal disease in humans. Despite the frequency of reports recording infections with this parasite, little research has been undertaken in terms of antimicrobial susceptibility. The aim of this study was to evaluate the susceptibility of D. fragilis to several commonly used antiparasitic...

A number of investigators have provided experimental evidence for synergistic effects in mixed infections with Escherichia coli and Bacteroides fragilis. In vitro studies have suggested that competition for serum opsonins and diminished subsequent phagocytosis by polymorphonuclear leukocytes might explain these effects. In the present study we evaluated the effect of B. fragilis on macrophage p...