Uncertainty surrounding the role of Dientamoeba fragilis in human disease could be due in part to the existence of pathogenic and nonpathogenic variants. Evidence for two genetically distinct forms was obtained using PCR-restriction fragment length polymorphism analysis of ribosomal genes. Future studies in humans will need to take D. fragilis diversity into account.

The effect of 10% carbon dioxide on the sensitivity to four antibiotics of 10 strains of Bacteroides fragilis was studied. The minimum inhibitory concentrations of erythromycin and lincomycin hydrochloride for these strains were four to 32 times higher, when grown in hydrogen plus 10% carbon dioxide, than the values obtained when the strains were grown in pure hydrogen. A similar effect was obt...

Hordeum, distributed worldwide in temperate zones, is the second largest genus in the tribe Triticeae and includes diploid, tetraploid, and hexaploid species. We determined, by DAPI staining and flow cytometry, the nuclear DNA content for 35 accessions of the genus Hordeum, from a total of 19 species, including specimens of 2 cultivars and 2 landraces of Hordeum vulgare ssp. vulgare as well as ...

A total of 94 clinical isolates of the Bacteroides fragilis group was tested for susceptibility to metronidazole, chloramphenicol, clindamycin, cefoxitin, cefotetan, cefmetazole, moxalactam, mezlocillin, amoxicillin-clavulanic acid, and imipenem. All the strains tested were susceptible to imipenem, metronidazole, amoxicillin-clavulanic acid, and chloramphenicol. The rate of resistance to clinda...

Oral, black-pigmented Bacteroides spp. are important pathogens in oral anaerobic infections and dental disease. We detected conjugation systems in isolates of Bacteroides denticola and Bacteroides intermedius that transferred tetracycline resistance (Tetr) and penicillin resistance to Bacteroides buccae and to Bacteroides fragilis, an intestinal Bacteroides species. A cloned Tetr gene from B. f...

The in vitro activities of ofloxacin alone and in combination with metronidazole against 177 anaerobic bacteria isolated from intra-abdominal infections, as determined by broth microdilution, showed that some Bacteroides fragilis strains were susceptible and that most other B. fragilis group species strains were resistant to ofloxacin. Isolates of other anaerobic species and genera, including t...

The extracellular production of hyaluronidase and chondroitin sulfatase was demonstrated in all of the subspecies of Bacteroides fragilis tested with the exception of B. fragilis subsp. vulgatus. Elastase was found only in one strain of B. coagulans tested. This appears to be the first report of these enzyme activities in this genus. Additional enzymes found to be produced by certain members ot...