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At least 19 recordsLinked to original sources
PubMed1977

[In vitro activity of mezlocillin, azlocillin and carbenicillin against bacteroidaceae with particular reference to bacteroides fragilis (author's transl)].

The in vitro susceptibility of approximately 90 Bacteroidaceae strains to the the new broad-spectrum penicillins mezlocillin and azlocillin was determined by tube dilution tests and compared to susceptibility to carbenicillin. Bacteroides fragilis and Bacteroides thetaiotaomicron predominated among the strains tested. These strains are particularly important as pathogens and are known to produce beta-lactamase. At concentrations of 16 microng/ml or less, mezlocilin inhibited 81% of the Bacteroides cultures, and at 32 microng/ml 96% of the cultures. The amount of Bacteroides strains inhibited by 16 and 32 microng/ml of azlocillin was 67% and 93% respectively. Similar results were obtained with carbenicillin, concentrations of 32, 64 and 256 microng/ml inhibiting 55%, 87% and 94% of the strains respectively. Mezlocillin and azlocillin did not appear to be any more effective than carbenicillin against Sphaerophorus strains. Statistical analysis of the relationship between minimal inhibiting concentration and inhibition zone diameter showed that the susceptibility of Bacteroidaceae to mezlocillin, azlocillin and carbenicillin cannot be determined with sufficient accuracy by a standardized agar diffusion test.

Bacteroidaceae↗
PubMed1970

Dehydrogenase patterns in the study of Bacteroidaceae.

Enzyme patterns were obtained by starch-gel electrophoresis of cell-free extracts from organisms in the family Bacteroidaceae. Esterases, phosphatases, and lactic and succinic dehydrogenases were detected but offered no possibility for classification purposes. Alpha-glycerophosphate dehydrogenase and 6-phosphogluconate dehydrogenase were not detected. Zymograms of malic, glutamic, and glucose-6-phosphate dehydrogenases separated Bacteroides species from Sphaerophorus and Fusobacterium species. Malic dehydrogenase and glucose-6-phosphate dehydrogenase were found in Bacteroides but not Sphaerophorus and Fusobacterium. These dehydrogenase zymograms placed three gram-negative, nonsporeforming anaerobic rod isolates with the Bacteroides species. A close correlation was found between the classification of Bacteroidaceae by zymogram analysis and a numerical taxonomy scheme previously published from this laboratory.

Bacteria↗
PubMed1989

Oxygen activation and defence against oxygen toxicity in a psychrophilic Bacteroidaceae.

When suddenly exposed to air the growth of the obligate anaerobic bacterium of the bacteroidaceae type, strain B6, continues for a few hours before coming to a complete stop. When air is shut off soon after growth has ceased, the organism is able to reestablish anaerobic conditions due to an ability to reduce O2, and resumes normal growth after another few hours. The O2 reducing ability of the organism is due to the presence in the cells of a particle-bound NADH oxidase, a soluble NADPH oxidase and a soluble pyruvate oxidase. The two pyridine nucleotide oxidases reduce O2 to H2O2, the pyruvate oxidase reduces O2 to H2O. Catalase and peroxidase were not detected in anaerobically grown cells. Kinetic studies with cell-free extracts showed that the pyruvate oxidase had a considerably greater affinity (smaller Km) for O2 and capacity (higher Vmax) for O2 reduction than the two other oxidases. It is postulated that the pyruvate oxidase acts as a scavenger for O2, leading to the non-toxic reduction product H2O, and thus functions as a defense mechanism against oxygen toxicity when the organism is exposed to aerobic condition.

Air Microbiology↗
PubMed1977

[In vitro susceptibility of bacteroidaceae to cefoxitin and cephalothin (author's transl)].

The activity of the new cephamycin C derivatives cefoxitin against 102 clinical isolates of Bacteroidaceae (95 Bacteroides strains and 7 Fusobacterium-Sphaerophorus cultures) was determined by tube dilution and standardized agar diffusion tests and compared to that of cephalothin. Cefoxitin was more active than cephalothin against 56 Bacteroides fragilis strains, 19 Bacteroides thetaiota-omicron strains and two Bacteroides splanchnicus strains. The difference seemed less pronounced with five Bacteroides vulgatus and four Bacteroides variabilis cultures. Three Bacteroides melaninogenicus and six Bacteroides oralis strains displayed similar sensitivity to both cephalosporins. At concentrations of 32 microng/ml or less, cefoxitin inhibited 91% and cephalothin 33% of the Bacteroides strains. Two strains of Sphaerophorus varius were likewise much more sensitive to cefoxitin than to cephalothin (MIC values 8 micron8/ml of cefoxitin and 256 microng/ml of cephalothin). Three other Sphaerophorus strains (the species necrophorus and freundii/mortiferum) and two of Fusobacterium fusiforme (Fusobacterium nucleatum) strains were very similar in their susceptibility to both cephalosporins. Statistical analysis of the relationship between MIC and zone size diameter showed relatively high correlation coefficients for cefoxitin and cephalothin (r=-0.741 and r=-0.703 respectively).

Bacteroidaceae↗
PubMed1986

In-vitro sensitivity of Bacteroidaceae, clostridia and propionibacteria to newer antimicrobial agents.

The susceptibility of 220 fresh clinical isolates of Bacteroidaceae, clostridia and propionibacteria to imipenem, ceftazidime, ciprofloxacin and four further substances were established by agar dilution tests. Imipenem was unique among the seven test antibiotics in that it was active against all the bacteria investigated. Whereas clindamycin suppressed all Gram-positive and 94 X 8% of the Gram-negative strains tested, and metronidazole was effective against all but the propionibacteria, ceftazidime and ciprofloxacin showed satisfactory activity against the Gram-positive bacteria only.

Anti-Bacterial Agents↗
PubMed1978

Gas-lipuid chromatographic analysis of metabolic products in the identification of bacteroidaceae of clinical interest.

The acid end-products of 185 isolates from the family Bacteroidaceae were separated and analysed by gas-liquid chromatography on broth cultures. Different media were evaluated and definitive studies were performed in a fully supplemented complex medium. The limitations of this approach to the identification of a wide range of strains from various clinical sources were determined and the results were compared with those of a series of morphological, biochemical, tolerance and antibiotic-resistance tests. All test strains were identified to generic level by simple microscopic and colonial observations and GLC analysis; additional tests were required to allow species or subspecies identification of most strains. Population differences were detected between some species or subspecies isolated from different clinical sites by quantitative analyses of fatty acids, but individual strains could not always be separated because of overlapping ranges of distribution of acids that were common products of more than one species or subspecies. Small differences in minor products between different species or subspecies were variable and are not considered adequate for discrimination at these taxonomic levels without support from other observations. The potential application of the GLC technique to the rapid and accurate identification of these organisms in hospital laboratories is considered.

Bacteroidaceae↗
PubMed1979

Cellulose degradation by a new isolate from sewage sludge, a member of the Bacteroidaceae family.

A mesophilic anaerobe, a member of the Bacteroidaceae family (NRC2248), isolated from a cellulose-enrichment culture, digested untreated Whatman cellulose powder and HCl-treated cotton battings while producing hydrogen, carbon dioxide, cellobiose, glucose, and acetic acid as the sole volatile acid. This organism also utilized cellobiose as carbon and energy source but did not utilize glucose. It grew well in synthetic medium containing ammonium salts as nitrogen source and having a pH value of 7.0-7.1 and an Eh value of -160mV or lower. The nutrient requirements of this organism were found to be similar to those of other anaerobes except for Na2S which inhibited cellulose degradation in concentrations above 0.75 mM. Best cellulose degradation occurred under an atmosphere of 80% N2-20% CO2. Use of H2 or 80% H2-20% CO2 as headspace gas inhibited growth. Although accumulation of acetic acid in about 15-16 mM concentrations inhibited the further formation of H2, CO2, and acetic acid in the broth, it did not stop the degradation of cellulose. The results indicate that this organism has the ability to grow in media containing up to 20 g/L of cellulose and to produce industrially important and easily separable end products from cellulose.

Acetates↗
PubMed1969

Growth of Bacteroidaceae in stirred fermentors.

The conditions for increasing bacterial yields in cultures of Bacteroidaceae by the use of stirred fermentors and pH control were investigated by means of three representative species: Sphaerophorus necrophorus, Bacteroides fragilis, and B. melaninogenicus. A medium containing tryptone, yeast extract, and glucose or sucrose was used. Horse serum had to be added to obtain substantial growth of B. melaninogenicus. The optimal pH for growth rate and yield was 7.0 to 7.2. Lysis of the bacteria occurred when the glucose (or sucrose) was exhausted. The rate of lysis was very high in cultures of S. necrophorus, less so in B. fragilis and B. melaninogenicus. Pleomorphism, manifested as large sperical forms of the bacteria, was observed in the late logarithmic phase of S. necrophorus. Great differences in the length of the lag phase and of the mean generation time were found among the three bacterial species. The yield in static cultures of the three species without pH control was approximately 0.4 g of dry cells per liter, but was increased, in stirred fermentors with pH control, to 3.5 g (S. necrophorus), 2.7 g (B. fragilis), and 4.3 g (B. melaninogenicus) per liter. With an inoculum density of 5 to 10 mg (dry weight) per liter, these yields were obtained in approximately 10 (S. necrophorus), 25 (B. fragilis), and 35 hr (B. melaninogenicus), respectively.

Bacteriological Techniques↗
PubMed1983

Reaction of clinical isolates and typed strains of the family Bacteroidaceae with rabbit anti-Bacteroides sera examined by radial immunodiffusion.

Antisera were produced which were reactive with Bacteroides fragilis, B. gingivalis, or B. melaninogenicus subsp. melaninogenicus. Anti-B. gingivalis serum exhibited strong reactions with strains of homologous species and reacted with only one other species, B. thetaiotaomicron. Antigens shared by organisms of the B. fragilis group and B. melaninogenicus subspecies of the Bacteroidaceae must be considered when serological methods are used for their identification.

Antibodies, Bacterial↗
PubMed1988

Perinatal septicemia due to the Bacteroidaceae.

Two cases of perinatal septicemia due to the Bacteroidaceae are discussed. In contrast to most cases of perinatal septicemia caused by aerobic bacteria, these cases were not associated with prolonged rupture of the fetal membranes.

Adolescent↗
PubMed1979

Comparison of three methods of susceptibility testing of bacteroidaceae, peptococcaceae and other anaerobes to doxycycline.

The in vitro activity of doxycycline against 147 strains of gram-positive and gram-negative anaerobes was determined by broth dilution, agar dilution and agar diffusion tests. The strains were isolated from clinical specimens in 1977. Saccharolytic Bacteroides strains (39 B. fragilis, 6 B. thetaiotaomicron, 4 B. vulgatus) showed broth dilution MICs of less than or equal to 0.0625-4.0 microgram/ml after 5 h incubation and MICs of less than or equal to 16 microgram/ml after 15 h incubation at 37 degrees C. With strains of B. oralis, B. melaninogenicus ss. intermedius, B. corrodens, Veillonella sp. and Megasphaera elsdenii the broth dilution MICs were less than or equal to 0.0625-32 microgram/ml after 15 h incubation. Peptostreptococcus spp., Propionibacterium acnes, Eubacterium sp., Bifidobacterium sp. and Clostridium sp. had broth dilution MICs of less than or equal to 2 microgram/ml, whereas Peptococcus spp. were inhibited by less than or equal to 0.0625 to greater than 32 microgram/ml. With the great majority of strains tested, MICs were 2 to 256 times higher in agar than in broth dilution tests. Clinical and experimental studies seem to be needed to determine which of the in vitro data are correlated to the outcome of doxycycline therapy. Several groups and species were separately considered for statistical analysis of the relationship between zone size and MIC. With gram-positive anaerobes, correlation was poor between broth dilution MIC and zone size (correlation coefficients r = - 0.168 for Peptococcaceae, and r = - 0.108 for P. acnes). When calculating the regression lines for agar dilution MICs and zone diameters, a higher correlation was found (r = - 0.9 for Peptococcaceae; r = - 0.397 for P. acnes). With B. fragilis and other Bacteroides species correlation coefficients were r = - 0.807 to r = - 0.891 for broth and agar dilution MICs and zone size but stochastic linearity was lacking.

Anaerobiosis↗