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Biomedical subjects

A Eley

Publications and source records attributed to A Eley.

At least 55 records · Page 3Linked to original sources
PubMed1990

Isolation of Bacteroides ureolyticus from the genital tract of men with and without non-gonococcal urethritis.

Urethral specimens from 247 heterosexual men--118 patients with non-gonococcal urethritis and 129 controls with no evidence of urethritis--were examined for the presence of Bacteroides ureolyticus. Bacteroides ureolyticus was isolated from 45 (34.9%) of the controls and from 31 (26.3%) of the urethritis patients; there was no significant difference between these rates (p = 0.1). There was no association between the density of Bacteroides ureolyticus on primary isolation plates in either group.

Bacteroides↗
PubMed1989

Selective and differential medium for isolation of Bacteroides ureolyticus from clinical specimens.

A new selective and differential medium for Bacteroides ureolyticus was compared with other commonly used selective media for anaerobes in a diagnostic trial with routine clinical specimens. All Bacteroides ureolyticus strains grew on nalidixic acid-teicoplaninurea agar, producing red colonies against a straw-coloured background. This medium was found to be the most selective for Bacteroides ureolyticus. In the diagnostic trial with 185 clinical specimens a 20% increase in the isolation rate of Bacteroides ureolyticus was obtained with this new medium.

Bacteroides↗
PubMed1989

A comparison of Bacteroides ureolyticus isolates from different clinical sources.

Clinical isolates of corroding, gram-negative, anaerobic bacilli (provisionally identified as Bacteroides ureolyticus) from superficial ulcers and soft tissue infections (15), non-gonococcal, non-chlamydial urethritis (12) and adult periodontal disease (14) were compared with reference strains of B. ureolyticus, B. gracilis and Wolinella recta in a series of conventional tests of morphology, biochemical activity, tolerance of dyes and bile salts, and antibiotic sensitivity, gas-liquid chromatographic analysis of metabolic products, and in whole-cell analysis by pyrolysis-mass spectrometry (Py-MS). A numerical taxonomic approach was used with the results of conventional tests and the grouping obtained was compared with that obtained by Py-MS. All the ulcer and soft-tissue isolates and the urethritis isolates were oxidase- and urease-positive and formed a homogeneous set consistent with the reference strain of B. ureolyticus. The dental isolates differed from B. ureolyticus strains and were heterogeneous amongst themselves. None corresponded with the reference strains of B. gracilis or W. recta. The conventional and Py-MS approaches to characterisation produced similar groupings and each distinguished between a single cluster of ulcer-urethritis strains and several clusters of dental strains, although the dendrograms derived from the two approaches differed in the order of the clusters; in the Py-MS dendrogram one subcluster of four dental strains came within the main ulcer-urethritis cluster and a cluster of five ulcer strains was separated as a distinct group.

Bacteroides↗
PubMed1988

The in-vitro effect of a titanium implant on oral microflora: comparison with other metallic compounds.

Dental implant research has been mostly concerned with the biocompatibility of materials for implantation. In this study the effects of titanium dioxide and other metallic salts on seven bacterial species commonly found in dental plaque, two which are uncommon, and a yeast, were determined by agar incorporation and diffusion techniques, and compared with the effects of a titanium implant abutment. Neither the titanium dioxide nor the implant abutment demonstrated any inhibitory activity, although other compounds such as cobalt used in dental alloys had some effects.

Bacteria↗
PubMed1986

Factors influencing the activity of the trometamol salt of fosfomycin.

The antibacterial activity of trometamol fosfomycin and its potentiation by glucose-6-phosphate were found to vary considerably in different culture media, although not all bacteria tested were equally affected. In general, the lowest MICs were obtained in the presence of glucose-6-phosphate in nutrient broth and Eugonbroth. The influence of inoculum size, pH and potentiation by glucose-6-phosphate were investigated by agar incorporation MIC titrations on nutrient agar. The activity of trometamol fosfomycin against many strains increased as the pH was lowered from 7.9 to 5.5. Only 9% of the strains showed an inoculum effect when tested at pH 5.5 in the presence of glucose-6-phosphate compared with 37% of the strains tested at pH 7.1 and 22% of the strains tested at pH 7.9. In the absence of glucose-6-phosphate, about 10% of the strains showed an inoculum effect at all three pH levels. The addition of glucose-6-phosphate to culture media seems reasonable for the testing of fosfomycin susceptibility.

Bacteria↗
PubMed1986

Characterization of beta-lactamases in clinical isolates of Bacteroides.

A total of 78 strains of Bacteroides was freshly isolated from clinical specimens; 60 of the strains were identified as B. fragilis and 16 as B. thetaiotaomicron. Overall, imipenem and the combination of benzylpenicillin and clavulanic acid were found to be considerably more active than cefoxitin or latamoxef (moxalactam) against these strains. Nearly all the strains exhibited weak beta-lactamase activity and 13 were judged to produce elevated levels of enzyme. These 13 strains fell into three groups: four strains that produced enzymes of low specific activity which were very susceptible to beta-lactamase inhibitors; three strains that produced enzymes of intermediate specific activity which hydrolysed cefoxitin and latamoxef at a variable rate; two of these enzymes rapidly inactivated imipenem and were insusceptible to beta-lactamase inhibitors; six strains that produced enzymes of high specific activity which were susceptible to beta-lactamase inhibitors; these strains did not inactivate beta-lactamase-stable beta-lactam antibiotics, but two of the strains nonetheless exhibited reduced susceptibility to latamoxef and imipenem.

Anti-Bacterial Agents↗
PubMed1986

Beta-lactamases of type culture strains of the Bacteroides fragilis group and of strains that hydrolyse cefoxitin, latamoxef and imipenem.

Susceptibilities to beta-lactam antibiotics and beta-lactamase content of two groups of Bacteroides strains were compared. Type cultures produced low levels of beta-lactamase and were susceptible to cefoxitin, latamoxef, imipenem and the combination of benzylpenicillin and clavulanic acid. Other Bacteroides strains that produced higher levels of beta-lactamase were generally less susceptible to these antibiotics; this resistance was more closely related to enzyme type than to the amount of enzyme present. The beta-lactamases produced by the test strains fell into three broad groups on the basis of antibiotic degradation and inhibitor profiles: those that inactivated benzylpenicillin, but not cefoxitin, latamoxef or imipenem, and were susceptible to inhibition by beta-lactamase inhibitors; those that hydrolysed benzylpenicillin, cefoxitin and latamoxef, but not imipenem, and which were less susceptible to inhibition by beta-lactamase inhibitors; an enzyme that inactivated all the antibiotics and was not inhibited by beta-lactamase inhibitors.

Bacteroides fragilis↗
PubMed1985

Laboratory evaluation of enoxacin: comparison with norfloxacin and nalidixic acid.

Enoxacin displayed activity similar to that of norfloxacin against enterobacteria, Pseudomonas aeruginosa, staphylococci, streptococci and Bacteroides spp. The activity of enoxacin against many strains was reduced in acid conditions, but the pH effect was not so marked as that seen with norfloxacin. Nalidixic acid was found to be more active in acid conditions, particularly against staphylococci, Streptococcus faecalis and Ps. aeruginosa. In conditions simulating the treatment of bacterial cystitis, a single dose of enoxacin, achieving a peak concentration of 50 mg/l, suppressed growth of nalidixic acid-sensitive and -resistant Gram-negative bacilli for periods of between 18 and 25 X 5 h. Reduced susceptibility of bacteria surviving exposure to enoxacin was observed in one nalidixic acid-resistant strain of Escherichia coli and in nalidixic acid-sensitive strains exposed to low doses (peak concentration = 5 mg/l) of enoxacin. These results are similar to those obtained with norfloxacin and substantially better than those obtained with nalidixic acid.

Anti-Bacterial Agents↗
PubMed1985

Comparative growth of Bacteroides species in various anaerobic culture media.

The growth of five species of Bacteroides in four anaerobic culture media was continuously monitored turbidimetrically. Interspecies differences were observed in the growth of Bacteroides spp. in the various media, but growth in Brain Heart Infusion broth supplemented with yeast extract, haemin and menadione, was consistently better than in Wilkins-Chalgren, Thioglycollate or Schaedler broths. Microscopy of cultures grown overnight in Brain Heart Infusion broth showed that the bacteria exhibited normal morphology but most species grown in the other media displayed filamentation or chain formation. Four of the five species grown in Schaedler broth also exhibited spheroplast formation. This morphological change occurred in the stationary phase of growth, was reduced by inclusion of NaCl in the medium and was abolished in Schaedler broth prepared at double the recommended strength.

Anaerobiosis↗