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Biomedical subjects

B Holmes

Publications and source records attributed to B Holmes.

At least 55 records · Page 3Linked to original sources
PubMed1994

Evaluation of two BBL Crystal systems for identification of some clinically important gram-negative bacteria.

The BBL Crystal system (Becton Dickinson Microbiology Systems, Cockeysville, Md.) is a miniaturized bacterial identification method employing modified conventional and chromogenic substrates. Two products are currently available, the Rapid Stool/Enteric ID Kit and the Enteric/Nonfermenter ID Kit, each comprising thirty tests. We report an evaluation of both systems (using database version 1.1 for both) in the identification of 51 gram-negative taxa likely to be encountered commonly in the clinical laboratory. In all, 266 strains were tested in the Enteric/Nonfermenter ID Kit, and these represented 36 taxa of the family Enterobacteriaceae (188 strains), 5 oxidase-positive fermentative taxa (26 strains), and 10 nonfermentative taxa (52 strains). The majority of these same strains (203 of 266) were also tested in the Rapid Stool/Enteric ID Kit. The Enteric/Nonfermenter ID Kit performed as follows: Enterobacteriaceae, 93% correct, 6% not identified, and 1% incorrect; oxidase-positive fermenters, 88, 12, and 0%, respectively; and nonfermenters, 100% correct, although several only to the genus or group level. The Rapid Stool/Enteric ID Kit gave the following results: Enterobacteriaceae, 91% correct, 7% not identified, and 2% incorrect; oxidase-positive fermenters, 80, 13, and 7%, respectively (but results were based on only 15 strains); and nonfermenters, 100% correct (but results were based on only 11 strains). We found the systems extremely easy and rapid to use, and for the Enteric/Nonfermenter ID Kit an identification rate of 100% in 40 of 51 taxa was achieved, with corresponding figures of 29 of 39 taxa for the Rapid Stool/Enteric ID Kit.

Bacteriological Techniques↗
PubMed1993

Quantitative organic acid analysis in cerebrospinal fluid and plasma: reference values in a pediatric population.

Quantitative reference values for the concentrations of organic acids in cerebrospinal fluid (CSF) and plasma, as well as ratios of individual organic acids between CSF and plasma, were determined in twenty-three pairs of samples from pediatric patients. Twenty-six organic acids were present and quantifiable in all or the majority of plasma and CSF specimens (limit of detection 1 mumol/l). There were substantial differences between subgroups of organic acids, best reflected by the ratios of individual acids between CSF and plasma. Metabolites related to fatty acid oxidation were present in CSF in substantially lower amounts than in plasma. Organic acids related to carbohydrate and energy metabolism and to amino acid degradation were present in CSF in equal or slightly lower amounts than in plasma. Finally, some organic acids were found in substantially higher amounts in CSF than in plasma, e.g. glycolate, glycerate, 2,4-dihydroxybutyrate, citrate and isocitrate. Quantitation of organic acids in CSF and plasma should aid diagnosis and monitoring of treatment of patients with organic acid disorders.

Acids↗
PubMed1993

Use of a thick-film capillary column for the analysis of organic acids in body fluids.

An improved method for the identification and quantification of organic acids in body fluids employing capillary gas chromatography-mass spectrometry has been developed. A thick-film capillary column, that combines the properties of a capillary column with those of a megabore column, has been successfully introduced into an existing method. Analysis over a concentration range from 1 mumol/l to 500 mumol/l body fluid is possible. This permits the assay of samples that are usually obtained in small volumes, e.g. cerebrospinal fluid.

Acids↗
PubMed1993

The use of a DNA probe and PCR to examine the distribution of the aac(6')-Ic gene in Serratia marcescens and other gram-negative bacteria.

A nucleotide probe for the chromosomal aminoglycoside 6' acetyltransferase gene (aac(6')-Ic) of Serratia marcescens was used in non-radioactive dot-blot hybridization experiments with 186 strains belonging to ten different species of Serratia. The gene was only detected in strains of S. marcescens (all strains tested), and positive hybridization was seen irrespective of whether or not strains were kanamycin-resistant. An additional 180 strains belonging to 28 Gram-negative bacterial species other than in the genus Serratia did not hybridize with the probe. A rapid PCR test for the aac(6')-Ic gene was developed and used to confirm that the aac(6')-Ic gene is only found in S. marcescens. Southern hybridization analysis of S. marcescens chromosomal DNA demonstrated that the gene was usually located on a PvuII fragment with a putative isoleucine tRNA-2 gene, but polymorphisms with respect to the size of this fragment were observed.

Acetyltransferases↗
PubMed1993

Neisseria weaveri sp. nov. (formerly CDC group M-5), from dog bite wounds of humans.

The taxonomic relationships of strains belonging to Centers for Disease Control group M-5 were examined. Previous studies of rRNA cistron similarities placed this organism on the Neisseriaceae rRNA branch of rRNA superfamily III; the closest neighbors included the genus Neisseria and groups EF-4a and EF-4b. The group M-5 strains were characterized by a range of phenotypic tests, and their G + C contents and DNA-DNA relatedness levels were determined. In addition, a numerical taxonomic analysis of the whole-cell protein patterns (obtained by sodium dodecyl sulfate-polyacrylamide gel electrophoresis) of group M-5 and related taxa was performed. The strains studied included 45 group M-5 strains, the type strains of six Neisseria species or subspecies, three group EF-4a reference strains, and three group EF-4b reference strains plus the type strain of the phenotypically similar organism Oligella urethralis. Our results showed that the group M-5 strains were members of a homogeneous taxon distinct from phylogenetically closely related taxa. The genomic divergence as revealed by levels of rRNA cistron similarity and phenotypic characteristics indicate that group M-5 can be considered a new species of the genus Neisseria. We therefore propose the new species Neisseria weaveri, with NCTC 12742 (= CCUG 4007 = ISL775/91 = LMG 5135) as the type strain. N. weaveri strains are strictly aerobic, gram-negative, nonmotile, rod-shaped organisms which are catalase and oxidase positive, nonsaccharolytic, and able to grow on MacConkey agar and do not reduce nitrate but generally reduce nitrite.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Identification and typing of Proteus penneri and Proteus vulgaris biogroups 2 and 3, from clinical sources, by computerized analysis of electrophoretic protein patterns.

Seventy-six strains of the Proteus vulgaris complex (Pr. penneri and Pr. vulgaris biogroups 2 and 3) were characterized by one-dimensional SDS-PAGE of cellular proteins. The protein patterns were highly reproducible. The strains came from various countries and were mainly of human origin: urine (28), respiratory tract (13), wounds (8), faeces (7), blood (3), miscellaneous sources (6) and unknown sources (11). The patterns of these strains, together with those of the type strains of seven Morganella, Proteus and Providencia species were subjected to two numerical analyses. In the first, in which the principal protein bands (in the 35.0-42.0 kDa range) were excluded, the strains of the Pr. vulgaris complex formed four clusters at the 83% similarity level. These corresponded to Pr. penneri, Pr. vulgaris biogroup 2, and two clusters (3a and 3b) represented biogroup 3. Each of these clusters was distinct from the Morganella, Proteus and Providencia reference strains. In the second analysis, which included all the protein bands, the 41 Pr. penneri strains showed little heterogeneity but 17 subphenons could be recognized among the 35 strains of Pr. vulgaris biogroups 2 and 3. These results support the division of biogroup 3 strains into at least two separate taxa. Other results indicate that biogroup 3 is heterogeneous and may contain further genomic groups. The method also provides a basis for typing clinical strains of Pr. vulgaris biogroups 2 and 3.

Bacterial Proteins↗
PubMed1993

Cellular fatty acid compositions of "Achromobacter groups B and E".

Strains of "Achromobacter groups B and E" were examined for cellular fatty acid (CFA) composition to evaluate their chemical relatedness to known bacterial species and groups. The CFAs were liberated from whole cells by base hydrolysis, methylated, and analyzed by capillary gas-liquid chromatography. The CFA profiles of the two groups were identical and were distinct from CFA profiles of all other bacteria we have previously tested. These data provide support for results from whole-cell protein pattern analysis and DNA-DNA and rRNA-DNA hybridization studies, which show that "Achromobacter groups B and E" are biotypes of a single new genus and species.

Alcaligenes↗
PubMed1993

Traumatic intracranial aneurysms: a contemporary review.

Intracranial aneurysms are rare complications of head injury. Clinical and pathologic features as well as the surgical treatment of patients harboring traumatic intracranial aneurysms are presented. The latest neuroradiologic procedures as they relate to traumatic aneurysms are discussed. An illustrative case report is followed by a review of the literature.

Adult↗
PubMed1992

Assessment of enzyme detection tests useful in identification of campylobacteria.

Twenty-one type or other reference strains, each representing a different Campylobacter, Helicobacter, or Arcobacter taxon, and a reference strain of Staphylococcus aureus were used to assess the reproducibility of nine enzyme detection tests used in the identification of campylobacters. For five of the tests (alkaline phosphatase, DNase, and H2S production, indoxyl acetate hydrolysis, and nitrate reduction), more than one procedure was employed to determine the most suitable method. Alkaline phosphatase test results were better defined and more reproducible if read after 1 h of incubation. Detection of DNase was fully reproducible with each method (except with Helicobacter pylori), but reactions were generally weaker than those of other DNase-producing organisms. Both procedures for determining H2S production were irreproducible for the same strains. The reproducibility of indoxyl acetate hydrolysis was improved by using disks impregnated with 25 microliters of substrate. Reduction of nitrate was best determined by Cook's plate method. Results for the other tests examined (catalase, oxidase, and urease production and hippurate hydrolysis) were both pertinent and fully reproducible for all strains.

Alkaline Phosphatase↗
PubMed1991

Effect of 12 and 20 weeks of resistance training on lumbar extension torque production.

This study compared the effect of varied training frequencies on the development of isometric lumbar extension torque (strength) over 12- and 20-week training periods. Fifty-six subjects were randomly assigned to training once every other week (training group 1, n = 10), once per week (training group 2, n = 12), twice per week (training group 3, n = 12), or three times per week (training group 4, n = 7) or to a nontraining control group (n = 15). Training consisted of one set of 8 to 12 variable-resistance lumbar extensions to volitional muscular fatigue. Prior to and following 12 and 20 weeks of training, subjects were given a test that evaluated isolated isometric lumbar extension torque in a seated position at seven positions (angles) through a 72-degree range of motion. The control group showed no change in isometric torque. All training groups showed significant increases in lumbar extension torque at 12 and 20 weeks of training, whereas no significant differences were found among the groups with respect to the magnitude of torque gained. Pooled training showed a significant time x angle interaction at 12 weeks and a continuing trend at 20 weeks, indicating that the shape of the isometric torque-angle curve changed as a result of training. This effect was due to greater increases in isometric torque at the fully extended position than at the fully flexed position at 12 weeks (92% versus 16%, respectively) and at 20 weeks (123% versus 17%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Typing of Proteus mirabilis from clinical sources by computerized analysis of electrophoretic protein patterns.

Seventy-five strains of Proteus mirabilis (mainly of human origin) were characterized by one-dimensional SDS-PAGE of cellular proteins. The strains came from various countries; 24 were from urine, 17 from faeces (including one from a dog and one from a monkey), 12 from the respiratory tract (including nine from sputum), four from a cerebral abscess, 12 from miscellaneous sources and six from unknown sources. The protein patterns, which contained 45 to 50 discrete bands, were highly reproducible. The patterns of the 75 P. mirabilis cultures plus those of the type strains of six Proteus and Providencia species were used as the basis for two numerical analyses. In the first, which included all the protein bands, the P. mirabilis cultures formed nine clusters at the 85% S level. In the second analysis, in which the principal protein bands (in the 34.0-44.6 kDa range) were excluded, 74 of the 75 cultures of P. mirabilis formed a single cluster at the 77% S level distinct from the six Proteus and Providencia reference strains. The P. mirabilis strain which failed to cluster with the others had a background band pattern typical of the species in the lower molecular weight region but appeared to be less typical in the heavier bands. It is concluded that high resolution PAGE combined with computerized analysis of protein patterns provides the basis for typing clinical strains of P. mirabilis. Reference strains of each of the nine PAGE types identified are available from NCTC for inclusion in future studies.

Animals↗
PubMed1991

Effect of inoculum size on the phenotypic characterization of Campylobacter species.

The type strains of six Campylobacter species or subspecies were examined in eight tests used for the identification of such organisms. False-positive results were obtained in certain tests (growth on 1% bile, brilliant green, selenite, trimethylamine-N-oxide, 2,3,5-triphenyl tetrazolium chloride, and minimal media) when an inoculum yielding 10(7) to 10(8) CFU/ml was used. Each tolerance test was examined with blood, nutrient, and brucella agars as basal media. The type of basal medium used could also affect the test outcome. With the inoculum standardized to a density yielding approximately 10(6) CFU/ml, reproducible and pertinent results were obtained, provided an appropriate basal medium was used. However, 95% confidence limits for viable counts done on these basal media indicated that blood agar may yield more consistent results than the other agars examined.

Agar↗