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Biomedical subjects

A Von Graevenitz

Publications and source records attributed to A Von Graevenitz.

At least 19 recordsLinked to original sources
PubMed2001

Natural antibiotic susceptibility of recently established coryneform bacteria.

The natural susceptibility of 20 strains each of Brevibacterium casei (formerly CDC coryneform groups B-1 and B-3), Dermabacter hominis (formerly CDC coryneform groups 3 and 5), and Turicella otitidis (formerly coryneform group ANF-1-like) isolated from clinical specimens to 71 antibiotics was investigated. Susceptibility testing was carried out with a microdilution procedure using H medium. All three species were naturally sensitive to tetracyclines, most aminoglycosides, carbapenems, macrolides, lincosamides, glycopeptides, and rifampin. Susceptibility patterns indicating natural resistance to pipemidic acid, sulfamethoxazole, and cotrimoxazole also were found for all three species. Species-dependent discrepancies in susceptibility leading to completely different categorizations (changing from sensitive to resistant or vice versa) were found for some penicillins (e.g., oxacillin and amoxicillin), a few cephalosporins (e.g., ceftibutene), aztreonam, tobramycin, norfloxacin, fleroxacin, trimethoprim, nitrofurantoin, fosfomycin, and fusidic acid. For the majority of antibiotics, Brevibacterium casei was the least susceptible species and Turicella otitidis the most susceptible taxon. The present study describes a database on the natural susceptibility of Brevibacterium casei, Dermabacter hominis, and Turicella otitidis to a wide range of antibiotics. This database can be applied for the validation of susceptibility testing results of these recently established coryneform bacteria.

Actinomycetales↗
PubMed2000

Identification of coryneform bacterial isolates by ribosomal DNA sequence analysis.

Identification of coryneform bacteria to the species level is important in certain circumstances for differentiating contamination and/or colonization from infection, which influences decisions regarding clinical intervention. However, methods currently used in clinical microbiology laboratories for the species identification of coryneform bacteria are often inadequate. We evaluated the MicroSeq 500 16S bacterial sequencing kit (Perkin-Elmer Biosystems, Foster City, Calif.), which is designed to sequence the first 527 bp of the 16S rRNA gene for bacterial identification, by using 52 coryneform gram-positive bacilli from clinical specimens isolated from January through June 1993 at the Mayo Clinic. Compared to conventional and supplemented phenotypic methods, MicroSeq provided concordant results for identification to the genus level for all isolates. At the species level, MicroSeq provided concordant results for 27 of 42 (64.3%) Corynebacterium isolates and 5 of 6 (83.3%) Corynebacterium-related isolates, respectively. Within the Corynebacterium genus, MicroSeq gave identical species-level identifications for the clinically significant Corynebacterium diphtheriae (4 of 4) and Corynebacterium jeikeium (8 of 8), but it identified only 50.0% (15 of 30) of other species (P < 0.01). Four isolates from the genera Arthrobacter, Brevibacterium, and Microbacterium, which could not be identified to the species level by conventional methods, were assigned a species-level identification by MicroSeq. The total elapsed time for running a MicroSeq identification was 15.5 to 18.5 h. These data demonstrate that the MicroSeq 500 16S bacterial sequencing kit provides a potentially powerful method for the definitive identification of clinical coryneform bacterium isolates.

Actinomycetales↗
PubMed1995

Growth differences of Capnocytophaga canimorsus strains and some other fastidious organisms on various Columbia-based blood agar media.

Three human isolates of Capnocytophaga canimorsus from blood cultures showed no growth when cultivated on sheep blood agar plates based on BBL Columbia agar base, whereas the same three strains grew excellently on sheep blood agar plates based on Difco Columbia agar bases No. 2 or EH. Two of the three strains also grew well on blood agar plates based on bioMérieux Columbia agar. Strains that grew better on either Difco or bioMérieux Columbia based blood agar plates were found among Eikenella corrodens, Haemophilus aphrophilus, Kingella kingae, Lactobacillus sp., and Streptococcus adjacens, but these strains were never lost when cultivated on BBL Columbia agar plates. One strain of Lactobacillus failed to grow on Difco Columbia No. 2 agar and showed best growth on bioMérieux Columbia agar. Strains of Corynebacterium G 2, Corynebacterium afermentans and Streptococcus adjacens showed poor growth on chocolate agar when compared to blood agar media. Microbiologists should be aware of the importance of media formulations for optimal recovery of fastidious organisms.

Agar↗
PubMed1991

Grouping of some clinically relevant gram-positive rods by automated fatty acid analysis. Diagnostic implications.

One hundred and ninety-four strains of aerobically growing Gram-positive rods of the genera Corynebacterium, Actinomyces, Arcanobacterium, Erysipelothrix, Listeria, Oerskovia, Nocardia, Rhodococcus, and of unnamed Center for Disease Control (CDC) groups were checked for cellular fatty acid profiles with the microbial Identification System (Microbial ID, Newark, Del., USA). In order to obtain unified data usable for the clinical laboratory, 24 or 48 h sheep blood agar cultures were used. It was thought that grouping and perhaps identification could be aided by this approach. With the aid of numerical analysis, four groups (two consisting of two subgroups each) were established. The discriminatory ability of the scheme, however, was only 77.2%, indicating that grouping of an unknown isolate could be done with some accuracy, but that speciation would still require biochemical testing.

Bacterial Infections↗
PubMed1986

Same day identification of gram-negative rods with the Quantum II Microbiology System.

The Quantum II Microbiology System was challenged with 479 strains of Enterobacteriaceae and 155 strains of nonfermenters (contained in the data base) and Aeromonas/Plesiomonas. The percentages of strains correctly diagnosed within 5h (i.e., with out additional tests) at greater than or equal to 80% probability were 78% and at greater than or equal to 50% probability, 84.7%.

Bacteriological Techniques↗