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Biomedical subjects

K M Nordstrom

Publications and source records attributed to K M Nordstrom.

9 recordsLinked to original sources
PubMed1990

Microbial ecology of interdigital infections of toe web spaces.

The microbial flora of normal and macerated interdigital toe web spaces was qualitatively and quantitatively identified in 77 patients. Dermatophyte fungi were recovered from 11% of normal patients compared with a 31% recovery from patients with macerated interspaces. Macerated interspaces were characterized by a greater recovery of organisms with pathogenic potential, with Staphylococcus aureus recovered from 36% of patients, Micrococcus sedentarius in 37%, Brevibacterium epidermidis in 54%, Corynebacterium minutissimum in 69%, and Pseudomonas species in 26%. The bacterial flora of macerated interspaces showed a significantly higher incidence of resistance to multiple antibiotics, and the recovery of antibiotic-resistant bacteria correlated with the recovery of dermatophytes that produce penicillin-like substances. The results of this study support the hypothesis that overgrowth of the resident bacterial population determines the severity of interdigital toe-web infections.

Adult↗
PubMed1987

Pitted keratolysis. The role of Micrococcus sedentarius.

Though pitted keratolysis of the foot is generally viewed to be caused by bacteria, there is confusion regarding the identity of the causative organism. Species of Corynebacterium, Actinomyces, Dermatophilus, and Micrococcus have been proposed by various investigators. We have studied eight cases of pitted keratolysis and have cultured an organism identified as Micrococcus sedentarius on the basis of colonial morphology, micromorphology, biochemical reactions, and chemical analysis of whole-cell components. Furthermore, pitted keratolysis was produced experimentally in a human volunteer by applying M sedentarius under an occlusive dressing onto the surface of the heel.

Bacteriological Techniques↗
PubMed1987

Skin microflora.

Explore the source record for details and available documents.

Actinomycetales↗
PubMed1986

Characterization of wax esters, triglycerides, and free fatty acids of follicular casts.

The abnormal impactation of a sebaceous follicle (the follicular cast) has been implicated as the preclinical lesion of acne vulgaris. We have characterized the lipid composition of these structures in the first of a series of studies aimed at the identification of sebaceous lipids that may be associated and/or responsible for the initiation of clinical lesions. The lipid composition of follicular casts was analyzed using thin-layer chromatography, gas chromatography, and mass spectrometry. The mean wet weight of the casts was 24.7 +/- 8.6 micrograms and 7.2 +/- 5.6 micrograms (29.4 +/- 13.5%) was lipid. Cholesterol (3.8 +/- 1.8%) and cholesterol esters (2.0 +/- 2.7%), wax esters (25.3 +/- 6.0%), squalene (19.9 +/- 6.6%), triglycerides (16.1 +/- 7.8%), and free fatty acids (33.0 +/- 10.0%) were all present in cast lipid. Fatty acids of the free fatty acid and triglyceride fraction ranged from C12 to C22. The major components of the free fatty acids were C14:0, C15:0, C16:1, C16:0, 2-me-C17:0, and C18:1. In the triglyceride fraction C14:0, C15:0, C16:0, C18:1, and C18:0 dominated. The free fatty acids were composed of normal saturated (50.6%), normal unsaturated (32.8%), and monomethyl branched (16.6%) acids; the triglyceride fraction contained (86.3%) normal saturated (10.8%), normal unsaturated, and (3.0%) monomethyl branched fatty acids. Wax esters of follicular casts included esters ranging from C26:1 to C38:0. Saturated esters predominated and both odd- and even-numbered esters were present. The most abundant fatty acid moieties of these esters were C16:0 and C15:0, whereas C14:0, C17:0, and C20:0 were the most frequently detected alcohol moieties.

Acne Vulgaris↗
PubMed1986

Measurement of sebum output using a lipid absorbent tape.

A sebum absorbent tape is introduced as a reproducible and convenient method for estimation of sebaceous gland output. We have tested the reproducibility of this method by serial measurements of sebum excretion rates (SER) of 10 individuals over a 6-week period, and in addition we have correlated this method with the conventional hexane extraction technique. The sebum absorbent tapes gave consistent values for the SERs, and within subjects variation over the 6-week period was statistically nonsignificant. A coefficient of variation for the tapes was calculated as 16.25 +/- 6.78% based on these serial measurements. Furthermore, the amount of total lipid collected using this technique (n = 16) correlated well with the hexane extraction technique, r = 0.89. Free fatty acids (r = 0.87), triglycerides (r = 0.92), wax and cholesterol esters (r = 0.83), and squalene (r = 0.88) also showed a good correlation. Cholesterol occasionally suffered from incomplete separation on thin-layer chromatograms; however, a sample cleanup procedure was developed for tape extracts that removed interfering materials and allowed complete separation of all sebum components.

Absorption↗
PubMed1985

Pathogenic JK group corynebacteria and their similarity to human cutaneous lipophilic diphtheroids.

Aerobic diphtheroids from human skin (commonly referred to as lipophilic diphtheroids), pathogenic bacteria of the JK group, and classic species of the genus Corynebacterium were studied for their cellular fatty acids and mycolates, composition of their cell wall peptidoglycans, nutritional requirements, biochemical reactions, and antibiotic sensitivities. Lipophilic diphtheroids and JK strains were catalase positive and contained corynemycolic acid and meso-diaminopimelic acid in their cell walls, a characteristic shared with all corynebacteria. The lipophilic diphtheroid and JK strains were found to have a strict nutritional requirement for lipid and a similar composition of cellular fatty acid, mycolic acid, and peptidoglycan; they differed only in the multiple antibiotic resistance of the JK strains. Results of the biochemical reactions were inconclusive and did not permit grouping of lipophilic diphtheroids or JK with any of the reference strains. The reference strains did not require lipid and contained cellular fatty acids that were clearly distinct from those of the JK strains or lipophilic diphtheroids. These results suggest that JK bacteria are Corynebacterium spp. and may represent resident lipophilic diphtheroids that have acquired antibiotic resistance.

Anti-Bacterial Agents↗
PubMed1985

Polyacrylamide gel electrophoresis (PAGE) of whole-cell proteins of cutaneous Propionibacterium species.

Polyacrylamide gel electrophoresis (PAGE) was applied to the study of whole-cell proteins of cutaneous propionibacteria in an attempt to characterise possible protein patterns that may be typical for strains isolated from acne skin. Isolates were obtained from the faces of 33 individuals aged 7-16 years. Some of these subjects had apparently normal healthy skin, whereas others had acne vulgaris of varying severity. Twenty-five facial isolates of Propionibacterium acnes and eight of P. granulosum were studied. A further seven axillary strains of P. avidum were included for purely taxonomic interest. No particular protein pattern was characteristic of an isolate from acne skin; in fact the P. acnes strains from all sources appeared to be identical.

Acne Vulgaris↗
PubMed1985

Analysis of cellular components, biochemical reactions, and habitat of human cutaneous lipophilic diphtheroids.

The cutaneous distribution of lipophilic diphtheroids was determined in normal human volunteers. The organisms were found to be plentiful in moist regions (scalp, nares, axilla, groin, and toe web) and scarce in dry and purely oily regions. The lipid requirement, cellular fatty acids, mycolic acid and cell wall diaminopimelic acid content of these lipophilic diphtheroids was compared to those of strains of Corynebacterium bovis, C. xerosis, C. diphtheriae, and C. minutissimum. Only lipophilic diphtheroids and C. bovis strains were found to have a strict lipid requirement. Lipophilic diphtheroids were found to have meso-diaminopimelic acid and corynemycolic acid in their cell walls, consistent with membership in the genus Corynebacterium. Lipophilic diphtheroids were also found to comprise a homogeneous group which was distinct from the speciated strains on the basis of cellular fatty acids and mycolic acids.

Actinomycetales↗