Analysis of lung air from patients with bronchogenic carcinoma and controls using gas chromatography-mass spectrometry.

Volatile metabolites present in expired lung air were collected by odor sampling techniques and analyzed by gas chromatography-mass spectrometry. The study population included controls matched for age and smoking history with patients newly diagnosed with lung carcinoma. Significantly greater concentrations of o-toluidine were found in the lung air of patients with lung carcinoma than either age-matched or younger controls. Aniline was present in half of the patient population but absent in age-matched controls.

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.

Characterization of pathogenic bacteria by automated headspace concentration-gas chromatography.

Automated headspace concentration-gas chromatography (AHC-GC) was used to profile the volatile metabolites produced by Proteus mirabilis, Klebsiella pneumoniae, Pseudomonas aeruginosa and Staphylococcus aureus. Bacterial cultures were incubated in trypticase soy broth and examined at 24 h. The profiles were consistent for each genus examined and variation observed among the different strains of each species was chiefly quantitative. The volatiles were identified by concurrent headspace concentration-gas chromatography-mass spectrometry and consisted mainly of isobutanol, isopentanol, isopentyl acetate, 1-undecene and methyl ketones. There were sufficient differences in the profiles in the 4-6 min elution period to distinguish P. aeruginosa and S. aureus from each other and from the other two bacteria. P. mirabilis and K. pneumoniae typically showed three intense peaks which corresponded to isobutanol, isopentyl acetate and isopentanol. The determination of volatiles by AHC-GC is sensitive, rapid and offers a possible alternative for automatic detection and characterization of pathogenic bacteria.

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.

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.

Volatiles of Pseudomonas aeruginosa and related species by automated headspace concentration--gas chromatography.

The volatile metabolites of three strains of Pseudomonas aeruginosa and one strain each of Pseudomonas cepacia, Pseudomonas maltophilia, Pseudomonas fluorescens, and Pseudomonas putida were analyzed using an automated headspace concentrator incorporating a gas chromatograph. The procedure does not require sample preparation and automates the entire analytical sequence to yield reproducible profiles of volatile constituents. Gas chromatographic profiles of the volatile metabolites of each species were obtained using a 20-min concentration period and two fused silica capillary columns of different polarities. The production of headspace metabolites from trypticase soy broth was studied in relationship to culture incubation time and initial cell concentration. The volatiles identified after 24 h incubation consisted of 1-butanol, isopentanol, toluene, 1-undecene, 2-butanone, 2-heptanone, 2-nonanone, and 2-undecanone. Sufficient amounts of specific metabolites were produced after 5 h incubation to provide information of possible diagnostic value. In particular, all P. aeruginosa strains produced a distinctive series of 1-undecene and methyl ketones after 5 h incubation of media inoculated to provide 2 X 10(6) cells/mL. The results indicate that when growth and analytical conditions are held constant, P. aeruginosa and related species produce characteristic profiles of headspace metabolites. Since conventional bacteriological tests require 24 h or more for the identification of these pseudomonads, automated volatile analysis could provide an alternative means for the rapid detection of these bacteria.

The microbiology of the human axilla and its relationship to axillary odor.

The axillary microflora of 229 subjects was characterized quantitatively and the results correlated with whether the odor was pungent body odor or instead a faint "acid odor". The axillary flora was found to be a stable mixture of Micrococcaceae, aerobic diphtheroids and Propionibacteria. Significantly higher numbers of bacteria were recovered from the axilla of those with pungent axillary odor than in those with acid odor. Aerobic diphtheroids in high numbers were recovered in all subjects having typical body odor. These included lipophilic as well as large-colony diphtheroids. When droplets of apocrine sweat placed on the forearm were inoculated with various bacteria which reside in the axilla, only diphtheroids generated typical body odor. Cocci produced a sweaty odor attributable to isovaleric acid.

Headspace analysis of volatile metabolites of Pseudomonas aeruginosa and related species by gas chromatography-mass spectrometry.

Gas chromatographic-mass spectrometric analysis of headspace volatiles was performed on cultures of 11 strains of Pseudomonas aeruginosa and 1 strain each of Pseudomonas cepacia, Pseudomonas putida, Pseudomonas putrefaciens, Pseudomonas fluorescens, and Pseudomonas maltophilia. All strains of Pseudomonas aeruginosa produced a distinctive series of odd-carbon methyl ketones, particularly 2-nonanone and 2-undecanone, and 2-aminoacetophenone. The other strains failed to produce 2-aminoacetophenone. Two sulfur compounds, dimethyldisulfide and dimethyltrisulfide, were present in strains of P. aeruginosa and in variable amounts in other species. Butanol, 2-butanone, 1-undecene, and isopentanol were also detected in P. aeruginosa cultures.

Steroid analysis of human apocrine secretion.

Analysis of the secretion of the human apocrine gland has shown the presence of dehydroepiandrosterone and androsterone sulfates, two androgen steroids previously identified in axillary sweat. These steroid sulfates were characterized by the gas chromatographic/mass spectrometric analysis of the odorous steroids formed on direct injection of the apocrine secretion into the host gas chromatographic injector. No spectral evidence was found for the presence of the delta16-androgen steroids which have axillary-like odors and have also been reported in axillary sweat. Cholesterol was the major steroid component of the secretion.

Characteristic gamma-lactone odor production of the genus Pityrosporum.

Mass spectrometric-gas chromatographic analysis of culture headspaces revealed that members of the genous Pityrosporum produce volatile gamma-lactones during growth on lipid-containing media. Representative members of other yeast genera found on humans failed to produce these compounds. Addition of lecithin, oleic acids, triolein, or human sebum to the culture media stimulated gamma-lactone production by Pityrosporum species. All yeasts tested produced isopentanol and phenylethanol. Production of gamma-lactones may serve as a valuable characteristic in the identification of organisms of the genus Pityrosporum.