Biomedical subjects
Publications and source records attributed to C W Moss.
The fatty acid compositions of selected strains of rickettsiae were studied by gas-liquid chromatography. The profiles of all the rickettsiae except Coxiella burnetii were qualitatively similar. The fatty acid composition of C. burnetii was similar to that of certain Legionella species.
Gram-negative bacilli resembling legionellae were isolated from contaminated culture media. These bacilli are distinguishable from legionellae by their thermophilic characteristic.
Mycolic acids were detected in both reference strains and clinical isolates of mycobacteria using gas chromatography of fatty acid methyl esters prepared by acid methanolysis. The methyl esters were extracted with hexane, concentrated, and analyzed with a gas chromatograph by using two different injector temperatures. When the samples were analyzed at high injector temperatures of 300 to 350 degrees C, characteristic thermal cleavage products from mycolic acids, C22:0, C24:0, or C26:0 fatty acid methyl esters, were detected. When analyzed at injector temperatures of 235 degrees C or lower, the mycolic acids were heat stable and the characteristic methyl ester cleavage products were not observed.
The cellular fatty acid composition of Brucella canis and Brucella suis was determined by gas-liquid chromatography. The presence of relatively large amounts of a 19-carbon cyclopropane fatty acid in B. suis was a major distinguishing feature between these organisms. The gas-liquid chromatography test for cellular fatty acids provides an additional criterion for the distinction of antigenically rough strains of B. suis which cannot be differentiated from B. canis by conventional procedures.
The cellular fatty acid composition of Pasteurella multocida and four unclassified groups of gram-negative bacteria (EF-4, M-5, IIj, and DF-2) which are frequently associated with human dog-bite infections was determined by gas-liquid chromatography. Strains of P. multocida were readily distinguished from the unclassified groups by the presence of 3-hydroxy myristic acid (3-OH- 14:0). Groups M-5 and EF-4 were characterized by the presence of 3-hydroxy lauric (3-OH-12:0) acid. Only group EF-4 organisms contained 2-OH-16:0, a-17:0, and 17:0 cyclopropane acids. Groups IIj and DF-2 differed from the other groups by the presence of large amounts of a branched-chain 15-carbon acid (i-15:0); they differed from each other by the presence of i-2-OH-15:0 and i-17:1 acids in IIj, which were absent in DF-2. The data indicate that gas-liquid chromatographic analysis for cellular fatty acids provides an additional test for rapid differentiation of these gram-negative organisms associated with dog-bite infections. Similarities observed in the fatty acid compositions of Flavobacterium, IIj, and DF-2 suggest that these two unclassified groups may be additional species of Flavobacterium.
The cellular fatty acid composition of Legionella longbeachae was determined by gas-liquid chromatography. As in other Legionella species, the fatty acids of this new species are characterized by relatively large amounts of branched-chain acids.
Pneumonia, empyema and lung abscesses developed in a patient following a neurosurgical procedure and associated short-term corticosteroid therapy. An organism identical to the TATLOCK/Pittsburgh pneumonia agent (Legionella micdadei) was the only organism isolated from multiple specimens from lung aspirates and chest tube drainage. The organism was isolated directly on charcoal yeast extract (CYE) agar and classified as identical to the TATLOCK bacterium by direct immunofluorescent staining and by gas-liquid chromatography of cellular fatty acids. The patient's pulmonary infection improved during treatment with penicillin. Serum specimens obtained from the patient during convalescence showed an indirect fluorescent antibody reciprocal titer of 16,000 to his homologous antigen, but he also had titers that were potentially diagnostic against antigens of the six serogroups of Legionella pneumophila and three other Legionella-like organisms. Legionella can be isolated from clinical specimens by the routine use of CYE agar, which should be incorporated as the primary isolation medium for chest fluids and lung specimens. It appears that a large battery of antigens will be required for serological testing to diagnose infections caused by L micadei, L pneumophila and Legionella-like organisms.
The cellular fatty acid composition of 29 human and animal isolates of Campylobacter fetus was determined with gas-liquid chromatography. All strains contained small amounts of 3-hydroxytetradecanoic acid, suggesting the presence of lipid A. Each of 13 different blood or stool isolates of C. fetus subsp. jejuni obtained from humans or fowl contained a 19-carbon cyclopropane acid which was not present in C. fetus subsp. fetus (6 strains from cattle) or C. fetus subsp. intestinalis (10 strains from humans and cattle). These findings indicate that C. fetus subsp. jejuni can be rapidly differentiated from other C. fetus by gas-liquid chromatography analysis of cellular fatty acids.
The cellular fatty acid composition of a group of gram-negative nonfermentative organisms designated group IVe was studied by gas-liquid chromatography. Strains of this group are isolated most frequently from urine and most closely resemble the Alcaligenes in conventional biochemical tests. On the basis of cellular fatty acids, however, we found these organisms to be strikingly different from Alcaligenes and other gram-negative species with similar phenotypic characteristics. The gas-liquid chromatography procedure offers an additional diagnostic test for rapid identification of unclassified bacteria like group IVe.
Phenylacetic and hydroxyphenylacetic acids were present as major acids in spent growth medium from Clostridium botulinum type G. These aromatic acids were identified by gas-liquid chromatography and mass spectrometry.
The use of flexible, fused-silica capillary column for gas-liquid chromatographic analysis of bacterial fatty acids is illustrated with Propionibacterium acnes, Propionibacterium shermanii, and a standard methyl ester mixture.
Peptostreptococcus anaerobius was found to metabolize tyrosine to p-hydroxyhydrocinnamic acid [3-(p-hydroxyphenyl)propionic acid]. This acid was detected in spent growth media by gas-liquid chromatography, and its identity was confirmed by mass spectrometry.
Two "rickettsia-like organisms," TATLOCK and HEBA, isolated from human blood via guinea pigs and embryonated eggs in 1943 and 1959, respectively, have been cultured on artificial media (charcoal yeast extract agar) for the first time and characterized. TATLOCK and HEBA have identical cultural, biochemical, and antigenic characteristics, as well as identical cellular fatty-acid composition and antimicrobial susceptibilities. These two bacteria have most of the cultural and biochemical characteristics of Legionella pneumophilia, and their gas-liquid chromatography cellular fatty-acid profile is similar to that of WIGA, another bacterium similar to L. pneumophila. Direct fluorescent-antibody reagents prepared for HEBA and TATLOCK gave equal high-titered reciprocal staining and were negative on 220 other bacteria, including L. pneumophila. Deoxyribonucleic acid relatedness studies, however, showed that these bacteria are not genetically related to either L. pneumophila or the WIGA bacterium.
Soluble antigens of whole yeast-phase cells were extracted with a 0.1 M phosphate buffer containing 0.1 M sodium chloride and 0.02% iodacetate. After being separated by differential filtration into fractions less than or greater than 50,000 daltons these antigens were purified by molecular sieve and chromatographic separations on ionic exchange resins. Two high molecular weight fractions obtained from diethylaminoethyl-cellulose (DEAE) at pH 8.0 and 7.0 with tris (hydroxymethyl) aminomethane (Tris) buffer were M antigens; those obtained at pH 4.0 and 4.0 with salt were H antigens. The four fractions had protein to carbohydrate ratios of 7.3, 14.0, 8.4, and 6.5 respectively, and all had essentially the same amino acid composition with no methionine and tyrosine and little histodine, arginine, phenylalanine and lysine. They had high concentrations of glucose, less mannose and traces of galactose. The low molecular weight fractions had the new complex "Y antigen", M antigen with protein to carbohydrate ratios of 1.4, 1.4 and 0.3 respectively. The amino acid and sugar composition of Y antigen strongly resembled the composition of the low molecular weight H and M antigens. Unlike the high molecular weight antigens, these low molecular weight antigens had methionine in relatively high concentrations; they had the same sugars as their respective high molecular weight counterparts. The yeast phase antigens differed from their respective mycelial counterparts in the following ways: glucose was the major sugar in the yeast phase with less amounts of mannose and traces of galactose, whereas in the mycelial antigens, mannose was the major sugar, with lesser amounts of galactose, and hexosamine. The H and M antigens of the yeast phase had high concentrations of glycine and alanine, whereas in the mycelial phase, these antigens had high concentrations of threonine and proline; the H and M antigens of the yeast phase had 5 to 16 times the protein to carbohydrate ratio observed for the same antigens of histoplasmin.
The cellular fatty acid composition of Pseudomonas paucimobilis (IIk-1) and group IIk-2, Ve-1, and Ve-2 was determined by gas-liquid chromatography. The unnamed groups were readily distinguished from P. paucimobilis by cellular fatty acids. The data strongly suggest that these bacteria may be additional species of Pseudomonas and Flavobacterium.
The cellular fatty acid composition of OLDA, a rickettsia-like agent isolated in 1947, was essentially identical to that of the Legionnaires disease bacterium (LDB). WIGA, another rickettsia-like agent isolated in 1959, contained the same fatty acids as OLDA and other LDB but differed significantly from these strains in relative amounts of the major acids present. The major acid of OLDA and other LDB was i-16:0 whereas a-15:0 was the major acid of WIGA.
Diaminopimelic acid was found to be a component of the cell wall of the Legionnaires disease bacterium, thus providing additional evidence that the organism is a bacterium. The presence of this amino acid was determined by gas-liquid chromatography and confirmed by gas chromatography-mass spectrometry.
A strain of the Legionnaires disease bacterium (LDB) that was isolated by Joseph E. McDade from a postmortem lung specimen of a patient with fatal atypical pneumonia at the Veterans Administration Hospital in Togus, Maine was serologically different from 16 other strains of LDB that had been isolated previously from patients in other geographic locations. The serological differences of the Togus isolate were shown in results of direct and indirect fluorescent antibody staining and of immunoelectrophoresis with soluble antigen extracts. Seroconversion for the Togus strain of LDB in acute- and convalescent-phase sera from a second patient with atypical pneumonia at the Veterans Administration Hospital in Togus indicated that this patient had been infected with an LDB that was serologically similar or identical to the Togus isolate. The Togus serogroup of LDB should be considered when performing serological tests for Legionnaires disease.