Capillary gas chromatographic analysis of alditol acetates of neutral and amino sugars in bacterial cell walls

Indirect fluorescence detection of amino sugars with the use of copper complexes of tryptophan and its analogues following high-performance liquid chromatographic separation

A simple, indirect fluorescence detection method has been developed for detecting specific mono-amino sugars (D-glucosamine, D-galactosamine, D-mannosamine) following chromatographic separation. The eluting amino sugars release L-tryptophan (L-Trp) from a copper-tryptophan complex which is introduced postcolumn. Analyte detection is based on measuring the increase in L-Trp fluorescence, which is quenched when complexed with copper. Two tryptophan analogues, 5-hydroxy-L-tryptophan (5-HTP) and DL-5-methoxytryptophan (5-MTP), were also evaluated as postcolumn reagents. 5-MTP was found to be a suitable alternative to L-Trp for the detection of these mono-amino sugars. Detection limits for D-glucosamine, D-galactosamine, and D-mannosamine are in the range of 0.15-0.30 nmol injected.

Analysis of a stable halogenated derivative of muramic acid by gas chromatography-negative ion chemical ionization tandem mass spectrometry

Muramic acid (Mur) is present in the cell wall of Eubacteria and serves as a chemical marker for the trace detection of bacteria and bacterial cell wall debris in complex matrices. There have been numerous studies using a variety of derivatives of Mur, particularly in combination with gas chromatography-tandem mass spectrometry (GC-MS-MS) where the detection limit has been steadily lowered. A stable, halogenated derivative, the pentafluorobenzyl oxime (PFBO) acetate of Mur, has been developed by others and successfully used for GC with electron-capture detection. The current report is the first use of this derivative for GC-MS-MS analysis of Mur, or indeed any other carbohydrate, using negative ion chemical ionization (NICI) with GC-MS-MS. Mur was readily detected in settled surface dust (166 ng/mg), as well as dust collected from indoor air (1.4-5.9 ng/mg). Analyses of Mur as a PFBO acetate by GC-NICI-MS-MS or as alditol acetates by electron impact GC-electron impact ionization MS-MS serve as complementary approaches for trace detection in complex matrices.

Bacteriophage receptors on Listeria monocytogenes cells are the N-acetylglucosamine and rhamnose substituents of teichoic acids or the peptidoglycan itself

Different approaches were used to examine the function of teichoic acids (TA) as phage receptors among selected Listeria strains, and to identify and characterize specific receptor structures of host cells belonging to different serovars. This included successive removal of cell wall constituents, preparation and purification of TA, and GLC analysis of TA components. Adsorption of Listeria monocytogenes bacteriophages could be inhibited by polyvalent antisera, specific lectins and addition of purified TA. The results confirmed the necessity of TA in general and of rhamnose and glucosamine in particular for adsorption of Listeria phage A118, which is a temperate Siphovirus (morphotype B1), attacking predominantly serovars 1/2. Host binding of siphoviral phage A500 (predominantly lysing serovars 4b), was also dependent on cell wall TA. A phage-resistant L. monocytogenes strain was shown to lack glucosamine in its TA. These results support the view that TA substituents may play an important role not only in antigenicity of Listeria cells, but also in specificity of host recognition by two temperate Listeria phages. In contrast, the broad-host-range virulent phage A511 (Myovirus, morphotype A1) uses the listerial peptidoglycan as primary receptor. This corresponds well with the observation that A511 is capable of lysing the majority of L. monocytogenes strains.

The structure of the lipopolysaccharide O antigen from Yersinia ruckeri serotype 01

The O antigen obtained from the lipopolysaccharide of Yersinia ruckeri serotype 01, by mild acid hydrolysis, is composed of a branched tetrasaccharide repeating unit containing 2-acetamidino-2,6-dideoxy-L-galactose (L-FucAm), 2-acetamido-2-deoxy-D-glucose (D-GlcNAc), and 7-acetamido-3,5,7,9-tetradeoxy-5-(4-hydroxybutyramido)-D-glycero-L -galacto- nonulosonic acid (L-Sug). Partial hydrolysis of the O antigen with 0.1 M HClafforded a trisaccharide and a tetrasaccharide having nonulosonic acid at their reducing ends. Cleavage of the O antigen with anhydrous methanolic hydrogen fluoride afforded the methyl glycoside derivatives of a trisaccharide and a tetrasaccharide. 1H and 13C NMR analysis, including 1H-13C heteronuclear multiple bond correlation spectroscopy to locate the N-acyl substituents, together with mass spectrometric analysis of the above oligosaccharides, allowed the structure of the O-specific polysaccharide to be assigned as: [formula: see text].

Determination of amino sugars and amino acids in glycoconjugates using precolumn derivatization with o-phthalaldehyde

This report examines the RP-HPLC separation of o-phthalaldehyde derivatives of amino acids, amino sugars, and amino sugar alcohols using either 2-mercaptoethanol or 3-mercaptopropionic acid. A method with pmol sensitivity for the analysis of N-acetylamino sugars of glycoconjugates was elaborated. Upon hydrolysis, amino sugars are reduced with borohydride. Automated precolumn derivatization and chromatographic conditions for the resulting hexosaminitols are the same as those used for the analysis of amino acids. The method has been tested with as little as 2 micrograms of bovine fetuin, with a glycopeptide from bromelain and with an oligosaccharide after periodate oxidation.

Simultaneous determination of neutral and amino sugars in biological materials

A method is described for the simultaneous analysis of nine neutral and three amino sugars. Mixtures of standard sugars and biological samples were acid hydrolyzed with a two step Saeman procedure, neutralized with BaCO3, reduced with sodium borohydride, acidified, evaporated and alditol acetates prepared. Baseline resolution was achieved on a glass-capillary SP-2340 column in ca. 52 min. Reproducibility, response factors and hydrolysis losses were determined. Quantitation was linear over the range of 10-20 micrograms/ml to 2000 micrograms/ml. Conditions were defined for the reproducible quantitation of muramic acid.

The bacteriophage kh receptor of Lactococcus lactis subsp. cremoris KH is the rhamnose of the extracellular wall polysaccharide

A receptor for bacteriophages of lactic acid bacteria, including Lactococcus lactis subsp. cremoris KH, was found on the cell wall and not on the cell membrane, as determined by a phage-binding assay of sodium dodecyl sulfate- and mutanolysin-treated cell walls. The cell wall carbohydrates of L. lactis subsp. cremoris KH were analyzed by gas chromatography and mass spectrometry and found to contain rhamnose, galactose, glucose and N-acetylglucosamine. Similar analysis of mutants that were reduced in the ability to bind phages kh, 643, c2, ml3, and 1 indicated that galactose was essential for binding all phages. In addition, rhamnose was required for binding phages kh and ml3. Inhibition studies of phage binding by using two different lectins with a specificity for galactose indicated that phage kh may not bind directly to galactose. Rather, galactose may be an essential structural component located in the vicinity of the receptor. Incubation of any of the five phages with rhamnose or of phage kh with purified cell walls inactivated the phages. Inactivation required divalent cations and was irreversible. Inactivation of phages was stereospecific for rhamnose, as neither L-(+)- nor D-(-)-fucose (the stereoisomers of rhamnose) inhibited the phage. Furthermore, phage infection of a culture was completely inhibited by the addition of rhamnose to the medium. Therefore, the receptor for phage kh appears to be a rhamnose component of the extracellular wall polysaccharide.

Capillary gas-chromatographic analysis of monosaccharides: improvements and comparisons using trifluoroacetylation and trimethylsilylation of sugar O-benzyl- and O-methyl-oximes

Two new procedures for the gas-chromatographic analysis of monosaccharides are reported. One involves derivatization of the sugars by reaction with O-benzylhydroxylamine followed by trifluoroacetylation with N-methylbis(trifluoroacetamide) and chromatography on a DB-1701 capillary column. This technique probably provides the best resolution achieved to date of the C3-C6 aldoses, as well as of the corresponding alditols. Ketoses can be qualitatively analyzed by this method, but complications interfere with their quantitative analysis. The second procedure also involves initial derivatization as the O-benzyloxime, but is followed by trimethylsilylation with 1-trimethylsilylimidazole, and chromatography on a DB-17 column. This technique is particularly useful for C5 sugars, C6 ketoses, and mixtures of sugars, alditols, and/or lactones. A number of additional, critical, observations on the derivatization and capillary gas-chromatographic analysis of monosaccharides are described.

Rapid identification of Haemophilus influenzae serovar b by gas liquid chromatography using carbohydrate fingerprints

Carbohydrates from whole-cell hydrolysates of 18 strains of the species Haemophilus influenzae (5 strains belonging to serovar b) were analysed by gas-liquid chromatography. The identity of the carbohydrate components was confirmed by comparison with the retention times of reference sugars and by gas chromatography mass spectrometry. Evidence was obtained that Haemophilus influenzae serovar b can easily be identified by the presence of one large peak representing ribitol. The method described can be routinely applied in bacteriological laboratories equipped with a gas chromatograph. It gives results within approximately 4 h, it is reproducible and easy to perform. Even single colonies isolated directly from agar plates can be used for analysis without further subculturing.

Isolation of a coaggregation-inhibiting cell wall polysaccharide from Streptococcus sanguis H1

Coaggregation between Streptococcus sanguis H1 and Capnocytophaga ochracea ATCC 33596 cells is mediated by a carbohydrate receptor on the former and an adhesin on the latter. Two methods were used to release the carbohydrate receptor from the gram-positive streptococcus, autoclaving and mutanolysin treatment. The polysaccharide released from the streptococcal cell wall by either treatment was purified by ion-exchange chromatography; this polysaccharide inhibited coaggregation when preincubated with the gram-negative capnocytophaga partner. After hydrolysis of the polysaccharide by hydrofluoric acid (HF), the major oligosaccharide of the polysaccharide was purified by high-performance liquid chromatography. By analysis of the HF hydrolysis of the polysaccharide and the purified oligosaccharide, this major oligosaccharide appeared to be the repeating unit of the polysaccharide, with minor components resulting from internal hydrolysis of the major oligosaccharide. Gas chromatography results showed that the oligomer was a hexasaccharide, consisting of rhamnose, galactose, and glucose, in the ratio of 2:3:1, respectively. By weight, the purified hexasaccharide was a fourfold-more-potent inhibitor of coaggregation than the native polysaccharide. Resistance to hydrolysis by sulfuric acid alone and susceptibility to hydrolysis by HF suggested that oligosaccharide chains of the polysaccharide are linked by phosphodiester bonds. Studies with a coaggregation-defective mutant of S. sanguis H1 revealed that the cell walls of the mutant contained neither the polysaccharide nor the hexasaccharide repeating unit. The purification of both a polysaccharide and its constituent hexasaccharide repeating unit, which both inhibited coaggregation, and the absence of this polysaccharide or hexasaccharide on a coaggregation-defective mutant strongly suggest that the hexasaccharide derived from the polysaccharide functions as the receptor for the adhesin from C. ochracea ATCC 33596.

Determination of the carbohydrate composition of mammalian glycoproteins by capillary gas chromatography/mass spectrometry

A technique to determine the carbohydrate composition of glycoproteins using capillary gas chromatography/mass spectrometry (electron impact) with selected ion monitoring is described. This method entails hydrolysis with methanolic-HCl followed by formation of trimethylsilyl methylglycoside derivatives, extraction of the carbohydrate derivatives into hexane, and GC/MS analysis. For those carbohydrates that are present in animal glycoproteins including fucose, mannose, galactose, glucosamine, galactosamine, and N-acetylneuraminic acid (sialic acid), the sensitivity of this assay was approximately 1-3 pmol and the assay was linear over a 100-fold range. The carbohydrate compositions determined on small quantities (1-10 pmol) of various glycoproteins including human transferrin and alpha-1 acid glycoprotein, fetuin, and ovalbumin were identical to their reported carbohydrate content and compositions. Major advantages of this technique include the time required to complete the sample preparation and analysis (less than 8 h), the sensitivity and specificity of the assay, and the fact that all carbohydrate moieties, including sialic acid, can be quantitated in a single hydrolysate of a glycoprotein.

Determination of environmental levels of peptidoglycan and lipopolysaccharide using gas chromatography with negative-ion chemical-ionization mass spectrometry utilizing bacterial amino acids and hydroxy fatty acids as biomarkers

D-Alanine and diaminopimelic acid originating from bacterial peptidoglycans and hydroxy fatty acids from lipopolysaccharides (endotoxins) were analysed by gas chromatography using a chiral column (Chirasil-Val as stationary phase) and selected-ion monitoring detection with negative-ion chemical-ionization mass spectrometry. The amino acids were analysed as N-heptafluorobutyryl isobutyl esters after rapid hydrolysis of peptidoglycan followed by isolation of the amino acids with disposable ion-exchange columns. Racemization of amino acid enantiomers was controlled by using deuterium chloride in the hydrolysis. The hydroxy acids were analysed as O-pentafluorobenzoyl methyl esters. Most of the bacteria present in airborne dust from a poultry confinement building were found to be Gram-positive according to the analytical chemical method whereas the Limulus amoebocyte lysate test suggested the presence of appreciable amounts of lipopolysaccharides of Gram-negative bacteria. Further studies are required to compare the utility of these two methods for determining endotoxins in complex environments.

Analysis of the amino acid and sugar composition of streptococcal cell walls by gas chromatography-mass spectrometry

A procedure for determining the amino acid and sugar composition of streptococcal peptidoglycan-polysaccharide complexes by capillary gas chromatography-mass spectrometry (GC-MS) was established. Amino acids are analysed as butyl heptafluorobutyl derivatives and sugars as alditol acetates. These two different groups of compounds are derivatized independently but chromatography in both cases utilizes the same OV-1701 fused-silica capillary column which simplifies GC-MS analysis. The butyl heptafluorobutyl procedure incorporates new pre- and post-derivatization clean-up steps. Additionally, selected-ion monitoring MS allows amino acids to be readily analysed without interference from background noise.

Carbohydrate profiling of bacteria by gas chromatography-mass spectrometry: chemical derivatization and analytical pyrolysis

Carbohydrate profiling by gas chromatography-mass spectrometry is a powerful tool for the identification and detection of bacteria. Its increasing applicability in the microbiology laboratory is illustrated by three examples. In the first, differentiation of legionellae by their sugar composition was determined with alditol acetate derivatization followed by selected- ion monitoring. In the second example, a carbohydrate pyrolysis product from Streptococcus agalactiae was used to differentiate group B streptococci from other Lancefield groups after direct sampling from culture plates. The third example employed the carbohydrates rhamnose and muramic acid as chemical markers for the direct detection of bacterial cell wall degradation products in mammalian tissues. The analysis of carbohydrate markers for bacteria by gas chromatography-mass spectrometry has great potential for use in clinical identification of isolated bacteria as well as in the rapid diagnosis of bacterial infections without prior culture.

Ultrasensitive analysis of microbial fatty acids using gas chromatography with electron capture detection

Pentafluorobenzyl and pentafluoropropionyl/pentafluorobenzyl esters of bacterial fatty acids were analysed by capillary gas chromatography using both flame ionization and electron capture detection. No differences between the relative peak areas of the various fatty acids were observed as regards the two detectors used except that response of the electron capture dectector to the hydroxy acid derivatives exceeded that to the non-hydroxy acid derivatives by 20%. Use of the described derivatives in combination with electron capture detection yields chromatograms comparable with those obtained by analysis of methyl esters using flame ionization detection but with superior sensitivity.

Determination of endotoxins by gas chromatography: evaluation of electron-capture and negative-ion chemical-ionization mass spectrometric detection of halogenated derivatives of beta-hydroxymyristic acid

The sensitivity and selectivity of gas chromatography for analysing several halogenated ester derivatives of beta-hydroxymyristic acid were studied using both selected-ion monitoring detection with negative-ion chemical-ionization mass spectrometry and electron-capture detection. Six different derivatization methods were compared with respect to yield, chemical stability and formation of by-products. Procedures for removal of excess reagents using disposable silica columns and thin-layer chromatography were elaborated. The 3-O-pentafluorobenzoyl-methyl ester was the preferred derivative since it provided high sensitivity and had the molecular ion as the base peak in the mass spectrum. The detection limit was 0.5 pg with electron-capture detection and 0.3 pg with the mass spectrometric system. Using beta-hydroxymyristic acid as a chemical marker it was possible to detect Escherichia coli endotoxin in aqueous solution at a level of 1 ng/ml.

The immunoglobulins of carcharhine sharks: a comparison of serological and biochemical properties

The immunoglobulins of three carcharhine sharks were isolated from serum by means of salt precipitation and gel chromatography. The Galapagos shark (Carcharhinus galapagensis), the sandbar shark (Carcharhinus plumbeus) and the tiger shark (Galeocerdo cuvieri) each contained high molecular weight (18S) and low molecular weight (7S) IgM-like molecules as the major serum immunoglobulins. Both within and between species 18S and 7S immunoglobulins closely resemble each other in antigenic character, polypeptide chain composition, chain mass, amino acid composition, carbohydrate content and amino-terminal sequence. These results suggest that the immunoglobulins of carcharhine sharks have undergone little structural divergence during their evolution.

Simultaneous determination of N-acetylglucosamine, N-acetylgalactosamine, N-acetylglucosaminitol and N-acetylgalactosaminitol by gas-liquid chromatography

A gas-liquid chromatographic procedure is described which will concomitantly separate and quantitate N-acetylglucosamine, N-acetylgalactosamine, N-acetylglucosaminitol and N-acetylgalactosaminitol in a single analytical run. The hexosamines, as their O-methyloximes, and the hexosaminitols can be separated as either their per-O-acetylated or per-O-trimethylsilylated derivatives. This method is particularly useful with samples that possess both N-acetylhexosaminitols and N-acetylhexosamines as are seen with N-linked oligosaccharides that are cleaved from glycoproteins by alkaline borohydride treatment. This procedure demonstrates a range of acceptable linearity of 1-1000 nmoles for each type of amino sugar.

Modifications in the alditol acetate method for analysis of muramic acid and other neutral and amino sugars by capillary gas chromatography-mass spectrometry with selected ion monitoring

Two alditol acetate methods for the gas chromatographic (GC) analysis of neutral and amino sugars were compared. Following sodium borohydride reduction, one method uses methylimidazole as an acetylation catalyst without prior removal of water or borate salts and the other method uses sodium acetate after removal of borate and water. Depending on the acetylation conditions, muramic acid produced different derivatives. With methylimidazole, reliable derivatization of muramic acid was not possible, although other sugars derivatized reliably. With sodium acetate, all sugars tested were reproducibly derivatized. The utility of the sodium acetate method is shown by the trace GC-mass spectrometric analysis of muramic acid and rhamnose derived from bacterial peptidoglycan-polysaccharide complexes in mammalian tissue.

Quantitative analysis of cell walls of nutritionally variant streptococci grown under various growth conditions

Strains of nutritionally variant streptococci are usually isolated from patients with subacute bacterial endocarditis. Only recently have these strains been subdivided into three serotypes; however, no group-specific antigen has been described. To understand the immunochemical basis for the serology of these microorganisms as well as set the groundwork for adherence studies, quantitative analysis of the cell walls of nutritionally variant streptococci was undertaken. The bacteria were grown in semisynthetic medium or pyridoxal-supplemented Todd-Hewitt broth and harvested during the exponential or stationary phase. Cell walls were isolated and analyzed for amino sugars, sugars, polyalcohols, amino acids, and phosphorus by gas chromatography, high-pressure liquid chromatography, or colorimetric assays. The peptidoglycans of the cell walls of the prototype strains from the three serotypes were representative of other streptococcal cell walls, including the presence of alanine as the possible cross-bridge. The composition of the peptidoglycan was similar for all three strains and included a decreased concentration of peptidoglycan in their cell walls during the stationary phase. Glucosamine, glucose, galactose, ribitol, and a small amount of rhamnose were found in each of the cell wall polysaccharides. Galactosamine was only found in serotype II and III cell walls and might be responsible for the previously described cross-reaction between these strains. The concentration of the other sugars and amino sugars varied in each of the cell wall preparations, depending on the growth conditions. Finally, all three strains expressed both ribitol and phosphorus in their cell walls, characteristic of the presence of a ribitol teichoic acid. Therefore the cell wall composition of the nutritionally variant streptococci varies depending on the growth conditions, and their composition appears similar to that of strains of Streptococcus mitis.

Evidence for the biclonal nature of a Waldenstrom's macroglobulinemia

The serum of a patient with Waldenstrom's macroglobulinemia was shown to contain two IgM(kappa) paraproteins of different electrophoretic mobilities on cellulose acetate and immunoelectrophoresis and were designated IgM slow (s) and IgM fast (f). Both existed as high molecular weight polymers and contained a J chain. The two pentameric IgM monoclonal proteins were shown to be completely distinct in carbohydrate composition as determined by gas chromatography and periodic acid-Schiff staining, in molecular weight, by physicochemical properties, peptide mapping, amino-acid composition, NH2-terminal sequence, subgroup of light chains, and by lack of shared idiotypic determinants as determined by hemagglutination inhibition studies. Our study presents strong evidence for the 'bioclonal' nature of this gammopathy. We conclude that both paraproteins are distinct and originated from different B cells.

Anomalous behavior of goldfish IgM heavy chain in sodium dodecylsulfate polyacrylamide gel electrophoresis

By sodium dodecylsulfate polyacrylamide gel electrophoresis, the heavy chain of the serum immunoglobulin (IgM) of the goldfish (Carassius auratus) differs not only from other studied vertebrate serum IgM heavy chains, but also from other vertebrate lymphocyte membrane IgM heavy chains including those from the goldfish itself. This difference, an increase in apparent Mr of approximately 5000, was investigated by assessing in comparison with the IgM heavy chain of human and rainbow trout (Salmo gairdneri) the following properties: (1) molecular size by gel filtration in denaturing buffers; (2) carbohydrate content, by direct analysis; (3) intrinsic net charge, by isoelectric focusing; (4) net hydrophobicity, deduced from amino acid analysis; and (5) sodium dodecylsulfate binding by direct measurement. Results indicate that goldfish IgM heavy chain is indistinguishable from other IgM heavy chains in terms of (a) its gel-filtration behavior in denaturing conditions, (b) its carbohydrate content (which is similar to trout IgM heavy chain) and (c) its intrinsic net charge and hydrophobicity. However, goldfish IgM does differ from the other proteins studied in its detergent-binding ability and it is this behavior that is concluded to be the cause of its unusual mobility in sodium dodecylsulfate polyacrylamide gel electrophoresis.

A quantitative determination by capillary gas-liquid chromatography of neutral and amino sugars (as O-methyloxime acetates), and a study on hydrolytic conditions for glycoproteins and polysaccharides in order to increase sugar recoveries

Complete gas-liquid chromatographic separation of O-methyloxime acetates (syn and anti isomers) prepared from eight neutral sugars, three hexosamines, and muramic acid has been obtained, using a fused-silica Carbowax 20M capillary column. A single hydrolytic step for carbohydrate-containing biological material (less than or equal to 2.5 X 10(-3) M sugar solution in 4 N trifluoroacetic acid at 125 degrees C for 1 h) has been developed, and results have been compared with those obtained with standard hydrolytic conditions in order to ensure complete release of amino sugars from glycoproteins, together with minimum losses of neutral sugars. The combination of this acid hydrolysis with the above improved derivatization procedure for the gas-liquid chromatographic analysis has led to a simple, rapid, and sensitive analytical method, which has been successfully tested on three glycoproteins (fetuin, mucin, and peroxidase) and two plant cell-wall polysaccharide fractions (soluble fibers from carrots and soybeans).

A chemical and physical comparison of ferritin subunit species fractionated by high-performance liquid chromatography

Selected chemical and physical properties were measured for different forms of ferritin subunits which had been separated by reverse-phase high-performance liquid chromatography. Ferritin subunits from porcine spleen behaved, on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, as though they were approximately Mr 2000 larger than equine spleen ferritin, whereas no difference in size was observed by gel chromatography in 6 M guanidinium chloride. All subunit species exhibited similar isoelectric focusing properties. In contrast to previous reports, no carbohydrate could be found associated with any of the isolated subunit species. Thus, the aberrant behavior of the porcine ferritin subunits between the two empirical molecular weight estimation methods appears to be the result of factor(s) other than protein intrinsic charge or covalently attached carbohydrate.

Capillary gas chromatography-mass spectrometry of carbohydrate components of legionellae and other bacteria

Capillary gas chromatography using fused-silica columns followed by electron impact or chemical ionization mass spectrometry was used to profile and identify neutral and amino sugars present in several legionellae and other bacteria. A modified alditol acetate derivatization method was employed to produce volatile carbohydrate derivatives. Muramic acid, a component of bacterial peptidoglycan, was detected in all legionellae examined. Heptose, a component of bacterial lipopolysaccharide, was identified in Escherichia coli organisms and in several purified Gram-negative bacterial lipopolysaccharides but not in the legionellae examined. Two amino dideoxyhexoses were found to be present in several of the Legionellae examined. The potential of gas chromatography-mass spectrometry for the direct chemical characterization of microorganisms is discussed.

Capillary gas chromatographic analysis of carbohydrates of Legionella pneumophila and other members of the family Legionellaceae

Legionella pneumophila, the causative agent of Legionnaires disease, and related organisms have previously been characterized primarily by conventional bacteriological methods, DNA-DNA hybridization, antigenic analysis, and fatty acid analysis. By capillary gas chromatographic analysis for carbohydrates, we have shown that muramic acid and glucosamine, characteristic markers of bacterial cell walls, were present in samples of L. pneumophila and a group of legionella-like organisms. Some bacterial samples contained two unusual isomeric aminodideoxyhexoses (X1 and X2). L. pneumophila was characterized by the absence of fucose and the presence of the peak X1. Tatlockia micdadei (Legionella micdadei) was distinguishable by the presence of large amounts of rhamnose and fucose and by the absence of X1 and X2. Fluoribacter strains were much more variable in their carbohydrate composition. These data suggest that, in addition to other reported techniques, carbohydrate profiling by capillary gas chromatography can be a valuable diagnostic method in reference microbiology laboratories for differentiating members of the family Legionellaceae.