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Aqueous-phenol extracts of Mycoplasma salivarium ATCC 23064 cells (APM) showed demonstrable differences from lipopolysaccharides (LPSs) of Veillonella rodentium ATCC 17743. These were as follows: smaller amounts of amino sugars and an absence of 2-keto-3-deoxyoctonate; local Shwartzman reactivity and body weight-decreasing activity, even though the activities were rather weak compared with those of LPSs. Therefore, phenol-water extractive components of Mycoplasma salivarium might be of pathogenic importance in mediating damaging effects on the periodontium.

The ability of lipid A preparations from strains of Bacteroides, Fusobacterium, and Veillonella to inhibit the lipid A-anti-lipid A reaction in an enzyme-linked immunosorbent assay was tested. Anti-lipid A serum was prepared with lipid A from Salmonella minnesota R595, and lipid A from Escherichia coli EH100 was used as control antigen. Preparations from three of four different species of Bacteroides were unable to inhibit the anti-lipid A activity, whereas lipid A preparations from Fusobacterium and Veillonella strains inhibited 50% of the activity at 1 to 141 micrograms. One of the Bacteroides strains, Bacteroides oralis, showed a very weak inhibiting activity at the highest concentration used. The results confirm that Bacteroides species have a unique lipopolysaccharide structure, in contrast to other anaerobic genera which have a lipopolysaccharide structure similar to that of the Enterobacteriaceae.

A qualitative and quantitative study has been carried out on 15 strains of the Veillonella genus, isolated in the oral cavity. Following two methods of preparation of samples for injection in a chromatograph GL, we have identified among the volatil monocarboxylic aliphatic acids from C2 to C6 the glucose fermentation products of these different strains. With the same methods, we studied in parallel these products from strains A.T.C.C. 10790-17444 (Veillonella parvula) and 17445-17446 and 17447 (Veillonella alcalescens). The results, despite the diversity of origin of all these strains, based on physiological and biochemical characteristics, confirm that volatil monocarboxylic aliphatic acids are characteristic of a genus specificity and not of a species. The presence of acetic acid, proprionic acid and iso-valeric acid was shown

Veillonella parvula ATCC 10790, an anaerobic gram-negative coccus, contains diacyl and alk-1-enyl acyl (plasmalogen) forms of phosphatidylethanolamine and phosphatidylserine. We studied the effect of growth temperature on the lipid composition of this strain. There was a small increase in the phosphatidylethanolamine content but no change in the content of plasmalogens at the lower growth temperatures tested. The total acyl chains and the plasmalogen acyl chains contained between 73 and 80% mono-unsaturated fatty acids at all growth temperatures. The plasmalogen alk-1-enyl chains were significantly more unsaturated in cells grown at 30 and 25 degrees C than in cells grown at 37 degrees C. Differential scanning calorimetry of the hydrated phospholipids showed lower phase transition temperatures for the lipids from the cells grown at the lower temperatures. In Megasphaera elsdenii lipids, which are similar in composition to the lipids of V. parvula, the proportion of phosphatidylethanolamine also increased slightly at lower growth temperatures, with no significant change in the content of plasmalogens. M. elsdenii contained cyclopropane fatty acyl and alk-1-enyl chains in addition to the mono-unsaturated and saturated chains previously reported. As cells entered the stationary phase of growth at 30 and 42.5 degrees C, there was a reciprocal increase in the proportion of cyclopropane acyl chains and decrease in the unsaturated moieties. The total proportion of cyclopropane and unsaturated acyl and alk-1-enyl chains was more than 65% at all growth temperatures studied, and there was no discernible increase in the sum of these moieties at the lower growth temperatures.

As a basis for physicochemical studies on the membranes of the strictly anaerobic bacteria Veillonella parvula, Anaerovibrio lipolytica, and Megasphaera elsdenii, the fatty acyl and alk-1-enyl moieties on the phosphoglycerides of these organism were characterized. Uncommon is the high proportion of a heptadecenoic acyl and alk-1-enyl moiety in these three lactate-fermenting bacteria. In contrast to V. parvula and A. lipolytica, M. elsdenii contains high amounts of branched-chain acyl and alk-1-enyl moieties. Freeze-etching electron microscopy showed that the lipids of the plasma membranes of V. parvula and A. lipolytica go from the liquid crystalline to the gel state upon lowering of the temperature, indicating that the membrane lipids are predominantly in the fluid state. No lipid-protein segregation could be detected in the plasma membrane of M. elsdenii. This can be explained by the abundance of branched-chain fatty acyl and alk-1-enyl residues in the membranes of this organism which may prevent lipid-protein segregation during the lipid-phase transition.

Lipopolysaccharides (LPS) were isolated by phenol-water extraction from 34 strains of Veillonella, and examined by paper chromatography and colorimetric methods for the presence of neutral sugars, amino sugars and 2-keto-3-deoxy-octonate (KDO). Several preparations were also examined for neutral sugars by gas liquid chromatography. The LPS had in common glucosamine, galactosamine, L-glycero-D-manno-heptose glucose and KDO. Most LPS contained galactose, and a few rhamnose. D-glycero-D-manno-heptose was found in LPS from one of the strains. Based on the sugar composition of the LPS, the Veillonella strains could be classified into four chemotypes.

Veillonellophage N2 adsorbed to polysaccharides (PSs) on Veillonella rodentium ATCC 17743 cell wall, and the bacteriophage receptor contained only glucosamine. D(+)-glucosamine hydrochloride (Sigma) also adsorbed the veillonellophage N2. These results therefore indicate that the receptor to the veillonellophage N2 is cell wall PSs. The PSs of the host cells as receptor have been characterized. Glucosamine accounted for approximately 100% of the weight of the PSs. The PSs which were partially resolved by Sephadex G-75 chromatography comprised approximately four glucosamine units. Their primary structure was determined by 400 MHz n.m.r. spectroscopy. One- and two-dimensional 1H-nmr experiments showed the PS to be a branched polymer. Glucosamine linkage was detected in one of the branches.

Endotoxic lipopolysaccharides (LPS) isolated from Fusobacterium are similar to those of Salmonella with respect to chemical composition, O-antigenic specificity and endotoxic activity. Bacteroides LPS are highly atypical with respect to the chemical composition, and their endotoxic activity is low. O-Antigenic specificity is present. B. fragilis LPS is chemotactic for polymorphonuclear leukocytes in vitro and in vivo. The chemotactic activity is brought about by activation of the alternative complement pathway.

The capacity of phenol/water extracted lipopolysaccharides (LPS) from Bacteroides, Fusobacterium and Veillonella to induce histamine release from rat peritoneal mast cells has been evaluated by means of a bioassay using atropinized guinea pig ileum and a fluorescence assay. Histamine release was found to be completely complement dependent. It was also found that LPS of Veillonella have the greatest capacity to induce histamine release and Bacteroides have the weakest.

Veillonellophage N2 prevented from adsorbing to Veillonella rodentium ATCC 17743 cells treated with polymyxin B, and also to lipopolysaccharides (LPSs) of the host cells treated with antibiotics. Therefore, these results indicate that receptor to phage N2 is cell wall LPSs. The LPSs of V. rodentium ATCC 17743 cells as receptor were characterized. Lipid A and total carbohydrate accounted for approximately 40% of the weight of the lipopolysaccharide complex. Heptose and 2-keto-3-deoxyoctonate were also present. Amino compounds included glucosamine, galactosamine, and glycine.

Veillonella alcalescens ATCC 17745, a strictly anaerobic, gram-negative small coccus, requires putrescine or cadaverine for growth (M. B. Ritchey, and E. A. Delwiche, J. Bacteriol. 124:1213-1219, 1975). Both putrescine and cadaverine were demonstrated to be incorporated exclusively into the peptidoglycan layer of V. alcalescens ATCC 17745. V. parvula GAI 0574 also proved to contain putrescine as a component of peptidoglycan. The primary chemical structure of the peptidoglycan common to the two Veillonella species is N-acetylglucosamine-N-acetylmuramic acid-L-alanine-D-glutamic acid gamma-meso-diaminopimelic acid-D-alanine. Putrescine or cadaverine links covalently to the alpha-carboxyl group of the D-glutamic acid residue of the peptidoglycan is necessary for normal cell growth. In V. alcalescens ATCC 17745, above 40% saturation at cadaverine linked to the alpha-carboxyl group of the D-glutamic acid residue of the peptidoglycan is necessary for normal growth.

The reaction between endotoxic lipopolysaccharide (LPS) and the guinea pig complement system was shown to proceed by way of an intermediate complex, LPS-X, which contains at least six guinea pig serum proteins. LPS-X, like [unk] (sheep erythrocytes carrying antibody molecules and [unk] complexes), destroys the C3 molecule by cleavage. On incubation at 37 degrees C, LPS-X loses its capacity to destroy C3 at about the same rate as the decay of [unk], so that it has been assumed that LPS-X carries [unk] sites that are responsible for the destruction of C3. We have now shown that monospecific rabbit antiguinea pig C2, which effectively inhibits C3 cleavage by [unk], does not interfere with the destruction of C3 by LPS-X. Furthermore, not more than a trace of C2a(d) is released from LPS-X on incubation at 37 degrees C. These results indicate that LPS-X does not carry a significant quantity of [unk] and, hence, that its capacity to destroy C3 is due to another factor which is presumably a component of the properdin system.

Large amounts of each C'3, C'5, C'6, C'7, C'8, and C'9 were consumed when guinea pig serum was incubated with endotoxic lipopolysaccharide, zymosan, or preformed immune complexes. Since these C' components subserve several of the biological activities which follow the injection of endotoxins into experimental animals, these experiments support the hypothesis that certain biological effects induced by endotoxins may be mediated via the C' system, and may account for some of the known similarity in the reactivities evoked by endotoxins and immune complexes in vivo.