Sucrose Broth Research Articles

The effect of erythrose and related compounds on the growth and acid production of streptococci and lactobacilli.

Erythrose, glyceraldehyde, glycollic aldehyde, and methyl glyoxal, at concentrations of approximately 0·02 m , inhibited the growth of streptococci and lactobacilli in glucose and sucrose broth. The minimal inhibitory concentrations of the agents were unaltered when the concentrations of glucose and sucrose were increased. When these inhibitory compounds were incorporated in gels containing dense aggregates of the test bacteria they greatly reduced the rate of acid production when the gels were moistened with sugar solution. These agents were without effect when added to the sugar solution instead of the gel.

Presence of an invertase-like enzyme and a sucrose permeation system in strains of Streptococcus mutans.

Enzyme preparations obtained from sonically-treated washed cells of <i>Streptococcus mutans</i> strain GS5 were found to contain ‘sucrase’ activity which was distinct from that of the glucosyl and fructosyl transferases known to be elaborated by this organism. This ‘sucrase’ activity was formed constitutively and could be separated from transferase activity by agarose chromatography. The enzyme appears similar, if not identical, to invertase on the basis of its catalytic action, its molecular size, and its heat sensitivity. Its presence in cells of Strep, mutans strain GS5 indicates that this organism is not solely dependent upon the glucosyl and fructosyl transferases for the utilization of sucrose for growth. The total observable ‘sucrase’ activity of glucose grown cells of Strep, mutans strains GS5 and 6715 was found to increase markedly when the organisms were treated with toluene, indicating they were relatively impermeable to sucrose. Untreated sucrose grown cells exhibited 10-fold higher total ‘sucrase’ activity than did untreated glucose grown cells, suggesting that growth in sucrose broth resulted in the induction of a sucrose transport system.

Bacteriocins of Clostridium perfringens. 2. Studies on mode of action.

The effects of bacteriocin 28 on sensitive strains of Clostridium perfringens are further described. Two indicator strains were chosen for detailed study. These strains, when treated with bacteriocin, were induced to produce spherical forms devoid of cell wall. The efficiency of conversion to spheroplasts in one strain was greatly enhanced when the organism was grown in 0.3 M sucrose broth. Sucrose, itself, was capable of inducing spheroplast formation in the other strain in the absence of bacteriocin, this being the only indicator strain observed to behave in this manner.Bacteriocin could not induce spheroplast formation when indicator bacteria were either heavily irradiated with ultraviolet light or when the culture was vigorously aerated, suggesting that metabolically active cells were required for the conversion phenomenon. When bacteriocin-treated cultures were plated on sucrose containing media, L-form colonies developed.Spheroplasts induced by bacteriocin could no longer adsorb a specific bacteriophage, which suggested that there might be a loss of cell wall receptors. Although the bacteriocin is sensitive to trypsin, it was impossible to reverse bacteriocin activity on sensitive cells by subsequent treatment with trypsin. Radioactive isotope incorporation revealed that cells treated with bacteriocin continued to synthesize DNA, RNA, and protein.

Selective Bacterial Adherence to Oral Epithelial Surfaces and Its Role as an Ecological Determinant

The possible relationship between the ability of Streptococcus species to adhere to oral epithelial cells and their natural distribution on epithelial surfaces within the mouth was studied. Strains of S. salivarius and S. sanguis, which are present in significant proportions on oral epithelial surfaces, were found to possess a definite capacity to adhere to epithelial cells obtained from cheek scrapings of humans, hamsters, and germ-free rats. In contrast, strains of S. mutans, which are found in only minor proportions, if at all, on oral epithelial surfaces exhibited feeble or no adherence to oral epithelial cells. S. salivarius cells attached well to human cheek cells over the range of pH 5 to 8. Its adherence was not found to be markedly influenced by saliva or by growth in sucrose broth. Several other types of bacteria were examined which also exhibited widely different abilities to attach to human cheek cells. Mixtures of streptomycin-labeled strains were introduced into the mouths of volunteers for study of the adherence of Streptococcus species to oral epithelial surfaces in vivo. Labeled S. salivarius and S. sanguis were recovered in high proportions from cheek and tongue surfaces, whereas the proportions of labeled S. mutans recovered from these surfaces were low in comparison to the original mixture. These data indicate that a correlation exists between the relative adherence of various Streptococcus species and their proportional distribution found naturally on oral epithelial surfaces. The ability of bacteria to adhere to surfaces is proposed as a critical ecological determinant affecting their colonization in environments with open surfaces exposed to bathing fluids.

Continuous culture of Streptococus mitis, strain ATCC 9811, with various sugar broth media and its bacterial plaque formation

Strain ATCC 9811 of Streptococcus mitis, which has been suggested to belong to Streptococcus sanguis by a recent worker, was subjected to continuous culture in various types of sugar broth at 37°C every 3 days.Culture was performed in a glass vessel (30ml in culture volume) at a flow rate of 18∼20ml per hour. The culture broth was agitated by a magnetic stirrer (at 3∼4 rps). One percent of such sugar as glucose, fructose, galactose, sucrose, or raffinose, and mixtures of monosaccharides were added to a basic broth which was composed of peptone, yeast extract and sodium chloride.Bacterial plaques were formed on the surface of the glass vessel in the early stage only when culture was made with sucrose broth. They were peeled by a rotating rod of the agitator. As they grew larger, flow-out cells decreased in number, and the pH of the culture broth remained at a low level, reaching the lowest value in sucrose broth. Bacterial plaques were also formed in such types of broth containing 0.5, 0.2 and 0.1% of sucrose. There was a decrease in pH value after plaque formation. When culture was performed in sugar-free broth with an intermittent addition of sucrose up to approximately 1.0% (3 times per day at intervals of 4 hours only in daytime; there was no addition at night), bacterial plaques were also formed and the number of flow-out cells fluctuated irregulary. The pH value was maintained at a low level even after the interruption of sucrose supply at night.

Synthesis of insoluble dextran and its significance in the formation of gelatinous deposits by plaque-forming streptococci

The synthesis of extracellular polysaccharides was studied in strains of streptococci known to induce plaque-formation in experimental animals. These organisms synthesized soluble and insoluble dextran and levan, and formed gelatinous “plaque-like” deposits in sucrose broth. Formation of these gelatinous deposits appeared to be dependent upon synthesis of insoluble dextran. Polysaccharide fractions extracted from the deposits possessed a higher average molecular weight and relative viscosity than soluble polymers present in culture liquors, suggesting that molecular weight is important in governing their solubility. Glucosyl acceptors known to promote synthesis of low molecular weight dextran were found to prevent the development of gelatinous deposits in sucrose broth, and these substances were found to inhibit the synthesis of insoluble dextran. Dextransucrase and levansucrase activity was detected in culture liquors, and in washed cell suspensions of the streptococcus strains studied. Enzyme preparations from culture liquors exhibited maximal dextran synthesis at pH 8, but displayed a plateau from pH 5 to 6. Approximately half of the dextran synthesized at pH 5–6 was soluble, whereas over 90 per cent of the dextran synthesized at pH 8 was insoluble. Levansucrase present in culture liquors formed maximal amounts of levan at pH 7. Preparations of cell-associated dextransucrase synthesized dextran optimally at pH 7, and predominantly insoluble polymers were formed from pH 5 through pH 8.

Hydrolysis of levan by human plaque streptococci

A large proportion of the cultivable bacteria present in human dental plaque were found to hydrolyse high molecular weight levan. All of the levan-hydrolysing organisms encountered proved to be streptococci which formed extracellular polysaccharides when grown in sucrose broth. Known strains of caries-inducing streptococci were also found to degrade levan. The fructan hydrolase formed by one strain of plaque streptococcus was studied in more detail. The enzyme was found to be inducible for it was formed in broth containing levan, inulin, or sucrose, but not in broth containing glucose or fructose. It was detected both in culture supernatant liquor, and in washed cell suspensions. Enzyme preparations hydrolysed both levan and inulin with maximal activity exhibited at pH 6.0. The enzyme was relatively stable and was not affected by NaF, but its activity was inhibited by glucose and various heavy metal salts. The enzyme appeared to act by cleaving terminal fructose units from the ends of the levan molecule.

Synthesis of extracellular dextran by cariogenic bacteria and its presence in human dental plaque

The extracellular polysaccharide synthesized primarily from sucrose by certain human and rodent cariogenic bacteria has been found to be a dextran-like polymer. Maximum quantities of this polysaccharide were synthesized in 10% sucrose broth, and the presence of free glucose or fructose did not markedly repress synthesis of dextran from sucrose. The dextrans synthesized by rat, hamster, and human cariogenic streptococci, and by a cariogenic strain of Lactobacillus acidophilus proved immunologically similar. The extracellular dextran was found to be relatively resistant to attack by mixed oral bacterial growth; to form insoluble precipitates with serum, clarified saliva, and various protein solutions; and to adhere to powdered hydroxyapatite. Samples of pooled human dental plaque were found to contain a constituent which was immunologically similar to dextran, and which comprised almost 2% of its dry weight. It is proposed that dextran synthesis by cariogenic but not non-cariogenic bacteria, enables these organisms to form dental plaque which is required for the production of dental caries.

Studies on the Bacteriophagy of Pseudomonas mors‐prunorum, Ps. syringae and Related Organisms

Summary: A group of 23 phages, mainly isolated with Pseudomonas mors‐prunorum and Ps. syringae as the propagating strains, was tested against more than 200 pseudomonads including named plant pathogens and a variety of saprophytes. The majority of the phages had a wide host range, and did not distinguish between plant pathogens and saprophytes, thus confirming the close relationship between these two groups. The most reactive bacteria were 60 English isolates of Ps. mors‐prunorum, 48 from cherry and 12 from plum, and 28 isolates of Ps. syringae from pear. Patterns of reaction within these 3 groups were relatively homogeneous and each group was distinct and differed from all other isolates tested. Ps. syringae isolates from other hosts were less uniform and occasionally shared reaction patterns with other species, e.g. Ps. cannabina and Ps. glycinea. Similar relationships were observed with phages at both high titre and at routine test dilution including the difference in phage sensitivity between the cherry and plum strains of Ps. mors‐prunorum. On the basis of 7 biochemical tests the plum and cherry strains were indistinguishable but they differed from all Ps. syringae isolates tested by giving white growth in 5% sucrose broth and in failing to liquefy gelatin. Furthermore, unlike most Ps. syringae isolates they were also unable to hydrolyze aesculin and were tyrosinase positive. There was no clear evidence in this investigation of correlation between phage sensitivity and biochemical activity. Eleven isolates from various European countries, designated Ps. mors‐prunorum, differed widely both in phage sensitivity and biochemical activity and some of them may be more appropriately called Ps. syringae. Others may be intermediate forms between these species. The relationship between Ps. mors‐prunorum and Ps. syringae and the nomenclature of these organisms are discussed and a concept of ecotypes suggested as a substitute for species.

Classification of the streptococci of subacute bacterial endocarditis.

SUMMARY: Twenty-nine strains of streptococci from patients with subacute bacterial endocarditis, three type cultures of Streptococcus sanguis, and eighty strains of streptococci from the blood of persons after dental extraction were tested physiologically and serologically. Six endocarditis strains fall into Lancefield group H and four into Lancefield group D; the remaining nineteen were serologically heterogenous. Thirteen of the endocarditis strains produced a serologically reactive dextran in sucrose broth. Of these five were group H streptococci; the rest represented several serological types. Of the three dextran-producing strains of Str. sanguis examined, types I and I/II were placed in Lancefield group H, whereas type II was serologically distinct. The eighty strains from dental bacteraemias included ten which produced a dextran; five of these were group H streptococci.

Serological Reactions of Levans Formed from Sucrose and Raffinose by Certain Bacilli.

SummaryLevans formed in sucrose and raffinose broth by B. subtilis, B. panis, 5 other strains of Bacillus, and 3 strains of non-sporulating Gram-positive rod-shaped bacteria possessed serological properties similar to those previously described for the levans of several strains of S. salivarius and of one strain of Bacillus. This evidence extends the serological information on the levari class of bacterial polysaccharide and gives a better basis for the application of serological procedures to the detection of bacterial levans both in laboratory culture fluids and In the various materials in which they occur in nature.

Serological Reactions of Levans Synthesized from Sucrose and Raffinose by Bacterial Enzymes.

SummaryCell- free, levan-synthesizing enzymes have been prepared from Streptococcus salivarius and from a spore-forming bacillus. The polysaccharide products formed by the action of these enzymes upon sucrose and raffinose possess serological properties similar to those recently described for the purified levans isolated from sucrose broth cultures of the living bacteria.

Serological Properties of Products Synthesized from Sucrose by Enzymes from Different Strains of Leuconostoc Bacteria

Previous reports, established the fact that sterile enzyme solutions obtained from Leuconostoc mesenteroides have the capacity to synthesize a serologically reactive polysaccharide from sucrose. These studies also showed, for one strain of leuconostoc, that the polysaccharide which was formed in the absence of cells agreed in major chemical respects and in serological properties with the dextran elaborated in cultures of the living bacteria. The purpose of the present paper is to present more complete evidence on the serological agreement between the products formed by the enzyme solutions and those formed in living culture. The new experiments were made with representatives of 2 serologically different types of leuconostoc bacteria., Strains of one type are characterized by the fact that their sucrose broth culture fluids cross-react in high dilution with types 2, 12 and 20 antipneumococcus serums; whereas the culture fluids of strains of the second type react in high dilution with types 2 and 20 antipneumococcus serums, but react only in low dilution with type 12 serum. Sterile enzyme solutions were prepared from sucrose broth cultures of 6 strains of Leuconostoc mesenteroides representing the 2 described sercological types. Material synthesized from sucrose by the enzymes war obtained for serological study as follows: 1 part of each enzymes solution was added aseptically to 3 parts of a sterile solution of 5% sucrose in 0.1 M. acetate buffer (pH 5.6); the enzyme-sucrose mixtures were then incubated for 5 days at 23° C, together with appropriate controls. The sterility of all the mixtures was proved by rigorous microscopic and cultural tests. The incubated enzyme-substrate mixtures, together with supernatant fluids obtained from sucrose broth cultures of the 6 different strains, were tested in a series of dilutions against types 2, 12 and 20 antipneumococcus rabbit serums. The serum-antigen mixtures were incubated for 1 hours at 37° C and were then observed for occurrence of precipitation. The type-specificity of the reactions was controlled by tests against types 1 and 8 pneumococcus antiserums.

SEROLOGICALLY REACTIVE POLYSACCHARIDES PRODUCED THROUGH THE ACTION OF BACTERIAL ENZYMES

A serologically reactive polysaccharide of dextran nature was produced from sucrose by the action of some enzyme or similar heat-labile agent contained in sterile filtered extracts derived from sucrose broth cultures of Leuconostoc mesenteroides. Rigorous controls were included to prove that this reaction occurred in the absence of microorganisms. Purified preparations of the dextran formed by the sterile extracts were similar to the dextran elaborated in sucrose broth cultures of the bacteria in respect to both chemical and serological properties. The serological likeness was established not only by tests against leuconostoc antiserums but also by cross reactions with antiserums of Types 2, 20, and 12 pneumococci and by tests against a series of variously absorbed antiserums.

Reactions of Dextrans of Leuconostoc Mesenteroides with the Antiserums of Leuconostoc and of Types 2, 20 and 12 Pneumococcus

Summary The paper dealt with the serological properties of the polysaccharides isolated from sucrose broth cultures of two strains of Leuconostoc mesenteroides. Chemical data were presented to indicate that the products were dextrans. The serological properties of these dextrans are of particular interest because they represent substances whose production is dependent upon the presence of a particular carbohydrate (sucrose) in the culture medium. The dextrans from both strains reacted not only with the leuconostoc antiserums but also with types 2, 20 and 12 antipneumococcal sera. The most prominent serological difference was that the dextran from one strain was only weakly reactive against the type 12 antiserum in comparison to its reactivity against the types 2 and 20 whereas the dextran from the other (the American Type Culture Collection strain) had approximately the same degree of reactivity against type 12 as against types 2 and 20.

Influence of Sucrose upon Production of Serologically Reactive Material by Certain Streptococci

SummaryWhen grown in sucrose broth some strains of group H streptococci produced large amounts of material reactive with types 2 and 20 antipneumococcus and with antileuconostoc serums; little or none was produced by the same streptococci when grown in dextrose broth. This reactive material was different from the streptococcus antigen involved in the usual Lancefield grouping test; as much of the latter was produced in dextrose as in sucrose broth culture.In addition to indicating an interrelationship of the different Gram-positive cocci the data furnished an example of the influence of a particular carbohydrate upon the capacity of some microorganisms to elaborate a serologically reactive polysaccharide.