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At least 19 recordsLinked to original sources
PubMed1979

Adjuvanticity of lactobacilli. I. Differential effects of viable and killed bacteria.

The adjuvanticity of Lactobacillus brevis and Lactobacillus plantarum was the subject of this study. The latter was the better adjuvant in both delayed hypersensivity and antibody formation to sheep red blood cells. Viable L. plantarum stimulated exclusively the delayed hypersensivity, where heat-killed bacteria had an adjuvant effect on antibody formation. For optimal adjuvant effects lactobacilli had to be injected in a dose of 10(8) into the same site as the antigen. Viable lactobacilli and to a lesser degree heat-killed bacteria induce hepato-splenomegaly, suggesting mediation of the adjuvant activity by the reticuloendothelial system. Granuloma formation with mainly mononuclear cell infiltrates could be observed after subcutaneous administration of viable lactobacilli whereas heat-killed lactobacilli induced granulomata containing about equal numbers of granulocytes and mononuclear cells. The possible clinical application of L. plantarium in the immunotherapy of tumours is suggested.

Adjuvants, Immunologic↗
PubMed1978

Effect of a lactobacilli preparation on traveler's diarrhea. A randomized, double blind clinical trial.

The effectiveness of prophylactic ingestion of a commercial preparation of lactobacilli (Lactinex) for the prevention or modification of traveler's diarrhea was tested in a randomized double blind clinical trial in 50 volunteer travelers to Mexico from the United States. Twenty-six subjects received the lactobacilli preparation and 24 received placebo. The incidence of diarrhea and its duration during the 4 weeks of observation were quite similar for the two preparations: 35% for lactobacilli-treated subjects and 29% for placebo subjects. Typically, the diarrhea was mild, lasting 2 days. From the observations during this study we conclude that prophylactic ingestion of lactobacilli for 1 week does not reduce the incidence or duration of traveler's diarrhea either during the period of ingestion or during the following 3 weeks.

Adolescent↗
PubMed1977

The importance of Lactobacilli in maintaining normal microbial balance in the crop.

1. The effect of lactobacilli on Escherichia coli has been examined in vitro and in chicken crop in vivo. 2. Inhibition of E. coli was dependent on the presence of sufficient numbers of lactobacilli. 3. In a standard test some lactobacilli were bacteriostatic and one was bactericidal. The bacteriostasis was due to the low pH produced by these strains but bactericidal activity could not be accounted for by pH alone. 4. In gnotobiotic animals the bactericidal strain was no more inhibitory for E. coli than was a bacteriostatic strain.

Animals↗
PubMed1977

Distribution of indigenous Lactobacilli in the digestive tract of conventional and gnotobiotic rats.

Distribution of indigenous lactobacilli in the gastrointestinal tracts of rats was investigated at the species level. The indigenous lactobacilli isolated from conventional rats were divided into three groups, Lactobacillus acidophilus and its related strains, L. fermentum, and L. murini. Localization of the Lactobacillus groups in the gastrointestinal tracts could be distinguished clearly based on arabinose and glucose fermentation reaction of isolates from each part of the gastrointestinal tract. Group I (L. acidophilus and the related strains) and Group II (L. fermentum) were the major populations of lactobacilli on the walls of the non-glandular part and in the contents of the stomachs of both conventional and gnotobiotic rats. Group I predominated in all the parts of the digestive tract of conventional rats, whereas Group II was in the minority in the lower part of the gastrointestinal tracts of both groups of rats. Group III (L. murini) was the predominant population of Lactobacillus in the lower part of small intestine of conventional rats and in all parts of the gastrointestinal tracts of gnotobiotic rats except for the wall of the non-glandular part of the stomach.

Animals↗
PubMed1977

Amino acid profiles and presumptive nutritional assessment of single-cell protein from certain lactobacilli.

The amino acid profiles, modified essential amino acid (MEAA) indexes, and in vitro pepsin digestibilities were determined for single-cell protein (SCP) from certain industrially important lactobacilli. For the three parameters examined, substantial differences were seen between different Lactobacillus species and between strains with a given species. SCP from all of the lactobacilli examined appeared relatively high in MEAA indexes and pepsin digestibility. SCP from L. acidophilus 3205 and L. fermenti 3954 had the highest MEAA indexes, whereas L. bulgaricus 2217 and L. thermophilus 3863 had the highest percentage of digestible crude protein. SCP from L. plantarum strains had the lowest MEAA indexes. The essential amino acid compositions of SCP from different lactobacilli appear comparable to that of Food and Agriculture Organization reference protein and SCP from other sources.

Amino Acids↗
PubMed1979

Models for study of the specificity by which indigenous lactobacilli adhere to murine gastric epithelia.

A Lactobacillus strain isolated from a mouse (indigenous) and another strain isolated from swine feces (nonindigenous) were compared in two model systems for their ability to adhere in vitro and in vivo to keratinizing squamous and columnar epithelia of mouse stomachs. In one model, stomachs dissected from specific-pathogen-free or germfree mice were injected with suspensions of lactobacilli labeled with [(3)H]thymidine and incubated at 37 degrees C. Thereafter, the non-secreting and secreting tissues were separated and washed vigorously. The radioactivity remaining with each tissue was counted by liquid scintillation spectrometry. When the radioactivity remaining with these tissues ranged between 500 and 100,000 cpm, the calculated radioactivity (disintegrations per minute) was related linearly to the number of lactobacilli adhering to the tissue. The estimate of the number of bacteria adherent to the tissue was not influenced significantly by artifacts in the techniques used. In this model, both Lactobacillus strains adhered in equally high numbers to both types of epithelial surfaces from stomachs from germfree mice. In contrast, in the second model, in which germfree mice were monoassociated with one or the other of the Lactobacillus strains, only the strain indigenous to the mouse formed dense layers on the epithelia of the nonsecreting portions of the stomachs, although both strains maintained high population levels throughout the gastrointestinal tracts of the animals. The capacity to adhere to the mucosal surface is undoubtedly necessary for lactobacilli to colonize gastric epithelia in mice. Our findings suggest, however, that nutritional or environmental conditions dictate whether particular Lactobacillus strains can colonize particular surfaces in the stomachs of living animals.

Animals↗
PubMed1977

Acid production from Lycasin, maltitol, sorbitol and xylitol by oral streptococci and lactobacilli.

The acid production from maltitol was compared with the acid production from hydrogenated starch hydrolysate (Lycasin), sorbitol and xylitol by a number of oral strains and reference strains of Streptococcus mutans, S. sanguis, S. salivarius, S. mitior, S. milleri, S. faecalis, S. faecium, S. avium, Lactobacillus casei and L. salivarius. The polyols were added to a final concentration of 1.0% to two different basal media. Incubation was performed at 37 degrees C for 7 days after which the pH was recorded. Maltitol was fermented only by the lactobacilli (about two thirds of the strains). Lycasin was fermented by all strains of S. faecalis, more than 90% of the lactobacilli, about half of the S. sanguis strains, about one third of the S. mutans strains, and by a few other streptococcal strains. Acid production from sorbitol was observed among more than 80% of the S. mutans strains and the S. faecalis strains and most of the lactobacilli strains. Sorbitol-fermenting strains of S. sanguis and of S. mitior, all isolated from sorbitol-consumers, were observed. No other sorbitol-fermenting streptococci were found. Only the reference strains L. salivarius subsp. salivarius ATCC 11741 and S. avium ATCC 14025 fermented xylitol.

Acids↗
PubMed1977

Allosteric and non-allosteric phosphofructokinases from Lactobacilli. Purification and properties of phosphofructokinases from L. plantarum and L. acidophilus.

Phosphofructokinase (ATP : D-fructose-6-phosphate 1 phosphotransferase, EC 2.7.1.11) from two different lactobacilli, Lactobacillus plantarum and Lactobacillus acidophilus were isolated and purified. Both enzymes have a molecular weight of 154 000 and consist of four subunits of identical size. Antisera from sheep immunized against the purified phosphofructokinase from L. plantarum showed immunologic cross reaction with the enzyme from L. acidophilus. In spite of the close molecular relationship indicated by the immunologic cross reaction, the kinetic behaviour of the two enzymes was strikingly different. Phosphofructokinase from L. plantarum showed pure Michaelis-Menten behaviour. Phosphofructokinase from L. acidophilus, however, showed sigmoidal substrate saturation curves for fructose 6-phosphate in the presence of slightly alkaline pH and high ATP concentrations; it was activated by fructose 1,6-biphosphate and inhibited by ADP. The results indicate that even enzymes which are structurally very similar may differ greatly with respect to their kinetic and regulatory properties and suggest that allosteric and non-allosteric phosphofructokinases have the same origin in evolution.

Adenosine Diphosphate↗
PubMed1977

Reduction of population levels of some indigenous bacteria by lactobacilli in the gastrointestinal tract of gnotobiotic rats.

Effects of each of three indigenous Lactobacillus groups on other bacterial populations were separately investigated in gnotobiotic rats. In the wall of the non-glandular part of the stomach, contents of the stomach and contents of the upper part of the small intestine, some pre-associated indigenous bacteria were reduced to conventional population levels by introducing three groups of lactobacilli: Group I (Lactobacillus acidophilus and related strains), Group II (L. fermentum) and the groups mixed. However, no obvious reduction in cell numbers of the pre-associated bacteria occurred in the case of Group III (L. murini).

Animals↗
PubMed1979

Comparative in vitro activity of five cephalosporins against Lactobacilli.

Of five parenteral cephalosporins tested against 43 lactobacilli, cephaloridine, cefazolin, and cefamandole were the most active inhibitory and bactericidal agents. Timed-kill analysis revealed a slow bactericidal effect, with significant declines in mean minimal bactericidal concentration values at 48 h versus 24 h.

Cephalosporins↗
PubMed1978

Extractability of cell wall polysaccharide from lactobacilli and streptococci by autoclaving and by dilue acid.

Autoclaving cell wall of Streptococcus mutans Ingbritt for 15 min under the Rantz and Randall conditions released one-tenth of the total cell wall carbohydrate, whereas two-thirds was extracted after autoclaving for 180 min. The extract contained the serotype c-specific antigen but lacked the lipoteichoic acid component extracted when whole cells were autoclaved. Autoclaving cell wall preparations from other strains of S. mutans and also Streptococcus salivarius and Streptococcus mitis in 0.85% NaCl for 180 min released the major proportion of the wall polysaccharide fraction. Approximately 50 to 90% of wall carbohydrate of Lactobacillus fermentum and Lactobacillus casei was released when cell wall preparations were autoclaved in 0.85% NaCl for 180 min. For wall preparations from several strains of S. mutans, autoclaving for 60 min at pH 3.75 released only 39 to 62% of wall carbohydrate, whereas almost total release could be achieved with the lactobacilli. Heating S. mutans Ingbritt cell wall for 24 h at 60 degrees C in 0.1 N H(2)SO(4) released only two-thirds of the wall carbohydrate; by comparison nearly all of the wall carbohydrate was released in 3 h from L. casei and L. fermentum. Autoclaving L. casei cell wall and purified soluble wall fractions hydrolyzed the phosphodiester bond between the polysaccharide and peptidoglycan. This was shown by the release of reactive N-acetylhexosamine in both cases and the presence of a phosphomonoester in the autoclaved soluble wall fractions. The results indicate that autoclaving can hydrolyze covalent linkages, and this must be considered when the Rantz and Randall procedure is used to obtain antigen preparations.

Cell Wall↗
PubMed1977

[Differentiation of several species of lactobacilli of the subgenus Thermobacterium according to their bacteriocin sensitivity spectra].

The method of retarded antagonism was applied to the study of L. acidophilus (187 cultures), L. salivarius (65 cultures), L. jugurti (16 cultures), L. helveticus (4 cultures) sensitivity to the action of 39 bacteriocines produced by various lactobacilli species. By the sensitivity spectra to bacteriocines L. ècidophilus cultures were divided into 76, L. salivarius--22, L. jugurti--15, and L. helveticus into 2 bacteriocines. By bacteriocine typing it was possible to differentiate into a number of bacteriocine types L. acidophilus and L. salivarius variants with the same biochemical and physiological properties.

Bacteriocins↗
PubMed1978

Effect of growth conditions on the antigenic components of Streptococcus mutans and lactobacilli.

1) The release of LTA from chemostat-grown cultures of S. mutans and L. fermentum is dependent on the generation time and pH. 2) The growth rate affects the immunogenicity of LTA and the wall polysaccharide of L. fermentum. 3) The growth of L. plantarum under glucose limitation influences the glucose content of the wall teichoic acid. The composition of the wall polysaccharide of S. mutans Ingbritt may also be changed under these conditions. 4) The conditions of autoclaving used to release cell wall antigens can hydrolyse the covalent linkage between polysaccharide and peptidoglycan.

Antigens, Bacterial↗
PubMed1975

Nature of the determinant responsible for the adhesion of lactobacilli to chicken crop epithelial cells.

Using an in vitro method, some factors affecting the attachment of a strain of lactobacillus to chicken crop epithelial cells have been studied. Time of contact beyond 10 min, pH value, age or growth temperature of the bacterial culture, or nature of the energy source in the growth medium had little or no effect on attachment. Heating to 100 degrees C for 10 min, or treatment with EDTA or surface active compounds was also without effect. Treatment with sodium periodate markedly decreased adhesion, proteolytic enzymes had a smaller effect but wheat germ lipase was completely inactive. The pronounced inhibition of adhesion by periodate suggested the invovement of carbohydrate. However, enzymes known to attack carbohydrate substrates were inactive in reducing adhesion. Concanavalin A, which binds specifically to certain sugar residues, reduced attachment. It is suggested that these concanavalin A receptors on the lactobacillus are responsible for its attachment to crop epithelial cells.

Adsorption↗