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Lactobacillus casei improves resistance to pneumococcal respiratory infection in malnourished mice.

We studied the effect of Lactobacillus casei CRL 431 used as a supplement in a repletion diet on the resistance to Streptococcus pneumoniae respiratory infection in malnourished mice. Weaned mice were malnourished after they consumed a protein-free diet (PFD) for 21 d. Malnourished mice were fed a balanced conventional diet (BCD) with or without supplemental L. casei for 7, 14, or 21 consecutive days, or BCD for 7 d with L. casei supplementation on d 6 and 7 (7dBCD+2dLc). The malnourished control (MNC) group was fed only the PFD, whereas well-nourished control (WNC) mice consumed the BCD ad libitum. Mice were challenged with S. pneumoniae at the end of each dietary treatment. Lung colonization and bacteremia were significantly greater in MNC than in WNC. Normalization of the immune response occurred in malnourished mice fed the BCD for 21 d. L. casei supplementation reduced the time required for a normal response from 21 to 7 d. Mice administered the 7dBCD+2dLc repletion treatment had a more effective pathogen clearance from blood and significantly lower lung damage than MNC. This treatment improved both the number of leukocytes and neutrophils in blood and bronchoalveolar lavages (BAL) and the bactericidal function of phagocytic cells to levels that did not differ from those of WNC. In the 7dBCD+2dLc mice, antipneumococcal IgA in BAL was higher than in WNC, whereas antipneumococcal IgG in serum and BAL did not differ. This study suggests that the addition of L. casei to the repletion diet has a beneficial effect because it accelerates the recovery of the innate immune response and improves the specific immune mechanisms against an S. pneumoniae respiratory infection in malnourished mice.

Animals↗

Expression of Lactobacillus casei ATCC 393 beta-galactosidase encoded by plasmid pLZ15 in Lactococcus lactis CNRZ 1123.

Lactococcus lactis subsp. lactis CNRZ 1123, a Lac- derivative of CNRZ 1122 was transformed by electroporation with the Lactobacillus casei ATCC 393 plasmid pLZ15, which bears a beta-galactosidase gene. The transformants expressed a constitutive beta-galactosidase activity at a higher level than in Lact. casei, and in the cell-free extract two additional protein bands were detected by SDS-PAGE which could correspond to lactose metabolism enzymes. Both plasmid and beta-gal activity were stable in Lactococcus after 100 generations in glucose-containing medium.

Gene Expression Regulation, Enzymologic↗

Enhanced immunological memory responses to Listeria monocytogenes in rodents, as measured by delayed-type hypersensitivity (DTH), adoptive transfer of DTH, and protective immunity, following Lactobacillus casei Shirota ingestion.

We have investigated the effect of orally administered Lactobacillus casei Shirota (L. casei) on immunological memory, as measured by delayed-type hypersensitivity (DTH) and acquired cellular resistance (ACR). The studies were performed in animal models in which the animals were rendered immune by a primary Listeria monocytogenes infection. It was shown that orally administered viable L. casei, and not heat-killed L. casei, enhanced significantly the antigen-specific DTH at 24 and 48 h in Wistar rats, Brown Norway rats, and BALB/c mice in a time- and dose-dependent fashion. L. casei had to be administered at least 3 days prior to the DTH assay at a daily dose of 10(9) CFU in order to induce significant effects. Long-term administration of 10(9) CFU of viable L. casei resulted in enhanced ACR, as demonstrated by reduced L. monocytogenes counts in the spleen and liver and diminished serum alanine aminotransferase activity after reinfection. Enhancement of cell-mediated immunological immune responses by L. casei was further established in an adoptive transfer study. Naïve recipient BALB/c mice, which were infused with nonadherent, immunized spleen cells from L. casei-fed donor BALB/c mice, showed significantly enhanced DTH responses at 24 and 48 h compared to recipient mice which received spleen cells from control donor mice. In conclusion, orally administered L. casei enhanced cell-mediated immunological memory responses. The effects relied on lactobacillus dose and viability as well as timing of supplementation and, further, appeared to be independent of host species or genetic background.

Administration, Oral↗

Effect of an oral administration of Lactobacillus casei strain Shirota on the natural killer activity of blood mononuclear cells in aged mice.

The natural killer (NK) activity of blood mononuclear cells and splenocytes in aged mice fed on a diet containing Lactobacillus casei strain Shirota (LcS group) was significantly (P < 0.01) higher than that in mice fed on a diet without LcS. In the LcS group, there was a significant positive correlation (r = 0.63, P < 0.01) between the NK activity of blood mononuclear cells and the NK activity of splenocytes.

Administration, Oral↗

Adjuvant effects of Lactobacillus casei added to a renutrition diet in a malnourished mouse model.

Nutritional deficiencies are associated with impaired immune response, affecting the body's defence mechanisms. It is also known that Lactic Acid Bacteria (LAB) and fermented products such us yogurt have immunopotentiator activity and nutritional properties, and could thus be used as a valuable supplement in a renutrition diet. The aim of this study was to determine, in a non-severe malnutrition model, the effective dose of Lactobacillus casei (L. casei), which when is used as an adjuvant in a renutrition diet, would modulate the mucosal immune system and induce recovery of the integrity of the intestinal barrier. The experiments were performed on groups of malnourished and renourished BALB/c mice. They received after milk renutrition a supplement of different doses and periods of L. casei feeding. We measured body weight; hematologic values and serum proteins. We also characterized small intestine immunoglobulin secreting cells, intraepithelial leukocytes, mastocytes and goblet cells. Structural and ultrastructural studies were performed. Our results suggest that impaired gut barrier and mucosal immune function produced by malnutrition can be reversed by L. casei and that the dose of 10(7) cfu/day/mouse administered during 5 consecutive days was the optimal one for recovery of the gut mucosal immune system. The clinical significance of these findings suggests ways for improving mucosal immunity, and generating protection against enteropathogens in hosts immunosuppressed by malnutrition.

Animals↗

Potentiation of the effectiveness of Lactobacillus casei in the prevention of E. coli induced diarrhea in conventional and gnotobiotic pigs.

The influence of preventive administration of Lactobacillus casei subsp. casei and maltodextrin KMS X-70 on Escherichia coli 08: K88 adhesion in the gastrointestinal tract of 11 conventional and 6 gnotobiotic piglets was investigated. The preventive administration of L. casei alone had almost no inhibitory effect on the adherence of E. coli to the jejunal mucosa of gnotobiotic and conventional piglets while the lactobacilli administered together with maltodextrin decreased the number of E. coli colonising jejunal mucosa of gnotobiotic piglets by 1 logarithm (4.95 log 10/cm2) in comparison with the control group (5.96 log 10/cm2). L. casei administered in combination with maltodextrin decreased the number of E. coli colonising the jejunum of conventional piglets by more than two and half logarithm (4.75 log 10/cm2, p < 0.05) in comparison with the control (7.42 log 10/cm2). The inhibitory effect of Lactobacillus casei and maltodextrin KMS X-70 on the adhesion of E. coli to the intestinal mucosa of conventional and gnotobiotic pigs was probably mediated by Lactobacillus--produced antibacterial substances and stimulation of immunity.

Animals↗

Expression of the protective antigen of Bacillus anthracis by Lactobacillus casei: towards the development of an oral vaccine against anthrax.

Bacillus anthracis is the causative organism of the disease anthrax. The ability of the organism to form resistant spores and infect via the aerosol route has led to it being considered as a potential biological warfare agent. The current available human vaccines are far from ideal, they are expensive to produce, require repeated doses and may invoke transient side-effects in some individuals. There is also evidence to suggest that they may not give full protection against all strains of B. anthracis. A new generation of anthrax vaccine is therefore needed. The use of Lactobacillus as a vector for expression of heterologous proteins from pathogens supplies us with a safe system, which can be given orally. Lactobacilli are commensals of the gut, generally regarded as safe and have intrinsic adjuvanticity. Oral vaccines may stimulate the mucosol immune system to produce local IgA responses in addition to systemic responses. These vectors are delivered at the mucosal surface, the site where the infection actually occurs and where the first line of defence lies. The gene encoding the protective antigen (PA) of B. anthracis, an immunogenic non-toxic component of the two toxins produced, is being cloned into different homologous vectors and subsequently transformed to various Lactobacillus strains. High intracellular expression levels for the PA in Lact. casei were achieved. Mucosal antigen presentation and humoral and cellular immune responses following immunization with transformants expressing PA in various ways (intracellular, surface-anchored and extracellular) are being studied.

Administration, Oral↗

Analysis of exopolysaccharide production by Lactobacillus casei CG11, isolated from cheese.

Exopolysaccharide-producing Lactobacillus casei CG11 was isolated from soft, white, homemade cheese. In basal minimal medium, it produces a neutral heteropolysaccharide consisting predominantly of glucose (about 75%) and rhamnose (about 15%). Plasmid curing experiments revealed that exopolysaccharide production by strain CG11 is linked to a plasmid approximately 30 kb in size.

Cheese↗

Evidence that Lactobacillus casei insertion element ISL1 has a narrow host range.

The 1.3-kilobase-pair insertion element ISL1, originally isolated from Lactobacillus casei S-1, was found to have an extremely restricted host range. By DNA-DNA hybrizations performed with Southern transfers by using a cloned internal fragment of ISL1 as a molecular probe, it was found that only 3 of 19 L. casei strains examined contained sequences that hybridized to the ISL1 probe. In two of these, the hybridizing sequences were found on lactose plasmids. No homologous sequences were detected in a survey of 14 other Lactobacillus strains (9 species) and 15 strains of other bacteria (8 genera, 12 species).

Blotting, Southern↗

Evaluation of a commercial radioisotopic kit for folate assays.

A commercial kit for the radioisotopic assay of folate in serum, the Bio-Rad 'Quanta Count' folate kit, produced lower results than the Lactobacillus casei microbiological assay method. Its normal range was 2-0-13-0 microng/l and the reproducibility was similar to that of the microbiological assay method. The kit was also satisfactory for whole bood folate assays. The cost requires careful consideration before the kit is used for routine purposes.

Biological Assay↗

Colonization capability of orally administered Lactobacillus strains in the gut of gnotobiotic piglets.

In the present study, the effect of Lactobacillus casei subsp. casei and Lactobacillus fermentum inoculation on jejunum and ileum colonization in gnotobiotic piglets has been observed. The characteristic features of the strains used were strong adherence to pig epithelial gut cells as well as inhibitory activity against enteropathogenic E. coli under in vitro conditions. Strains were inoculated to 2, 3, and 4 day old gnotobiotic piglets at a dose of 2 ml (1 x 10(8) germs/ml). On the second day after the last inoculation, Lactobacillus casei subsp. casei strain counts adhered to the jejunum mucosa and those adhered to the ileum mucosa were 4.54 log 10.cm-2 and 5.40 log 10.cm-2, respectively. Lactobacillus fermentum counts adhered to the jejunum mucosa and those adhered to the ileum mucosa were 5.73 log 10.cm-2 and 4.01 log 10.cm-2, respectively. On day 5 after the last inoculation, the counts in both strains were by one log higher. The results obtained point out to the fact that Lactobacillus casei subsp. casei and Lactobacillus fermentum colonized the mucosa of both jejunum and ileum and survived in the intestinal tract. The adherence of lactobacilli to gut cells in vitro correlated with their capability to adhere to the mucosa of both jejunum and ileum in vivo.

Administration, Oral↗

Polyarthritis in rats following the systemic injection of Lactobacillus casei cell walls in aqueous suspension.

Postdysenteric Reiter's syndrome and the arthritis associated with jejunal bypass surgery for obesity suggest that the gastrointestinal tract is a possible source of bacterial products capable of initiating chronic inflammatory arthritis. Lactobacillus casei, a common component of the enteric flora, has a cell wall structure similar to that of arthritogenic streptococci. In this study we have demonstrated that a single intraperitoneal injection of an aqueous suspension of the cell walls of Lactobacillus casei induces a dose-dependent, chronic, symmetric, erosive, peripheral polyarthritis in inbred LEW/N female rats. This model suggests that bacteria in the "normal enteric flora" may be a source of inflammatory products capable of inducing chronic erosive polyarthritis.

Amino Acids↗

Production of probiotic cabbage juice by lactic acid bacteria.

Research was undertaken to determine the suitability of cabbage as a raw material for production of probiotic cabbage juice by lactic acid bacteria (Lactobacillus plantarum C3, Lactobacillus casei A4, and Lactobacillus delbrueckii D7). Cabbage juice was inoculated with a 24-h-old lactic culture and incubated at 30 degrees C. Changes in pH, acidity, sugar content, and viable cell counts during fermentation under controlled conditions were monitored. L. casei, L. delbrueckii, and L. plantarum grew well on cabbage juice and reached nearly 10x10(8) CFU/mL after 48 h of fermentation at 30 degrees C. L. casei, however, produced a smaller amount of titratable acidity expressed as lactic acid than L. delbrueckii or L. plantarum. After 4 weeks of cold storage at 4 degrees C, the viable cell counts of L. plantarum and L. delbrueckii were still 4.1x10(7) and 4.5x10(5) mL(-1), respectively. L. casei did not survive the low pH and high acidity conditions in fermented cabbage juice and lost cell viability completely after 2 weeks of cold storage at 4 degrees C. Fermented cabbage juice could serve as a healthy beverage for vegetarians and lactose-allergic consumers.

Bacteria↗

Methotrexate analogues. 12. Synthesis and biological properties of some aza homologues.

Methotrexate analogues, in which an additional nitrogen atom is inserted between the phenyl ring and the carbonyl group of the side chain, were prepared by photochemical methods. The compounds were less inhibitory toward dihydrofolate reductase and thymidylate synthetase derived from Lactobacillus casei than was methotrexate. They were also less cytotoxic against human lymphoblastic leukemia cells (CCRF-CEM). In vivo against L-1210 leukemia in mice, the aza homologue of methotrexate showed significant antitumor activity (%ILS = 55%) compared to methotrexate (%ILS = 88%).

Animals↗

Effects of a specially designed fermented milk product containing probiotic Lactobacillus casei DN-114 001 and the eradication of H. pylori in children: a prospective randomized double-blind study.

GOALS: To determine the efficacy of triple therapy supplemented with a specially designed fermented milk product containing specific probiotic Lactobacillus casei (L. casei) DN-114 001 strain on Helicobacter pylori eradication in children. BACKGROUND: Lactobacillus species possess in vitro activity against H. pylori. There are no consistent data on the impact of eradication therapy supplemented with probiotics on H. pylori cure rates in childhood in vivo. STUDY: Multicenter, prospective, randomized, double-blind controlled study. Eighty-six symptomatic H. pylori-positive children were randomized either to receive the control treatment of omeprazole, amoxicillin, and clarithromycin (OAC) for 7 days or the test treatment of omeprazole, amoxicillin, and clarithromycin for 7 days supplemented with fermented milk (Actimel) containing L. casei DN-114 001 (OAC-LC), for 14 days. H. pylori status was assessed at 4 weeks following therapy using two noninvasive tests. RESULTS: Intention-to-treat (ITT) based eradication rates for the OAC-LC group were 84.6% (95% CI, 71.2%-95.5%), and 91.6% (95% CI, 76.9%-98.2%) by per-protocol (PP) analysis. Eradication in the OAC group was 57.5% (95% CI, 42.2%-72.3%) in the ITT set and 61.3% (95% CI, 44.4%-75.0%) in the PP group. Eradication success was higher in the OAC-LC group compared with the OAC group in both ITT (P=0.0045) and PP analysis (P=0.0019). Primary resistance for clarithromycin could be determined in 21.2%. Side effects were infrequent. Drug compliance was good throughout the study. CONCLUSION: Supplementation with fermented milk, containing live special probiotic L. casei DN-114 001, confers an enhanced therapeutic benefit on H. pylori eradication in children with gastritis on triple therapy.

Antigens, Bacterial↗

Vancomycin-resistant Leuconostoc mesenteroides and Lactobacillus casei synthesize cytoplasmic peptidoglycan precursors that terminate in lactate.

The emergence of acquired high-level resistance among Enterococcus species has renewed interest in mechanisms of resistance to glycopeptide antibiotics in gram-positive bacteria. In Enterococcus faecalis and Enterococcus faecium, resistance is encoded by the van gene cluster and is due to the production of a peptidoglycan precursor terminating in D-alanyl-D-lactate, to which vancomycin does not bind. Most Leuconostoc and many Lactobacillus species are intrinsically resistant to high levels of glycopeptide antibiotics, but the mechanism of resistance has not been elucidated. To determine whether the mechanisms of resistance are similar in intrinsically resistant bacteria, cytoplasmic peptidoglycan precursors were isolated from Leuconostoc mesenteroides and Lactobacillus casei and analyzed by mass spectrometry, revealing structures consistent with UDP-N-acetylmuramyl-L-Ala-D-Glu-L-Lys-(L-Ala)-D-Ala-D-lactate and UDP-N-acetylmuramyl-L-Ala-D-Glu-L-Lys-D-Ala-D-lactate, respectively.

Amino Acid Sequence↗

The primary structure of Lactobacillus casei thymidylate synthetase. II. The complete amino acid sequence of the active site peptide, CNBr 4.

The 102 amino acid residues of CNBr 4, the largest of 5 cyanogen bromide peptides from the Lactobacillus casei thymidylate synthetase were completely sequenced by means of limited tryptic, tryptic, chymotryptic, and staphylococcal protease peptides. CNBr 4 contains both of the cysteines in an enzyme subunit, with the 5-fluorodeoxyuridylate-reactive cysteine at residue 198 and the other at residue 244.

Amino Acid Sequence↗