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PubMedDate not supplied

["Lactobacillus murinus" n. sp., a new species of the autochtoneous dominant flora of the digestive tract of rat and mouse (author's transl)].

Lactobacillus murinus, a new species isolated from rat and mouse digestive tracts, is described. It belongs to the subgenus Thermobacterium although it is able to ferment pentoses. The electrophoretic mobilities of soluble proteins and lactic dehydrogenase, the guanine + cytosine content (43.7%), the L-lysine-D-Aspartic acid cell wall (b type, Kandler), the immunological relationship with other Lactobacillus species and also the aminoacid requirements show that it has to be assigned to a new species, Lactobacillus murinus. This species settles in the digestive tract of rodents in their first days of life and remains ther as a dominant flora throughtout the whole life of the animal.

Amino Acids↗

PubMed1995

Molecular cloning and DNA sequence analysis of pepL, a leucyl aminopeptidase gene from Lactobacillus delbrueckii subsp. lactis DSM7290.

A genomic library of Lactobacillus delbrueckii subsp. lactis DSM7290 DNA fragments from a Sau3A partial digestion in the low-copy-number vector pLG339, was used to screen Escherichia coli for the presence of peptidases. Using the chromogenic substrate leucine-beta-naphthylamide (Leu-NH-Nap) and E. coli strain CM89 lacking the corresponding enzyme activity in an enzymic plate assay, allowed the isolation of two peptidase genes; the newly described pepL and the recently cloned and sequenced pepN. Clones could be distinguished not only by the restriction pattern of isolated plasmids but also by the rate and intensity of their colour reaction with Leu-NH-Nap. Three out of five clones were identified to express the Lactobacillus pepN gene; the others were shown to express a second aminopeptidase gene, designated pepL. This gene, together with 200 bp upstream of the proposed AUG initiation codon, was further subcloned and sequenced. The corresponding open reading frame of 897 nucleotides is predicted to encode a protein of 299 amino acids (34,541 Da). Searching the EMBL database revealed similarity to the prolinase of Lactobacillus helveticus (45.8% identity), to the iminopeptidases of Lb. delbrueckii subsp. lactis and Lb. delbrueckii subsp. bulgaricus (25.5%), and to the Bacillus coagulans prolinase (21.5%). Minor similarities were detected for hydrolytic enzymes with serine active sites. The product encoded by the pepL gene was functional but could not be visualized on Coomassie-blue-stained polyacrylamide gels. High level expression of peptidase L in E. coli was achieved by placing the gene under the control of the T7 promoter.

Amino Acid Sequence↗

PubMed1996

[Change in various biological properties of Lactobacillus as affected by ribonuclease].

The influence of RNAse from Bacillus intermedius on the growth of the industrial strain Lactobacillus plantarum 8R-A3 was studied. It was shown that the stimulating effect of the enzyme depended on its dose and manifested itself in decreasing the growth lag phase. At the same time the growth stimulating dose of RNAse increased the Lactobacillus adhesion to the epithelial cells and promoted secretion of proteinases from Lactobacillus to the culture medium. The possible use of RNAse as a stimulant of the growth of industrial strains was demonstrated which is advantageous for colonization of the biological surfaces.

4-Aminobenzoic Acid↗

PubMed1998

Lactobacillus species associated with active caries lesions.

Lactobacilli that are most frequently associated with active caries lesions in dentine were isolated and identified as part of a research project which aims to determine the role of the predominant species of these organisms in the carious process. Samples of carious dentine were collected from 12 patients with open caries lesions (Group A) and stimulated saliva samples were collected from 12 patients with a DMFT = 0 and confirmed presence of lactobacilli in the oral cavity (Group B). After serial dilutions samples were plated on Rogosa agar and incubated anaerobically at 37 degrees C for 48 hours. Representative colonies were isolated from each sample, using Harrison's disc and species were identified by classical taxonomy. A total of 153 isolates were identified. The redefinition and description of lactobacilli species in recent systematic literature resulted in a new and different species composition of oral lactobacilli as shown in this study, namely: homofermentative species (Group A = 82 per cent; Group B = 90 per cent) were predominantly Lactobacillus paracasei (Group A = 39 per cent; Group B = 30 percent) and Lactobacillus rhamnosus (Group A = 31 per cent; Group B = 41 per cent). Heterofermentative species (Group A = 18 per cent; Group B = 10 per cent) were predominantly Lactobacillus fermentum (Group A = 68 per cent; Group B = 100 percent).

Bacteriological Techniques↗

PubMed1998

Orally administered Lactobacillus strains differentially affect the direction and efficacy of the immune response.

In mice, strain dependent cytokine production profiles are induced after oral administration of Lactobacillus. Such a cytokine profile seems to determine the direction and efficacy of the humoral response. In SJL mice lactobacilli are able to enhance or inhibit the development of disease after induction of experimental autoimmune encephalomyelitis (EAE). Immuno-histochemical analysis of cytokine profiles showed that differential modulation is obtained dependent on the Lactobacillus strain applied. Serum antibody responses to i.p. immunisation with chicken gamma globulin in BALB/c mice are also modulated by oral application of Lactobacillus. Lactobacilli are now being developed as safe live antigen carriers for application in vaccine technology, but also for the excretion of autoantigens in order to induce tolerance. The findings of this study imply that by proper strain selection the direction of the response can be influenced by the induction of a specific cytokine profile.

Adjuvants, Immunologic↗

PubMed1998

[Lactobacillus acidophilus endocarditis].

BACKGROUND: Lactobacillus is a commensal germ found in the buccal cavity, the digestive tract and the vagina. Usually non-pathogenic except in case of dental caries, it can occasionally be the causal agent in severe endocarditis. CASE REPORT: A 70-year-old woman developed endocarditis on an aortic valve bioprosthesis. Lactobacillus acidophilus was isolated from blood cultures of the valve after surgery. COMMENTS: Forty-four cases of Lactobacillus endocarditis have been reported in the literature to date. Mortality is high (26%). The main difficulty in treatment is germ tolerance to penicillin and aminosides found in all cases. Cure requires high dose parenteral antibiotics and surgery in many cases (26%).

Aged↗

PubMed1998

[Use of exogenous ribonuclease for improvement of Lactobacillus biological properties].

The influence of exogenous RNAse on the dynamics of the acid formation by the industrial strain 8R-A3 of Lactobacillus plantarum, its antibiotic sensitivity and antagonistic activity was studied. In the presence of the RNAase growth stimulating dose both a decrease of the culture lag-phase and a more intensive accumulation of lactic acid in the incubation medium resulting in an increase of the Lactobacillus antagonistic activity were observed. It was shown that RNAase increased the Lactobacillus stability to tetracycline and erythromycin by 32 to 57 per cent as compared to the control.

Anti-Bacterial Agents↗

PubMed2006

Parameters affecting the adsorption of plantaricin 423, a bacteriocin produced by Lactobacillus plantarum 423 isolated from sorghum beer.

Plantaricin 423 is bactericidal to logarithmic and stationary-phase cells of Enterococcus sp. HKLHS and L. sakei DSM 20017. Detection of extracellular DNA and beta-galactosidase suggests that the mode of action is most probably by destabilizing of the cell membrane. Adsorption of plantaricin 423 to target cells ranged from 17% for Streptococcus caprinus ATCC 700066 to 67% for Lactobacillus plantarum LMG 13556, Lactobacillus curvatus DF38, Listeria innocua LMG 13568 and Lactobacillus sakei DSM 20017. Treatment of Enterococcus sp. HKLHS and L. sakei DSM 20017 with Triton X-100, Triton X-114 and chloroform increased the adsorption of plantaricin.

Adsorption↗

PubMed1999

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↗

PubMed1998

Use of 16S rRNA gene sequencing to identify Lactobacillus casei in septicaemia secondary to a paraprosthetic enteric fistula.

Human infections caused by Lactobacillus spp. are rarely reported in the literature. Underlying conditions are frequently reported, and identification of lactobacilli to the species level remains rare. A case of Lactobacillus casei septicaemia secondary to a vascular graft infection is reported. The 16S rRNA sequencing technique was used to definitively identify Lactobacillus casei.

Aged↗

PubMed2006

Fluorescence in situ hybridisation detection of Lactobacillus plantarum group on olives to be used in natural fermentations.

At present there are very few studies on the bacterial diversity of olives and on the importance of the microbial species for the fermentation of olives aimed to table olives production. Most of the authors report on the occurrence of Lactobacillus plantarum as principal member of these communities or at least as the species responsible for the fermentation. In this study, fluorescence in situ hybridisation (FISH) with 16S rRNA probes was used to evaluate the occurrence of L. plantarum in olives. A 18-bp oligonucleotide probe was used in FISH experiments to evaluate the specificity of detection among Lactobacillus species. The probe was tested against 30 Lactobacillus species and appeared to be specific for L. plantarum, L. paraplantarum and L. pentosus. The probe was then used to investigate the occurrence of these species in 25 samples of olives (cultivar "Leccino") collected in Campania region (Southern Italy). The olives were washed in a saline solution and the suspensions were then analysed by FISH and observed by fluorescence microscopy. No hybridisation signal was detected in at least 30 fields of observation when the L. plantarum-specific probe was used, probably due to the low sensitivity of the FISH method. Olive samples were plated on Rogosa agar and about 40% of the samples did not give growth after 5 days. When colony growth was observed, bulk cells from Rogosa agar plates were collected and analysed by DNA extraction followed by 16S rDNA Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). The different microbial species were identified by direct sequencing of DGGE bands. Leuconostoc pseudomesenteroides was the most frequently found species, occurring in more than 50% of the samples that had shown growth on Rogosa agar. The closest relatives of the species of the genera: Leuconostoc, Pediococcus, Pseudomonas and Raoultella were also identified suggesting that guided fermentation by using selected LAB starters is advisable for a safe and desired table olives production.

Base Sequence↗

PubMed2006

Determination of specific activities and kinetic constants of biotinidase and lipoamidase in LEW rat and Lactobacillus casei (Shirota).

Enzyme kinetic parameters, such as K(m), V(max) (or V), k(cat)/K(m), and K(i) (by biotin or lipoic acid) for biotinidase and lipoamidase were determined in Lewis (LEW) rat and Lactobacillus casei (Shirota) using fluorimetric high-performance liquid chromatography (HPLC). It was found that the final protein concentration below 0.1mg/ml is sufficient to obtain linear hydrolytic reaction and to determine the Michaelis-Menten type kinetic parameters (K(m), V, K(i)). We applied this HPLC enzyme assay method onto the rat and some bacteria. The highest specific activities (Vs) for biotinidase were found in Lactobacillus casei (Shirota) and rat kidney. It was also found that the largest K(i) by product for biotinidase and lipoamidase were present in the Lactobacillus casei (Shirota). There has been found specie (between rat and mouse) differences and tissue (organ) differences, together with tissue region differences and sex differences in some tissues. Summary of the distributions of both enzymes in LEW rat was also presented. Therefore, this HPLC determination method for the enzyme kinetic parameters in tissues is expected to be an indispensable tool for the investigation of the various diseases in humans.

Amidohydrolases↗

PubMed2004

Lactobacillus casei, dominant species in naturally fermented Sicilian green olives.

This study investigated the phenotypic and genotypic characteristics of lactic acid bacteria in naturally fermented green olives, collected from different areas of Sicily. Both classical biochemical tests and PCR/Restriction Fragments Length Polymorphism (RFLP) of 16S rDNA were used to characterize the isolates. The identity of the isolates was obtained by the partial sequencing analysis of the 16S rDNA. The BioMerieux software assigned the 13 heterofermentative strains to the Lactobacillus brevis species; 24 homofermentative strains were classified as Lactobacillus casei and the remaining 11 homofermentative lactobacilli were identified as Lactobacillus plantarum. The rapid ID 32 STREP test identified coccal-shaped strains as Enterococcus faecium species. The PCR/RFLP analysis showed a remarkable bacterial heterogeneity within the isolates. The 16S rDNA partial sequencing did not confirm biochemical identification, revealing a strong dominance of isolates belonging to the L. casei species. It is noteworthy that this species has never been reported as dominant species in fermented vegetables.A combination of molecular and biochemical analysis allowed the identification of species involved in natural food fermentations.

Fermentation↗

PubMed2004

Identification and characterization of a conserved nuclease secreted by strains of the Lactobacillus casei group.

AIMS: Nuclease secretion was evaluated for five species of Lactobacillus and the activity was characterized in terms of thermal resistance, molecular weight and mode of action on plasmid DNA. METHODS AND RESULTS: Assays of nuclease from L. rhamnosus ATCC 9595 on DNA of different origins indicates a broad activity spectrum. Secreted nuclease from this strain resists a thermal treatment of 20 min at 100 degrees C, is not sensitive to a treatment for disruption of disulphide bonds nor to EDTA treatment under 10 mM l(-1). Nuclease production is not growth linked and seems to be constitutive. Extracellular nuclease of L. rhamnosus ATCC 9595 introduces a single-stranded nick in supercoiled DNA, thus potentially reducing the transformability of plasmid DNA. In seven of eight tested strains, SDS-PAGE revealed a major protein with a molecular weight of ca 35 kDa. Minor degradation products also showed nuclease activity. CONCLUSIONS: A comparative analysis of the extracellular fractions of 14 different Lactobacillus strains indicate that nuclease secretion seems to be a widely distributed function among species of milk-related lactobacilli. The production of secreted nuclease may contribute to the low ability of Lactobacillus spp. to be transformed and maintain exogenous DNA. SIGNIFICANCE AND IMPACT OF THE STUDY: Determination of the characteristics and distribution of nuclease activity contribute to developing strategies to overcome this barrier to efficient transformation of milk lactobacilli.

Animals↗

PubMed2001

Cytokine production in arthritis susceptible and resistant rats: a study with arthritogenic and non-arthritogenic Lactobacillus cell walls.

The basis of the different susceptibility to bacterial cell wall-induced arthritis between Lewis and Fischer rats is unclear. Likewise, it is not known why cell walls of some species of Lactobacillus are arthritogenic and those of others are not. With these two questions in mind, we investigated the role of anti-inflammatory (interleukin (IL)-10, IL-4) and proinflammatory (tumour necrosis factor (TNF)-alpha, IL-1 beta) cytokines in Lewis and Fischer rats injected intraperitoneally with cell walls from arthritogenic or nonarthritogenic species of Lactobacillus. Cytokine levels in the serum and in vitro production by peritoneal macrophages and splenocytes were studied. The results obtained indicate that the differences in the production of IL-10, IL-4, TNF-alpha or IL-1 beta do not explain the difference in the arthritis susceptibility between Lewis and Fischer rats. Likewise, the arthritogenicity of different Lactobacillus cell walls appears not to be dependent on their capacity to stimulate cytokine production.

Animals↗

PubMedDate not supplied

[Persistent Lactobacillus casei subspecies rhamnosus bacteremia in a 14 year old girl with acute myeloid leukemia. A case report].

The present clinical observation is related to a 14-year-old girl suffering from acute myeloid leukemia. The clinical course was complicated by episodes of severe enterocolitis, E. coli- septicemia, pancreatitis and pneumonia. In the course of continued cytostatic and antibiotic treatment a persistent asymptomatic Lactobacillus casei subsp. rhamnosus-bacteremia became detectable by a total of 18 blood cultures. Microbial cultures of the faeces revealed colony-forming unites of this germ in orders of 10(9)/g. Antibiotic eradication attempts according to the resistogram were not successful. The Lactobacillus-bacteremia disappeared only after 13 months when the cytostatic therapy was terminated. An adjuvant influence of the Lactobacillus infection on the outcome of the underlying disease cannot be excluded.

Adolescent↗

PubMed2001

Lactobacillus casei subsp. rhamnosus sepsis in a patient with ulcerative colitis.

Lactobacillus species are part of normal gastrointestinal flora and are an uncommon cause of bacteremia. Lactobacillus casei subsp. rhamnosus was repeatedly isolated in the blood cultures of a 43-year-old woman with ulcerative colitis. Lactobacillus spp. could be considered a potential opportunistic pathogen whenever there is disruption of the physiologic architecture of the intestinal mucosa, such as in abdominal surgery, endoscopic procedures, or enteric pathologies. Clinicians and clinical microbiologists need to be aware of this infective complication in patients with ulcerative colitis.

Adult↗

PubMed2001

Comparative sequence analysis of a recA gene fragment brings new evidence for a change in the taxonomy of the Lactobacillus casei group.

The taxonomic positions of species of the Lactobacillus casei group have been evaluated by sequencing and phylogenetic analysis of a 277 bp recA gene fragment. High sequence similarity between strain ATCC 393T, currently designated as the type strain of L. casei, and the type strain of Lactobacillus zeae, LMG 17315T, has been established, while L. casei ATCC 334 and Lactobacillus paracasei NCDO 151T form a single phylogenetic group. The taxonomic status of species and strains at issue is discussed.

DNA, Bacterial↗