Biomedical subjects

D Matteuzzi

Publications and source records attributed to D Matteuzzi.

At least 19 recordsLinked to original sources

PubMed2004

High-performance anion-exchange chromatography coupled with pulsed amperometric detection and capillary zone electrophoresis with indirect ultra violet detection as powerful tools to evaluate prebiotic properties of fructooligosaccharides and inulin.

Fructooligosaccharides (FOS) and inulin are food grade non-digestible carbohydrates that exert beneficial nutritional effect. This paper describes the suitability of high-performance anion-exchange chromatography coupled with pulsed amperometric detection (HPAEC-PAD) and capillary zone electrophoresis (CZE) to evaluate fermentation properties of FOS and inulin in pure Bifidobacterium cultures; and to study their effects on faecal cultures (microbial population and short-chain fatty acids). Prebiotic effectiveness of FOS and inulin of different degrees of polymerization was evaluated monitoring the changes in their molecular weight distribution during the in vitro growth of selected Bifidobacterium strains. The qualitative analysis of the residual soluble oligosaccharides or polysaccharides from Raftilose Synergy, Raftiline HP and Raftilose P95 was carried out by HPAEC-PAD, using a CarboPac PA 100 column and an appositely optimized gradient elution program. Under the optimized gradient elution conditions, glucose, fructose, sucrose were resolved from each other and from fructans with a DP ranging from 3 (1-kestose) to 60. The chromatographic profiles of the spent broths pointed out that almost every strain presented a different capability to ferment fructan chains of variable DP, indicating wide strain to strain differences. To explore the prebiotic effect of FOS and inulin, related to of short chain fatty acids (SCFAs) accumulation in faecal cultures due to fermentative metabolism of intestinal microflora, analysis of SCFAs, acetic and lactic acid was achieved by co-electroosmotic capillary electrophoresis, where the electrophoretic mobility of the anionic analytes and electroosmotic flow (EOF) were similarly directed. Moreover, the use of UV detection for the analyses of our organic anions required a running electrolyte which allowed indirect detection. The optimization of the capillary electrophoretic conditions was carried out by applying a chemometric study based on the use of the experimental design, the effects of three parameters, i.e. temperature, voltage and percentage of methanol added to the background electrolyte were investigated.

Anion Exchange Resins↗

PubMed2004

Identification method based on PCR combined with automated ribotyping for tracking probiotic Lactobacillus strains colonizing the human gut and vagina.

AIMS: A molecular methodology based on PCR-associated automated ribotyping was developed to specifically detect the Lactobacillus strains of two probiotic products (an orally administered lyophilized preparation and vaginal tablets) in human faeces and vaginal swabs. METHODS AND RESULTS: The 16S-23S rDNA sequences and the ribotype profiles of the probiotic lactobacilli were characterized and new species-specific primer sets were designed. The identification of faecal and vaginal lactobacilli isolated from subjects administered with the probiotic products was performed by using PCR with species-specific primers followed by strain-specific automated ribotyping. CONCLUSIONS: The PCR-ribotyping identification allowed to study the colonization patterns of the probiotic lactobacilli in the human gut and vagina evidencing the strains with the best survival capability. SIGNIFICANCE AND IMPACT OF THE STUDY: The proposed molecular method represents a powerful tool of strain-specific identification, useful for differentiating exogenous from indigenous strains in any microbial ecosystem and for rationally choosing probiotic bacteria with the best chance of survival in the host.

Colony Count, Microbial↗

PubMed2004

Evaluation of the rrn operon copy number in Bifidobacterium using real-time PCR.

AIMS: A real-time PCR-based method was developed to evaluate the Bifidobacterium rRNA operon copy number. As a result of their repetitive nature, rRNA operons are very suitable targets for chromosomal integration of heterologous genes. METHODS AND RESULTS: The rrn operon multiplicity per chromosome was determined by real-time PCR quantification of the 16S rRNA amplicons obtained from genomic DNA. The values obtained in several bifidobacterial strains of human origin ranged from 1 to 5. The reliability of the method developed was confirmed by Southern hybridization technique. CONCLUSIONS: In the Bifidobacterium genus the rrn operon copies showed variability at species and strain level. The identification of Bifidobacterium strains with high rRNA multiplicity allowed the selection of potential hosts for chromosomal integration. SIGNIFICANCE AND IMPACT OF THE STUDY: The methodology here proposed represents a rapid, reliable and sensitive new tool for the quantification of rrn operon copy number in bacteria.

Bifidobacterium↗

PubMed2002

Characterization and selection of vaginal Lactobacillus strains for the preparation of vaginal tablets.

AIMS: To characterize and select Lactobacillus strains for properties that would make them a good alternative to the use of antibiotics to treat human vaginal infections. METHODS AND RESULTS: Ten Lactobacillus strains belonging to four different Lactobacillus species were analysed for properties relating to mucosal colonization or microbial antagonism (adhesion to human epithelial cells, hydrogen peroxide production, antimicrobial activity towards Gardnerella vaginalis and Candida albicans and coaggregation with pathogens). The involvement of electrostatic interactions and the influence of bacterial metabolic state in the binding of lactobacilli to the cell surface were also studied. Adherence to epithelial cells varied greatly among the Lactobacillus species and among different strains belonging to the same Lactobacillus species. The reduction in surface negative electric charge promoted the binding of several Lactobacillus strains to the cell membrane whereas lyophilization reduced the adhesion capacity of many isolates. The antimicrobial activity of lactobacilli culture supernatant fluids was not directly related to the production of H2O2. CONCLUSIONS: Three strains (Lactobacillus brevis CD2, Lact. salivarius FV2 and Lact. gasseri MB335) showed optimal properties and were, therefore, selected for the preparation of vaginal tablets. The selected strains adhered to epithelial cells displacing vaginal pathogens; they produced high levels of H2O2, coaggregated with pathogens and inhibited the growth of G. vaginalis. SIGNIFICANCE AND IMPACT OF THE STUDY: The dosage formulation developed in this study appears to be a good candidate for the probiotic prophylaxis and treatment of human vaginal infections.

Bacterial Adhesion↗

PubMed2002

Effects of rifaximin administration on the intestinal microbiota in patients with ulcerative colitis.

The effect of rifaximin on the intestinal bacterial population was studied in a clinical trial. Twelve patients with ulcerative colitis were administered rifaximin 1800 mg/day in 3 treatment periods of 10 days, each followed by 25 days of wash-out. Fecal samples were collected at the beginning and at the end of each treatment period to perform microbiological examinations. Titer variations of enterococci, coliforms, lactobacilli, bifidobacteria, Bacteroides spp., and Clostridium perfringens as well as their susceptibility to rifaximin during the different phases of the study were evaluated. The presence of Candida spp. was also monitored. After each wash-out period, concentrations of the intestinal microbial groups tested returned to initial values, showing that the administration of high doses of rifaximin does not significantly modify the colonic microbiota. Rifaximin-resistant isolates were also found, particularly in bacteria belonging to Bifidobacterium genus, included as probiotics in several fermented foods and in pharmaceutical preparations.

Adult↗

PubMed2001

Effects of probiotic administration upon the composition and enzymatic activity of human fecal microbiota in patients with irritable bowel syndrome or functional diarrhea.

In a clinical trial, 10 patients suffering from irritable bowel syndrome or functional diarrhea were administered the probiotic preparation VSL-3. Preliminary results indicated that administration of VSL-3 improved the clinical picture and changed the composition and biochemistry of fecal microbiota. Titer variations of intestinal bacterial groups were evaluated by culture and PCR techniques. A significant increase in lactobacilli, bifidobacteria and Streptococcus thermophilus was observed as a consequence of probiotic treatment, while enterococci, coliforms, Bacteroides and Clostridium perfringens did not change significantly. The strains Bifidobacterium infantis Y1 and Bifidobacterium breve Y8, included in VSL-3, were specifically detected in feces of patients treated with the probiotic by using strain-specific PCR primers. In addition, fecal beta-galactosidase increased and urease activities decreased as a result of changes in the intestinal microbiota induced by VSL-3 administration.

Adult↗

PubMed2001

Reduction of oxaluria after an oral course of lactic acid bacteria at high concentration.

BACKGROUND: Hyperoxaluria is a major risk factor for renal stones, and in most cases, it appears to be sustained by increased dietary load or increased intestinal absorption. Previous studies have shown that components of the endogenous digestive microflora, in particular Oxalobacter formigenes, utilize oxalate in the gut, thus limiting its absorption. We tested the hypothesis of whether oxaluria can be reduced by means of reducing intestinal absorption through feeding a mixture of freeze-dried lactic acid bacteria. METHODS: Six patients with idiopathic calcium-oxalate urolithiasis and mild hyperoxaluria (>40 mg/24 h) received daily a mixture containing 8 x 10(11) freeze-dried lactic acid bacteria (L. acidophilus, L. plantarum, L. brevis, S. thermophilus, B. infantis) for four weeks. The 24-hour urinary excretion of oxalate was determined at the end of the study period and then one month after ending the treatment. The ability of bacteria to degrade oxalate and grow in oxalate-containing media, and the gene expression of Ox1T, an enzyme that catalyzes the transmembrane exchange of oxalate, also were investigated. RESULTS: The treatment resulted in a great reduction of the 24-hour excretion of oxalate in all six patients enrolled. Mean levels +/- SD were 33.5 +/- 15.9 mg/24 h at the end of the study period and 28.3 +/- 14.6 mg/24 h one month after treatment was interrupted compared with baseline values of 55.5 +/- 19.6 mg/24 h (P < 0.05). The treatment was associated with a strong reduction of the fecal excretion of oxalate in the two patients tested. Two bacterial strains among those used for the treatment (L. acidophilus and S. thermophilus) proved in vitro to degrade oxalate effectively, but their growth was somewhat inhibited by oxalate. One strain (B. infantis) showed a quite good degrading activity and grew rapidly in the oxalate-containing medium. L. plantarum and L. brevis showed a modest ability to degrade oxalate even though they grew significantly in oxalate-containing medium. No strain expressed the Ox1T gene. CONCLUSIONS: The urinary excretion of oxalate, a major risk factor for renal stone formation and growth in patients with idiopathic calcium-oxalate urolithiasis, can be greatly reduced with treatment using a high concentration of freeze-dried lactic acid bacteria. We postulate that the biological manipulation of the endogenous digestive microflora can be a novel approach for the prevention of urinary stone formation.

Adolescent↗

PubMed2000

Enhanced production of L-(+)-lactic acid in chemostat by Lactobacillus casei DSM 20011 using ion-exchange resins and cross-flow filtration in a fully automated pilot plant controlled via NIR.

Due to the lack of suitable in-process sensors, on-line monitoring of fermentation processes is restricted almost exclusively to the measurement of physical parameters only indirectly related to key process variables, i.e., substrate, product, and biomass concentration. This obstacle can be overcome by near infrared (NIR) spectroscopy, which allows not only real-time process monitoring, but also automated process control, provided that NIR-generated information is fed to a suitable computerized bioreactor control system. Once the relevant calibrations have been obtained, substrate, biomass and product concentration can be evaluated on-line and used by the bioreactor control system to manage the fermentation. In this work, an NIR-based control system allowed the full automation of a small-scale pilot plant for lactic acid production and provided an excellent tool for process optimization. The growth-inhibiting effect of lactic acid present in the culture broth is enhanced when the growth-limiting substrate, glucose, is also present at relatively high concentrations. Both combined factors can result in a severe reduction of the performance of the lactate production process. A dedicated software enabling on-line NIR data acquisition and reduction, and automated process management through feed addition, culture removal and/or product recovery by microfiltration was developed in order to allow the implementation of continuous fermentation processes with recycling of culture medium and cell recycling. Both operation modes were tested at different dilution rates and the respective cultivation parameters observed were compared with those obtained in a conventional continuous fermentation. Steady states were obtained in both modes with high performance on lactate production. The highest lactate volumetric productivity, 138 g L(-1) h(-1), was obtained in continuous fermentation with cell recycling.

Automation↗

PubMed2000

Specific detection of bifidobacterium strains in a pharmaceutical probiotic product and in human feces by polymerase chain reaction.

For PCR specific detection of the strains Bifidobacterium longum Y 10, B. infantis Y 1 and B. breve Y 8 used in a new probiotic product (VSL-3), strains-specific rDNA primers have been developed. Spacer regions between the 16S and 23S rRNA genes (ITS) of the three strains were amplified by PCR with conserved primers and the nucleotide sequence of these ITSs were determined. On the basis of their comparison with the rDNA sequences retrieved from GenBank, we designed new primers which specifically recognize the species B. breve and the two strains B. infantis Y 1 and B. breve Y 8. Specificity of these primers was confirmed through the analysis of 60 bifidobacteria strains belonging to the more representative human species. The feasibility of this PCR method was investigated in commercial VSL-3 product and fecal samples collected from 4 patients affected by inflammatory bowel deseases and two healthy subjects before and after the VSL-3 administration. By PCR analysis of different VSL-3 commercial batches we were successful in differentiating and quantifying the strains B. longum Y 10, B. infantis Y 1 and B. breve Y 8. B. infantis Y 1 and B. breve Y 8 could be detected at high concentration in fecal specimens of both patients and subjects treated with the probiotic preparation, showing a different colonization behaviour. Seven days after the VSL-3 treatment suspension, no patients and subjects harbored B. infantis Y 1 and B. breve Y 8, indicating a transient presence of these exogenous strains.

Bacterial Typing Techniques↗

PubMed2000

Technological and biological evaluation of tablets containing different strains of lactobacilli for vaginal administration.

Ten strains of lactobacilli were evaluated for the administration of viable microorganisms to restore the normal indigenous flora in the treatment of urogenital tract infections (UTI) in women. As the strains considered are facultative anaerobes, optimization of the production process was particularly critical to preserve bacterial viability. The microorganisms were formulated in single- and double-layer vaginal tablets. The two layers were characterized by different release properties: one is an effervescent composition that ensures a rapid and complete distribution of the active ingredient over the whole vaginal surface; while the second is a sustained release composition capable of releasing the lactobacilli over a longer period of time. Three different retarding polymers were tested, and all the formulations and tablets were evaluated in terms of technological processability, bacterial viability and stability, and cell adhesion properties of the microorganisms. From the results obtained, three out of ten strains appear particularly suitable for their application in the treatment of UTI. A larger batch of tablets made with a mixture of the three strains was then evaluated, confirming the feasibility of their industrial production and a good bacterial viability in the final dosage form.

Administration, Intravaginal↗

PubMed2000

Oral bacteriotherapy as maintenance treatment in patients with chronic pouchitis: a double-blind, placebo-controlled trial.

BACKGROUND & AIMS: Pouchitis is the major long-term complication after ileal pouch-anal anastomosis for ulcerative colitis. Most patients have relapsing disease, and no maintenance treatment study has been performed. We evaluated the efficacy of a probiotic preparation (VSL#3) containing 5 x 10(11) per gram of viable lyophilized bacteria of 4 strains of lactobacilli, 3 strains of bifidobacteria, and 1 strain of Streptococcus salivarius subsp. thermophilus compared with placebo in maintenance of remission of chronic pouchitis. METHODS: Forty patients in clinical and endoscopic remission were randomized to receive either VSL#3, 6 g/day, or an identical placebo for 9 months. Patients were assessed clinically every month and endoscopically and histologically every 2 months or in the case of a relapse. Fecal samples were collected for stool culture before and after antibiotic treatment and each month during maintenance treatment. RESULTS: Three patients (15%) in the VSL#3 group had relapses within the 9-month follow-up period, compared with 20 (100%) in the placebo group (P < 0.001). Fecal concentration of lactobacilli, bifidobacteria, and S. thermophilus increased significantly from baseline levels only in the VSL#3-treated group (P < 0.01). CONCLUSIONS: These results suggest that oral administration of this new probiotic preparation is effective in preventing flare-ups of chronic pouchitis.

Administration, Oral↗

PubMed1999

Impact on the composition of the faecal flora by a new probiotic preparation: preliminary data on maintenance treatment of patients with ulcerative colitis.

BACKGROUND: Although 5-aminosalicylic acid (5-ASA) oral compounds are the standard maintenance treatment for ulcerative colitis in remission, some patients cannot use them because of side-effects. Clinical and experimental observations have suggested the potential role of probiotics in inflammatory bowel disease therapy. AIM: To evaluate the effects on intestinal microflora and the clinical efficacy of a new probiotic preparation in patients with ulcerative colitis in remission. PATIENTS AND METHODS: Twenty patients with ulcerative colitis, intolerant or allergic to 5-ASA, have been treated with a new probiotic preparation (VSL#3, CSL, Milan, Italy) containing 5x10(11) cells/g of 3 strains of bifidobacteria, 4 strains of lactobacilli and 1 strain of Streptococcus salivarius ssp. thermophilus. Two doses of 3 g were administered o.d. for 12 months. Faecal samples for stool culture were obtained from the patients at the beginning of the trial and after 10, 20, 40, 60, 75, 90 days, 12 months and at 15 days after the end of the treatment. The following bacterial groups have been evaluated in the faeces: total aerobic and anaerobic bacteria, enterococci, Streptococcus thermophilus, lactobacilli, bifidobacteria, Bacteroides, clostridia, coliforms. Patients were assessed clinically every two months, and assessed endoscopically at 6 and 12 months or in relapse. RESULTS: Faecal concentrations of Streptococcus salivarius ssp. thermophilus, lactobacilli and bifidobacteria increased significantly in all patients, compared to their basal level, from the 20th day of treatment (P<0.05) and remained stable throughout the study. Concentrations of Bacteroides, clostridia, coliforms, total aerobic and anaerobic bacteria did not change significantly during treatment (P = N.S.). Fifteen of 20 treated patients remained in remission during the study, one patient was lost to follow up, while the remaining relapsed. No significant side-effects have been reported. CONCLUSIONS: These results show that this probiotic preparation is able to colonize the intestine, and suggest that it may be useful in maintaining the remission in ulcerative colitis patients intolerant or allergic to 5-ASA. Controlled trials are warranted to confirm these preliminary results.

Adult↗

PubMed1998

Characterization of Bifidobacterium strains for use in soymilk fermentation.

Soybean milk, which serves as a base for a variety of beverages, contains raffinose, stachyose, pentanal and n-hexanal; the former two may be responsible for flatulence after fermentation, whilst the latter two for a beany flavour. Twenty-seven strains of Bifidobacterium were analyzed for their alpha-galactosidase activity and the production of lactic and acetic acids to determine their potential for use in the production of fermented soymilk. The behaviour of three strains in soymilk was studied to determine their ability to reduce alpha-D-galactosyl oligosaccharides and produce lactic and acetic acids. They all were able to reduce stachyose and raffinose. Pentanal and n-hexanal were metabolized by Bifidobacterium breve MB233. These data indicate that bifidobacteria can be used for biotechnological processes that employ soymilk as the substrate. A product with low levels of alpha-D-galactosyl oligosaccharides and alkylic aldehydes may be obtained.

Acetic Acid↗

PubMed1998

Improved cloning vectors for Bifidobacterium spp.

The recombinant plasmids pDLI41, pDGA7 and pDCO7 were constructed by cloning in pDG7, a vector based on Bifidobacterium longum replicon pMB1, the following heterologous genes: Pseudomonas fluorescens lipase, Bacillus licheniformis alpha-amylase and Streptomyces sp. cholesterol oxidase. The hybrid plasmids efficiently transformed Bifidobacterium belonging to five different species. A novel Escherichia coli-Bifidobacterium set of shuttle vectors based on the replicon pMB1 (pLF5, pCLJ15, pSPEC1) featuring chloramphenicol, erythromycin and spectinomycin resistance genetic determinants as selection marker for bifidobacteria, was developed. The plasmid pTRE3, a derivative of pLF5, was the smallest (2.8 kb) Bifidobacterium vector, possessed a convenient multicloning site and presented high structural and segregational stability.

Bifidobacterium↗

PubMed1994

New shuttle vector for cloning in Bacillus stearothermophilus.

Cloning vector plasmid pRP9 was constructed on the basis of the broad host-range plasmid pLM6. pRP9 was a small plasmid (2.9 kb), possessed a convenient polyrestriction site sequence and efficiently transformed Bacillus subtilis, Bacillus stearothermophilus and Escherichia coli. Furthermore, pRP9 presented a very high segregational stability in Bacillus hosts. Also, the structural stability in Bacillus strains, grown under selective pressure, of pRP9 carrying a 3-kb fragment, was high. No single-stranded and high-molecular weight pRP9 DNA was found in B. stearothermophilus. The host/vector systems described possessed all the properties required for efficient gene cloning.

Bacillus subtilis↗

PubMed1993

Cloning of the gene for cholesterol oxidase in Bacillus spp., Lactobacillus reuteri and its expression in Escherichia coli.

The cloning of the cholesterol oxidase gene in several Gram-positive bacteria, including Lactobacillus reuteri of intestinal origin, was obtained. Only the transformants of Escherichia coli harbouring the recombinant plasmid pCHOA showed a good intracellular enzyme activity. The heterologous gene was stably maintained in Gram-positive transformants but no enzyme activity was detected.

Bacillus↗

PubMed1991

Characterization of gram-positive broad host-range plasmids carrying a thermophilic replicon.

The cryptic plasmid pBC1 (1.6 kb) isolated from Bacillus coagulans Zu1961 was genetically marked with the genes for chloramphenicol and ampicillin resistance (CmR and ApR) from the Escherichia coli plasmid pJH101. The recombinant vector obtained (pCP49, 7.0 kb) replicated and expressed CmR in B. subtilis and CmR and ApR in E. coli. Different shuttle vectors for Gram+ bacteria were also constructed by inserting pBC1 into the Staphylococcus aureus plasmid pC194. The smallest of these, pLM6 (2.8 kb), containing essentially pBC1 and the chloramphenicol acetyl transferase gene from pC194, replicated in B. subtilis at a copy number of 60. By electroporation, these plasmids were introduced and stably maintained in B. subtilis, B. amyloliquefaciens, S. aureus, S. carnosus and Lactobacillus reuteri.

Bacillus subtilis↗

PubMed1990

Genetic transformation of intact cells of Bacillus subtilis by electroporation.

Plasmid DNAs were introduced by electroporation into Bacillus subtilis PB1424 as an alternative to competent-cell or protoplast transformation. The maximum electroporation efficiency was 10(4) transformants/microgram DNA. Parameters including growth phase of cells, ionic strength of the suspending medium, concentration and size of plasmid DNAs, amplitude and duration of the pulse, were evaluated in order to determine conditions that improved transformation efficiency.

Bacillus subtilis↗