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In this study, the influence of the probiotics, Pediococcus acidilactici (PA) and Saccharomyces cerevisiae boulardii (SCB), on intestinal immune traits and resistance to enterotoxigenic Escherichia coli (ETEC) infection was evaluated in pigs. Two weeks before farrowing, 30 sows and their future litters were allocated to the following treatments: 1) control group without antibiotic or probiotic treatment (CTRL), 2) control with antibiotic (tiamulin) added to weanling feed (ABT), or litters treated with 3) PA, 4) SCB, or 5) PA+SCB from 24 h after birth. During lactation, PA, SCB, or PA+SCB were given to piglets 3 times a week by gavage. After weaning at 21 d of age, probiotics or ABT were added to the diet. Four pigs per litter were chosen to evaluate performance and blood concentrations of folic acid and vitamin B(12). Three of these were orally challenged with an ETEC strain on d 49 to 51 and killed on d 52. Three piglets from the rest of the litter were slaughtered on d 18 and 3 others on d 24. Blood, ileum, and mesenteric lymph node (MLN) samples were taken to characterize leukocyte populations, determine IgA concentrations in ileal flushes, and evaluate bacterial translocation in MLN. No treatment effect on postweaning performance and on blood concentrations of folic acid and vitamin B(12) was observed. In the ileum, the percentage of CD4(-)CD8(+low) T cells was greater (P = 0.05) in 18-d-old nursed piglets treated with PA than in those of the CTRL and PA+SCB groups. In the MLN, the percentage of CD8(+) T cells was not affected by any of the treatments at d 18 and 24 but decreased (P = 0.006) after weaning. In the blood, CD8(+) T cells were not affected by treatments or weaning. After the ETEC challenge (d 52), bacterial translocation to MLN was reduced (P = 0.05) in pigs treated with PA, SCB, PA+SCB, or ABT compared with CTRL. No treatment effect was observed on blood leukocyte populations after ETEC challenge, although a time effect (d 42 vs. 52) indicated that blood CD4(+) and gammadelta-T lymphocytes were increased (P < 0.05) on d 52 compared with d 42, whereas CD4(-)CD8(+low) T lymphocytes and monocytes were markedly reduced (P < 0.01). Finally, the IgA concentration in ileal flushes collected on d 42 and 52 was greater in SCB and CTRL piglets than in ABT and PA piglets. In conclusion, probiotics may have the potential to modulate establishment of lymphocyte populations and IgA secretion in the gut and to reduce bacterial translocation to MLN after ETEC infection.

In the present study, we studied the potential regulation by rat myometrial alpha1-adrenergic receptors (alpha1-AR) of the newly identified Gh alpha protein/phospholipase C delta 1 (PLC delta 1) signaling pathway and compared myometrial inositol phosphates (InsP) production and activity of the uterine circular muscle in response to alpha1-AR activation between mid-pregnancy and term. For this, we quantified the level of rat myometrial alpha1-AR coupling to Gh alpha protein by photoaffinity-labeling, the cytosolic amount of PLC delta 1 enzyme by immunoblotting, and the expression level of alpha1-AR subtypes by RT-PCR. The results showed an increased level of alpha1-AR/Gh alpha protein coupling and the amount of PLC delta 1 at term (+147 and +65% respectively, versus mid-pregnancy). This was correlated with an up-regulation of alpha 1d-AR subtype (+70% versus mid-pregnancy). Incubation of myometrial strips with phenylephrine (Phe), a global alpha1-agonist, increased InsP production in a dose-dependent manner at both mid-pregnancy and term, but with an enhanced potency (tenfold decrease in EC(50) value) at term. Phe also dose-dependently induced contraction of the circular muscle at both mid-pregnancy and term. However, unlike InsP response, no amelioration of potency was observed at term. Similar results were obtained with the endogenous agonist norepinephrine. Our results show, for the first time, that rat myometrial alpha 1d-AR/Gh alpha/PLC delta 1 signaling pathway is up-regulated at term. This is associated with an increased potency of alpha1-AR to elicit InsP production but not uterine contraction at this period. It is thus hypothesized that alpha1-AR, through activation of Gh alpha/PLC delta 1 system, are not primarily involved in the initiation of labor but may rather regulate responses such as myometrial cell proliferation or hypertrophy.

Soil microorganisms exhibit a high degree of spatial variation, even in homogenously managed agroecosystems. The spatial pattern of microbial biomass and activity may be related to soil properties like hydrology, texture, organic matter and pH. This study took place in a 0.4-ha field with research plots under wheat and maize production. Soil microbial biomass, respiration and extractable nutrient levels were not generally affected by fertilizer treatments (inorganic NP fertilizer, poultry manure), relative to the unfertilized plots. This was probably due to soil heterogeneity; for instance, soil pH (1:2, soil:water) ranged from 5.8 to 7.2 across the field. Exploratory path analysis revealed that soil pH, dissolved organic carbon and total organic carbon concentrations were directly related to the spatial pattern in soil microbial biomass and respiration. This work demonstrates that path analysis could be used to identify independent soil variables and describe relationships between soil properties and microbial indicators in spatially heterogeneous agroecosystems. Key words: Field variability, microbial biomass, mineral fertilizer, organic amendment, soil respiration, spatial dependence

International audience; The first accelerated exotic beam of the SPIRAL (Production System of Radioactive Ion and Acceleration On-Line) facility at GANIL at Caen has been delivered for experiments in September 2001. After working for almost 5 years, 32 experiments were performed in the facility using exotic isotopes of helium, oxygen, neon, argon and krypton. The intensities of the radioactive beams increased since the first beam was delivered. Nominal intensity values are achieved for most of noble gas beams. Developments of new beams as well as the increasing of present intensities for a number of isotopes are being undertaken. In particular, in this contribution it is presented the first results obtained for the production of light alkali beams. Other developments are also envisaged in the close future.

Since 2001, the SPIRAL I Facility (Systeme de Production d’Ions Radioactifs en Ligne, version I) located at GANIL in Caen (France) has delivered radioactive ion beams mainly of “light” gaseous elements, from He to Kr. In March 2004, a beam of some pps of 31Ar (15 ms) was produced. Very soon, a new target-and-ion-source system (TISS) will be tested for the production of radioactive multi-charged ions of alkaline elements. For making radioactive ion beams of heavier elements, the SPIRAL II project is under study. The proposed technique is to produce heavy fragments by fission of uranium induced by neutrons, themselves produced by a 200 kW deuteron beam hitting a carbon converter. The technical studies should be completed by the end of 2004. After a short presentation of results from the operation of SPIRAL I, the design of the SPIRAL II target and ion-source system is presented.

We report a series of measurements performed to characterize the atom-to-ion transformation time in singly charged electron cyclotron resonance ion sources (ECRISs). Three ECRISs were used with He, Ne, Ar and Kr noble gases. The transformation time as a function of the support gas flow, the ionization efficiency, and source volume is presented and compared to a calculation made with a simple dynamic model.

Affinity interaction based resins have long been the foundation for various purification platforms of biological molecules. For the purification of rAAV, the affinity resin AVB Sepharose HP (AVB) has been used to successfully purify a number of different serotypes. However, to date the use of AVB for the purification of the AAV8 serotype has been relatively unsuccessful due in part to modest binding capacity. In this work we investigate the use of a new, prototype affinity resin for the purification of AAV8 from crude feed streams. Performance of the AVB and prototype resins were directly compared for the purification of selected AAV8 feed streams. Differences in capacities, loading steps, wash step tolerances and elution steps will be discussed. In addition, the resulting performance of purifying AAV8 using the prototype resin is directly compared against the best case performance of the AVB resin purifying a different serotype more commonly used on AVB. Finally, the scale-up use of the prototype resin from bench to manufacturing will be discussed. These results demonstrate that the prototype affinity resin is a viable option for the scaleable, chromatographic purification of AAV8 from crude harvest streams.

Measurements of the transformation time of atoms into ions were carried out with two 2.45 GHz electron cyclotron resonance ion sources (ECRIS) in the case of the simple ionization of He, Ne, Ar and Kr gases. The effect of the plasma volume, of the dead volumes and of the ionization efficiency are presented. Some rules are deduced for the design of the next ECRIS dedicated to radioactive ion production with noble gases.

Minimono is a 2.45 GHz electron cyclotron resonance ion source for singly charged ions which uses only permanent magnets. Measurements of ionization efficiencies, maximum currents extracted, and emittances for H+, 3,4He+, N+, Ne+, Ar+, Kr+, S+, and Si+ were carried out. In the case of buckminster fullerenes, C60+, C602+, and C603+ ions were extracted. The results obtained, the general mechanical simplicity of this ion source, and its low cost make this source attractive for the production of stable and radioactive ions.

Summary The effects of retinol (ROL), retinoic acid (RA) and B-carotene (CAR) on the response of chicken lymphocyte blastogenesis and on the cytotoxic activity of natural killer (NK) cells were evaluated in vitro. Speenocytes were isolated from healthy growing chicks and cultured in presence of different concentrations of ROL, RA and CAR under similar experimental conditions. Lymphocyte response to concanavalin A (Con A) was affected by adding ROL, RA and CAR to the cultures, by the time of exposure and by methods used for diluting ROL, RA and CAR stock solutions. Addition of ROL stock solutions diluted in cell culture medium suppressed lymphocyte response in a linear dose-dependent manner whereas pre-dilution of ROL stock solutions in fetal bovine serum (ROL-FBS) increased blastogenesis in a linear manner. Addition of 10 μM of ROL-FBS at the beginning of the incubation period or 16 h after enhanced proliferative responses by 5 and 9 times, respectively, as compared to Con A-induced cells without ROL. Suppressed proliferative response of Con A-induced cells was seen when both RA and CAR working solutions were added at a concentration of 10 μM and 1 μM, respectively. However, RA and CAR pre-diluted in FBS (RA-FBS, CAR-FBS) increased proliferative response of Con A-induced cells in a quadratic dose-dependent manner. At peak levels of RA-FBS and CAR-FBS, blastogenesis was respectively 2.1 and 1.3 times higher than activated cells without RA-FBS or CAR-FBS. No significant increase was detected with RA or CAR directly diluted in RPMi medium. Cytotoxic activity of chicken NK cells was reduced when ROL was added to the cultures, whereas RA and CAR enhanced NK activity. Both preparations of tested compounds had similar effects on NK activity. Our results showed that immunocompetent cell functions were modulated by retinol, retinoic acid and B-carotene in a dose-dependent manner and by the method used to prepare the working solutions.

A Zea mays callus culture containing chlorophyll was established and grown photomixotrophically. Cell chloroplast structure, and pigment and soluble protein contents were examined. Expression of some key enzymes of C4 carbon metabolism was compared with that of etiolated (heterotrophic) and green photoautotrophic leaves. Chlorophyll content of the callus was 15–20% that of green leaves. Soluble protein content of callus was half that of leaf cells. Electron microscopic observations showed that green callus cells contained only typical granal chloroplasts. Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco, EC 4.1.1.38) activities in green callus were ca 30% those of green leaves but 2–3 times higher than in etiolated leaves. Quantitative enzyme protein determination, using antibodies specific to maize leaf Rubisco showed that the chloroplastic carboxylase represented about 7% of total soluble protein in green callus, in parallel to its low chlorophyll content. The specific activity of Rubisco in callus and leaves was unchanged. Phosphoenolpyruvate carboxylase (PEPC, EC 4.1.1.31) activity in green callus was about 20% that of green leaves and similar to that measured in etiolated leaves. Apparent Km (PEP) values (0.08 mM) for PEPC isolated from green callus and etiolated leaves were very different from values (0.5 mM) obtained with PEPC from green leaves. These kinetic characteristics together with the absence of inhibition by malate and activation by glucose-6-phosphate suggest that the properties of PEPC isolated from green callus and etiolated maize leaves are very similar to those of PEPPC from C3 plants. Using PEPC antibodies specific to green maize leaf enzyme, immunotitration of PEPC preparations containing identical enzyme units allowed complete precipitation of the green leaf enzyme with increasing antibody volumes. In contrast, 60–70% of the activity of PEPC from etiolated and green callus was inhibited, suggesting low affinity for the maize green leaf PEPC antiserum (typical C4 form). Ouchterlony double diffusion tests revealed only partial recognition of PEPC in green callus and etiolated leaves. NAD-malate dehydrogenase (NAD-MDH, EC 1.1.1.37) activity in callus was 2 and 3 times higher, respectively, than in etiolated and green leaves. NADP-malic enzyme (NADP-ME, EC 1.1.1.40) activity in callus cultures was much lower than in green leaves. All our data support the hypothesis that cultures of fully dedifferentiated chlorophyllous tissues of Zea mays possess a C3-like metabolism.

A summary of recent and future developments in metallic ion production with an electron cyclotron resonance ion source (ECRIS) at GANIL is presented. Multicharged metallic ions are routinely produced with an ECRIS (ECR4 14 GHz) and accelerated for nuclear and atomic physics experiments. We present the various methods which have been used to generate these multicharged metallic ions. The accelerator requires stable beams for periods of weeks. The results obtained recently by direct ion plasma sputtering of Ni, Nb, and U samples are remarkable and stable beams from these metals have been delivered continuously for weeks. A pulsed EXCIMER laser, injecting a beam axially through the extraction hole of the ECRIS, has been tested for ablation on a rotating uranium target for uranium beam production. The metal ions from volatile compounds technique using volatile compounds has been also tested with ferrocene [Fe(C5H5)2] to produce multicharged Fe ions. We plan to install a third high voltage platform using an EC...

A method was developed for the determination of several phenylurea and triazine herbicides and their transformation products in oysters at the low microg/kg level. Pressurised liquid extraction (PLE) of lyophilisated samples had required successive SPE combined with a liquid/liquid extraction to provide relatively clean extracts for the determination in LC-MS/MS. This procedure was validated according to the 2002/657/EC analytical decision. Efficiency of the analytical method led to confirmatory CCalpha values ranging from 0.1 to 14 microg/kg with an R.S.D. value ranging from 14% to 66% and a recovery yield ranging from 32% to 46% for phenylureas and from 29% to 75% for triazines.

International audience; The 100 kV platform used for the production of primary beams has been modified in order to increase the beam intensity. The configuration of the new platform is described and preliminary results are reported. A gain intensity of a factor of 2 has already been obtained for sulfur: $^{36}$S (65% enriched) 3.2 kW at 77.5 MeV/u, i.e., 1.14 p$\mu$A, as well as for nickel: $^{58}$Ni (68%) 1.5 kW at 74.5 MeV/uA, i.e., 0.35 p$\mu$A.

Production of radioactive ions has started at GANIL on the SPIRAL facility since 2001 and numerous multicharged radioactive ion beams have been delivered for high energy nuclear experiments. This article makes an overview of the different beams that have been produced. In the mean time, an important R and D research program is continued in oder to produce new species of radioactive elements. A new concept of multicharged radioactive production that couples a monocharged ion source, based on the monolithe concept, to an ecr ion source like nanogan3 is under developments and is described The development of monocharged ion sources with high efficiencies is also motivated by a new big project that is under studies at GANIL : the SPIRAL 2 Project. The goal of this project consists in extending the disponible radioactive ion beams to very heavy elements created with a new method of production : while the spiral 1 facility uses the projectile fragmentation for radioactive nuclei production, the spiral 2 project is based on the fission of a Uranium carbide target induced by a neutron flow created by a high intensity deuton beam. The principle and an overview of the project is presented.Production of radioactive ions has started at GANIL on the SPIRAL facility since 2001 and numerous multicharged radioactive ion beams have been delivered for high energy nuclear experiments. This article makes an overview of the different beams that have been produced. In the mean time, an important R and D research program is continued in oder to produce new species of radioactive elements. A new concept of multicharged radioactive production that couples a monocharged ion source, based on the monolithe concept, to an ecr ion source like nanogan3 is under developments and is described The development of monocharged ion sources with high efficiencies is also motivated by a new big project that is under studies at GANIL : the SPIRAL 2 Project. The goal of this project consists in extending the disponible radioactive ion beams to very heavy elements created with a new method of production : while the spiral 1 facility uses the projectile fragmentation for radioactive nuclei production, the spiral 2 project ...

This paper discusses the use of a single wafer process tool to deposit As-doped amorphous silicon emitter films on double polysilicon, self-aligned SiGe heterojunction NPN bipolar transistors. In-situ processing has the advantage of reducing the number and complexity of process steps while being compatible with sub-350 nm emitter technologies. Below 350 nm implanted polysilicon emitters are expected to encounter adverse perimeter effects and the plug effect. We report increased transistor gain with amorphous silicon emitters compared with similarly doped polysilicon emitters caused by a reduction in the base current. We will demonstrate how the base current can be controlled by polysilicon deposition temperature. Also, with in-situ doping, we show how improved uniformity of the As concentration at the base-emitter junction translates into improved across-wafer uniformity for the pinch base sheet resistance.

After running for three weeks with a 76Ge beam provided by the ECR-4 ion source at GANIL we have investigated the recycling effect of an SF6 plasma. The initial beam was produced by the classical method, using germanium dioxide in our micro-oven and helium as support gas. The overall ionization efficiency was measured and found to be around 3%. Without the oven, and using SF6 instead of helium, the ECR-4 ion source has been able to produce a very stable beam during a two-week period. The intensity of 76Ge13+ (enrichment 88%) was increased to 40 e μA, and the overall ionization efficiency reached 40%. The oven method of production, the recycling effect and perspectives are described in this paper.

A 45-year-old man developed a painful and rapidly progressive sensory-motor polyneuropathy associated with confusion and convulsions. This resulted in hypoventilation and led to respiratory failure and coma. A rapid and diffuse alopecia occurred after 3 weeks in the intensive care unit. Examination of hair roots under polarized light detected dystrophic anagen hairs with dark bands caused by empty spaces in the disorganized cortex. These dark zones were originally reported in patients with thallium poisoning and a toxicological investigation confirmed thallium exposure. The classical systemic symptoms and the various dermatological signs are reviewed, and the origins of contamination and physiopathology discussed.

The SPIRAL 2 facility is now under construction and will deliver either stable or radioactive ion beams. First tests of nickel beam production have been performed at GANIL with a new version of the large capacity oven, and a calcium beam has been produced on the heavy ion low energy beam transport line of SPIRAL 2, installed at LPSC Grenoble. For the production of radioactive beams, several target∕ion-source systems (TISSs) are under development at GANIL as the 2.45 GHz electron cyclotron resonance ion source, the surface ionization source, and the oven prototype for heating the uranium carbide target up to 2000 °C. The existing test bench has been upgraded for these developments and a new one, dedicated for the validation of the TISS before mounting in the production module, is under design. Results and current status of these activities are presented.

The binding of insulin to cultured IM-9 human lymphocytes was studied by flow cytometry using FITC-insulin and biotinylated insulins coupled to streptavidin-phycoerythrin (N alpha beta 1-biotinylinsulin (B-insulin) and N alpha B1-(biotinyl-epsilon-aminocaproyl)insulin (NBC-insulin)). The reference methods were 125I-insulin binding and the insulin-antiinsulin antibody complexes for flow cytometry. There was a close correlation between 125I-insulin binding and increase in fluorescence for B-insulin, NBC-insulin, and insulin-anti-insulin antibody complexes, but not for FITC-insulin. NBC-insulin gave the largest increase in fluorescence (79 +/- 9 channels) and the the insulin-antiinsulin antibody complexes the smallest (34 +/- 2 channels) (P < 0.05). FITC-insulin and B-insulin gave similar results: 47 +/- 6 and 59 +/- 6 channels. The concentration reducing 125I-insulin binding by 50% was 1.1 x 10(-9) M for native insulin, 2.7 x 10(-9) M for B-insulin, 3.3 x 10(-9) M for NBC-insulin, and 6.6 x 10(-9) M for FITC-insulin (P < 0.05). Nonspecific binding was low for B-insulin and NBC-insulin but reached 75% for 10(-6) M FITC-insulin. These results suggest that B-insulin and NBC-insulin are suitable ligands for insulin binding studies using flow cytometry. This two-step procedure is easier than the insulin-antiinsulin antibody complex technique. Its poor affinity, specificity, and sensitivity make FITC-insulin less suitable.

In this work, we present a few spectroscopic results deduced from a multiparticle–multihole Gogny energy density functional. Both pairing correlations in the ground state and low-lying spectroscopy of a few tin isotopes are discussed. All the results have been obtained using the same D1S Gogny interaction in the one-body mean-field and the residual part associated with a two-body and density-dependent Hamiltonian.

International audience; In the last two years the development of the large-capacity oven was continued. First tests on-line with calcium, lead, tin and magnesium beams were achieved. We successfully produced 30 $\mu$A of $Ca^9+$, 13 $\mu$A of $Pb^23+$, 8 $\mu$A of $Sn^21+$, and 50 $\mu$A of $Mg^7+$. Some deformation of the filament appeared when working at high temperature. Several configurations of the filament and the use of an alternate power supply have been tested to solve this problem. The beam's intensities and the ionization efficiencies were improved in comparison with the standard microoven performances. The results of magnesium beam, 110 $\mu$A of $Mg^5+$ obtained with the "MIVOC" method are compared with those using the oven technique.

Ginkgo biloba extract is known to be efficient in diseases associated with free radical generation. The purpose of this work was to study, under in vitro conditions, the action of Ginkgo biloba extract (Gbe) against superoxide anion (O2-.), which is directly or indirectly implicated in cell damage. Gbe appears to have both an O2-. scavenging effect and also a superoxide dismutase activity. Its antiradical effect was demonstrated by low temperature electron spin resonance and in a non-enzymatic system (phenazine methosulfate-NADH), and its enzymatic activity was shown by polarographic determination.

Applying bubble method and gold decoration technique to the study of the crystal—melt interface of Czochralski grown mixed NaClLiCl crystals, with variable compositions, phase separation on a microscopic scale is observed in different domains of the phase diagram. The shape, surface morphology, and growth mechanism of these phases are discussed, sometimes in relation with the microscopic wetting of the growing interface by the melt. Durch Anwendung der Blaschen-Methode und der Golddekorationstechnik auf die Untersuchung der Grenzflache Kristall-Schmelze von nach dem Czochralski-Verfahren gezuchteten NaClLiCl-Mischkristallen variabler Zusammensetzung wird in verschiedenen Bereichen des Phasendiagramms eine Phasentrennung von mikroskopischer Grosenordnung beobachtet. Die Kristallform, Oberflachenmorphologie und der Wachstumsmechanismus dieser Phasen werden diskutiert, zum Teil in Beziehung zu einer mikroskopischen Benetzung der Grenzflache durch die Schmelze.

Crude and milled fibers from different asbestos mines in Quebec have been analyzed for their metallic content. Crude fibers present a few metal concentrations that are characteristic for each mine. Manganese and iron can be used as discriminators, zinc and cobalt are constantly present in minute quantities, and calcium is virtually absent from crude fibers. Milled fibers are enriched in metals by factors ranging from 1.3 to > 15. Chromium and nickel concentrations are many times higher than in crude fibers and iron content is increased by more than 100%. Total metal content in milled fibers is mainly due to nonchrysotile material.

1. Goat kidney beta-mannosidase was purified 8500-fold to a specific activity of 65,000 nmol/h per mg of protein with a 6% yield by using multiple steps including cation-exchange and anion-exchange fast protein liquid chromatography. This is the first description of a highly purified preparation from goat tissue; however, it was not homogeneous, as judged by silver-stained SDS/polyacrylamide-gel electrophoresis. 2. The enzyme exhibited microheterogeneity when analysed by isoelectric focusing (pI 5.5-6.5). 3. Purified beta-mannosidase hydrolysed the terminal beta-(1→4)-linkage of oligosaccharides that accumulate in beta-mannosidosis.

A Ginkgo biloba extract (Gbe) containing flavonoids, among other compounds, was tested for the release of activated oxygen species (O-2, H2O2, OH.) during the stimulation of human neutrophils (PMNs) by a soluble agonist. The extract slows down O2 consumption (respiratory burst) of stimulated cells by its inhibitory action on NADPH-oxidase, the enzyme responsible for the reduction of O2 to O-2. Consequently, superoxide anion (O-.2) and hydrogen peroxide (H2O2) production is significantly decreased when the PMNs stimulation is done in the presence of the extract at concentrations of 500, 250 and 125 micrograms/ml. Moreover, the hydroxyl radical generation (OH.) is very much decreased at concentrations as low as 15.6 micrograms Gbe/ml, which indicates that the extract also has free radical scavenging activity. Gbe is able at least to reduce very severely the activity of myeloperoxidase contained in neutrophils. This enzyme, secreted into the intra and extracellular medium, catalyzes the oxidation of chloride (Cl-) by H2O2 to yield strong oxidants (HOCl, chloramines) which are implicated in inflammatory processes.

In this study, ribosomal intergenic spacer analysis (RISA) was used to monitor changes of intestinal microbiota of piglets treated at birth with or without Pediococcus acidilactici (PA) and/or Saccharomyces cerevisiae ssp. boulardii (SCB) and weaned piglets fed with control diet supplemented with PA and/or SCB or antibiotic. During lactation, probiotics were given orally to piglets three times a week. At weaning (day 21), probiotics and the antibiotic, tiamulin, were added to the diet. Fifteen piglets per treatment were slaughtered at day 18 and day 24. The tracking of each probiotic from colonic samples was done using PCR primers specific for PA targeting the 16S rRNA gene or a specific culture medium for enumeration of SCB. The results showed the presence of probiotics in colonic samples of piglets supplemented with probiotics. Dendograms (UPGMA and Ward’s method), and non-metric multidimensional scaling analysis showed that the variability of RISA profiles in colonic microflora between individual piglets within a treatment was too high to obtain a grouping based on probiotic supplementation. Based on the relative frequency of internal transcribed spacers from RISA profiles (indicator species analysis) and diversity indices (Shannon, richness and evenness), both PA and the antibiotic treatments reduced the bacterial diversity in the gut of piglets after weaning compared with preweaning, while diversity was slightly increased postweaning compared with preweaning in control without antibiotic and SCB groups. In conclusion, all dietary additives differently affected postweaning microbial community composition; however, both antibiotic and PA reduced postweaning microbial diversity suggesting a possible benefit of PA supplementation during the postweaning transition period. Key words: Intestinal flora, piglet, PCR, probiotic, RISA profile, weaning