Multiplication of Orally AdministeredClostridium butyricumin Rats

Effects of Clostridium butyricum on growth performance, immune function, and cecal microflora in broiler chickens challenged with Escherichia coli K88

This study was conducted to investigate the effects of Clostridium butyricumon growth performance, immune function, and cecal microflora in broiler chickens challenged with Escherichia coli K88. Three hundred sixty 1-d-old broiler chickens were randomly divided into 4 treatments: negative control (NC) birds were fed a basal diet and not challenged with E. coli K88; positive control (PC) birds were fed a basal diet and challenged with E. coli K88; C. butyricum treatment (CB) birds were fed a diet containing 2 × 10(7) cfu C. butyricum/kg of diet and challenged with E. coli K88; and colistin sulfate treatment (CS) birds were fed a diet containing 20 mg of colistin sulfate/kg of diet and challenged with E. coli K88. Birds fed CB had greater (P < 0.05) BW than the PC birds from 3 to 21 d postchallenge. Birds fed CB had greater (P < 0.05) serum IgA and IgY at 14 d postchallenge, greater (P < 0.05) serum IgM at 21 d postchallenge, and greater (P < 0.05) mucosal secreted IgA at 3 and 7 d postchallenge than the PC birds. Birds fed CB had greater concentrations of serum complement component 3 at 14 d postchallenge, and greater (P < 0.05) concentrations of serum complement component 4 at 3, 7, and 14 d postchallenge than the PC birds. Birds in the CS or CB treatments had less cecal E. coli population at 3, 7, and 21 d postchallenge, and less cecal Clostridium perfringens counts at 21 d postchallenge compared with the PC birds. The CB treatment increased (P < 0.05) the population of cecal Lactobacillus at 3 d postchallenge and the number of cecal Bifidobacterium at 3, 14, and 21 d postchallenge in comparison with the PC treatment. The results indicate that dietary supplementation of CB promotes growth performance, improves immune function, and benefits the cecal microflora in Escherichia coli K88-challenged chickens.

Growth Limiting pH, Water Activity, and Temperature for Neurotoxigenic Strains of Clostridium butyricum

Some rare strains of Clostridium butyricum carry the gene encoding the botulinal type E neurotoxin and must be considered as possible hazards in certain types of food. The limiting growth conditions for C. butyricum were determined in peptone yeast glucose starch (PYGS) broth incubated anaerobically at 30°C for up to 42 days. The minimum pH values permitting growth depended on the acidulant and strain. Organic acids were more effective at inhibiting growth than HCl as expected. The lowest pH values at which growth of toxigenic and nontoxigenic strains of C. butyricum was observed in broth acidified with HCl were 4.1 and 4.2, respectively. In organic acids, however, the minimum pH varied between 4.4 and 5.1 depending on acid type and concentration. The minimum water activity for growth of toxigenic strains of C. butyricum was 0.96. The minimum growth temperatures of the toxigenic strains of C. butyricum (ca 10-11°C) were somewhat higher than for non-toxigenic ones (8°C). It was concluded that control of toxigenic C. butyricum in the food industry needs to allow for the greater pH tolerance of this species compared with proteolytic C. botulinum.

Spore-forming bacteria and their utilisation as probiotics

In this review article, the beneficial application of bacterial spore formers as probiotics in the food industry is discussed based on the knowledge gleaned from current publications. The summary of new scientific results provides evidence of the advantages of the utilisation of Bacillus or Clostridium strains in the food industry. Both bacteria are able to produce a very stable duration form: the endospore. Compared to the widely used lactic acid bacteria, bacterial spores offer the advantage of a higher survival rate during the acidic stomach passage and better stability during the processing and storage of the food product. In many food products, germination of the spores does not occur. Hence the product quality of the food is not affected because of their inactive metabolism. Besides the possible utilisation and functional properties, an overview of the fast-developing knowledge about the mechanisms of the beneficial health effects of spore-forming bacteria is provided.

Intestinal transit of an orally administered streptomycin-rifampicin-resistant variant of Bifidobacterium longum SBT2928: its long-term survival and effect on the intestinal microflora and metabolism

AIMS

The objectives of this study are to investigate the fate of a streptomycin-rifampicin-resistant variant of Bifidobacterium longum SBT2928 (BL2928SR) and the influence of its oral administration on the composition and metabolism of the intestinal microflora.

METHODS AND RESULTS

Intestinal passage of BL2928SR was monitored by a combination of selection with antibiotics and identification by a randomly amplified polymorphic DNA (RAPD)-PCR method. Intestinal microflora was analysed by the method developed by Mitsuoka et al. (1965, 1974). Long-term survival of orally administered BL2928SR in the human intestine was confirmed. BL2928SR ingestion specifically lowered faecal populations of Enterobacteriaceae and clostridia, including lecithinase-positive Clostridium spp.

CONCLUSION

BL2928SR and its parent strain, BL2928, are considered to be appropriate candidates for probiotics.

SIGNIFICANCE AND IMPACT OF THE STUDY

It is clarified that BL2928SR has the ability for long-term survival in the human gastrointestinal tract, and alters the composition and metabolism of the intestinal microflora.

Modified pyrogallol-initiated immunogold-silver enhancement technique applicable to prokaryotes

A modified immunogold-silver enhancement technique that was designed to reduce the nonspecific granular background staining, particularly for application on prokaryotic organisms, is reported. Aerial oxidation of pyrogallol contained in the commercial silver enhancer solution was effectively controlled during storage and in the reaction mixture. A combination of strategies such as storing the reagent under argon, modifying it using 0.5% (w/v) anhydrous sodium sulfite, reducing the concentration of silver ions in the reaction mixture and limiting the length of the silver enhancement reaction considerably reduced the granular background staining. The modified technique was demonstrated on the bacterium Xanthomonas campestris pv. malvacearum (Smith) Dye. A 7-min silver enhancement step produced little background staining, while optimal silver intensification of the bacterium pre-treated with the immunogold label was achieved.

Intestinal distribution and intraluminal localization of orally administered Clostridium butyricum in rats

Clostridium butyricum has been used as a probiotic in animals and humans for years, however, its fate in the intestine has not been clarified yet. We investigated the intestinal fate of C. butyricum using a selective medium and a monoclonal antibody after orally administering C. butyricum spores to rats. The number of C. butyricum, both viable and dead cells, in the intestinal contents were counted by enzyme-linked immunosorbent assay (ELISA) at various times after a single oral administration. The total viable number of C. butyricum was counted using a selective medium, and viable resting spores were selectively detected by treating the samples with ethanol. To investigate the intraluminal localization of the C. butyricum cells, frozen intestinal tracts were imprinted onto slides and stained with immunogold-silver. Total viable spores exceeded the number of viable resting spores by more than 10-fold from the proximal to middle of the small intestine 30 min after administration. Vegetative cells of C. butyricum were first detected in the distal small intestine after 2 hr, and vegetative growth was observed from the cecum to the colon 5 hr after administration. Dead vegetative cells were detected 9 hr after administration, and C. butyricum cells were not detected in the intestine after 3 days. The C. butyricum cells in the intestinal imprints were stained specifically by immunogold-silver staining, and proliferative cells were observed in the cecum after 3 hr. These results suggest that the administered C. butyricum germinated in the upper small intestine, grew mainly from the distal small intestine to the colon and were excreted from the rat intestine within 3 days.