Innate immunity is shaped by a complex of redundant and pleiotropic factors that ensure recognition, alert and suppression of pathogens. Innate immune responses in the gut are complicated by the requirement of parallel tolerance to commensal microflora predominating in cell numbers and species. In normal individuals, the intestinal mucosa together with relevant lymph nodes represents a robust barrier against systemic spread of non-typhoid Salmonella. Contemporary insights into these defense mechanisms are reviewed.

• MeSH
• Gastrointestinal Tract immunology   MeSH
• Humans MeSH
• Immunity, Innate * MeSH
• Salmonella immunology   MeSH
• Salmonella Infections immunology   MeSH
• Immunity, Mucosal * MeSH
• Intestinal Mucosa immunology   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH

A total of 142 human and 88 calf bifidobacteria were isolated and identified; approximately 12 % of all isolated strains exhibited auto-aggregation (Agg) phenotype (Agg+). Properties considered to be predicting for their adhesion to intestine, i.e. auto-aggregation, and hydrophobicity were determined by xylene extraction in 18 human and 8 calf origin bifidobacteria. Co-aggregation of 8 human bifidobacteria with 8 clostridia was also evaluated. Agg varied between 16.3 and 96.4 %, hydrophobicity values ranged from 0 to 82.8 %. The strongest Agg and hydrophobicity were observed in B. bifidum and B. merycicum isolates. However, there were no statistically significant correlations between these two properties. Variability in the percentage of Agg and hydrophobicity was observed after cultivation of bifidobacteria on different carbon sources. All bifidobacteria showed co-aggregation ability with clostridia tested but there were remarkable differences depending on specific combinations of strains. The bifidobacterial strains with the highest ability to co-aggregate with clostridia were B. bifidum I4 and B. longum I10 isolated from infants; these strains gave also high values of Agg. Agg properties together with co-aggregation ability with potential pathogen can be used for preliminary selection of probiotic bacteria.

• MeSH
• Bacterial Adhesion * MeSH
• Bifidobacterium classification   growth & development   isolation & purification   physiology   MeSH
• Clostridium growth & development   isolation & purification   physiology   MeSH
• Feces microbiology   MeSH
• Hydrophobic and Hydrophilic Interactions MeSH
• Culture Media MeSH
• Humans MeSH
• Surface Properties MeSH
• Cattle MeSH
• Intestines microbiology   MeSH
• Carbon metabolism   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Cattle MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Culture Media MeSH
• Carbon MeSH

The intestinal environment accommodates a wide range of contents ranging from harmless beneficial dietary and microbial flora to harmful pathogenic bacteria. This has resulted in the development of highly adapted epithelial cells lining the intestine. This adaptation involves the potential of crypt cells to proliferate and to constantly replace villous cells that are lost due to maturity or death. As a result, the normal intestinal epithelial integrity and functions are maintained. This phenomenon is eminent in intestinal defense whereby the intestinal epithelial cells serve as a physical barrier against luminal agents. The protection against agents in the gut lumen can only be effective if the epithelium is intact. Restitution of the damaged epithelium is therefore crucial in this type of defense.

• MeSH
• Antibiosis * MeSH
• Bacteria * growth & development   pathogenicity   MeSH
• Bacterial Infections microbiology   prevention & control   MeSH
• Caco-2 Cells MeSH
• Epithelial Cells immunology   metabolism   microbiology   MeSH
• Gastrointestinal Diseases microbiology   prevention & control   MeSH
• Humans MeSH
• Probiotics * MeSH
• Heat-Shock Proteins metabolism   MeSH
• Intestines cytology   immunology   microbiology   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH
• Names of Substances
• Heat-Shock Proteins MeSH

A rat animal model of left colostomy was found to significantly impair the growth curve of rats. Assessment of the intestinal flora showed that colostomy mostly affects the cecal but not colonic microflora. Generally, the number of enterococci was increased in both ileum and cecum; cecal lactobacilli also rose, accounting for a promotion of lactic acid bacteria in colostomised rats. No significant differences between colostomised, laparotomised and control rats could be observed for the translocation of intestinal bacteria to internal organs of rats (i.e. spleen, kidneys, lungs or liver), whatever their diet. Heat-killed Lactobacillus acidophilus strain LB administration (dead probiotic bacteria) tended to exhibit a stimulatory effect on bifidobacteria, probably affecting the culture-medium fermentation substances included in the pharmaceutical product. This effect was abolished by laparotomy and colostomy. A trend towards a probiotic-like effect, not susceptible to colostomy, was also witnessed as counts of lactobacilli tended to increase in both cecum and colon of all animals fed with L. acidophilus LB.

• MeSH
• Bacterial Translocation * MeSH
• Bacterial Physiological Phenomena * MeSH
• Colostomy adverse effects   MeSH
• Rats MeSH
• Lactobacillus acidophilus metabolism   MeSH
• Models, Animal MeSH
• Colonic Diseases microbiology   surgery   MeSH
• Rats, Wistar MeSH
• Intestines microbiology   MeSH
• Hot Temperature MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Pseudobutyrivibrio xylanivorans strain Mz5(T), an anaerobic bacterium (originating from the rumen of a Holstein-Friesian cow), has some attributes that make it a possible probiotic strain (very active hydrolases, bacteriocin and conjugated linoleic acid production). For the estimation of its adhesion ability, the adhesion test on Caco-2 cells was introduced and adapted. The adhesion was performed in an anaerobic glove box in standard 24-well plates at neutral pH for 30 min. The best method for separation of the adhered bacteria from Caco-2 cells appeared to be homogenization with an automatic pipette. The number of adhered bacteria was too small to be determined microscopically, so a new approach, i.e. detection of the apparent lag phase in liquid growth medium was tested. Under the selected assay conditions 1.04 bacterial cells from the late exponential phase adhered to one Caco-2 cell, which confirms the adhesion capability of P. xylanivorans Mz5(T). The adapted adhesion test using Caco-2 cells is suitable for estimation of adhesion capability of anaerobic bacteria.

• MeSH
• Bacterial Adhesion physiology   MeSH
• Cell Culture Techniques MeSH
• Butyrivibrio cytology   metabolism   MeSH
• Caco-2 Cells microbiology   MeSH
• Oxygen metabolism   MeSH
• Humans MeSH
• Probiotics MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Oxygen MeSH

The region of the prtR gene coding for the active site of PrtR proteinase was detected in natural isolates of lactobacilli, previously determined as Lactobacillus rhamnosus. This region was present in all L. rhamnosus strains with proteolytic activity. The PCR primers used were constructed on the basis of the sequence of the catalytic domain of the prtR proteinase gene. These primers generated in colony-PCR procedure specific 611 1-bp product with DNA from natural isolates of L. rhamnosus. No PCR amplifications using these primers were obtained for closely related bacteria of genus Lactobacillus, regardless of their proteolytic activity. In addition, these primers could be used singly or in multiplex PCR together with the Lactobacillus genus-specific primers. Compared with the other proteinases within the genus Lactobacillus (PrtP, PrtB and PrtH) which retained the activity in cell-free proteinase extracts, PrtR proteinase showed proteolytic activity only under in vivo conditions (whole cells of the producing strains).

• MeSH
• Bacterial Proteins chemistry   genetics   metabolism   MeSH
• Cysteine Endopeptidases chemistry   genetics   metabolism   MeSH
• DNA, Bacterial analysis   genetics   MeSH
• DNA Primers MeSH
• Catalytic Domain MeSH
• Lacticaseibacillus rhamnosus enzymology   genetics   isolation & purification   MeSH
• Humans MeSH
• Polymerase Chain Reaction MeSH
• Food Microbiology MeSH
• Vagina microbiology   MeSH
• Binding Sites genetics   MeSH
• Check Tag
• Humans MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH
• Names of Substances
• Bacterial Proteins MeSH
• Cysteine Endopeptidases MeSH
• DNA, Bacterial MeSH
• DNA Primers MeSH
• prtR protein, Porphyromonas gingivalis W50 MeSH Browser