A quantitative approach has been proposed to evaluate the competitive inhibition of Escherichia coli and Salmonella typhi by live and heat-inactivated laboratory isolated Lactobacillus sp. on adhesion to monolayer of Caco-2 cells. Three species of Lactobacillus (L. casei, L. acidophilus, L. agilis) isolated from human neonate feces and two commercial probiotic strains (L. casei, L. acidophilus) have been compared for probiotic activity. All lactobacilli were able to attach to the Caco-2 cells, however, the degree of adhesion was bacterial strain-dependent. The adhesion indices of the two commercial probiotic strains were not significantly different from the values obtained for the other two similar fecal strains (p > 0.01). The inhibition of attachment of the pathogenic bacteria by inactivated cells of fecal L. acidophilus was examined and compared to the results of live bacteria. The inhibition pattern was similar for live and heat-inactivated L. acidophilus (p > 0.01). The number of attached pathogenic bacteria to the Caco-2 cells decreased when the number of L. acidophilus increased from 10(6) to 10(9) CFU/mL. The heat-inactivated L. acidophilus displayed similar probiotic activity compared to the live bacteria.

• MeSH
• Bacterial Adhesion * MeSH
• Caco-2 Cells MeSH
• Escherichia coli physiology   MeSH
• Feces microbiology   MeSH
• Lactobacillus isolation & purification   physiology   MeSH
• Humans MeSH
• Infant, Newborn MeSH
• Probiotics isolation & purification   MeSH
• Salmonella typhi physiology   MeSH
• Intestines microbiology   MeSH
• Hot Temperature MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Infant, Newborn MeSH
• Female MeSH
• Publication type
• Journal Article 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