Electron Microscopic Study of the Adherence Properties of <i>Lactobacillus acidophilus</i>

Hood, Scott; Zottola, E. A.

doi:10.1111/j.1365-2621.1987.tb06728.x

Cited by 26 publications

(19 citation statements)

References 6 publications

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“…A targeted approach for identifying adhesion factors and creating isogenic chromosomal mutations allows us to systematically evaluate cell surface proteins for their contributions to adherence or attachment capability. Previous studies have concentrated on identifying the locations of adhesive determinants (16,20), determining the nature of adhesive determinants (8,10,(17)(18)(19), comparing the adhesiveness of different strains (8,42), or identifying adhesion molecules using binding assays (17,22,33). In contrast, this is the first study that has relied on genome sequence data to identify multiple cell surface proteins potentially involved in adhesion and specifically investigated their individual contributions via isogenic strain comparisons.…”

Section: Discussionmentioning

confidence: 89%

Functional Analysis of Putative Adhesion Factors in Lactobacillus acidophilus NCFM

Buck

Altermann

Svingerud

et al. 2005

Appl Environ Microbiol

346

297

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Lactobacilli are major inhabitants of the normal microflora of the gastrointestinal tract, and some select species have been used extensively as probiotic cultures. One potentially important property of these organisms is their ability to interact with epithelial cells in the intestinal tract, which may promote retention and host-bacterial communication. However, the mechanisms by which they attach to intestinal epithelial cells are unknown. The objective of this study was to investigate cell surface proteins in Lactobacillus acidophilus that may promote attachment to intestinal tissues. Using genome sequence data, predicted open reading frames were searched against known protein and protein motif databases to identify four proteins potentially involved in adhesion to epithelial cells. Homologous recombination was used to construct isogenic mutations in genes encoding a mucin-binding protein, a fibronectin-binding protein, a surface layer protein, and two streptococcal R28 homologs. The abilities of the mutants to adhere to intestinal epithelial cells were then evaluated in vitro. Each strain was screened on Caco-2 cells, which differentiate and express markers characteristic of normal small-intestine cells. A significant decrease in adhesion was observed in the fibronectin-binding protein mutant (76%) and the mucin-binding protein mutant (65%). A surface layer protein mutant also showed reduction in adhesion ability (84%), but the effect of this mutation is likely due to the loss of multiple surface proteins that may be embedded in the S-layer. This study demonstrated that multiple cell surface proteins in L. acidophilus NCFM can individually contribute to the organism's ability to attach to intestinal cells in vitro.Probiotics are commonly included in dairy products, especially fermented milks. One major criterion considered for selection of probiotic bacteria has been their capacity to adhere to the human intestinal epithelial cells. Adhesion is believed to be a requirement for the realization of certain probiotic effects, such as immunomodulation (37, 44) and pathogen exclusion (6, 28). However, the mechanisms of attachment are not understood. Association with the intestinal mucosa can initiate and extend transient associations, which affords these bacteria a distinct advantage when in the gastrointestinal tract. Lactobacillus acidophilus NCFM is an industrial bacterial strain used widely in dietary supplements and cultured yogurts (36). Recent studies have implicated the involvement of some surface proteins from lactobacilli in adhesion to epithelial cells (16), mucin (32), and various extracellular matrix (ECM) proteins (40). The surface layer protein, SlpA, from other lactobacilli has also been shown to bind epithelial cells and ECM components (4, 21). However, no studies have demonstrated unequivocally the function and significance of S-layers in either adherence or improved retention of probiotic cultures in the gastrointestinal tract.Lactobacilli are normal components of the intestinal microbiota and a...

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Section: Discussionmentioning

confidence: 89%

Functional Analysis of Putative Adhesion Factors in Lactobacillus acidophilus NCFM

Buck

Altermann

Svingerud

et al. 2005

Appl Environ Microbiol

346

297

View full text Add to dashboard Cite

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“…Together, this set shows high synteny to reported EPS clusters in streptococci (40) and recently reported in L. gasseri and L. johnsonii (6). Scanning electron microscopy of NCFM did not detect an external polysaccharide layer (41), and it remains unclear whether the EPS cluster is functional or whether any EPS produced is excreted rather than anchored. Three ORFs in the NCFM EPS cluster encode for two UDP-galactopyranose mutases and a membrane protein involved with the export of O-antigen and teichoic acid.…”

Section: Resultsmentioning

confidence: 95%

Complete genome sequence of the probiotic lactic acid bacteriumLactobacillus acidophilusNCFM

Altermann

Russell

Azcarate‐Peril

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

557

453

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Lactobacillus acidophilus NCFM is a probiotic bacterium that has been produced commercially since 1972. The complete genome is 1,993,564 nt and devoid of plasmids. The average GC content is 34.71% with 1,864 predicted ORFs, of which 72.5% were functionally classified. Nine phage-related integrases were predicted, but no complete prophages were found. However, three unique regions designated as potential autonomous units (PAUs) were identified. These units resemble a unique structure and bear characteristics of both plasmids and phages. Analysis of the three PAUs revealed the presence of two R͞M systems and a prophage maintenance system killer protein. A spacers interspersed direct repeat locus containing 32 nearly perfect 29-bp repeats was discovered and may provide a unique molecular signature for this organism. In silico analyses predicted 17 transposase genes and a chromosomal locus for lactacin B, a class II bacteriocin. Several mucus-and fibronectin-binding proteins, implicated in adhesion to human intestinal cells, were also identified. Gene clusters for transport of a diverse group of carbohydrates, including fructooligosaccharides and raffinose, were present and often accompanied by transcriptional regulators of the lacI family. For protein degradation and peptide utilization, the organism encoded 20 putative peptidases, homologs for PrtP and PrtM, and two complete oligopeptide transport systems. Nine two-component regulatory systems were predicted, some associated with determinants implicated in bacteriocin production and acid tolerance. Collectively, these features within the genome sequence of L. acidophilus are likely to contribute to the organisms' gastric survival and promote interactions with the intestinal mucosa and microbiota.adhesion ͉ stress response ͉ proteolytic system ͉ sugar metabolism ͉ in silico analysis

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“…Identification of putative adhesins of lactobacilli is also at a preliminary stage. Protein (Conway and Kjelleberg, 1989;Henrikson et al, 1991;Cocconier et al, 1992), carbohydrate (Hood and Zottola, 1989), and lipoteichoic acid adhesins (Sherman and Savage, 1986) have been reported to occur on the surfaces of intestinal lactobacilli, but none has been identified in oral strains.…”

Section: Discussionmentioning

confidence: 94%

Specific and Charge Interactions Mediate Collagen Recognition by Oral Lactobacilli

et al. 1995

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The mechanisms by which oral lactobacilli, one of the three major genera of cariogenic bacteria, attach to tooth surfaces are unknown. We hypothesize that recognition of collagen, the major component of dentin, may be a mechanism which localizes these bacteria to exposed root surfaces as well as to carious lesions which have penetrated the dentin. We found that the majority of oral Lactobacillus spp. strains recognize and bind collagen type I. Binding of 125I-labeled collagen type I to two strains of L. casei rhamnosus has been characterized in some detail. These strains were previously characterized with respect to their attachment to dentin (Switalski and Butcher, 1994). The process of 125I-collagen binding was mediated via specific as well as charge interactions. The putative adhesin-mediated (specific) interaction involved a limited number of bacterial surface components (2 x 10(3)/cell). Under conditions conducive for non-specific interactions (low ionic strength), the binding was higher by an order of magnitude. Collagen binding strains were found to adhere to collagen-coated surfaces, while strains unable to bind collagen adhered to a much lesser extent. Adherence of bacteria to collagen-coated surfaces could be competitively inhibited with collagen. These interactions may target collagen-binding strains of lactobacilli to dentin collagen in the oral cavity and thus play a role in the pathogenesis of root surface and/or coronal caries. Interference with this collagen-mediated attachment of lactobacilli may provide effective means of caries control, particularly in view of the fact that other oral acidogenic microbiota also interact with collagen.

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Electron Microscopic Study of the Adherence Properties of Lactobacillus acidophilus

Cited by 26 publications

References 6 publications

Functional Analysis of Putative Adhesion Factors in Lactobacillus acidophilus NCFM

Functional Analysis of Putative Adhesion Factors in Lactobacillus acidophilus NCFM

Complete genome sequence of the probiotic lactic acid bacteriumLactobacillus acidophilusNCFM

Specific and Charge Interactions Mediate Collagen Recognition by Oral Lactobacilli

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