Probiotics Down-Regulate Genes in  Serovar Typhimurium Pathogenicity Islands 1 and 2

Bayoumi, Mohamed A.; Griffiths, Mansel W.

doi:10.4315/0362-028x-73.3.452

Cited by 45 publications

(42 citation statements)

References 53 publications

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“…Certain bifidobacteria may influence Enterobacteriaceae by decreasing their virulence gene expression, such as shiga toxin 2 expression in enterohemorrhagic E. coli 0157: H7 (36) and the expression patterns of the Salmonella pathogenicity islands SPI1 and SPI2 (37). Probiotic strains may also exert direct effects on the host mucosa.…”

Section: Discussionmentioning

confidence: 99%

Bifidobacterium animalis subsp. lactis fermented milk product reduces inflammation by altering a niche for colitogenic microbes

Veiga

Gallini

Beal

et al. 2010

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

202

164

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Intestinal health requires the coexistence of eukaryotic self with the gut microbiota and dysregulated host-microbial interactions can result in intestinal inflammation. Here, we show that colitis improved in T-bet −/− Rag2 −/− mice that consumed a fermented milk product containing Bifidobacterium animalis subsp. lactis DN-173 010 strain. A decrease in cecal pH and alterations in short chain fatty acid profiles occurred with consumption, and there were concomitant increases in the abundance of select lactate-consuming and butyrate-producing bacteria. These metabolic shifts created a nonpermissive environment for the Enterobacteriaceae recently identified as colitogenic in a T-bet −/− Rag2 −/− ulcerative colitis mouse model. In addition, 16S rRNA-based analysis of the T-bet −/− Rag2 −/− fecal microbiota suggest that the structure of the endogenous gut microbiota played a key role in shaping the host response to the bacterial strains studied herein. We have identified features of the gut microbiota, at the membership and functional level, associated with response to this B. lactis -containing fermented milk product, and therefore this model provides a framework for evaluating and optimizing probiotic-based functional foods.

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Section: Discussionmentioning

confidence: 99%

Bifidobacterium animalis subsp. lactis fermented milk product reduces inflammation by altering a niche for colitogenic microbes

Veiga

Gallini

Beal

et al. 2010

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

202

164

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“…In addition, probiotics mitigate the pathogenicity of bacteria through interference of quorum sensing. For instance, the cell-free spent media (CFSM) of Lactobacillus acidophilus strain La-5 or Bifidobacterium bifidum have been shown to be effective against enterohemorrhagic E. coli (EHEC) 0157:H7 (20,21) and Salmonella Typhimurium infection (3). When E. coli 0157:H7 was grown in the presence of L. acidophilus La-5 CFSM, a significant reduction of both extracellular AI-2 concentration and the expression of important virulence-related genes were observed.…”

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confidence: 99%

Cell-Free Preparations of Lactobacillus acidophilus Strain La-5 and Bifidobacterium longum Strain NCC2705 Affect Virulence Gene Expression in Campylobacter jejuni

Mundi

Delcenserie

Amiri-Jami

et al. 2013

Journal of Food Protection

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Campylobacter spp. are among the most commonly reported bacterial causes of acute diarrheal disease in humans worldwide. Potential virulence factors include motility, chemotaxis, colonization ability, adhesion to intestinal cells, invasion and epithelial translocation, intracellular survival, and formation of toxins. Probiotic Lactobacillus and Bifidobacterium strains are known to have an inhibitory effect against the growth of various foodborne pathogens. The objective of this study was to investigate the effect of Lactobacillus acidophilus strain La-5 and Bifidobacterium longum strain NCC2705 cell-free spent media (CFSM) on the expression of virulence genes (cadF, cdtB, flaA, and ciaB) of Campylobacter jejuni strain 81-176 and a luxS mutant, using real-time PCR. Our results demonstrated that the CFSM of both probiotic strains were able to down-regulate the expression of ciaB (ratio of -2.80 and -5.51, respectively) and flaA (ratio of -7.00 and -5.13, respectively) in the wild-type Campylobacter strain. In the luxS mutant, where the activated methyl cycle is disrupted, only the ciaB gene (ratio -7.21) was repressed in the presence of La-5 CFSM. A supplementation of homocysteine to restore the disrupted cycle was able to partially reestablish the probiotic effect of both strains. luxS and the activated methyl cycle might play an active role in the modulation of virulence of C. jejuni by probiotic extracts.

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“…Studies show that ssrB can respond to multiple environmental signals, including acidic pH, low Mg ϩ and PO 4 3Ϫ concentrations, and nutrient limitations (49)(50)(51). Extracts from Bifidobacterium bifidum, considered a probiotic strain, downregulated expression of an ssrB-luxCDABE reporter (52). An ssrAB mutant showed tissue-and inoculation method-specific differences in colonization during the infection of pigs (53).…”

Section: Figmentioning

confidence: 99%

Influence of Salmonella enterica Serovar Typhimurium ssrB on Colonization of Eastern Oysters (Crassostrea virginica) as Revealed by a Promoter Probe Screen

Cox

Wright

McClelland

et al. 2016

Appl Environ Microbiol

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cAlthough Salmonella has been isolated from 7.4 to 8.6% of domestic raw oysters, representing a significant risk for food-borne illness, little is known about the factors that influence their initial colonization by Salmonella. This study tested the hypothesis that specific regulatory changes enable a portion of the invading Salmonella population to colonize oysters. An in vivo promoter probe library screen identified 19 unique regions as regulated during colonization. The mutants in the nearest corresponding downstream genes were tested for colonization defects in oysters. Only one mutation, in ssrB, resulted in a significantly reduced ability to colonize oysters compared to that of wild-type Salmonella. Because ssrB regulates Salmonella pathogenicity island 2 (SPI-2)-dependent infections in vertebrate macrophages, the possibility that ssrB mediated colonization of oyster hemocytes in a similar manner was examined. However, no difference in hemocyte colonization was observed. The complementary hypothesis that signal exchange between Salmonella and the oyster's native microbial community aids colonization was also tested. Signals that triggered responses in quorum sensing (QS) reporters were shown to be produced by oyster-associated bacteria and present in oyster tissue. However, no evidence for signal exchange was observed in vivo. The sdiA reporter responded to salinity, suggesting that SdiA may also have a role in environmental sensing. Overall, this study suggests the initial colonization of live oysters by Salmonella is controlled by a limited number of regulators, including ssrB. Market surveys in the United States have isolated Salmonella in 7.4 to 8.6% of raw, market-ready oysters, with local contamination rates as high as 77% within a single sample (1-3). Because oysters are typically consumed raw or lightly cooked, they present a significant risk for exposure to live pathogens (4, 5). Oysters are capable of sustaining high filtration rates and are known to concentrate bacteria, including pathogens, present in the environment (6-8). Colonization is rapid; detectable contamination occurs in as little as 15 min following exposure to water containing Salmonella (9). Despite the clear evidence that Salmonella colonizes oysters, the mechanisms mediating Salmonella colonization of, and persistence inside, shellfish remain unclear.Oysters are typically colonized by a diverse microbial community, with 90% of the inhabiting bacteria being associated with the digestive tract. The composition of oyster microbiota is derived, but clearly differs, from the surrounding seawater and becomes progressively dissimilar from the seawater from the stomach to the lower intestine (10). This divergence in community structure indicates selection for certain species and suggests that the ability to resist shedding is responsible for the enhanced persistence. Experimental contamination of oysters by Salmonella typically results in a rapid initial colonization at a density 1-to 2-log-fold below that of the inoculum, followed by a ...

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Probiotics Down-Regulate Genes in Serovar Typhimurium Pathogenicity Islands 1 and 2

Cited by 45 publications

References 53 publications

Bifidobacterium animalis subsp. lactis fermented milk product reduces inflammation by altering a niche for colitogenic microbes

Bifidobacterium animalis subsp. lactis fermented milk product reduces inflammation by altering a niche for colitogenic microbes

Cell-Free Preparations of Lactobacillus acidophilus Strain La-5 and Bifidobacterium longum Strain NCC2705 Affect Virulence Gene Expression in Campylobacter jejuni

Influence of Salmonella enterica Serovar Typhimurium ssrB on Colonization of Eastern Oysters (Crassostrea virginica) as Revealed by a Promoter Probe Screen

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