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E. coli Nissle 1917 Affects Salmonella adhesion to porcine intestinal epithelial cells.

Schierack P, Kleta S, Tedin K, Babila JT, Oswald S, Oelschlaeger TA, Hiemann R, Paetzold S, Wieler LH - PLoS ONE (2011)

Bottom Line: Another E. coli strain expressing F1C fimbriae was also adherent to IPEC-J2 cells, and was similarly inhibitory against Salmonella invasion like EcN.We propose that EcN affects Salmonella adhesion through secretory components.This mechanism appears to be common to many E. coli strains, with strong adherence being a prerequisite for an effective reduction of SiiE-mediated Salmonella adhesion.

View Article: PubMed Central - PubMed

Affiliation: Institut für Mikrobiologie und Tierseuchen, Freie Universität Berlin, Berlin, Germany. Peter.Schierack@HS-Lausitz.de

ABSTRACT

Background: The probiotic Escherichia coli strain Nissle 1917 (EcN) has been shown to interfere in a human in vitro model with the invasion of several bacterial pathogens into epithelial cells, but the underlying molecular mechanisms are not known.

Methodology/principal findings: In this study, we investigated the inhibitory effects of EcN on Salmonella Typhimurium invasion of porcine intestinal epithelial cells, focusing on EcN effects on the various stages of Salmonella infection including intracellular and extracellular Salmonella growth rates, virulence gene regulation, and adhesion. We show that EcN affects the initial Salmonella invasion steps by modulating Salmonella virulence gene regulation and Salmonella SiiE-mediated adhesion, but not extra- and intracellular Salmonella growth. However, the inhibitory activity of EcN against Salmonella invasion always correlated with EcN adhesion capacities. EcN mutants defective in the expression of F1C fimbriae and flagellae were less adherent and less inhibitory toward Salmonella invasion. Another E. coli strain expressing F1C fimbriae was also adherent to IPEC-J2 cells, and was similarly inhibitory against Salmonella invasion like EcN.

Conclusions: We propose that EcN affects Salmonella adhesion through secretory components. This mechanism appears to be common to many E. coli strains, with strong adherence being a prerequisite for an effective reduction of SiiE-mediated Salmonella adhesion.

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Related in: MedlinePlus

Inhibitory effects of E. coli Nissle 1917 on Salmonella Typhimurium invasion is dependent on adhesion.Confluent monolayers of IPEC-J2 cells were pre-incubated with E. coli Nissle 1917 (EcN), EcN ΔfocA, EcN Δfim or EcN ΔfliA using an MOI of 100∶1 E. coli to host cells. After two or six hours, cells were washed and infected with Salmonella Typhimurium using an MOI of 100∶1 Salmonella to host cells. Invasion levels in percent (%) are expressed as invasion of Salmonella relative to invasion without pre-incubation with E. coli (Salmonella mono-infection). The data are the mean ± S.E.M. of at least three separate experiments in duplicate wells. * = p<0.01 compared to Salmonella mono-infection. A) Effects of EcN ΔfocA and EcN Δfim mutants on Salmonella invasion after a 2 or 6 hours pre-incubation period. B) Effects of EcN ΔfocA and EcN ΔfliA mutants and their respective strains complemented with the plasmid pACYC 177 containing the relevant gene on Salmonella invasion after 2 hours pre-incubation.
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pone-0014712-g002: Inhibitory effects of E. coli Nissle 1917 on Salmonella Typhimurium invasion is dependent on adhesion.Confluent monolayers of IPEC-J2 cells were pre-incubated with E. coli Nissle 1917 (EcN), EcN ΔfocA, EcN Δfim or EcN ΔfliA using an MOI of 100∶1 E. coli to host cells. After two or six hours, cells were washed and infected with Salmonella Typhimurium using an MOI of 100∶1 Salmonella to host cells. Invasion levels in percent (%) are expressed as invasion of Salmonella relative to invasion without pre-incubation with E. coli (Salmonella mono-infection). The data are the mean ± S.E.M. of at least three separate experiments in duplicate wells. * = p<0.01 compared to Salmonella mono-infection. A) Effects of EcN ΔfocA and EcN Δfim mutants on Salmonella invasion after a 2 or 6 hours pre-incubation period. B) Effects of EcN ΔfocA and EcN ΔfliA mutants and their respective strains complemented with the plasmid pACYC 177 containing the relevant gene on Salmonella invasion after 2 hours pre-incubation.

Mentions: Initially, we verified a probiotic effect of E. coli Nissle 1917 (EcN) on Salmonella invasion of porcine intestinal epithelial cells (IPEC-J2). We compared the effects of EcN with those of two control E. coli strains (E. coli 140815 and E. coli MG1655), and the effects of EcN in a mix with these two strains, and included two multiplicities of infections (MOI). In general, employing the gentamicin protection assay the invasion efficiency of Salmonella Typhimurium strain SL1344 into the porcine intestinal epithelial cell line IPEC-J2 was 27%. A two-hour pre-incubation of IPEC-J2 cells with EcN resulted in a decrease in Salmonella invasion efficiency, while pre-incubation with E. coli 140815 or E. coli MG1655 did not. This effect was stronger using an MOI of 100∶1 (E. coli:epithelial cells) compared to 10∶1 (Figure 1). The inhibitory effect of EcN was markedly increased by a pre-incubation period of six hours compared to two hours (Figure 2A).


E. coli Nissle 1917 Affects Salmonella adhesion to porcine intestinal epithelial cells.

Schierack P, Kleta S, Tedin K, Babila JT, Oswald S, Oelschlaeger TA, Hiemann R, Paetzold S, Wieler LH - PLoS ONE (2011)

Inhibitory effects of E. coli Nissle 1917 on Salmonella Typhimurium invasion is dependent on adhesion.Confluent monolayers of IPEC-J2 cells were pre-incubated with E. coli Nissle 1917 (EcN), EcN ΔfocA, EcN Δfim or EcN ΔfliA using an MOI of 100∶1 E. coli to host cells. After two or six hours, cells were washed and infected with Salmonella Typhimurium using an MOI of 100∶1 Salmonella to host cells. Invasion levels in percent (%) are expressed as invasion of Salmonella relative to invasion without pre-incubation with E. coli (Salmonella mono-infection). The data are the mean ± S.E.M. of at least three separate experiments in duplicate wells. * = p<0.01 compared to Salmonella mono-infection. A) Effects of EcN ΔfocA and EcN Δfim mutants on Salmonella invasion after a 2 or 6 hours pre-incubation period. B) Effects of EcN ΔfocA and EcN ΔfliA mutants and their respective strains complemented with the plasmid pACYC 177 containing the relevant gene on Salmonella invasion after 2 hours pre-incubation.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3040738&req=5

pone-0014712-g002: Inhibitory effects of E. coli Nissle 1917 on Salmonella Typhimurium invasion is dependent on adhesion.Confluent monolayers of IPEC-J2 cells were pre-incubated with E. coli Nissle 1917 (EcN), EcN ΔfocA, EcN Δfim or EcN ΔfliA using an MOI of 100∶1 E. coli to host cells. After two or six hours, cells were washed and infected with Salmonella Typhimurium using an MOI of 100∶1 Salmonella to host cells. Invasion levels in percent (%) are expressed as invasion of Salmonella relative to invasion without pre-incubation with E. coli (Salmonella mono-infection). The data are the mean ± S.E.M. of at least three separate experiments in duplicate wells. * = p<0.01 compared to Salmonella mono-infection. A) Effects of EcN ΔfocA and EcN Δfim mutants on Salmonella invasion after a 2 or 6 hours pre-incubation period. B) Effects of EcN ΔfocA and EcN ΔfliA mutants and their respective strains complemented with the plasmid pACYC 177 containing the relevant gene on Salmonella invasion after 2 hours pre-incubation.
Mentions: Initially, we verified a probiotic effect of E. coli Nissle 1917 (EcN) on Salmonella invasion of porcine intestinal epithelial cells (IPEC-J2). We compared the effects of EcN with those of two control E. coli strains (E. coli 140815 and E. coli MG1655), and the effects of EcN in a mix with these two strains, and included two multiplicities of infections (MOI). In general, employing the gentamicin protection assay the invasion efficiency of Salmonella Typhimurium strain SL1344 into the porcine intestinal epithelial cell line IPEC-J2 was 27%. A two-hour pre-incubation of IPEC-J2 cells with EcN resulted in a decrease in Salmonella invasion efficiency, while pre-incubation with E. coli 140815 or E. coli MG1655 did not. This effect was stronger using an MOI of 100∶1 (E. coli:epithelial cells) compared to 10∶1 (Figure 1). The inhibitory effect of EcN was markedly increased by a pre-incubation period of six hours compared to two hours (Figure 2A).

Bottom Line: Another E. coli strain expressing F1C fimbriae was also adherent to IPEC-J2 cells, and was similarly inhibitory against Salmonella invasion like EcN.We propose that EcN affects Salmonella adhesion through secretory components.This mechanism appears to be common to many E. coli strains, with strong adherence being a prerequisite for an effective reduction of SiiE-mediated Salmonella adhesion.

View Article: PubMed Central - PubMed

Affiliation: Institut für Mikrobiologie und Tierseuchen, Freie Universität Berlin, Berlin, Germany. Peter.Schierack@HS-Lausitz.de

ABSTRACT

Background: The probiotic Escherichia coli strain Nissle 1917 (EcN) has been shown to interfere in a human in vitro model with the invasion of several bacterial pathogens into epithelial cells, but the underlying molecular mechanisms are not known.

Methodology/principal findings: In this study, we investigated the inhibitory effects of EcN on Salmonella Typhimurium invasion of porcine intestinal epithelial cells, focusing on EcN effects on the various stages of Salmonella infection including intracellular and extracellular Salmonella growth rates, virulence gene regulation, and adhesion. We show that EcN affects the initial Salmonella invasion steps by modulating Salmonella virulence gene regulation and Salmonella SiiE-mediated adhesion, but not extra- and intracellular Salmonella growth. However, the inhibitory activity of EcN against Salmonella invasion always correlated with EcN adhesion capacities. EcN mutants defective in the expression of F1C fimbriae and flagellae were less adherent and less inhibitory toward Salmonella invasion. Another E. coli strain expressing F1C fimbriae was also adherent to IPEC-J2 cells, and was similarly inhibitory against Salmonella invasion like EcN.

Conclusions: We propose that EcN affects Salmonella adhesion through secretory components. This mechanism appears to be common to many E. coli strains, with strong adherence being a prerequisite for an effective reduction of SiiE-mediated Salmonella adhesion.

Show MeSH
Related in: MedlinePlus