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Red Seaweeds Sarcodiotheca gaudichaudii and Chondrus crispus down Regulate Virulence Factors of Salmonella Enteritidis and Induce Immune Responses in Caenorhabditis elegans.

Kulshreshtha G, Borza T, Rathgeber B, Stratton GS, Thomas NA, Critchley A, Hafting J, Prithiviraj B - Front Microbiol (2016)

Bottom Line: Spread plate assay revealed that SG and CC (1%, w/v) significantly reduced the growth of S.Addition of SWE (0.2 mg/ml, CC and SG) significantly decreased biofilm formation and reduced the motility of S.Enteritidis.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental Sciences, Faculty of Agriculture, Dalhousie UniversityTruro, NS, Canada; Acadian Seaplants LimitedDartmouth, NS, Canada.

ABSTRACT
Red seaweeds are a rich source of unique bioactive compounds and secondary metabolites that are known to improve human and animal health. S. Enteritidis is a broad range host pathogen, which contaminates chicken and poultry products that end into the human food chain. Worldwide, Salmonella outbreaks have become an important economic and public health concern. Moreover, the development of resistance in Salmonella serovars toward multiple drugs highlights the need for alternative control strategies. This study evaluated the antimicrobial property of red seaweeds extracts against Salmonella Enteritidis using the Caenorhabditis elegans infection model. Six red seaweed species were tested for their antimicrobial activity against S. Enteritidis and two, Sarcodiotheca gaudichaudii (SG) and Chondrus crispus (CC), were found to exhibit such properties. Spread plate assay revealed that SG and CC (1%, w/v) significantly reduced the growth of S. Enteritidis. Seaweed water extracts (SWE) of SG and CC, at concentrations from 0.4 to 2 mg/ml, significantly reduced the growth of S. Enteritidis (log CFU 4.5-5.3 and log 5.7-6.0, respectively). However, methanolic extracts of CC and SG did not affect the growth of S. Enteritidis. Addition of SWE (0.2 mg/ml, CC and SG) significantly decreased biofilm formation and reduced the motility of S. Enteritidis. Quantitative real-time PCR analyses showed that SWE (CC and SG) suppressed the expression of quorum sensing gene sdiA and of Salmonella Pathogenesis Island-1 (SPI-1) associated genes sipA and invF, indicating that SWE might reduce the invasion of S. Enteritidis in the host by attenuating virulence factors. Furthermore, CC and SG water extracts significantly improved the survival of infected C. elegans by impairing the ability of S. Enteritidis to colonize the digestive tract of the nematode and by enhancing the expression of C. elegans immune responsive genes. As the innate immune response pathways of C. elegans and mammals show a high degree of conservation, these results suggest that these SWE may also impart beneficial effects on animal and human health.

No MeSH data available.


Related in: MedlinePlus

Effect of SWE treatment on biofilm formation of S. Enteritidis. S. Enteritidis culture was statically grown for 24 h at 37°C in polyvinyl chloride microtitre plates in the presence of 200 μl/ml SWE (SG or CC). (A) Biofilm formation was quantified by staining with crystal violet and determining the optical density at 600 nm. (B) Effect of SWE on the relative gene expression of sdiA gene (homolog of quorum-sensing regulators LuxR). Values with different superscript letters (Tukey multiple mean comparison) are significantly different (one-way Anova; p < 0.05). Values represent Mean ± Standard deviation from three independent experiments; each experiment had three biological replicates. Picture insert: C, positive control; B, negative control; SG200, 200 μl/ml SG extract; CC200, 200 μl/ml CC extract.
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Figure 5: Effect of SWE treatment on biofilm formation of S. Enteritidis. S. Enteritidis culture was statically grown for 24 h at 37°C in polyvinyl chloride microtitre plates in the presence of 200 μl/ml SWE (SG or CC). (A) Biofilm formation was quantified by staining with crystal violet and determining the optical density at 600 nm. (B) Effect of SWE on the relative gene expression of sdiA gene (homolog of quorum-sensing regulators LuxR). Values with different superscript letters (Tukey multiple mean comparison) are significantly different (one-way Anova; p < 0.05). Values represent Mean ± Standard deviation from three independent experiments; each experiment had three biological replicates. Picture insert: C, positive control; B, negative control; SG200, 200 μl/ml SG extract; CC200, 200 μl/ml CC extract.

Mentions: Biofilms are increasing the survival of bacteria in adverse environmental conditions and contributes to the virulence. As motility regulates biofilm formation, we tested if SWE reduces biofilm formation by S. Enteritidis. Addition of SWE (200 μg/ml, CC and SG) significantly decreased (p < 0.05) biofilm formed by S. Enteritidis (Figures 5A,B). Presence of CC and SG in the culture medium resulted in biofilm formation equivalent to an optical density of 0.06 ± 0.004 and 0.05 ± 0.005 respectively, which is 3–4-fold lower when compared to control (OD600 = 0.17 ± 0.01) (Figures 5A,B).


Red Seaweeds Sarcodiotheca gaudichaudii and Chondrus crispus down Regulate Virulence Factors of Salmonella Enteritidis and Induce Immune Responses in Caenorhabditis elegans.

Kulshreshtha G, Borza T, Rathgeber B, Stratton GS, Thomas NA, Critchley A, Hafting J, Prithiviraj B - Front Microbiol (2016)

Effect of SWE treatment on biofilm formation of S. Enteritidis. S. Enteritidis culture was statically grown for 24 h at 37°C in polyvinyl chloride microtitre plates in the presence of 200 μl/ml SWE (SG or CC). (A) Biofilm formation was quantified by staining with crystal violet and determining the optical density at 600 nm. (B) Effect of SWE on the relative gene expression of sdiA gene (homolog of quorum-sensing regulators LuxR). Values with different superscript letters (Tukey multiple mean comparison) are significantly different (one-way Anova; p < 0.05). Values represent Mean ± Standard deviation from three independent experiments; each experiment had three biological replicates. Picture insert: C, positive control; B, negative control; SG200, 200 μl/ml SG extract; CC200, 200 μl/ml CC extract.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4814495&req=5

Figure 5: Effect of SWE treatment on biofilm formation of S. Enteritidis. S. Enteritidis culture was statically grown for 24 h at 37°C in polyvinyl chloride microtitre plates in the presence of 200 μl/ml SWE (SG or CC). (A) Biofilm formation was quantified by staining with crystal violet and determining the optical density at 600 nm. (B) Effect of SWE on the relative gene expression of sdiA gene (homolog of quorum-sensing regulators LuxR). Values with different superscript letters (Tukey multiple mean comparison) are significantly different (one-way Anova; p < 0.05). Values represent Mean ± Standard deviation from three independent experiments; each experiment had three biological replicates. Picture insert: C, positive control; B, negative control; SG200, 200 μl/ml SG extract; CC200, 200 μl/ml CC extract.
Mentions: Biofilms are increasing the survival of bacteria in adverse environmental conditions and contributes to the virulence. As motility regulates biofilm formation, we tested if SWE reduces biofilm formation by S. Enteritidis. Addition of SWE (200 μg/ml, CC and SG) significantly decreased (p < 0.05) biofilm formed by S. Enteritidis (Figures 5A,B). Presence of CC and SG in the culture medium resulted in biofilm formation equivalent to an optical density of 0.06 ± 0.004 and 0.05 ± 0.005 respectively, which is 3–4-fold lower when compared to control (OD600 = 0.17 ± 0.01) (Figures 5A,B).

Bottom Line: Spread plate assay revealed that SG and CC (1%, w/v) significantly reduced the growth of S.Addition of SWE (0.2 mg/ml, CC and SG) significantly decreased biofilm formation and reduced the motility of S.Enteritidis.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental Sciences, Faculty of Agriculture, Dalhousie UniversityTruro, NS, Canada; Acadian Seaplants LimitedDartmouth, NS, Canada.

ABSTRACT
Red seaweeds are a rich source of unique bioactive compounds and secondary metabolites that are known to improve human and animal health. S. Enteritidis is a broad range host pathogen, which contaminates chicken and poultry products that end into the human food chain. Worldwide, Salmonella outbreaks have become an important economic and public health concern. Moreover, the development of resistance in Salmonella serovars toward multiple drugs highlights the need for alternative control strategies. This study evaluated the antimicrobial property of red seaweeds extracts against Salmonella Enteritidis using the Caenorhabditis elegans infection model. Six red seaweed species were tested for their antimicrobial activity against S. Enteritidis and two, Sarcodiotheca gaudichaudii (SG) and Chondrus crispus (CC), were found to exhibit such properties. Spread plate assay revealed that SG and CC (1%, w/v) significantly reduced the growth of S. Enteritidis. Seaweed water extracts (SWE) of SG and CC, at concentrations from 0.4 to 2 mg/ml, significantly reduced the growth of S. Enteritidis (log CFU 4.5-5.3 and log 5.7-6.0, respectively). However, methanolic extracts of CC and SG did not affect the growth of S. Enteritidis. Addition of SWE (0.2 mg/ml, CC and SG) significantly decreased biofilm formation and reduced the motility of S. Enteritidis. Quantitative real-time PCR analyses showed that SWE (CC and SG) suppressed the expression of quorum sensing gene sdiA and of Salmonella Pathogenesis Island-1 (SPI-1) associated genes sipA and invF, indicating that SWE might reduce the invasion of S. Enteritidis in the host by attenuating virulence factors. Furthermore, CC and SG water extracts significantly improved the survival of infected C. elegans by impairing the ability of S. Enteritidis to colonize the digestive tract of the nematode and by enhancing the expression of C. elegans immune responsive genes. As the innate immune response pathways of C. elegans and mammals show a high degree of conservation, these results suggest that these SWE may also impart beneficial effects on animal and human health.

No MeSH data available.


Related in: MedlinePlus