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A Strong Impact of Genetic Background on Gut Microflora in Mice.

Esworthy RS, Smith DD, Chu FF - Int J Inflam (2010)

Bottom Line: We used diet to modulate ileocolitis; a casein-based defined diet with AIN76A micronutrients (AIN) attenuates inflammation compared to conventional LabDiets.We found that mouse strain had the strongest impact on the composition of microbiota than diet and GPx genotypes.From 129 DKO strictly, we found overgrowth of Escherichia coli.

View Article: PubMed Central - PubMed

Affiliation: Department of Cancer Biology, Beckman Research Institute of the City of Hope, 1500 Duarte Road, Duarte, CA 91010-3000, USA.

ABSTRACT
Genetic background affects susceptibility to ileocolitis in mice deficient in two intracellular glutathione peroxidases, GPx1 and GPx2. The C57BL/6 (B6) GPx1/2 double-knockout (DKO) mice have mild ileocolitis, and 129S1/Sv (129) DKO mice have severe inflammation. We used diet to modulate ileocolitis; a casein-based defined diet with AIN76A micronutrients (AIN) attenuates inflammation compared to conventional LabDiets. Because luminal microbiota induce DKO ileocolitis, we assessed bacterial composition with automated ribosomal intergenic-spacer analysis (ARISA) on cecal DNA. We found that mouse strain had the strongest impact on the composition of microbiota than diet and GPx genotypes. In comparing AIN and LabDiet, DKO mice were more resistant to change than the non-DKO or WT mice. However, supplementing yeast and inulin to AIN diet greatly altered microflora profiles in the DKO mice. From 129 DKO strictly, we found overgrowth of Escherichia coli. We conclude that genetic background predisposes mice to colonization of potentially pathogenic E. coli.

No MeSH data available.


Related in: MedlinePlus

ARISA analysis of DNA from cecal contents of 129 N5. This DKO colony was established by backcrossing the mixed strain B6;129 colony to 129Sv/J for 5 generations. The plots were generated from 15 DKO mice on AIN diet (AINDKO), 18 DKO mice on LabDiet (LabDietDKO), 7 DKO mice on AIN diet supplemented with 1% yeast (Yeast DKO), 13 non-DKO mice on AIN diet (AIN non-DKO), and 13 non-DKO mice on LabDiet (LabDiet non-DKO). Non-DKO mice were the sibs of DKO mice, heterozygous for Gpx1 and/or Gpx2 (thus no inflammation). DKO mice on LabDiet did not have the distinctive peaks at 385–390 bp, 421 bp, 481 bp, and 498 bp found in other groups. DKO mice on the yeast-containing diet had a similar profile as AIN-fed mice, except having a prominent 317 bp peak. The 442 bp ribotype found in these 129 N5 DKO mice had lower abundance in the non-DKO sibs on both LabDiet and AIN diets.
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fig6: ARISA analysis of DNA from cecal contents of 129 N5. This DKO colony was established by backcrossing the mixed strain B6;129 colony to 129Sv/J for 5 generations. The plots were generated from 15 DKO mice on AIN diet (AINDKO), 18 DKO mice on LabDiet (LabDietDKO), 7 DKO mice on AIN diet supplemented with 1% yeast (Yeast DKO), 13 non-DKO mice on AIN diet (AIN non-DKO), and 13 non-DKO mice on LabDiet (LabDiet non-DKO). Non-DKO mice were the sibs of DKO mice, heterozygous for Gpx1 and/or Gpx2 (thus no inflammation). DKO mice on LabDiet did not have the distinctive peaks at 385–390 bp, 421 bp, 481 bp, and 498 bp found in other groups. DKO mice on the yeast-containing diet had a similar profile as AIN-fed mice, except having a prominent 317 bp peak. The 442 bp ribotype found in these 129 N5 DKO mice had lower abundance in the non-DKO sibs on both LabDiet and AIN diets.

Mentions: For comparing time-to-event endpoints, such as survival time on different diets, the results were plotted with Kaplan-Meier curves and analyzed with the log-rank test. Analysis of variance (ANOVA) was used to compare the means ± standard deviations (SDs). To compare pair-wise diets versus a control, Dunnett's correction was made for multiple testing and the Dunnett-corrected P-values were applied. Each ARISA data panel represents results pooled from 6 to 21 mice analyzed individually. The electropherograms were digitized, and the results for each group were averaged using the statistical programming language R [21, 22]. The data were cleaned and passed to the Ribosort package created for R by Scallan et al. [23]. Ribosort detects and classifies peak-generating fragments in ARISA data with a two-pass algorithm [24]. Output from Ribosort contains information on the ribotype (represented by a specific size of PCR product) abundances, ribotype proportions, and sequencer detections. A Euclidean discriminant test was applied to the final step in ARISA data set analysis. Finally, a Czekanowski similarity index was run for pair-wise comparisons from all panels in the ARISA Figures 4, 6, and 8. The quantitative version of the Czekanowski similarity index is defined as 2W/(A + B), where A and B are the abundance of species in two given sample conditions and W is the number of species shared in the two samples. A convention for interpreting the Czekanowski similarity index is as follows: index between 0.5 to 0.75 indicates similar abundances; index between 0.25 to 0.5 indicates different abundances; index between 0 to 0.25 indicates very different abundances.


A Strong Impact of Genetic Background on Gut Microflora in Mice.

Esworthy RS, Smith DD, Chu FF - Int J Inflam (2010)

ARISA analysis of DNA from cecal contents of 129 N5. This DKO colony was established by backcrossing the mixed strain B6;129 colony to 129Sv/J for 5 generations. The plots were generated from 15 DKO mice on AIN diet (AINDKO), 18 DKO mice on LabDiet (LabDietDKO), 7 DKO mice on AIN diet supplemented with 1% yeast (Yeast DKO), 13 non-DKO mice on AIN diet (AIN non-DKO), and 13 non-DKO mice on LabDiet (LabDiet non-DKO). Non-DKO mice were the sibs of DKO mice, heterozygous for Gpx1 and/or Gpx2 (thus no inflammation). DKO mice on LabDiet did not have the distinctive peaks at 385–390 bp, 421 bp, 481 bp, and 498 bp found in other groups. DKO mice on the yeast-containing diet had a similar profile as AIN-fed mice, except having a prominent 317 bp peak. The 442 bp ribotype found in these 129 N5 DKO mice had lower abundance in the non-DKO sibs on both LabDiet and AIN diets.
© Copyright Policy - open-access
Related In: Results  -  Collection

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fig6: ARISA analysis of DNA from cecal contents of 129 N5. This DKO colony was established by backcrossing the mixed strain B6;129 colony to 129Sv/J for 5 generations. The plots were generated from 15 DKO mice on AIN diet (AINDKO), 18 DKO mice on LabDiet (LabDietDKO), 7 DKO mice on AIN diet supplemented with 1% yeast (Yeast DKO), 13 non-DKO mice on AIN diet (AIN non-DKO), and 13 non-DKO mice on LabDiet (LabDiet non-DKO). Non-DKO mice were the sibs of DKO mice, heterozygous for Gpx1 and/or Gpx2 (thus no inflammation). DKO mice on LabDiet did not have the distinctive peaks at 385–390 bp, 421 bp, 481 bp, and 498 bp found in other groups. DKO mice on the yeast-containing diet had a similar profile as AIN-fed mice, except having a prominent 317 bp peak. The 442 bp ribotype found in these 129 N5 DKO mice had lower abundance in the non-DKO sibs on both LabDiet and AIN diets.
Mentions: For comparing time-to-event endpoints, such as survival time on different diets, the results were plotted with Kaplan-Meier curves and analyzed with the log-rank test. Analysis of variance (ANOVA) was used to compare the means ± standard deviations (SDs). To compare pair-wise diets versus a control, Dunnett's correction was made for multiple testing and the Dunnett-corrected P-values were applied. Each ARISA data panel represents results pooled from 6 to 21 mice analyzed individually. The electropherograms were digitized, and the results for each group were averaged using the statistical programming language R [21, 22]. The data were cleaned and passed to the Ribosort package created for R by Scallan et al. [23]. Ribosort detects and classifies peak-generating fragments in ARISA data with a two-pass algorithm [24]. Output from Ribosort contains information on the ribotype (represented by a specific size of PCR product) abundances, ribotype proportions, and sequencer detections. A Euclidean discriminant test was applied to the final step in ARISA data set analysis. Finally, a Czekanowski similarity index was run for pair-wise comparisons from all panels in the ARISA Figures 4, 6, and 8. The quantitative version of the Czekanowski similarity index is defined as 2W/(A + B), where A and B are the abundance of species in two given sample conditions and W is the number of species shared in the two samples. A convention for interpreting the Czekanowski similarity index is as follows: index between 0.5 to 0.75 indicates similar abundances; index between 0.25 to 0.5 indicates different abundances; index between 0 to 0.25 indicates very different abundances.

Bottom Line: We used diet to modulate ileocolitis; a casein-based defined diet with AIN76A micronutrients (AIN) attenuates inflammation compared to conventional LabDiets.We found that mouse strain had the strongest impact on the composition of microbiota than diet and GPx genotypes.From 129 DKO strictly, we found overgrowth of Escherichia coli.

View Article: PubMed Central - PubMed

Affiliation: Department of Cancer Biology, Beckman Research Institute of the City of Hope, 1500 Duarte Road, Duarte, CA 91010-3000, USA.

ABSTRACT
Genetic background affects susceptibility to ileocolitis in mice deficient in two intracellular glutathione peroxidases, GPx1 and GPx2. The C57BL/6 (B6) GPx1/2 double-knockout (DKO) mice have mild ileocolitis, and 129S1/Sv (129) DKO mice have severe inflammation. We used diet to modulate ileocolitis; a casein-based defined diet with AIN76A micronutrients (AIN) attenuates inflammation compared to conventional LabDiets. Because luminal microbiota induce DKO ileocolitis, we assessed bacterial composition with automated ribosomal intergenic-spacer analysis (ARISA) on cecal DNA. We found that mouse strain had the strongest impact on the composition of microbiota than diet and GPx genotypes. In comparing AIN and LabDiet, DKO mice were more resistant to change than the non-DKO or WT mice. However, supplementing yeast and inulin to AIN diet greatly altered microflora profiles in the DKO mice. From 129 DKO strictly, we found overgrowth of Escherichia coli. We conclude that genetic background predisposes mice to colonization of potentially pathogenic E. coli.

No MeSH data available.


Related in: MedlinePlus