<it>aes</it>, the gene encoding the esterase B in <it>Escherichia coli</it>, is a powerful phylogenetic marker of the species
<p>Abstract</p> <p>Background</p> <p>Previous studies have established a correlation between electrophoretic polymorphism of esterase B, and virulence and phylogeny of <it>Escherichia coli</it>. Strains belonging to the phylogenetic group B2 are more frequen...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
BMC
2009-12-01
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| Series: | BMC Microbiology |
| Online Access: | http://www.biomedcentral.com/1471-2180/9/273 |
| _version_ | 1828300220711043072 |
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| author | Tuffery Pierre Darlu Pierre Garry Louis Clermont Olivier Hoede Claire Lescat Mathilde Denamur Erick Picard Bertrand |
| author_facet | Tuffery Pierre Darlu Pierre Garry Louis Clermont Olivier Hoede Claire Lescat Mathilde Denamur Erick Picard Bertrand |
| author_sort | Tuffery Pierre |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Background</p> <p>Previous studies have established a correlation between electrophoretic polymorphism of esterase B, and virulence and phylogeny of <it>Escherichia coli</it>. Strains belonging to the phylogenetic group B2 are more frequently implicated in extraintestinal infections and include esterase B<sub>2 </sub>variants, whereas phylogenetic groups A, B1 and D contain less virulent strains and include esterase B<sub>1 </sub>variants. We investigated esterase B as a marker of phylogeny and/or virulence, in a thorough analysis of the esterase B-encoding gene.</p> <p>Results</p> <p>We identified the gene encoding esterase B as the acetyl-esterase gene (<it>aes</it>) using gene disruption. The analysis of <it>aes </it>nucleotide sequences in a panel of 78 reference strains, including the <it>E. coli </it>reference (ECOR) strains, demonstrated that the gene is under purifying selection. The phylogenetic tree reconstructed from <it>aes </it>sequences showed a strong correlation with the species phylogenetic history, based on multi-locus sequence typing using six housekeeping genes. The unambiguous distinction between variants B<sub>1 </sub>and B<sub>2 </sub>by electrophoresis was consistent with Aes amino-acid sequence analysis and protein modelling, which showed that substituted amino acids in the two esterase B variants occurred mostly at different sites on the protein surface. Studies in an experimental mouse model of septicaemia using mutant strains did not reveal a direct link between <it>aes </it>and extraintestinal virulence. Moreover, we did not find any genes in the chromosomal region of <it>aes </it>to be associated with virulence.</p> <p>Conclusion</p> <p>Our findings suggest that <it>aes </it>does not play a direct role in the virulence of <it>E. coli </it>extraintestinal infection. However, this gene acts as a powerful marker of phylogeny, illustrating the extensive divergence of B2 phylogenetic group strains from the rest of the species.</p> |
| first_indexed | 2024-04-13T13:05:53Z |
| format | Article |
| id | doaj.art-0ca7627c63c24bf29bc932fb793ec675 |
| institution | Directory Open Access Journal |
| issn | 1471-2180 |
| language | English |
| last_indexed | 2024-04-13T13:05:53Z |
| publishDate | 2009-12-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Microbiology |
| spelling | doaj.art-0ca7627c63c24bf29bc932fb793ec6752022-12-22T02:45:47ZengBMCBMC Microbiology1471-21802009-12-019127310.1186/1471-2180-9-273<it>aes</it>, the gene encoding the esterase B in <it>Escherichia coli</it>, is a powerful phylogenetic marker of the speciesTuffery PierreDarlu PierreGarry LouisClermont OlivierHoede ClaireLescat MathildeDenamur ErickPicard Bertrand<p>Abstract</p> <p>Background</p> <p>Previous studies have established a correlation between electrophoretic polymorphism of esterase B, and virulence and phylogeny of <it>Escherichia coli</it>. Strains belonging to the phylogenetic group B2 are more frequently implicated in extraintestinal infections and include esterase B<sub>2 </sub>variants, whereas phylogenetic groups A, B1 and D contain less virulent strains and include esterase B<sub>1 </sub>variants. We investigated esterase B as a marker of phylogeny and/or virulence, in a thorough analysis of the esterase B-encoding gene.</p> <p>Results</p> <p>We identified the gene encoding esterase B as the acetyl-esterase gene (<it>aes</it>) using gene disruption. The analysis of <it>aes </it>nucleotide sequences in a panel of 78 reference strains, including the <it>E. coli </it>reference (ECOR) strains, demonstrated that the gene is under purifying selection. The phylogenetic tree reconstructed from <it>aes </it>sequences showed a strong correlation with the species phylogenetic history, based on multi-locus sequence typing using six housekeeping genes. The unambiguous distinction between variants B<sub>1 </sub>and B<sub>2 </sub>by electrophoresis was consistent with Aes amino-acid sequence analysis and protein modelling, which showed that substituted amino acids in the two esterase B variants occurred mostly at different sites on the protein surface. Studies in an experimental mouse model of septicaemia using mutant strains did not reveal a direct link between <it>aes </it>and extraintestinal virulence. Moreover, we did not find any genes in the chromosomal region of <it>aes </it>to be associated with virulence.</p> <p>Conclusion</p> <p>Our findings suggest that <it>aes </it>does not play a direct role in the virulence of <it>E. coli </it>extraintestinal infection. However, this gene acts as a powerful marker of phylogeny, illustrating the extensive divergence of B2 phylogenetic group strains from the rest of the species.</p>http://www.biomedcentral.com/1471-2180/9/273 |
| spellingShingle | Tuffery Pierre Darlu Pierre Garry Louis Clermont Olivier Hoede Claire Lescat Mathilde Denamur Erick Picard Bertrand <it>aes</it>, the gene encoding the esterase B in <it>Escherichia coli</it>, is a powerful phylogenetic marker of the species BMC Microbiology |
| title | <it>aes</it>, the gene encoding the esterase B in <it>Escherichia coli</it>, is a powerful phylogenetic marker of the species |
| title_full | <it>aes</it>, the gene encoding the esterase B in <it>Escherichia coli</it>, is a powerful phylogenetic marker of the species |
| title_fullStr | <it>aes</it>, the gene encoding the esterase B in <it>Escherichia coli</it>, is a powerful phylogenetic marker of the species |
| title_full_unstemmed | <it>aes</it>, the gene encoding the esterase B in <it>Escherichia coli</it>, is a powerful phylogenetic marker of the species |
| title_short | <it>aes</it>, the gene encoding the esterase B in <it>Escherichia coli</it>, is a powerful phylogenetic marker of the species |
| title_sort | it aes it the gene encoding the esterase b in it escherichia coli it is a powerful phylogenetic marker of the species |
| url | http://www.biomedcentral.com/1471-2180/9/273 |
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