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Rhodococcus equi's extreme resistance to hydrogen peroxide is mainly conferred by one of its four catalase genes.

Bidaud P, Hébert L, Barbey C, Appourchaux AC, Torelli R, Sanguinetti M, Laugier C, Petry S - PLoS ONE (2012)

Bottom Line: Moreover, katA deletion seems to significantly affect the ability of R. equi to survive within murine macrophages.In untreated bacteria, katB, katC and katD were overexpressed from 4.3 to 17.5 times in the stationary compared to the exponential phase.Taken together, our results show that KatA is the major catalase involved in the extreme H(2)O(2) resistance capability of R. equi.

View Article: PubMed Central - PubMed

Affiliation: Dozulé Laboratory for Equine Diseases, Unit Bacteriology and Parasitology, ANSES, Goustranville, France.

ABSTRACT
Rhodococcus equi is one of the most widespread causes of disease in foals aged from 1 to 6 months. R. equi possesses antioxidant defense mechanisms to protect it from reactive oxygen metabolites such as hydrogen peroxide (H(2)O(2)) generated during the respiratory burst of phagocytic cells. These defense mechanisms include enzymes such as catalase, which detoxify hydrogen peroxide. Recently, an analysis of the R. equi 103 genome sequence revealed the presence of four potential catalase genes. We first constructed ΔkatA-, ΔkatB-, ΔkatC-and ΔkatD-deficient mutants to study the ability of R. equi to survive exposure to H(2)O(2)in vitro and within mouse peritoneal macrophages. Results showed that ΔkatA and, to a lesser extent ΔkatC, were affected by 80 mM H(2)O(2). Moreover, katA deletion seems to significantly affect the ability of R. equi to survive within murine macrophages. We finally investigated the expression of the four catalases in response to H(2)O(2) assays with a real time PCR technique. Results showed that katA is overexpressed 367.9 times (± 122.6) in response to exposure to 50 mM of H(2)O(2) added in the stationary phase, and 3.11 times (± 0.59) when treatment was administered in the exponential phase. In untreated bacteria, katB, katC and katD were overexpressed from 4.3 to 17.5 times in the stationary compared to the exponential phase. Taken together, our results show that KatA is the major catalase involved in the extreme H(2)O(2) resistance capability of R. equi.

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Phylogenetic relationships between the catalases of Rhodococcus equi 103.Catalases were aligned using Phylogeny.fr (http://www.phylogeny.fr/) [37].
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pone-0042396-g001: Phylogenetic relationships between the catalases of Rhodococcus equi 103.Catalases were aligned using Phylogeny.fr (http://www.phylogeny.fr/) [37].

Mentions: The in silico analysis of the genome sequence of the R. equi 103 strain [10] revealed the presence of four potential catalase genes, designated katA, katB, katC and katD. These four genes are at separate locations on the chromosome and do not seem to share genetic links. Sequence analysis of these proteins shows that KatA, KatB and KatC share the conserved catalytic residues and metal ligand amino acids of members of monofunctional heme catalases [12]. KatD shares the conserved catalytic residues and metal ligand amino acids of members of the nonheme catalases. These nonheme catalases utilize manganese ions instead of ferric heme in their active site and are therefore also known as manganese catalases [13]. No catalase of the bifunctional catalase-peroxidase family was identified. Phylogenetic relationships between the four catalases are represented in Figure 1, which shows that the three heme and manganese catalases constitute a distinct group, and that KatA and KatB are closely related. No signal sequence and/or transmembrane domain were identified for these four catalases by TMHMM [14] or SignalP [15] analysis.


Rhodococcus equi's extreme resistance to hydrogen peroxide is mainly conferred by one of its four catalase genes.

Bidaud P, Hébert L, Barbey C, Appourchaux AC, Torelli R, Sanguinetti M, Laugier C, Petry S - PLoS ONE (2012)

Phylogenetic relationships between the catalases of Rhodococcus equi 103.Catalases were aligned using Phylogeny.fr (http://www.phylogeny.fr/) [37].
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3412833&req=5

pone-0042396-g001: Phylogenetic relationships between the catalases of Rhodococcus equi 103.Catalases were aligned using Phylogeny.fr (http://www.phylogeny.fr/) [37].
Mentions: The in silico analysis of the genome sequence of the R. equi 103 strain [10] revealed the presence of four potential catalase genes, designated katA, katB, katC and katD. These four genes are at separate locations on the chromosome and do not seem to share genetic links. Sequence analysis of these proteins shows that KatA, KatB and KatC share the conserved catalytic residues and metal ligand amino acids of members of monofunctional heme catalases [12]. KatD shares the conserved catalytic residues and metal ligand amino acids of members of the nonheme catalases. These nonheme catalases utilize manganese ions instead of ferric heme in their active site and are therefore also known as manganese catalases [13]. No catalase of the bifunctional catalase-peroxidase family was identified. Phylogenetic relationships between the four catalases are represented in Figure 1, which shows that the three heme and manganese catalases constitute a distinct group, and that KatA and KatB are closely related. No signal sequence and/or transmembrane domain were identified for these four catalases by TMHMM [14] or SignalP [15] analysis.

Bottom Line: Moreover, katA deletion seems to significantly affect the ability of R. equi to survive within murine macrophages.In untreated bacteria, katB, katC and katD were overexpressed from 4.3 to 17.5 times in the stationary compared to the exponential phase.Taken together, our results show that KatA is the major catalase involved in the extreme H(2)O(2) resistance capability of R. equi.

View Article: PubMed Central - PubMed

Affiliation: Dozulé Laboratory for Equine Diseases, Unit Bacteriology and Parasitology, ANSES, Goustranville, France.

ABSTRACT
Rhodococcus equi is one of the most widespread causes of disease in foals aged from 1 to 6 months. R. equi possesses antioxidant defense mechanisms to protect it from reactive oxygen metabolites such as hydrogen peroxide (H(2)O(2)) generated during the respiratory burst of phagocytic cells. These defense mechanisms include enzymes such as catalase, which detoxify hydrogen peroxide. Recently, an analysis of the R. equi 103 genome sequence revealed the presence of four potential catalase genes. We first constructed ΔkatA-, ΔkatB-, ΔkatC-and ΔkatD-deficient mutants to study the ability of R. equi to survive exposure to H(2)O(2)in vitro and within mouse peritoneal macrophages. Results showed that ΔkatA and, to a lesser extent ΔkatC, were affected by 80 mM H(2)O(2). Moreover, katA deletion seems to significantly affect the ability of R. equi to survive within murine macrophages. We finally investigated the expression of the four catalases in response to H(2)O(2) assays with a real time PCR technique. Results showed that katA is overexpressed 367.9 times (± 122.6) in response to exposure to 50 mM of H(2)O(2) added in the stationary phase, and 3.11 times (± 0.59) when treatment was administered in the exponential phase. In untreated bacteria, katB, katC and katD were overexpressed from 4.3 to 17.5 times in the stationary compared to the exponential phase. Taken together, our results show that KatA is the major catalase involved in the extreme H(2)O(2) resistance capability of R. equi.

Show MeSH
Related in: MedlinePlus