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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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In untreated bacteria, katB, katC and katD are overexpressed in the stationary growth phase.R. equi WT was grown in BHI broth without any H2O2 treatment and cells were collected at the exponential (OD of 0.4) and stationary (OD of 1) growth phases for total RNA extraction. cDNAs derived from total RNA, were used for real time PCR. The overexpression factor was calculated using the 2−ΔΔCt method [36]. The data are the mean of overexpression factor in stationary phase collected bacteria compared to exponential phase collected bacteria ± standard deviation of triplicate measurements from four reverse transcriptions of two independent experiments.
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pone-0042396-g005: In untreated bacteria, katB, katC and katD are overexpressed in the stationary growth phase.R. equi WT was grown in BHI broth without any H2O2 treatment and cells were collected at the exponential (OD of 0.4) and stationary (OD of 1) growth phases for total RNA extraction. cDNAs derived from total RNA, were used for real time PCR. The overexpression factor was calculated using the 2−ΔΔCt method [36]. The data are the mean of overexpression factor in stationary phase collected bacteria compared to exponential phase collected bacteria ± standard deviation of triplicate measurements from four reverse transcriptions of two independent experiments.

Mentions: In untreated bacteria, we observed overexpressions of katB, katC and katD in the stationary phase compared to the exponential phase. Irrespective of exposure to oxidative stress, katB was overexpressed 17.55 (±3.22) times in the stationary phase compared to the exponential phase (Figure 5). katC and katD were overexpressed 4.51 (±0.59) and 4.31 (±0.50) times in the stationary phase compared to the exponential phase, respectively (Figure 5).


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)

In untreated bacteria, katB, katC and katD are overexpressed in the stationary growth phase.R. equi WT was grown in BHI broth without any H2O2 treatment and cells were collected at the exponential (OD of 0.4) and stationary (OD of 1) growth phases for total RNA extraction. cDNAs derived from total RNA, were used for real time PCR. The overexpression factor was calculated using the 2−ΔΔCt method [36]. The data are the mean of overexpression factor in stationary phase collected bacteria compared to exponential phase collected bacteria ± standard deviation of triplicate measurements from four reverse transcriptions of two independent experiments.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0042396-g005: In untreated bacteria, katB, katC and katD are overexpressed in the stationary growth phase.R. equi WT was grown in BHI broth without any H2O2 treatment and cells were collected at the exponential (OD of 0.4) and stationary (OD of 1) growth phases for total RNA extraction. cDNAs derived from total RNA, were used for real time PCR. The overexpression factor was calculated using the 2−ΔΔCt method [36]. The data are the mean of overexpression factor in stationary phase collected bacteria compared to exponential phase collected bacteria ± standard deviation of triplicate measurements from four reverse transcriptions of two independent experiments.
Mentions: In untreated bacteria, we observed overexpressions of katB, katC and katD in the stationary phase compared to the exponential phase. Irrespective of exposure to oxidative stress, katB was overexpressed 17.55 (±3.22) times in the stationary phase compared to the exponential phase (Figure 5). katC and katD were overexpressed 4.51 (±0.59) and 4.31 (±0.50) times in the stationary phase compared to the exponential phase, respectively (Figure 5).

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