Enterococcus faecalis is a significant human pathogen worldwide and is responsible for severenosocomial and community-acquired infections. Although enterococcal meningitis is rare,mortality is considerable, reaching 21 %. Nevertheless, the pathogenetic mechanisms of thisinfection remain poorly understood, even though the ability of E. faecalis to avoid or survivephagocytic attack in vivo may be very important during the infection process. We previouslyshowed that the manganese-cofactored superoxide dismutase (MnSOD) SodA of E. faecalis wasimplicated in oxidative stress responses and, interestingly, in the survival within mouse peritonealmacrophages using an in vivo–in vitro infection model. In the present study, we investigated therole of MnSOD in the interaction of E. faecalis with microglia, the brain-resident macrophages. Byusing an in vitro infection model, murine microglial cells were challenged in parallel with the wildtypestrain JH2-2 and its isogenic sodA deletion mutant. While both strains were phagocytosedby microglia efficiently and to a similar extent, the DsodA mutant was found to be significantlymore susceptible to microglial killing than JH2-2, as assessed by the antimicrobial protectionassay. In addition, a significantly higher percentage of acidic DsodA-containing phagosomes wasfound and these also underwent enhanced maturation as determined by the expression ofendolysosomal markers. In conclusion, these results show that the MnSOD of E. faecaliscontributes to survival of the bacterium in microglial cells by influencing their antimicrobial activity,and this could even be important for intracellular killing in neutrophils and thus for E. faecalispathogenesis.

Role of the (Mn)superoxide dismutase of Enterococcus faecalis in the in vitro interaction with microglia / Peppoloni, Samuele; B., Posteraro; Colombari, Bruna; Manca, Lidia; A., Hartke; J. C., Giard; M., Sanguinetti; G., Fadda; Blasi, Elisabetta. - In: MICROBIOLOGY. - ISSN 1350-0872. - STAMPA. - 157:(2011), pp. 1816-1822. [10.1099/mic.0.047381-0]

Role of the (Mn)superoxide dismutase of Enterococcus faecalis in the in vitro interaction with microglia

PEPPOLONI, Samuele;COLOMBARI, Bruna;MANCA, LIDIA;BLASI, Elisabetta
2011

Abstract

Enterococcus faecalis is a significant human pathogen worldwide and is responsible for severenosocomial and community-acquired infections. Although enterococcal meningitis is rare,mortality is considerable, reaching 21 %. Nevertheless, the pathogenetic mechanisms of thisinfection remain poorly understood, even though the ability of E. faecalis to avoid or survivephagocytic attack in vivo may be very important during the infection process. We previouslyshowed that the manganese-cofactored superoxide dismutase (MnSOD) SodA of E. faecalis wasimplicated in oxidative stress responses and, interestingly, in the survival within mouse peritonealmacrophages using an in vivo–in vitro infection model. In the present study, we investigated therole of MnSOD in the interaction of E. faecalis with microglia, the brain-resident macrophages. Byusing an in vitro infection model, murine microglial cells were challenged in parallel with the wildtypestrain JH2-2 and its isogenic sodA deletion mutant. While both strains were phagocytosedby microglia efficiently and to a similar extent, the DsodA mutant was found to be significantlymore susceptible to microglial killing than JH2-2, as assessed by the antimicrobial protectionassay. In addition, a significantly higher percentage of acidic DsodA-containing phagosomes wasfound and these also underwent enhanced maturation as determined by the expression ofendolysosomal markers. In conclusion, these results show that the MnSOD of E. faecaliscontributes to survival of the bacterium in microglial cells by influencing their antimicrobial activity,and this could even be important for intracellular killing in neutrophils and thus for E. faecalispathogenesis.
2011
157
1816
1822
Role of the (Mn)superoxide dismutase of Enterococcus faecalis in the in vitro interaction with microglia / Peppoloni, Samuele; B., Posteraro; Colombari, Bruna; Manca, Lidia; A., Hartke; J. C., Giard; M., Sanguinetti; G., Fadda; Blasi, Elisabetta. - In: MICROBIOLOGY. - ISSN 1350-0872. - STAMPA. - 157:(2011), pp. 1816-1822. [10.1099/mic.0.047381-0]
Peppoloni, Samuele; B., Posteraro; Colombari, Bruna; Manca, Lidia; A., Hartke; J. C., Giard; M., Sanguinetti; G., Fadda; Blasi, Elisabetta
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11380/684341
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