In vitro treatment of Enterococcus faecalis with calcium hydroxide impairs phagocytosis by human macrophages.
Acta Odontol Scand
; 77(2): 158-163, 2019 Mar.
Article
em En
| MEDLINE
| ID: mdl-30618320
ABSTRACT
OBJECTIVE:
Monocyte-derived macrophages (MDMs) ability to phagocytize and produce nitric oxide (NO) was tested against root-canal strains of Enterococcus faecalis submitted to alkaline stress. Root-canal strains were also compared with urine Enterococci. MATERIALS ANDMETHODS:
Enterococcus faecalis were stressed with alkaline-BHI broth and incubated in vitro at a cell/bacteria ratio of 15. Phagocytosis was analyzed by fluorescence microscopy using acridine orange stain, and NO concentration was measured in supernatants. RESULTS ANDCONCLUSIONS:
Alkaline-stress significantly impaired MDMs phagocytosis of E. faecalis strains analyzed, except in ATCC4083 isolated from a pulpless tooth, but NO production was unchanged. Comparison of different strains showed the urine isolate had higher NO levels than root canal strains. Alterations in the bacterial cell wall structures after alkaline-stress possibly made bacteria less recognizable and phagocytized by MDMs but did not affect their ability to activate NO production. Furthermore, root canal strains elicited different responses by immune cells compared with strains from urine. Clinically, impaired phagocytosis of E. faecalis could contribute to their persistence in root canal systems previously treated with calcium hydroxide.Palavras-chave
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Irrigantes do Canal Radicular
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Hidróxido de Cálcio
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Infecções por Bactérias Gram-Positivas
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Enterococcus faecalis
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Cavidade Pulpar
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Anti-Infecciosos Locais
Limite:
Humans
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article