Bactericidal effects of human neutrophils and sera on selected endodotic pathogenic bacteria in an anaerobic environment

Wu, Min-Kai; Henry, Clay A.; Gutmann, James L.

doi:10.1111/j.1365-2591.1990.tb00099.x

Cited by 7 publications

(3 citation statements)

References 17 publications

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“…Capsule structures give bacteria a hydrophilic character and may confer protection from phagocytosis (1). But among Actinomyces species, only strains of A. viscosus have been reported to be capsulated and, in some assays, poorly phagocytosed (44,49). The fimbriae play an important role by mediating adhesion to a variety of other cells and tissues.…”

Section: Discussionmentioning

confidence: 99%

Pathogenicity of Actinomyces israelii and Arachnid propionica: experimental infection in guinea pigs and phagocytosis and intracellular killing by human polymorphonuclear leukocytes in vitro

Figdor¹,

Sjögren²,

Sörlin³

et al. 1992

Oral Microbiology and Immunology

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Strains of Actinomyces israelii and Arachnia propionica, isolated from clinical cases of failed endodontic therapy, were examined for: (i) their ability to survive and establish themselves in the soft connective tissue that grew into subcutaneously implanted tissue cages in guinea pigs; (ii) cell-surface hydrophobicity; and (iii) phagocytosis and killing by human polymorphonuclear leukocytes (PMNs) under aerobic and anaerobic conditions. Bacteria were inoculated into the tissue cages in guinea pigs and the cage contents were retrieved after 1, 7, 14 and 21 d for culturing and light and electron microscopy. Both bacterial species showed substantial decline in the number of bacteria by day 7 after the inoculation. Thereafter, the A. israelii strain recovered and, by day 21, had started to increase in number. Light and electron microscopy revealed the formation of typical actinomycotic colonies. A. propionica, on the other hand, continued to decline in number during the entire period of experimental infection and did not form colonies. Both strains were hydrophobic, readily phagocytosed and were efficiently killed by human PMNs under aerobic and anaerobic conditions in vitro. These results suggest that the pathogenicity of A. israelii is due to its ability to establish characteristic cohesive colonies consisting of branching filamentous organisms that are enmeshed in an extracellular matrix. It seems that the organisms existing in such colonies can collectively evade destruction and elimination by host phagocytic cells, whereas in vitro suspensions of the bacteria are easily phagocytosed and efficiently killed by PMNs. With respect to A. propionica, further investigations are necessary to understand its pathogenicity.

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Section: Discussionmentioning

confidence: 99%

Pathogenicity of Actinomyces israelii and Arachnid propionica: experimental infection in guinea pigs and phagocytosis and intracellular killing by human polymorphonuclear leukocytes in vitro

Figdor¹,

Sjögren²,

Sörlin³

et al. 1992

Oral Microbiology and Immunology

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“…6iscosus or Pstr. anaerobius (28). Another in 6itro study, using explant cultures has found that IgG from those cultures is reactive with many endodontic microorganisms (29).…”

Section: Microen6ironmentsmentioning

confidence: 98%

Microbial Ecology of the Dental Root Canal

Drucker

2000

Microbial Ecology in Health and Disease

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“…1992, Saunders & Sannders 1992, 1994a, Gutmann 1993, Gengoglu et al 1993a,b, Karagoz-Kugiilcay 1994, Lloyd et al, 1995. As yet undetermined however is the effect of smear layer removal on obturation when challenged from the coronal direction by bacteria (Krakow et al 1977, Wu et al 1990. Does the removal of the smear layer prevent or retard bacterial leakage in teeth when it is left intact.?…”

Section: Abstract: Bacteria Coronal Leakage Edta Guttapecha Smearmentioning

confidence: 99%

An in‐vitro study of smear layer removal and microbial leakage along root‐canal fillings

1996

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The objective of this study was to determine the effect of removal of the smear layer on canal obturation as measured by penetration of bacteria from a coronal direction. Fifty-four extracted human teeth were decoronated and instrumented in a uniform manner. Following instrumentation the root canals of 20 teeth were rinsed with 17% EDTA and 5.25% NaOCl to remove the smear layer before obturation. A second group of 20 teeth were flushed with NaOCl alone. The teeth of both groups were obturated with Thermafil plastic carriers and Roth's sealer. The root canals of another 10 teeth, five rinsed with EDTA and five without, were obturated with Thermafil without sealer. Two teeth serving as positive controls were instrumented but not obturated, while another set of two were sealed coronally and apically to serve as negative controls. The root surface of each tooth was sealed with nail varnish. A small chamber was thoroughly sealed around the coronal aspect of each tooth so that bacteria placed therein could move only through the obturated canal space. Each tooth was placed in a test tube containing sterile trypticase soy broth (TSB). An inoculum of Proteus vulgaris in TSB was placed in each coronal chamber at five day intervals and daily observations were made for bacterial growth in the apical reservoir for 21 days. Both positive control teeth showed bacterial penetration after 24 h. Neither of the two negative control teeth demonstrated penetration for the duration of the study. The frequency of bacterial penetration through teeth obturated with intact smear layer (70%) was-significantly greater than that of teeth from which the smear layer had been removed (30%) P < 0.05. All but one tooth obturated without sealer exhibited bacterial penetration, irrespective of the presence or absence of smear layer. Removal of the smear layer enhanced sealability as evidenced by increased resistance to bacterial penetration.

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Bactericidal effects of human neutrophils and sera on selected endodotic pathogenic bacteria in an anaerobic environment

Cited by 7 publications

References 17 publications

Pathogenicity of Actinomyces israelii and Arachnid propionica: experimental infection in guinea pigs and phagocytosis and intracellular killing by human polymorphonuclear leukocytes in vitro

Pathogenicity of Actinomyces israelii and Arachnid propionica: experimental infection in guinea pigs and phagocytosis and intracellular killing by human polymorphonuclear leukocytes in vitro

Microbial Ecology of the Dental Root Canal

An in‐vitro study of smear layer removal and microbial leakage along root‐canal fillings

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