Comparative Pathogenicity of Actinomyces Species in Mice

Behbehani, M. J.; Jordan, H.V.

doi:10.1099/00222615-15-4-465

Cited by 25 publications

(17 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The observation that very high numbers of Actitwtnyees organisms are needed to form persistent infections (3,17) is corroborated by our attempt to induce experimental infections in this study. But it is unlikely that such high numbers of these bacteria may gain entry into the periapical tissue from an infected root canal.…”

Section: Discussionsupporting

confidence: 77%

“…israelii that grew with rough aggregates and intermeshed filaments regularly caused progressive chronic infections in mice, whereas smooth strains which did not grow in aggregates failed to establish persistent infections. The importance of the ability to form aggregates is further supported by the observation that homogenization of inocula from rough strains eliminated or dramatically decreased the infectivity (3,9). The size of bacterial aggregates is important in phagocytosis (30) and the nature of growth appears to be important in the transition of the infection from an acute stage to a slowly progressive chronic infection.…”

Section: Discussionmentioning

confidence: 98%

See 1 more Smart Citation

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

View full text Add to dashboard Cite

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.

show abstract

Section: Discussionsupporting

confidence: 77%

Section: Discussionmentioning

confidence: 98%

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

View full text Add to dashboard Cite

show abstract

“…Actinomyces israclii, Actinoinyces tiaeslutidii and Arachtiia propiotiia are nonrtal inhabitants of the oral eavity (7,8). Their pathogenicity has been shown in anitiial studies (9). Gram-positive filamentous tnierobes were demonstiated in the colonies of ail specimens studied, but a suspicion of periapical actinoniyco.sis was originally raised only in 2 cases on the basis of the colonial morphology in sections stained with hernatoxylin and eosin.…”

Section: Discussionmentioning

confidence: 91%

Immunocytochemical demonstration of Actinomyces species and Arachnia propionica in periapical infections

Happonhn

Söderling

Viander

et al. 1985

J Oral Pathology Medicine

View full text Add to dashboard Cite

Immunocytochemical methods were used for the demonstration of Actinomyces israelii, Actinomyces naeslundii and Arachnia propionica in bacterial colonies found in 7 routine biopsies from periapical inflammatory lesions. All 3 species were found in one specimen, both A. israelii and A. propionica in 3 specimens, and one of each species in the remaining 3 biopsies. Specificity controls by enzyme immunoassay showed that antiserum to A. israelii reacted also with A. odontolylicus, and that to A. naeslundii with A. viscosus, while antiserum to A. propionica did not show any cross‐reactions with Actinomyces species. The results indicate that immunocytochemical methods can be used for the diagnosis of periapical actinomycosis at the species level. Actinomyces and Arachnia species seem to have an important role in the pathogenesis of complicated periapical infections.

show abstract

“…Very high numbers of Actinomyces cells are usually needed to form persistent infections. [41] The low pathogenicity of these microorganisms and the consequent minimal host response may be the reasons for the perpetuation of the chronic periapical lesion.…”

Section: Periapical Biofilmsmentioning

confidence: 99%

Microbial Biofilms in Endodontic Infections: An Update Review

Mohammadi¹,

Palazzi²,

Giardino³

et al. 2013

Biomed J

View full text Add to dashboard Cite

Biofilms and microbial aggregates are the common mechanisms for the survival of bacteria in nature. In other words, the ability to form biofilms has been regarded as a virulence factor. Microbial biofilms play an essential role in several infectious diseases such as pulp and periradicular pathosis. The aim of this article was to review the adaptation mechanisms of biofilms, their roles in pulpal and periapical pathosis, factors influencing biofilm formation, mechanisms of their antimicrobial resistance, models developed to create biofilms, observation techniques of endodontic biofilms, and the effects of root canal irrigants and medicaments as well as lasers on endodontic biofilms. The search was performed from 1982 to December 2010, and was limited to papers in English language. The keywords searched on Medline were "biofilms and endodontics," "biofilms and root canal irrigation," "biofilms and intra-canal medicament," and "biofilms and lasers." The reference section of each article was manually searched to find other suitable sources of information.

show abstract

Comparative Pathogenicity of Actinomyces Species in Mice

Cited by 25 publications

References 4 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

Immunocytochemical demonstration of Actinomyces species and Arachnia propionica in periapical infections

Microbial Biofilms in Endodontic Infections: An Update Review

Contact Info

Product

Resources

About