Book contents
- Frontmatter
- Dedication
- Contents
- List of Contributors
- Preface
- Part I Clinical syndromes: general
- Part II Clinical syndromes: head and neck
- Part III Clinical syndromes: eye
- Part IV Clinical syndromes: skin and lymph nodes
- Part V Clinical syndromes: respiratory tract
- Part VI Clinical syndromes: heart and blood vessels
- Part VII Clinical syndromes: gastrointestinal tract, liver, and abdomen
- Part VIII Clinical syndromes: genitourinary tract
- Part IX Clinical syndromes: musculoskeletal system
- Part X Clinical syndromes: neurologic system
- Part XI The susceptible host
- Part XII HIV
- Part XIII Nosocomial infection
- Part XIV Infections related to surgery and trauma
- Part XV Prevention of infection
- Part XVI Travel and recreation
- Part XVII Bioterrorism
- Part XVIII Specific organisms: bacteria
- 123 Actinomycosis
- 124 Anaerobic infections
- 125 Anthrax and other Bacillus species
- 126 Bartonella bacilliformis
- 127 Cat scratch disease and other Bartonella infections
- 128 Bordetella
- 129 Branhamella–Moraxella
- 130 Brucellosis
- 131 Campylobacter
- 132 Clostridium
- 133 Corynebacteria
- 134 Enterobacteriaceae
- 135 Enterococcus
- 136 Erysipelothrix
- 137 HACEK
- 138 Helicobacter pylori
- 139 Gonococcus: Neisseria gonorrhoeae
- 140 Haemophilus
- 141 Legionellosis
- 142 Leprosy
- 143 Meningococcus and miscellaneous neisseriae
- 144 Listeria
- 145 Nocardia
- 146 Pasteurella multocida
- 147 Pneumococcus
- 148 Pseudomonas, Stenotrophomonas, and Burkholderia
- 149 Rat-bite fevers
- 150 Salmonella
- 151 Staphylococcus
- 152 Streptococcus groups A, B, C, D, and G
- 153 Viridans streptococci
- 154 Poststreptococcal immunologic complications
- 155 Shigella
- 156 Tularemia
- 157 Tuberculosis
- 158 Nontuberculous mycobacteria
- 159 Vibrios
- 160 Yersinia
- 161 Miscellaneous gram-positive organisms
- 162 Miscellaneous gram-negative organisms
- Part XIX Specific organisms: spirochetes
- Part XX Specific organisms: Mycoplasma and Chlamydia
- Part XXI Specific organisms: Rickettsia, Ehrlichia, and Anaplasma
- Part XXII Specific organisms: fungi
- Part XXIII Specific organisms: viruses
- Part XXIV Specific organisms: parasites
- Part XXV Antimicrobial therapy: general considerations
- Index
- References
123 - Actinomycosis
from Part XVIII - Specific organisms: bacteria
Published online by Cambridge University Press: 05 April 2015
- Frontmatter
- Dedication
- Contents
- List of Contributors
- Preface
- Part I Clinical syndromes: general
- Part II Clinical syndromes: head and neck
- Part III Clinical syndromes: eye
- Part IV Clinical syndromes: skin and lymph nodes
- Part V Clinical syndromes: respiratory tract
- Part VI Clinical syndromes: heart and blood vessels
- Part VII Clinical syndromes: gastrointestinal tract, liver, and abdomen
- Part VIII Clinical syndromes: genitourinary tract
- Part IX Clinical syndromes: musculoskeletal system
- Part X Clinical syndromes: neurologic system
- Part XI The susceptible host
- Part XII HIV
- Part XIII Nosocomial infection
- Part XIV Infections related to surgery and trauma
- Part XV Prevention of infection
- Part XVI Travel and recreation
- Part XVII Bioterrorism
- Part XVIII Specific organisms: bacteria
- 123 Actinomycosis
- 124 Anaerobic infections
- 125 Anthrax and other Bacillus species
- 126 Bartonella bacilliformis
- 127 Cat scratch disease and other Bartonella infections
- 128 Bordetella
- 129 Branhamella–Moraxella
- 130 Brucellosis
- 131 Campylobacter
- 132 Clostridium
- 133 Corynebacteria
- 134 Enterobacteriaceae
- 135 Enterococcus
- 136 Erysipelothrix
- 137 HACEK
- 138 Helicobacter pylori
- 139 Gonococcus: Neisseria gonorrhoeae
- 140 Haemophilus
- 141 Legionellosis
- 142 Leprosy
- 143 Meningococcus and miscellaneous neisseriae
- 144 Listeria
- 145 Nocardia
- 146 Pasteurella multocida
- 147 Pneumococcus
- 148 Pseudomonas, Stenotrophomonas, and Burkholderia
- 149 Rat-bite fevers
- 150 Salmonella
- 151 Staphylococcus
- 152 Streptococcus groups A, B, C, D, and G
- 153 Viridans streptococci
- 154 Poststreptococcal immunologic complications
- 155 Shigella
- 156 Tularemia
- 157 Tuberculosis
- 158 Nontuberculous mycobacteria
- 159 Vibrios
- 160 Yersinia
- 161 Miscellaneous gram-positive organisms
- 162 Miscellaneous gram-negative organisms
- Part XIX Specific organisms: spirochetes
- Part XX Specific organisms: Mycoplasma and Chlamydia
- Part XXI Specific organisms: Rickettsia, Ehrlichia, and Anaplasma
- Part XXII Specific organisms: fungi
- Part XXIII Specific organisms: viruses
- Part XXIV Specific organisms: parasites
- Part XXV Antimicrobial therapy: general considerations
- Index
- References
Summary
Etiologic agents
Actinomycosis is an infectious syndrome caused by anaerobic or microaerophilic bacteria, primarily from the genus Actinomyces. It is most commonly caused by Actinomyces israelii. However, Actinomyces naeslundii, Actinomyces odontolyticus, Actinomyces viscosus, Actinomyces meyeri, and Actinomyces gerencseriae are less common causes of infection. Advances in microbiologic taxonomy, using genotypic methods such as comparative 16S ribosomal RNA (rRNA) or sequencing of alternative genes, have led to the identification of many new Actinomyces species from both human and animal specimens. Presently 46 species and 2 subspecies have been recognized (http://www.bacterio.cict.fr/a/actinomyces.html). Although the syndrome of actinomycosis can be caused by these more recently described agents, most of the infections are not “classic” actinomycosis. Infections due to Actinomyces neuii have been increasingly recognized. Nearly all of actinomycotic infections are polymicrobial in nature. Aggregatibacter (formerly Actinobacillus) actinomycetemcomitans, Eikenella corrodens, Fusobacterium, Bacteroides, Capnocytophaga, Staphylococcus, Streptococcus, and Enterobacteriaceae are commonly co-isolated (“companion organisms”) with the agents of actinomycosis in various combinations depending on the site of the infection.
Epidemiology and pathogenesis
The etiologic agents of actinomycosis are members of the normal oral flora and are often present in bronchi and the gastrointestinal and female genital tracts. Although males have a higher incidence of infection (perhaps due to more frequent trauma and poorer dental hygiene), actinomycosis occurs in all age groups and geographic locations. Disruption of the mucosal barrier is the critical step for the development of actinomycosis. Subsequently, local infection may ensue and once established, if untreated, spreads contiguously ignoring tissue planes in a slow, progressive manner. Although acute inflammation may initially occur at the site of infection, the hallmark of actinomycosis is the characteristic chronic, indolent phase. This stage is manifested by lesions that usually appear as single or multiple indurations. Central necrosis develops that consists of neutrophils and sulfur granules (a finding virtually diagnostic of this disease). The walls of the mass are fibrotic and characteristically described as “wooden.” Over time sinus tracts to the skin, adjacent organs, or bone may develop. Rarely distant hematogenous seeding occurs. Foreign bodies appear to facilitate infection. This occurs most frequently with intrauterine contraceptive devices (IUCDs). Although actinomycosis has been described in the setting of various immunosuppressive therapies or states of host compromise, it remains unclear which arm(s) of host defense prevents/control infection. The contribution of the non-Actinomyces co-isolates or companion organisms to the pathogenesis of actinomycosis is also uncertain.
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- Clinical Infectious Disease , pp. 829 - 834Publisher: Cambridge University PressPrint publication year: 2015