Actinomycosis pathophysiology: Difference between revisions
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{{CMG}}; {{AE}}{{ADG}} | {{CMG}}; {{AE}}{{ADG}} | ||
==Overview== | ==Overview== | ||
[[Actinomycosis]] is a chronic pyogenic bacterial infection caused by [[actinomyces]] species. Infection most frequently follows dental work, trauma, surgery, or other medical conditions. When there is break in the [[Mucosal|mucosa]], anywhere from the [[mouth]] to the [[rectum]] they reach tissues and cause damage. Incubation period of [[actinomycosis]] varies from one to four weeks. But occasionally, it may be as long as several months. [[Actinomycosis]] elicits both [[Humoral immunity|humoral]] and [[Cell-mediated immune response|cell-mediated immune responses]] | [[Actinomycosis]] is a chronic [[pyogenic]] [[bacterial]] [[infection]] caused by [[actinomyces]] species. Infection most frequently follows dental work, [[trauma]], [[surgery]], or other medical conditions. When there is break in the [[Mucosal|mucosa]], anywhere from the [[mouth]] to the [[rectum]] they reach tissues and cause damage. Incubation period of [[actinomycosis]] varies from one to four weeks. But occasionally, it may be as long as several months. [[Actinomycosis]] elicits both [[Humoral immunity|humoral]] and [[Cell-mediated immune response|cell-mediated immune responses]] | ||
== Pathophysiology== | == Pathophysiology== | ||
| Line 9: | Line 9: | ||
===Transmission=== | ===Transmission=== | ||
*[[Actinomyces]] are part of the natural flora of human body, resides in the oral cavity, lower gastrointestinal tract and urogenital tract. | *[[Actinomyces]] are part of the natural [[flora]] of human body, resides in the [[oral cavity]], lower [[gastrointestinal tract]] and [[Urogenital tract|urogenital tract.]] | ||
*They are [[Virulence|nonvirulent]] under normal conditions | *They are [[Virulence|nonvirulent]] under normal conditions | ||
*When there is a breach in normal mucosal architecture, anywhere from the [[mouth]] to the [[rectum]] they enter tissues and cause damage. | *When there is a breach in normal [[mucosal]] architecture, anywhere from the [[mouth]] to the [[rectum]] they enter [[tissues]] and cause damage. | ||
{| class="wikitable" | {| class="wikitable" | ||
!Types | !Types | ||
| Line 18: | Line 18: | ||
!Source of infection | !Source of infection | ||
|- | |- | ||
!Cervicofacial actinomycosis | ![[Cervicofacial actinomycosis]] | ||
| | | | ||
* [[Neck]] | * [[Neck]] | ||
| Line 28: | Line 28: | ||
* Dental problems like [[tooth decay]] | * Dental problems like [[tooth decay]] | ||
|- | |- | ||
!Thoracic | ![[Thoracic actinomycosis|Thoracic]] | ||
actinomycosis | [[Thoracic actinomycosis|actinomycosis]] | ||
| | | | ||
* [[Lungs]] | * [[Lungs]] | ||
| Line 37: | Line 37: | ||
* [[Mediastinum]] | * [[Mediastinum]] | ||
| | | | ||
* Inhalation of droplets of contaminated fluid | * [[Inhalation]] of [[droplets]] of contaminated [[fluid]] | ||
* Aspiration of oropharyngeal secretions or gastric contents | * [[Aspiration]] of [[oropharyngeal]] secretions or [[gastric]] contents | ||
* Direct extension of cervicofacial infection into the [[mediastinum]] | * Direct extension of cervicofacial infection into the [[mediastinum]] | ||
* Transdiaphragmatic or [[retroperitoneal]] spread from the abdomen | * Transdiaphragmatic or [[retroperitoneal]] spread from the [[abdomen]] | ||
* Hematogenous spread | * Hematogenous spread | ||
|- | |- | ||
!Abdominal actinomycosis | !Abdominal actinomycosis | ||
|Abdomen | |[[Abdomen]] | ||
| | | | ||
* Secondary to abdominal infections like [[appendicitis]] | * Secondary to [[abdominal]] [[infections]] like [[appendicitis]] | ||
* Accidental swallowing of a foreign body such as chicken bone containing the actinomycetes bacteria | * Accidental swallowing of a foreign body such as chicken bone containing the [[Actinomycetes|actinomycetes bacteria]] | ||
* [[Penetrating trauma]] | * [[Penetrating trauma]] | ||
* [[Perforation of inflamed diverticulum|Perforation of the gut]] (e.g., the [[colon]] or [[appendix]]) | * [[Perforation of inflamed diverticulum|Perforation of the gut]] (e.g., the [[colon]] or [[appendix]]) | ||
* Surgical manipulation of GI tract | * Surgical manipulation of [[GI tract]] | ||
|- | |- | ||
!Pelvic | !Pelvic | ||
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|[[Pelvis]] | |[[Pelvis]] | ||
| | | | ||
* Occurs most commonly in woman as the bacteria enters into the pelvis | * Occurs most commonly in woman as the [[bacteria]] enters into the [[pelvis]] | ||
* Long-term use of [[IUD]] type of contraceptive | * Long-term use of [[IUD]] type of contraceptive | ||
|- | |- | ||
!Central nervous system | ![[Central nervous system actinomycosis|Central nervous system]] | ||
actinomycosis | [[Central nervous system actinomycosis|actinomycosis]] | ||
|[[CNS]] | |[[CNS]] | ||
| | | | ||
* Secondary to hematogenous spread from primary infection in the [[lung]], [[Abdomen|abdomen,]] or [[pelvis]] | * Secondary to hematogenous spread from primary [[infection]] in the [[lung]], [[Abdomen|abdomen,]] or [[pelvis]] | ||
* Direct extension from [[paranasal sinuses]], [[ears]], and cervicofacial regions<ref name="pmid3317731">{{cite journal| author=Smego RA| title=Actinomycosis of the central nervous system. | journal=Rev Infect Dis | year= 1987 | volume= 9 | issue= 5 | pages= 855-65 | pmid=3317731 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=3317731 }} </ref> | * Direct extension from [[paranasal sinuses]], [[ears]], and cervicofacial regions<ref name="pmid3317731">{{cite journal| author=Smego RA| title=Actinomycosis of the central nervous system. | journal=Rev Infect Dis | year= 1987 | volume= 9 | issue= 5 | pages= 855-65 | pmid=3317731 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=3317731 }} </ref> | ||
|} | |} | ||
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Following transmission, lesions spread by direct extension. | Following transmission, lesions spread by direct extension. | ||
===Seeding=== | ===Seeding=== | ||
*Once the [[Endogenous|endogenous bacteria]] are introduced into the tissues, they multiply due to low oxygen tension. | *Once the [[Endogenous|endogenous bacteria]] are introduced into the [[tissues]], they multiply due to low [[oxygen]] tension. | ||
*It leads to the formation of hard yellow hard granules(sulfur granules). | *It leads to the formation of hard yellow hard granules ([[sulfur]] [[granules]]). | ||
*These granules represent solidified bacterial filaments with surrounding tissue [[Exudate|exudates.]] | *These granules represent solidified bacterial filaments with surrounding tissue [[Exudate|exudates.]] | ||
*These triggers an [[Inflammatory responses|inflammatory reaction]]. | *These triggers an [[Inflammatory responses|inflammatory reaction]]. | ||
*[[Inflammation|Inflammatory]] mediators along with various | *[[Inflammation|Inflammatory]] mediators along with various [[Toxins|bacterial toxins]] and [[Proteolytic enzyme|proteolytic]] enzymes from the [[neutrophils]] are released leading to [[abscess]] formation. | ||
*A fibrous wall develops around the abscess. | *A fibrous wall develops around the [[abscess]]. | ||
*Extension of the abscess to skin leads to the formation of sinus tracts and pus drains out through these sinuses. | *Extension of the abscess to [[skin]] leads to the formation of sinus tracts and [[Pustulate|pus]] drains out through these sinuses. | ||
===Immune response=== | ===Immune response=== | ||
[[Actinomycosis]] elicits both [[Humoral immunity|humoral]] and [[Cell-mediated immunity|cell-mediated]] [[immune]] responses | [[Actinomycosis]] elicits both [[Humoral immunity|humoral]] and [[Cell-mediated immunity|cell-mediated]] [[immune]] responses | ||
| Line 89: | Line 89: | ||
*Single or multiple [[abscesses]] | *Single or multiple [[abscesses]] | ||
*[[Induration|Indurated]] masses with hard fibrous walls and soft central loculations containing white or yellow pus. | *[[Induration|Indurated]] masses with hard fibrous walls and soft central loculations containing white or yellow pus. | ||
*Granules are seen grossly. | *[[Granules]] are seen grossly. | ||
*Sinus tracts extended from [[abscesses]] to the skin surface or into organs; [[Vertebra|vertebral bone]], and [[retroperitoneal]] tissue. | *[[Sinus]] tracts extended from [[abscesses]] to the [[skin]] surface or into organs; [[Vertebra|vertebral bone]], and [[retroperitoneal]] [[tissue]]. | ||
*[[Pleural]], [[pericardial]], or serosal thickening if the infection involves [[lung]], [[heart]], and [[Bowel|wall of the bowel.]] | *[[Pleural]], [[pericardial]], or [[Serosa|serosal]] thickening if the [[infection]] involves [[lung]], [[heart]], and [[Bowel|wall of the bowel.]] | ||
==Microscopic pathology== | ==Microscopic pathology== | ||
Microscopic findings include | Microscopic findings include | ||
*Liquefaction type of [[necrosis]] in the center of abscess with a surrounding outer layer of granulation tissue along with [[lymphocytes]] and [[neutrophils]]. | *[[Liquefaction]] type of [[necrosis]] in the center of [[abscess]] with a surrounding outer layer of [[granulation tissue]] along with [[lymphocytes]] and [[neutrophils]]. | ||
*[[Gram-positive]] organism with branching filaments like structures appear as colonies. | *[[Gram-positive]] [[organism]] with branching [[filaments]] like structures appear as colonies. | ||
[[Image: Actinomycosis1.jpg|center|alt=This is a low-power photomicrograph of the retroperitoneal abscess. At this magnification, multiple dark-staining foci can be appreciated. These foci are Actinomyces colonies (arrows). These colonies are known as "sulfur granules" because in gross specimens they are visible to the naked eye as yellow grains, thus resembling grains of sulfur.|This is a low-power photomicrograph of the retroperitoneal abscess. At this magnification, multiple dark-staining foci can be appreciated. These foci are Actinomyces colonies (arrows). These colonies are known as "sulfur granules" because in gross specimens they are visible to the naked eye as yellow grains, thus resembling grains of sulfur.|frame|400px|]]\ | [[Image: Actinomycosis1.jpg|center|alt=This is a low-power photomicrograph of the retroperitoneal abscess. At this magnification, multiple dark-staining foci can be appreciated. These foci are Actinomyces colonies (arrows). These colonies are known as "sulfur granules" because in gross specimens they are visible to the naked eye as yellow grains, thus resembling grains of sulfur.|This is a low-power photomicrograph of the retroperitoneal abscess. At this magnification, multiple dark-staining foci can be appreciated. These foci are Actinomyces colonies (arrows). These colonies are known as "sulfur granules" because in gross specimens they are visible to the naked eye as yellow grains, thus resembling grains of sulfur.|frame|400px|]]\ | ||
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[[Category:Bacterial diseases]] | [[Category:Bacterial diseases]] | ||
[[Category:Disease]] | [[Category:Disease]] | ||
[[Category:Overview complete]] | [[Category:Overview complete]] | ||
[[Category:Dermatology]] | [[Category:Dermatology]] | ||
Latest revision as of 16:18, 18 September 2017
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Actinomycosis pathophysiology On the Web |
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Aditya Ganti M.B.B.S. [2]
Overview
Actinomycosis is a chronic pyogenic bacterial infection caused by actinomyces species. Infection most frequently follows dental work, trauma, surgery, or other medical conditions. When there is break in the mucosa, anywhere from the mouth to the rectum they reach tissues and cause damage. Incubation period of actinomycosis varies from one to four weeks. But occasionally, it may be as long as several months. Actinomycosis elicits both humoral and cell-mediated immune responses
Pathophysiology
- Actinomycosis is caused by the bacteria Actinomyces. The pathophysiology of actinomycosis can be described in the following steps. [1][2][3][4][5][6]
Transmission
- Actinomyces are part of the natural flora of human body, resides in the oral cavity, lower gastrointestinal tract and urogenital tract.
- They are nonvirulent under normal conditions
- When there is a breach in normal mucosal architecture, anywhere from the mouth to the rectum they enter tissues and cause damage.
| Types | Site of Infection | Source of infection |
|---|---|---|
| Cervicofacial actinomycosis |
| |
| Thoracic |
| |
| Abdominal actinomycosis | Abdomen |
|
| Pelvic
actinomycosis |
Pelvis | |
| Central nervous system | CNS |
Incubation
Incubation period of actinomycosis varies from one to four weeks.
Dissemination
Following transmission, lesions spread by direct extension.
Seeding
- Once the endogenous bacteria are introduced into the tissues, they multiply due to low oxygen tension.
- It leads to the formation of hard yellow hard granules (sulfur granules).
- These granules represent solidified bacterial filaments with surrounding tissue exudates.
- These triggers an inflammatory reaction.
- Inflammatory mediators along with various bacterial toxins and proteolytic enzymes from the neutrophils are released leading to abscess formation.
- A fibrous wall develops around the abscess.
- Extension of the abscess to skin leads to the formation of sinus tracts and pus drains out through these sinuses.
Immune response
Actinomycosis elicits both humoral and cell-mediated immune responses
Genetics
There is no known genetic association to actinomycosis
Gross Pathology
On gross pathology, the following features can be noticed:
- Single or multiple abscesses
- Indurated masses with hard fibrous walls and soft central loculations containing white or yellow pus.
- Granules are seen grossly.
- Sinus tracts extended from abscesses to the skin surface or into organs; vertebral bone, and retroperitoneal tissue.
- Pleural, pericardial, or serosal thickening if the infection involves lung, heart, and wall of the bowel.
Microscopic pathology
Microscopic findings include
- Liquefaction type of necrosis in the center of abscess with a surrounding outer layer of granulation tissue along with lymphocytes and neutrophils.
- Gram-positive organism with branching filaments like structures appear as colonies.
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References
- ↑ Volante M, Contucci AM, Fantoni M, Ricci R, Galli J (2005). "Cervicofacial actinomycosis: still a difficult differential diagnosis". Acta Otorhinolaryngol Ital. 25 (2): 116–9. PMC 2639881. PMID 16116835.
- ↑ Sharkawy AA (2007). "Cervicofacial actinomycosis and mandibular osteomyelitis". Infect. Dis. Clin. North Am. 21 (2): 543–56, viii. doi:10.1016/j.idc.2007.03.007. PMID 17561082.
- ↑ Peipert, Jeffrey F. (2004). "Actinomyces: Normal Flora or Pathogen?". Obstetrics & Gynecology. 104 (Supplement): 1132–1133. doi:10.1097/01.AOG.0000145267.59208.e7. ISSN 0029-7844.
- ↑ Higashi Y, Nakamura S, Ashizawa N, Oshima K, Tanaka A, Miyazaki T, Izumikawa K, Yanagihara K, Yamamoto Y, Miyazaki Y, Mukae H, Kohno S (2017). "Pulmonary Actinomycosis Mimicking Pulmonary Aspergilloma and a Brief Review of the Literature". Intern. Med. 56 (4): 449–453. doi:10.2169/internalmedicine.56.7620. PMID 28202870.
- ↑ Schaal KP, Lee HJ (1992). "Actinomycete infections in humans--a review". Gene. 115 (1–2): 201–11. PMID 1612438.
- ↑ Brown, James R. (1973). "Human actinomycosisA study of 181 subjects". Human Pathology. 4 (3): 319–330. doi:10.1016/S0046-8177(73)80097-8. ISSN 0046-8177.
- ↑ Smego RA (1987). "Actinomycosis of the central nervous system". Rev Infect Dis. 9 (5): 855–65. PMID 3317731.