Actinomycosis pathophysiology: Difference between revisions

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Latest revision as of 16:18, 18 September 2017

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	Neck Jaw Mouth	Dental problems like tooth decay
Thoracic actinomycosis	Lungs Pleura Chest wall Mediastinum	Inhalation of droplets of contaminated fluid Aspiration of oropharyngeal secretions or gastric contents Direct extension of cervicofacial infection into the mediastinum Transdiaphragmatic or retroperitoneal spread from the abdomen Hematogenous spread
Abdominal actinomycosis	Abdomen	Secondary to abdominal infections like appendicitis Accidental swallowing of a foreign body such as chicken bone containing the actinomycetes bacteria Penetrating trauma Perforation of the gut (e.g., the colon or appendix) Surgical manipulation of GI tract
Pelvic actinomycosis	Pelvis	Occurs most commonly in woman as the bacteria enters into the pelvis Long-term use of IUD type of contraceptive
Central nervous system actinomycosis	CNS	Secondary to hematogenous spread from primary infection in the lung, abdomen, or pelvis Direct extension from paranasal sinuses, ears, and cervicofacial regions^[7]

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.

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.

\

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.

Template:Bacterial diseases

[pmid16116835-1] 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.

[pmid17561082-2] 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.

[Peipert2004-3] 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.

[pmid28202870-4] 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.

[pmid1612438-5] Schaal KP, Lee HJ (1992). "Actinomycete infections in humans--a review". Gene. 115 (1–2): 201–11. PMID 1612438.

[Brown1973-6] 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.

[pmid3317731-7] Smego RA (1987). "Actinomycosis of the central nervous system". Rev Infect Dis. 9 (5): 855–65. PMID 3317731.

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[2]

[3]

[4]

[5]

[6]

[7]

@@ Line 1: / Line 1: @@
 __NOTOC__
-{{Actinomycosis}}{{CMG}}
+{{Actinomycosis}}
+{{CMG}}; {{AE}}{{ADG}}
 ==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]]
 == Pathophysiology==
-*Actinomycosis is caused by the bacteria [[Actinomyces]].
+*[[Actinomycosis]] is caused by the bacteria [[Actinomyces]]. The pathophysiology of actinomycosis can be described in the following steps. <ref name="pmid16116835">{{cite journal |vauthors=Volante M, Contucci AM, Fantoni M, Ricci R, Galli J |title=Cervicofacial actinomycosis: still a difficult differential diagnosis |journal=Acta Otorhinolaryngol Ital |volume=25 |issue=2 |pages=116–9 |year=2005 |pmid=16116835 |pmc=2639881 |doi= |url=}}</ref><ref name="pmid17561082">{{cite journal |vauthors=Sharkawy AA |title=Cervicofacial actinomycosis and mandibular osteomyelitis |journal=Infect. Dis. Clin. North Am. |volume=21 |issue=2 |pages=543–56, viii |year=2007 |pmid=17561082 |doi=10.1016/j.idc.2007.03.007 |url=}}</ref><ref name="Peipert2004">{{cite journal|last1=Peipert|first1=Jeffrey F.|title=Actinomyces: Normal Flora or Pathogen?|journal=Obstetrics & Gynecology|volume=104|issue=Supplement|year=2004|pages=1132–1133|issn=0029-7844|doi=10.1097/01.AOG.0000145267.59208.e7}}</ref><ref name="pmid28202870">{{cite journal |vauthors=Higashi Y, Nakamura S, Ashizawa N, Oshima K, Tanaka A, Miyazaki T, Izumikawa K, Yanagihara K, Yamamoto Y, Miyazaki Y, Mukae H, Kohno S |title=Pulmonary Actinomycosis Mimicking Pulmonary Aspergilloma and a Brief Review of the Literature |journal=Intern. Med. |volume=56 |issue=4 |pages=449–453 |year=2017 |pmid=28202870 |doi=10.2169/internalmedicine.56.7620 |url=}}</ref><ref name="pmid1612438">{{cite journal |vauthors=Schaal KP, Lee HJ |title=Actinomycete infections in humans--a review |journal=Gene |volume=115 |issue=1-2 |pages=201–11 |year=1992 |pmid=1612438 |doi= |url=}}</ref><ref name="Brown1973">{{cite journal|last1=Brown|first1=James R.|title=Human actinomycosisA study of 181 subjects|journal=Human Pathology|volume=4|issue=3|year=1973|pages=319–330|issn=00468177|doi=10.1016/S0046-8177(73)80097-8}}</ref>
 ===Transmission===
-*Actinomyces are part of 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 non virulent under normal conditions
-*When there is break in the mucosa, anywhere from the mouth to the rectum they reach tissues and cause damage.
-===Incubation ===
-[[Incubation period]] of Actinomycosis varies from one to four weeks. But occasionally, it may be as long as several months.
-=== '''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 triggers an inflammatory reaction which results in formation of hard yellow hard granules(sulfur granules).
-*These are solidified bacterial filaments with surrounding tissue exudates.
-*Abscesses with fibrous walls and pus along with sulfur granules develop.
-*It finally drain out through sinuses.
-===Immune response===
-Actinomycosis elicits both [[Humoral immunity|humoral]] and [[Cell-mediated immunity|cell-mediated]] [[immune]] responses
-===Microscopic pathology===
-*Positive for sulphur granules in pus
-*Gram positive organism with branching filaments forming segment-like structures
-*Surrounded by neutrophils
-[[Image: Actinomyces.high magnification.jpg|center|500px]]
+*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.
 {| class="wikitable"
 !Types
@@ Line 32: / Line 18: @@
 !Source of infection
 |-
-!Cervicofacial actinomycosis
+![[Cervicofacial actinomycosis]]
 |
-* Neck
+* [[Neck]]
-* Jaw
+* [[Jaw]]
-* Mouth
+* [[Mouth]]
 |
-* Dental problems like tooth decay
+* Dental problems like [[tooth decay]]
 |-
-!Thoracic
+![[Thoracic actinomycosis|Thoracic]]
-actinomycosis
+[[Thoracic actinomycosis|actinomycosis]]
 |
-* Lungs
+* [[Lungs]]
-* Pleura
+* [[Pleura]]
-* Chest wall
+* [[Chest wall]]
-* 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
 |-
 !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 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
 actinomycosis
-|Pelvis
+|[[Pelvis]]
 |
-* Occurs most commonly in woman as the bacteria passes from the female genitals 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, 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
+* 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>
 |}
+===Incubation ===
+[[Incubation period]] of [[actinomycosis]] varies from one to four weeks.
+=== '''Dissemination''' ===
+Following transmission, lesions spread by direct extension.
+===Seeding===
+*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]]).
+*These granules represent solidified bacterial filaments with surrounding tissue [[Exudate|exudates.]]
+*These triggers an [[Inflammatory responses|inflammatory reaction]].
+*[[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]].
+*Extension of the abscess to [[skin]] leads to the formation of sinus tracts and [[Pustulate|pus]] drains out through these sinuses.
+===Immune response===
+[[Actinomycosis]] elicits both [[Humoral immunity|humoral]] and [[Cell-mediated immunity|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]]
+*[[Induration|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; [[Vertebra|vertebral bone]], and [[retroperitoneal]] [[tissue]].
+*[[Pleural]], [[pericardial]], or [[Serosa|serosal]] thickening if the [[infection]] involves [[lung]], [[heart]], and [[Bowel|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.
+[[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|]]\
+{{#ev:youtube|pvasI_yy3R4}}
 ==References==
@@ Line 89: / Line 110: @@
 [[Category:Bacterial diseases]]
 [[Category:Disease]]
-[[Category:Infectious disease]]
 [[Category:Overview complete]]
 [[Category:Dermatology]]