Brucellosis pathophysiology: Difference between revisions

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__NOTOC__
__NOTOC__
{{CMG}}; {{AE}}{{VD}}   
 
{{CMG}}; {{AE}}{{DL}}{{VD}}   
{{Brucellosis}}
{{Brucellosis}}
== Overview ==
== Overview ==
''[[Brucella]]'' is usually transmitted via the digestive route to the [[human]] [[Host (biology)|host]]. Following transmission, [[white blood cells]] [[phagocyte]] the [[pathogen]] and transports it via the [[hematologic]] or [[Lymphatic system|lymphatic]] route to different organs, specially to those of the [[reticuloendothelial system]].
''[[Brucella|Brucellosis]]'' is a [[zoonotic]] disease, [[humans]] could be infected by eating undercook meat or raw [[Dairy product|dairy]] products, inhalation of the [[bacteria]] and direct contact of bacteria with [[skin]] [[wounds]] or [[Mucous membranes|mucous membranes.]] Following transmission, [[white blood cells]] phagocyte the pathogen and transports it via hematologic or [[Lymphatic system|lymphatic route]] to different organs, specially to those of the [[reticuloendothelial system]].


== Pathophysiology ==
== Pathophysiology ==
''[[Brucella|Brucellosis]]'' is a [[zoonotic]] disease, [[Humans]] could be infected by eating undercook meat or raw [[Dairy product|dairy]] products, inhalation of the [[bacteria]], and direct contact of bacteria with [[skin]] [[wounds]] or [[Mucous membranes|mucous membranes.]] Following transmission, [[white blood cells]] phagocyte the pathogen and transports it via hematologic or [[Lymphatic system|lymphatic route]] to different organs, specially to those of the [[reticuloendothelial system]]. [[Endotoxic]] [[lipopolysaccharide]] LPS, plays an important role in survival of bacteria inside [[Monocytic|monocytic cel]]<nowiki/>l, supressing [[Lysosome|phagosome-lysosome fusion]], and internalizing bacteria into [[endoplasmic reticulum]]. The pathophysiology of Brucellosis can be described in the following steps:<ref name="pmid15930423">{{cite journal| author=Pappas G, Akritidis N, Bosilkovski M, Tsianos E| title=Brucellosis. | journal=N Engl J Med | year= 2005 | volume= 352 | issue= 22 | pages= 2325-36 | pmid=15930423 | doi=10.1056/NEJMra050570 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15930423  }}</ref><ref name=":0">{{Cite web|url=https://www.cdc.gov/brucellosis/transmission/index.html|title=CDC|date=|access-date=|website=|publisher=|last=|first=}}</ref><ref name="pmid8698508">{{cite journal| author=Zhan Y, Liu Z, Cheers C| title=Tumor necrosis factor alpha and interleukin-12 contribute to resistance to the intracellular bacterium Brucella abortus by different mechanisms. | journal=Infect Immun | year= 1996 | volume= 64 | issue= 7 | pages= 2782-6 | pmid=8698508 | doi= | pmc=174139 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=8698508  }} </ref><ref name="pmid1574477">{{cite journal| author=Larralde de Luna M, Raspa ML, Ibargoyen J| title=Oral-facial-digital type 1 syndrome of Papillon-Léage and Psaume. | journal=Pediatr Dermatol | year= 1992 | volume= 9 | issue= 1 | pages= 52-6 | pmid=1574477 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1574477  }} </ref><ref name="pmid2915152">{{cite journal| author=Gazapo E, Gonzalez Lahoz J, Subiza JL, Baquero M, Gil J, de la Concha EG| title=Changes in IgM and IgG antibody concentrations in brucellosis over time: importance for diagnosis and follow-up. | journal=J Infect Dis | year= 1989 | volume= 159 | issue= 2 | pages= 219-25 | pmid=2915152 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=2915152  }} </ref><ref name="pmid10858243">{{cite journal| author=Arenas GN, Staskevich AS, Aballay A, Mayorga LS| title=Intracellular trafficking of Brucella abortus in J774 macrophages. | journal=Infect Immun | year= 2000 | volume= 68 | issue= 7 | pages= 4255-63 | pmid=10858243 | doi= | pmc=101738 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10858243  }} </ref><ref name="pmid12414154">{{cite journal| author=Boschiroli ML, Ouahrani-Bettache S, Foulongne V, Michaux-Charachon S, Bourg G, Allardet-Servent A et al.| title=Type IV secretion and Brucella virulence. | journal=Vet Microbiol | year= 2002 | volume= 90 | issue= 1-4 | pages= 341-8 | pmid=12414154 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=12414154  }} </ref><ref name="pmid15694858">{{cite journal| author=Lapaque N, Moriyon I, Moreno E, Gorvel JP| title=Brucella lipopolysaccharide acts as a virulence factor. | journal=Curr Opin Microbiol | year= 2005 | volume= 8 | issue= 1 | pages= 60-6 | pmid=15694858 | doi=10.1016/j.mib.2004.12.003 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15694858  }} </ref><ref name="pmid12414174">{{cite journal| author=DelVecchio VG, Kapatral V, Elzer P, Patra G, Mujer CV| title=The genome of Brucella melitensis. | journal=Vet Microbiol | year= 2002 | volume= 90 | issue= 1-4 | pages= 587-92 | pmid=12414174 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=12414174  }} </ref><ref name="pmid11782541">{{cite journal| author=Moreno E, Moriyon I| title=Brucella melitensis: a nasty bug with hidden credentials for virulence. | journal=Proc Natl Acad Sci U S A | year= 2002 | volume= 99 | issue= 1 | pages= 1-3 | pmid=11782541 | doi=10.1073/pnas.022622699 | pmc=117501 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=11782541  }} </ref><ref name="pmid12414149">{{cite journal| author=Gorvel JP, Moreno E| title=Brucella intracellular life: from invasion to intracellular replication. | journal=Vet Microbiol | year= 2002 | volume= 90 | issue= 1-4 | pages= 281-97 | pmid=12414149 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=12414149  }} </ref><ref name="pmid12525425">{{cite journal| author=Ko J, Splitter GA| title=Molecular host-pathogen interaction in brucellosis: current understanding and future approaches to vaccine development for mice and humans. | journal=Clin Microbiol Rev | year= 2003 | volume= 16 | issue= 1 | pages= 65-78 | pmid=12525425 | doi= | pmc=145300 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=12525425  }} </ref><ref name="pmid12414158">{{cite journal| author=Dornand J, Gross A, Lafont V, Liautard J, Oliaro J, Liautard JP| title=The innate immune response against Brucella in humans. | journal=Vet Microbiol | year= 2002 | volume= 90 | issue= 1-4 | pages= 383-94 | pmid=12414158 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=12414158  }} </ref>
''[[Brucella|Brucellosis]]'' is a [[zoonotic]] disease, [[humans]] could be infected by eating undercook meat or raw [[Dairy product|dairy]] products, inhalation of the [[bacteria]] and direct contact of bacteria with [[skin]] [[wounds]] or [[Mucous membranes|mucous membranes.]] Following transmission, [[white blood cells]] phagocyte the pathogen and transports it via hematologic or [[Lymphatic system|lymphatic route]] to different organs specially to those of the [[reticuloendothelial system]]. [[Endotoxic]] [[lipopolysaccharide]] LPS, plays an important role in: survival of bacteria inside [[Monocytic|monocytic cel]]<nowiki/>l, supressing [[Lysosome|phagosome-lysosome fusion]] and internalizing bacteria into [[endoplasmic reticulum]]. The pathophysiology of Brucellosis can be described in the following steps:<ref name="pmid15930423">{{cite journal| author=Pappas G, Akritidis N, Bosilkovski M, Tsianos E| title=Brucellosis. | journal=N Engl J Med | year= 2005 | volume= 352 | issue= 22 | pages= 2325-36 | pmid=15930423 | doi=10.1056/NEJMra050570 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15930423  }}</ref><ref name=":0">{{Cite web|url=https://www.cdc.gov/brucellosis/transmission/index.html|title=CDC|date=|access-date=|website=|publisher=|last=|first=}}</ref><ref name="pmid8698508">{{cite journal| author=Zhan Y, Liu Z, Cheers C| title=Tumor necrosis factor alpha and interleukin-12 contribute to resistance to the intracellular bacterium Brucella abortus by different mechanisms. | journal=Infect Immun | year= 1996 | volume= 64 | issue= 7 | pages= 2782-6 | pmid=8698508 | doi= | pmc=174139 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=8698508  }} </ref><ref name="pmid1574477">{{cite journal| author=Larralde de Luna M, Raspa ML, Ibargoyen J| title=Oral-facial-digital type 1 syndrome of Papillon-Léage and Psaume. | journal=Pediatr Dermatol | year= 1992 | volume= 9 | issue= 1 | pages= 52-6 | pmid=1574477 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1574477  }} </ref><ref name="pmid2915152">{{cite journal| author=Gazapo E, Gonzalez Lahoz J, Subiza JL, Baquero M, Gil J, de la Concha EG| title=Changes in IgM and IgG antibody concentrations in brucellosis over time: importance for diagnosis and follow-up. | journal=J Infect Dis | year= 1989 | volume= 159 | issue= 2 | pages= 219-25 | pmid=2915152 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=2915152  }} </ref><ref name="pmid10858243">{{cite journal| author=Arenas GN, Staskevich AS, Aballay A, Mayorga LS| title=Intracellular trafficking of Brucella abortus in J774 macrophages. | journal=Infect Immun | year= 2000 | volume= 68 | issue= 7 | pages= 4255-63 | pmid=10858243 | doi= | pmc=101738 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10858243  }} </ref><ref name="pmid12414154">{{cite journal| author=Boschiroli ML, Ouahrani-Bettache S, Foulongne V, Michaux-Charachon S, Bourg G, Allardet-Servent A et al.| title=Type IV secretion and Brucella virulence. | journal=Vet Microbiol | year= 2002 | volume= 90 | issue= 1-4 | pages= 341-8 | pmid=12414154 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=12414154  }} </ref><ref name="pmid15694858">{{cite journal| author=Lapaque N, Moriyon I, Moreno E, Gorvel JP| title=Brucella lipopolysaccharide acts as a virulence factor. | journal=Curr Opin Microbiol | year= 2005 | volume= 8 | issue= 1 | pages= 60-6 | pmid=15694858 | doi=10.1016/j.mib.2004.12.003 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15694858  }} </ref><ref name="pmid12414174">{{cite journal| author=DelVecchio VG, Kapatral V, Elzer P, Patra G, Mujer CV| title=The genome of Brucella melitensis. | journal=Vet Microbiol | year= 2002 | volume= 90 | issue= 1-4 | pages= 587-92 | pmid=12414174 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=12414174  }} </ref><ref name="pmid11782541">{{cite journal| author=Moreno E, Moriyon I| title=Brucella melitensis: a nasty bug with hidden credentials for virulence. | journal=Proc Natl Acad Sci U S A | year= 2002 | volume= 99 | issue= 1 | pages= 1-3 | pmid=11782541 | doi=10.1073/pnas.022622699 | pmc=117501 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=11782541  }} </ref><ref name="pmid12414149">{{cite journal| author=Gorvel JP, Moreno E| title=Brucella intracellular life: from invasion to intracellular replication. | journal=Vet Microbiol | year= 2002 | volume= 90 | issue= 1-4 | pages= 281-97 | pmid=12414149 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=12414149  }} </ref><ref name="pmid12525425">{{cite journal| author=Ko J, Splitter GA| title=Molecular host-pathogen interaction in brucellosis: current understanding and future approaches to vaccine development for mice and humans. | journal=Clin Microbiol Rev | year= 2003 | volume= 16 | issue= 1 | pages= 65-78 | pmid=12525425 | doi= | pmc=145300 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=12525425  }} </ref><ref name="pmid12414158">{{cite journal| author=Dornand J, Gross A, Lafont V, Liautard J, Oliaro J, Liautard JP| title=The innate immune response against Brucella in humans. | journal=Vet Microbiol | year= 2002 | volume= 90 | issue= 1-4 | pages= 383-94 | pmid=12414158 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=12414158  }} </ref>


=== Transmission===
=== Transmission===
According to CDC, humans are generally infected with Brucellosis in one of the following three ways:<ref name="pmid15930423" /><ref>{{Cite web|url=CDC|title=https://www.cdc.gov/brucellosis/transmission/index.html|last=|first=|date=|website=|publisher=|access-date=}}</ref>
According to CDC, humans are generally infected with Brucellosis in one of the following three ways:<ref name="pmid15930423" /><ref>{{Cite web|url=CDC|title=https://www.cdc.gov/brucellosis/transmission/index.html|last=|first=|date=|website=|publisher=|access-date=}}</ref>
{| class="wikitable"
{| class="wikitable"
! colspan="2" |Humans are generally infected with brucellosis in one of three ways
! colspan="2" |ROUTE OF TRANSMISSION
|-
|-
|[[Gastrointestinal]]
|
|
'''Eating undercooked meat or consuming unpasteurized/raw dairy products'''
Eating undercooked meat or consuming [[Unpasteurized milk|unpasteurized]]/raw dairy products
|
* The most common way to be infected is by eating or drinking [[Unpasteurized milk|unpasteurized]]/raw dairy products.
* When sheep, goats, cows, or camels are infected, their milk becomes contaminated with the [[bacteria]].
* If the milk from infected animals is not pasteurized, the infection will be transmitted to people who consume the milk and/or [[cheese]] products.
|-
|-
|[[Inhalation]]
|
|
 
[[Breathing]] in the [[bacteria]] that cause brucellosis (inhalation)
'''Breathing in the bacteria that cause brucellosis (inhalation)'''
|
* Breathing in the bacteria that causes brucellosis may also lead to infection.
* This risk is generally greater for people in laboratories that work with the bacteria.
* In addition, slaughterhouse and meat-packing employees have also been known to be exposed to the [[bacteria]] and ultimately become infected.
|-
|-
|[[Cutaneous]]
|
|
 
[[Bacteria]] entering the body through skin [[wounds]] or [[mucous membranes]]
'''Bacteria entering the body through skin wounds or mucous membranes'''
|
* Bacteria can also enter wounds in the [[skin]]/[[mucous membranes]] through contact with infected animals.
* This poses a problem for workers who have close contact with animals or animal excretions (newborn animals, [[fetuses]], and excretions that may result from birth). Such workers may include:
**slaughterhouse workers
**meat-packing plant employees
**veterinarians
|-
|-
|
|Other modes of transmission
 
'''Other mode of transmission'''
|
|
*Person-to-person spread of [[brucellosis]] is extremely rare.
*Person-to-person spread of [[brucellosis]] is extremely rare.
*Infected mothers who are breast-feeding may transmit the infection to their infants.
*Infected mothers who are breast-feeding may transmit the infection to their infants.
*Sexual transmission has been rarely reported.
*Sexual transmission has been rarely reported.
*While uncommon, [[transmission]] may also occur via tissue transplantation or blood transfusions.
*While uncommon, [[transmission]] may also occur via [[Transplantation|tissue transplantation]] or [[blood transfusions]].
|}
|}


=== '''Incubation''' ===
=== '''Incubation''' ===
Incubation period of Brucellosis varies from one to four weeks. But occasionally, it may be as long as several months. 
[[Incubation period]] of brucellosis varies from one to four weeks. But occasionally, it may be as long as several months. 


=== '''Dissemination''' ===
=== '''Dissemination''' ===
Following transmission, Brucellae is ingested by [[macrophages]] and [[Polymorphonuclear cells|polymorphonuclea]]<nowiki/>r cells. On ingestion, they replicate [[intracellularly]] inside the lysed cells and disseminate systemically. 
Following transmission, brucellae is ingested by [[macrophages]] and [[Polymorphonuclear cells|polymorphonuclea]]<nowiki/>r cells. On ingestion, they replicate [[Intracellular|intracellularly]] inside the lysed cells and disseminate systemically. 
 
===Seeding===
===Seeding===
* On transmission, bacteria is actively [[phagocytosed]]  by neurophilic granulocutes and monocytes.
* On [[transmission]], [[bacteria]] is actively [[phagocytosed]]  by neurophilic [[granulocytes]] and [[monocytes]].


*On entry into the body, [[Brucella|Brucellae]] multiply in the [[Neutrophil|neutrophilic]] [[granulocytes]] and [[monocytes]], initially in [[lymph nodes]], which is followed by systemic hematogenous spread resulting in multiple localizing [[infection]]
*On entry into the body, [[Brucella|brucellae]] multiply in the [[Neutrophil|neutrophilic]] [[granulocytes]] and [[monocytes]], initially in [[lymph nodes]], which is followed by systemic hematogenous spread resulting in multiple localizing [[infection]]


===Immune response===
===Immune response===
Line 62: Line 49:
====Humoral immune response====
====Humoral immune response====
* [[Humoral immune system|Humoral]] response has a limited role in protecting host from [[Brucellosis|Brucellae]].  
* [[Humoral immune system|Humoral]] response has a limited role in protecting host from [[Brucellosis|Brucellae]].  
* On activation, [[Chronic lymphocytic leukemia|B-cell]] produce [[IgM]] class antibody, which is followed by [[IgG]] antibodies .  
* On activation, [[Chronic lymphocytic leukemia|B-cell]] produce [[IgM]] class [[antibody]], which is followed by [[IgG]] antibodies .  
* Antibodies promote clearance of extracellular bacteria and facilitate [[phagocytosis]] of the Brucellae.
* [[Antibodies]] promote clearance of extracellular [[bacteria]] and facilitate [[phagocytosis]] of the Brucellae.


====Cell mediates immune response====
====Cell mediates immune response====
*Tumor necrosis factor α ([[TNF-α]]) produce on activation of [[cell mediated immunity]], stimulates [[T lymphocytes]] and [[macrophages]], which help in eliminating intracellular [[brucellae]]. Virulent brucellae tend to suppress the activity of tumor necrosis factor α (TNF-α) and  [[IFN|IFN-gamma]].
*Tumor necrosis factor α ([[TNF-α]]) produces on activation of [[cell mediated immunity]], stimulates [[T lymphocytes]] and [[macrophages]], which help in eliminating intracellular [[brucellae]]. Virulent brucellae tend to suppress the activity of tumor necrosis factor α (TNF-α) and  [[IFN|IFN-gamma]].
*Cytokines such as [[interleukin (IL)]] 12 promote production of Interferon γ ([[Interferon|IFN-γ]]) responses. IFN-γ, which drives [[TH1]]-type responses and stimulates [[macrophage]] activation. [[Cytokines]], which include , [[IL-6]], [[IL-4]]<nowiki/>and [[IL-10]], down-regulate the protective response.
*[[Cytokines]] such as [[Interleukin 12|interleukin (IL) 12]] promote production of Interferon γ ([[Interferon|IFN-γ]]) responses. IFN-γ, which drives [[TH1]]-type responses and stimulates [[macrophage]] activation. [[Cytokines]], which include , [[IL-6]], [[IL-4]]<nowiki/>and [[IL-10]], down-regulate the protective response.


==Pathogenesis==
==Pathogenesis==
Line 74: Line 61:
By avoiding [[innate immunity]], [[Brucella infection|brucella]] survive with in [[Monocytic|monocytic cells]].
By avoiding [[innate immunity]], [[Brucella infection|brucella]] survive with in [[Monocytic|monocytic cells]].
*Endotoxic [[lipopolysaccharide]] (LPS), plays a key role in survival of bacteria inside [[monocytic]] cell.
*Endotoxic [[lipopolysaccharide]] (LPS), plays a key role in survival of bacteria inside [[monocytic]] cell.
*[[LPS]] helps in survival of the bacteria inside the [[monocytic]] cell, by suppressing [[phagosome]]–[[lysosome]] fusion, internalizing bacteria into [[endoplasmic reticulum]] and inhibiting [[apoptosis]] of infected cell.
*[[LPS]] helps in survival of the [[bacteria]] inside the [[monocytic]] cell, by suppressing [[phagosome]]–[[lysosome]] fusion, internalizing bacteria into [[endoplasmic reticulum]] and inhibiting [[apoptosis]] of [[infected]] cell.
*Type IV secretion system (VirB) and  type III secretion system, that regulates [[intracellular]] survival and trafficking has been identified, although type 3 not yet confirmed. Secretion system plays an important role in [[intracellular]] transport of the bacteria Acid-stable [[proteins]] produced by brucella, facilitates the survival in [[phagosomes]]
*Type IV secretion system (VirB) and  type III secretion system, that regulates [[intracellular]] survival and trafficking has been identified, although type 3 not yet confirmed. Secretion system plays an important role in [[intracellular]] transport of the bacteria acid-stable [[proteins]] produced by brucella, facilitates the survival in [[phagosomes]]
*Cu-Zn superoxide dismutase, produced by brucellae, gives them resistance from [[reactive oxygen]] intermediates.
*Cu-Zn [[superoxide dismutase]], produced by brucellae, gives them resistance from [[reactive oxygen]] intermediates.
*Two component BvrS/BvrR system, codes for [[External|histidine]] [[kinase]] [[sensor]]. Histidine kinase sensor plays an important role in controlling the expression of [[molecular]] determinants which are necessary for cell invasion.<ref name="pmid159304232">{{cite journal| author=Pappas G, Akritidis N, Bosilkovski M, Tsianos E| title=Brucellosis. | journal=N Engl J Med | year= 2005 | volume= 352 | issue= 22 | pages= 2325-36 | pmid=15930423 | doi=10.1056/NEJMra050570 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15930423  }}</ref>
*Two component BvrS/BvrR system, codes for [[histidine]] [[kinase]] [[sensor]]. Histidine kinase sensor plays an important role in controlling the expression of [[molecular]] determinants which are necessary for cell invasion.<ref name="pmid159304232">{{cite journal| author=Pappas G, Akritidis N, Bosilkovski M, Tsianos E| title=Brucellosis. | journal=N Engl J Med | year= 2005 | volume= 352 | issue= 22 | pages= 2325-36 | pmid=15930423 | doi=10.1056/NEJMra050570 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15930423  }}</ref>
*[[Hemolysin|Hemolysins]] help the bacteria to be realeased from a [[cell]] and induce cell [[necrosis]].
*[[Hemolysin|Hemolysins]] help the [[bacteria]] to be realeased from a [[cell]] and induce cell [[necrosis]].
==Genetics==
==Genetics==
There is no known genetic association to Brucellosis.
There is no known genetic association to Brucellosis.
== Associated factors==
* Brucella is not an [[opportunistic infection]].
* Severity of infection in patients with HIV depends on number of CD4+T lymphocytes.<ref name="pmid9721960">{{cite journal| author=Moreno S, Ariza J, Espinosa FJ, Podzamczer D, Miró JM, Rivero A et al.| title=Brucellosis in patients infected with the human immunodeficiency virus. | journal=Eur J Clin Microbiol Infect Dis | year= 1998 | volume= 17 | issue= 5 | pages= 319-26 | pmid=9721960 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=9721960  }}</ref>
== Gross Pathology ==


== Microscopic Pathology ==
== Microscopic Pathology ==
[[Brucella|''Brucella spp''.]] are poorly staining, small gram-negative coccobacilli (0.5-0.7 x 0.6-1.5 µm).
[[File:Brucellosis histopathology.png|center|thumb|673x673px|Brucella spp. are poorly staining, small gram-negative coccobacilli (0.5-0.7 x 0.6-1.5 µm), and are seen mostly as single cells and appearing like “fine sand”.- By Photo Credit:Content Providers(s): CDC/Courtesy of Larry Stauffer, Oregon State Public Health Laboratory - This media comes from the Centers for Disease Control and Prevention's Public Health Image Library (PHIL), with identification number #1901.Note: Not all PHIL images are public domain; be sure to check copyright status and credit authors and content providers.English | Slovenščina | +/−, Public Domain, https://commons.wikimedia.org/w/index.php?curid=723156]]
[[Brucella|''Brucella spp.'']] are seen mostly as single cells and appearing like “fine sand”.<ref name="a2">Brucellosis. Wikipedia. https://en.wikipedia.org/wiki/Brucellosis. Accessed on January 29, 2016</ref>
[[File:Brucella granuloma with necrosis.png|center|thumb|705x705px|Histopathology of guinea pig liver in experimental Brucella suis infection. Granuloma with necrosis. - Public Domain, https://commons.wikimedia.org/w/index.php?curid=2255655]]
Common findings on microscopic histopathological analysis of the liver include:
*[[Granulomas]] with centrilobular necrosis or focal necrosis and parenchyma destruction.<ref>Hunt A, Bothwell P. Histological findings in human brucellosis. ''J Clin Pathol''. 1967; 20: 267-272</ref>
<gallery>
Image:Brucella-histo.jpg|thumb|200px|Brucella spp. are poorly staining, small gram-negative coccobacilli (0.5-0.7 x 0.6-1.5 µm), and are seen mostly as single cells and appearing like “fine sand”.
Image:Bruce-granulomanecrosis.jpg|thumb|200px|Histopathology of guinea pig liver in experimental Brucella suis infection. Granuloma with necrosis.
</gallery>


==Reference==
==Reference==
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Latest revision as of 20:45, 29 July 2020


Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Danitza LukacVishal Devarkonda, M.B.B.S[2]

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Overview

Brucellosis is a zoonotic disease, humans could be infected by eating undercook meat or raw dairy products, inhalation of the bacteria and direct contact of bacteria with skin wounds or mucous membranes. Following transmission, white blood cells phagocyte the pathogen and transports it via hematologic or lymphatic route to different organs, specially to those of the reticuloendothelial system.

Pathophysiology

Brucellosis is a zoonotic disease, humans could be infected by eating undercook meat or raw dairy products, inhalation of the bacteria and direct contact of bacteria with skin wounds or mucous membranes. Following transmission, white blood cells phagocyte the pathogen and transports it via hematologic or lymphatic route to different organs specially to those of the reticuloendothelial system. Endotoxic lipopolysaccharide LPS, plays an important role in: survival of bacteria inside monocytic cell, supressing phagosome-lysosome fusion and internalizing bacteria into endoplasmic reticulum. The pathophysiology of Brucellosis can be described in the following steps:[1][2][3][4][5][6][7][8][9][10][11][12][13]

Transmission

According to CDC, humans are generally infected with Brucellosis in one of the following three ways:[1][14]

ROUTE OF TRANSMISSION
Gastrointestinal

Eating undercooked meat or consuming unpasteurized/raw dairy products

Inhalation

Breathing in the bacteria that cause brucellosis (inhalation)

Cutaneous

Bacteria entering the body through skin wounds or mucous membranes

Other modes of transmission

Incubation

Incubation period of brucellosis varies from one to four weeks. But occasionally, it may be as long as several months. 

Dissemination

Following transmission, brucellae is ingested by macrophages and polymorphonuclear cells. On ingestion, they replicate intracellularly inside the lysed cells and disseminate systemically. 

Seeding

Immune response

Brucellosis elicits both humoral and cell-mediated immune responses:[1][2][3][4][5][6][7][8][9][15][16]

Humoral immune response

Cell mediates immune response

Pathogenesis

The pathogenesis of brucellosis is complex and not fully understood:[1][2][3][4][5][6][7][8][9][17][18][19]

By avoiding innate immunity, brucella survive with in monocytic cells.

Genetics

There is no known genetic association to Brucellosis.

Microscopic Pathology

+/−, Public Domain, https://commons.wikimedia.org/w/index.php?curid=723156
Histopathology of guinea pig liver in experimental Brucella suis infection. Granuloma with necrosis. - Public Domain, https://commons.wikimedia.org/w/index.php?curid=2255655

Reference

  1. 1.0 1.1 1.2 1.3 Pappas G, Akritidis N, Bosilkovski M, Tsianos E (2005). "Brucellosis". N Engl J Med. 352 (22): 2325–36. doi:10.1056/NEJMra050570. PMID 15930423.
  2. 2.0 2.1 2.2 "CDC".
  3. 3.0 3.1 3.2 Zhan Y, Liu Z, Cheers C (1996). "Tumor necrosis factor alpha and interleukin-12 contribute to resistance to the intracellular bacterium Brucella abortus by different mechanisms". Infect Immun. 64 (7): 2782–6. PMC 174139. PMID 8698508.
  4. 4.0 4.1 4.2 Larralde de Luna M, Raspa ML, Ibargoyen J (1992). "Oral-facial-digital type 1 syndrome of Papillon-Léage and Psaume". Pediatr Dermatol. 9 (1): 52–6. PMID 1574477.
  5. 5.0 5.1 5.2 Gazapo E, Gonzalez Lahoz J, Subiza JL, Baquero M, Gil J, de la Concha EG (1989). "Changes in IgM and IgG antibody concentrations in brucellosis over time: importance for diagnosis and follow-up". J Infect Dis. 159 (2): 219–25. PMID 2915152.
  6. 6.0 6.1 6.2 Arenas GN, Staskevich AS, Aballay A, Mayorga LS (2000). "Intracellular trafficking of Brucella abortus in J774 macrophages". Infect Immun. 68 (7): 4255–63. PMC 101738. PMID 10858243.
  7. 7.0 7.1 7.2 Boschiroli ML, Ouahrani-Bettache S, Foulongne V, Michaux-Charachon S, Bourg G, Allardet-Servent A; et al. (2002). "Type IV secretion and Brucella virulence". Vet Microbiol. 90 (1–4): 341–8. PMID 12414154.
  8. 8.0 8.1 8.2 Lapaque N, Moriyon I, Moreno E, Gorvel JP (2005). "Brucella lipopolysaccharide acts as a virulence factor". Curr Opin Microbiol. 8 (1): 60–6. doi:10.1016/j.mib.2004.12.003. PMID 15694858.
  9. 9.0 9.1 9.2 DelVecchio VG, Kapatral V, Elzer P, Patra G, Mujer CV (2002). "The genome of Brucella melitensis". Vet Microbiol. 90 (1–4): 587–92. PMID 12414174.
  10. Moreno E, Moriyon I (2002). "Brucella melitensis: a nasty bug with hidden credentials for virulence". Proc Natl Acad Sci U S A. 99 (1): 1–3. doi:10.1073/pnas.022622699. PMC 117501. PMID 11782541.
  11. Gorvel JP, Moreno E (2002). "Brucella intracellular life: from invasion to intracellular replication". Vet Microbiol. 90 (1–4): 281–97. PMID 12414149.
  12. Ko J, Splitter GA (2003). "Molecular host-pathogen interaction in brucellosis: current understanding and future approaches to vaccine development for mice and humans". Clin Microbiol Rev. 16 (1): 65–78. PMC 145300. PMID 12525425.
  13. Dornand J, Gross A, Lafont V, Liautard J, Oliaro J, Liautard JP (2002). "The innate immune response against Brucella in humans". Vet Microbiol. 90 (1–4): 383–94. PMID 12414158.
  14. [CDC "https://www.cdc.gov/brucellosis/transmission/index.html"] Check |url= value (help). External link in |title= (help)
  15. Khan M, Harms JS, Marim FM, Armon L, Hall CL, Liu YP; et al. (2016). "The Bacterial Second Messenger Cyclic di-GMP Regulates Brucella Pathogenesis and Leads to Altered Host Immune Response" Check |url= value (help). Infect Immun. 84 (12): 3458–3470. doi:10.1128/IAI.00531-16. PMC 5116723. PMID 27672085.
  16. Pappas G, Akritidis N, Bosilkovski M, Tsianos E (2005). "Brucellosis". N Engl J Med. 352 (22): 2325–36. doi:10.1056/NEJMra050570. PMID 15930423.
  17. Barquero-Calvo E, Chaves-Olarte E, Weiss DS, et al. Brucella abortus uses a stealthy strategy to avoid activation of the innate immune system during the onset of infection. PLoS One 2007; 2:e631.
  18. Gorvel JP, Moreno E. Brucella intracellular life: from invasion to intracellular replication. Vet Microbiol 2002; 90:281.
  19. Pappas G, Akritidis N, Bosilkovski M, Tsianos E (2005). "Brucellosis". N Engl J Med. 352 (22): 2325–36. doi:10.1056/NEJMra050570. PMID 15930423.
  20. Pappas G, Akritidis N, Bosilkovski M, Tsianos E (2005). "Brucellosis" Check |url= value (help). N Engl J Med. 352 (22): 2325–36. doi:10.1056/NEJMra050570. PMID 15930423.