Title: Capnocytophaga canimorsus

{{Short description|Species of bacteria}}
{{Speciesbox
| image = 
| image_alt =
| image_caption =
| status =
| status_system =
| status_ref =
| genus = Capnocytophaga
| species = canimorsus
| authority = Brenner ''et al.'' 1989
| synonyms =
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}}

'''''Capnocytophaga canimorsus''''' is a [[Fastidious organism|fastidious]], slow-growing, [[Gram-negative bacteria|Gram-negative rod]] of the genus ''[[Capnocytophaga]]''.&lt;ref name = &quot;Per&quot;&gt;{{cite journal | last1=Pers | first1=C. | last2=Gahrn-Hansen | first2=B. | last3=Frederiksen | first3=W. | title=Capnocytophaga canimorsus Septicemia in Denmark, 1982-1995: Review of 39 Cases | journal=Clinical Infectious Diseases | volume=23 | issue=1 | date=1996-07-01 | issn=1058-4838 | doi=10.1093/clinids/23.1.71 | pages=71–75| pmid=8816132 }}&lt;/ref&gt;&lt;ref name = &quot;Brenner&quot;&gt;{{cite journal | last1=Brenner | first1=D J | last2=Hollis | first2=D G | last3=Fanning | first3=G R | last4=Weaver | first4=R E | title=Capnocytophaga canimorsus sp. nov. (formerly CDC group DF-2), a cause of septicemia following dog bite, and C. cynodegmi sp. nov., a cause of localized wound infection following dog bite | journal=Journal of Clinical Microbiology | volume=27 | issue=2 | date=1989 | issn=0095-1137 | pmid=2915017 | pmc=267282 | doi=10.1128/jcm.27.2.231-235.1989 | pages=231–235}}&lt;/ref&gt;  It is a [[Commensalism|commensal]] bacterium in the normal gingival [[microbiota]] of canine and feline species, but can cause illness in humans. Transmission may occur through bites, licks, or even close proximity with animals.&lt;ref name = &quot;Fischer&quot;&gt;{{cite journal | last1=Fischer | first1=L J | last2=Weyant | first2=R S | last3=White | first3=E H | last4=Quinn | first4=F D | title=Intracellular multiplication and toxic destruction of cultured macrophages by Capnocytophaga canimorsus | journal=Infection and Immunity | volume=63 | issue=9 | date=1995 | issn=0019-9567 | pmid=7642281 | pmc=173481 | doi=10.1128/iai.63.9.3484-3490.1995 | pages=3484–3490}}&lt;/ref&gt;  ''C. canimorsus'' generally has low virulence in healthy individuals,&lt;ref name = &quot;Lion&quot;&gt;{{cite journal | last1=Lion | first1=C. | last2=Escande | first2=F. | last3=Burdin | first3=J.C. | title=Capnocytophaga canimorsus infections in human: Review of the literature and cases report | journal=European Journal of Epidemiology | volume=12 | issue=5 | date=1996 | doi=10.1007/BF00144007 | pages=521–533| pmid=8905316 | s2cid=22408402 }}&lt;/ref&gt; but has been observed to cause severe, even grave, illness in persons with pre-existing conditions.&lt;ref name = &quot;Le Moal&quot;&gt;{{cite journal
|author1=Le Moal G |author2=Landron C |author3=Grollier G |author4=Robert R |author5=Burucoa C | year = 2003
| title = Meningitis Due to ''Capnocytophaga canimorsus'' after Receipt of a Dog Bite: Case Report and Review of the Literature
| journal = Clin Infect Dis
| volume = 36
|issue=3 | pages = e42–46
| pmid = 12539089
| doi=10.1086/345477| doi-access=free}}&lt;/ref&gt;  The [[pathogenesis]] of ''C. canimorsus'' is still largely unknown, but increased clinical diagnoses have fostered an interest in the bacillus.  Treatment with antibiotics is effective in most cases, but the most important yet basic diagnostic tool available to clinicians remains the knowledge of recent exposure to canines or felines.&lt;ref name = &quot;Fischer&quot;/&gt;

==History==
''Capnocytophaga canimorsus'' was first observed in 1976 by Bobo and Newton.  The pair isolated a previously unknown [[Gram-negative]] bacterium from a patient presenting with [[meningitis]] in addition to [[sepsis]].  The patient had been previously exposed to two canine bites on two consecutive days from two different dogs.  Noting the coincidence between the timing of the bites with the onset of symptoms, Butler ''et al''. analyzed 17 similar cases of patients presenting with either sepsis or meningitis from 1961 to 1975.  The cases had been sent to the CDC for examination due to the presence of an unknown Gram-negative bacillus isolated from infected individuals.  Butler notified the CDC of the high incidence of dog bites in connection with the infections.  The CDC could not identify the organism, so they applied the name CDC group DF-2.  DF-2 stands for dysgonic fermenter, meaning that the bacterium is a slow-growing, fermentative bacillus.  In 1989, while analyzing the properties of the unknown bacterium, Weaver et al. noted many similarities to bacteria of the genus ''Capnocytophaga''.  Later that same year, Brenner et al. proposed the name ''Capnocytophaga canimorsus'' after examining the morphology, [[GC-content|G+C% content]], and motility of the species.&lt;ref name = &quot;Lion&quot;/&gt;

=== Etymology ===
The name ''Capnocytophaga'' is derived from the Greek word ''kapnos'', meaning &quot;smoke&quot;, and given here because of its dependence on carbon dioxide for growth. It was added to distinguish this genus from the [[Cytophaga]] genus, originating from the Greek words of ''kytos'' (meaning &quot;cell&quot;), and ''phagein'' (meaning &quot;eat&quot;). The species name of ''canimorsus'' comes from the Latin words ''canis'' and ''morsus'', meaning &quot;dog&quot; and &quot;bite&quot; respectively.&lt;ref&gt;{{cite journal | last=Henry | first=Ronnie | title=Etymologia: Capnocytophaga canimorsus | journal=Emerging Infectious Diseases | volume=24 | issue=12 | date=2018 | issn=1080-6040 | pmc=6256413 | doi=10.3201/eid2412.ET2412 | pages=2201|doi-access=free}}&lt;/ref&gt;

==Epidemiology==
Significant dog bites affect tens of millions of people globally each year, and cases of human infection following exposure to ''C. canimorsus'' have been observed worldwide.&lt;ref name=WHO2013&gt;{{cite web|title=Animal bites Fact sheet N°373|url=https://www.who.int/mediacentre/factsheets/fs373/en/|website=World Health Organization|access-date=5 May 2014|date=February 2013|archive-date=4 May 2015|archive-url=https://web.archive.org/web/20150504100257/http://www.who.int/mediacentre/factsheets/fs373/en/|url-status=live}}&lt;/ref&gt; It is estimated that 2% of the [[demography of the United States|U.S. population]],  4.5–4.7 million people, are bitten by dogs each year.&lt;ref name=&quot;Dog Bite Prevention&quot;&gt;{{cite web|title=Dog Bite Prevention|url=https://www.cdc.gov/homeandrecreationalsafety/dog-bites/biteprevention.html|publisher=[[Centers for Disease Control and Prevention]]|access-date=22 April 2013|url-status=dead|archive-url=https://web.archive.org/web/20130501205632/http://www.cdc.gov/HomeandRecreationalSafety/Dog-Bites/biteprevention.html|archive-date=1 May 2013}}&lt;/ref&gt;&lt;ref name = &quot;Janda&quot;&gt;{{cite journal | last1=Janda | first1=J. Michael | last2=Graves | first2=Margot H. | last3=Lindquist | first3=David | last4=Probert | first4=Will S. | title=Diagnosing ''Capnocytophaga canimorsus'' Infections | journal=Emerging Infectious Diseases | publisher=Centers for Disease Control and Prevention (CDC) | volume=12 | issue=2 | year=2006 | issn=1080-6040 | doi=10.3201/eid1202.050783 | pages=340–342 |pmc=3373098 |pmid=16494769}}&lt;/ref&gt;    Cases have been reported in the United States, Canada, Europe, Australia and S. Africa.&lt;ref name = &quot;Lion&quot;/&gt;  Symptoms may appear within 2–3 days after exposure, or up to 4 weeks later.  Middle-aged and elderly persons are at greater risk for contraction of disease; more than 60% of sufferers are 50 years of age or older.&lt;ref name = &quot;Lion&quot;/&gt;  In addition, individuals who spend a greater portion of their time with canines and felines are also at higher risk.  This includes veterinarians, breeders, pet owners, and keepers.  Having certain pre-existing medical conditions exacerbates the risk.  Chance of infection by any bacterial species after dog bites varies between 3 and 20%; for cats, it may be as high as 50%.&lt;ref name = &quot;Gaastra&quot;&gt;{{cite journal | last1=Gaastra | first1=Wim | last2=Lipman | first2=Len J.A. | title=Capnocytophaga canimorsus | journal=Veterinary Microbiology | publisher=Elsevier BV | volume=140 | issue=3–4 | year=2010 | issn=0378-1135 | doi=10.1016/j.vetmic.2009.01.040 | pages=339–346| pmid=19268498 | url=https://hal.science/hal-00556047 }}&lt;/ref&gt;

==Morphology, culture, and isolation==

[[File:Capnocytophaga_canimorsus_colony_on_blood_agar_3.jpg|thumb|''C. canimorsus'' on [[blood agar]]]]
''C. canimorsus'' is a fastidious, Gram-negative, fermentative, encapsulated, nonspore-forming rod.&lt;ref name=&quot;:0&quot;&gt;{{cite journal |last1=Renzi |first1=Francesco |last2=Ittig |first2=Simon J. |last3=Sadovskaya |first3=Irina |last4=Hess |first4=Estelle |last5=Lauber |first5=Frederic |last6=Dol |first6=Melanie |last7=Shin |first7=Hwain |last8=Mally |first8=Manuela |last9=Fiechter |first9=Chantal |last10=Sauder |first10=Ursula |last11=Chami |first11=Mohamed |last12=Cornelis |first12=Guy R. |title=Evidence for a LOS and a capsular polysaccharide in Capnocytophaga canimorsus |journal=Scientific Reports |article-number=38914 |doi=10.1038/srep38914 |date=15 December 2016|volume=6 |doi-access=free |pmid=27974829 |pmc=5156936 |bibcode=2016NatSR...638914R }}&lt;/ref&gt;  Bacilli are usually 1-3 μm in length.  After growth on [[agar]] plates, longer rods tend to have a curved shape.  The bacteria do not have [[flagella]], but move with a gliding motion, although this can be difficult to see.&lt;ref name = &quot;Brenner&quot;/&gt;  ''C. canimorsus'' requires the right medium for growth. The bacterium grows well on blood agar plates (heart infusion agar with 5% sheep or rabbit blood) and chocolate agar plates.&lt;ref name = &quot;Per&quot;/&gt;&lt;ref name = &quot;Brenner&quot;/&gt;&lt;ref name = &quot;Lion&quot;/&gt;&lt;ref name = &quot;Shin&quot;&gt;{{cite journal | last1=Shin | first1=Hwain | last2=Mally | first2=Manuela | last3=Meyer | first3=Salome | last4=Fiechter | first4=Chantal | last5=Paroz | first5=Cécile | last6=Zaehringer | first6=Ulrich | last7=Cornelis | first7=Guy R. | title=Resistance of Capnocytophaga canimorsus to Killing by Human Complement and Polymorphonuclear Leukocytes | journal=Infection and Immunity | volume=77 | issue=6 | date=2009 | issn=0019-9567 | pmid=19307219 | pmc=2687352 | doi=10.1128/IAI.01324-08 | pages=2262–2271}}&lt;/ref&gt;&lt;ref name = &quot;Boer&quot;&gt;{{cite journal | last1=de Boer | first1=M.G.J. | last2=Lambregts | first2=P.C.L.A. | last3=van Dam | first3=A.P. | last4=van ’t Wout | first4=J.W. | title=Meningitis caused by Capnocytophaga canimorsus: When to expect the unexpected | journal=Clinical Neurology and Neurosurgery | publisher=Elsevier BV | volume=109 | issue=5 | year=2007 | issn=0303-8467 | doi=10.1016/j.clineuro.2007.02.010 | pages=393–398| pmid=17408852 | s2cid=8501012 }}&lt;/ref&gt;  Colonies may not be visible for up to 48 hours due to slow growth.&lt;ref name = &quot;Lion&quot;/&gt;  At 18 hours, colonies are usually less than 0.5&amp;nbsp;mm in diameter, and are spotty and convex.  At 24 hours, colonies may be up to 1&amp;nbsp;mm in diameter.  After 48 hours, colonies are narrow, flat, and smooth, with spreading edges.  At this time, colonies may appear white-grey or grey, rather translucent, and once they are scraped from the agar plate, they may have a slightly yellow tint.

== Genome ==
The genome of  ''C. canimorsus'' strain Cc5 consists of a single circular chromosome of 2,571,406 bp with a [[GC-content|G+C content]] of 36.11%, and it encodes 2,405 [[open reading frame]]s.&lt;ref name=&quot;Manfredi&quot;&gt;{{Cite journal
 | pmid = 21914877
| year = 2011
| last1 = Manfredi
| first1 = P
| title = Complete genome sequence of the dog commensal and human pathogen Capnocytophaga canimorsus strain 5
| journal = Journal of Bacteriology
| volume = 193
| issue = 19
| pages = 5558–9
| last2 = Pagni
| first2 = M
| last3 = Cornelis
| first3 = G. R.
| doi = 10.1128/JB.05853-11
| pmc = 3187460
}}&lt;/ref&gt;

==In animals==
Members of the [[genus]] ''Capnocytophaga'' are found in the oral cavities of humans and animals. Most of these species are not found in humans.&lt;ref name = &quot;Lion&quot;/&gt;  ''C. canimorsus'' is a [[Commensalism|commensal]] bacterium found in dogs and cats; it is not a member of the normal [[microbiota (microbiology)|microbiota]] of humans.  About 26% of dogs carry these commensal bacteria in their mouths.  ''C. canimorsus'' rarely causes disease symptoms in animals.  One case of ''C. canimorsus'' isolated from a dog bite wound on a small dog's head has been reported; the bacteria were localized to the wound, and the dog did not present with [[bacteremia]]. A few cases of infection have been reported in rabbits after being bitten by dogs.  Clinical manifestations of ''C. canimorsus'' in rabbits causes a range of symptoms, including [[disseminated intravascular coagulation]], cellular [[necrosis]] (tissue death), low blood pressure, [[gangrene]], and [[kidney failure]].&lt;ref name = &quot;Gaastra&quot;/&gt;

==High-risk categories==
{{More citations needed section|date=October 2021}}
In addition to those at higher risk of developing complications from ''C. canimorsus'' due to greater contact with felines and canines, certain pre-existing conditions place individuals in a critically high-risk category.  Among these are those who have undergone a splenectomy, alcoholics, and individuals with immunosuppression due to the use of steroids such as glucocorticoids.  Individuals with [[β-thalassemia]] and smokers are also listed as high-risk.  These individuals, like asplenics and alcoholics, have increased levels of alimentary iron in their bloodstream.  ''C. canimorsus'' requires large amounts of iron to grow, so these conditions are optimal for the bacillus.&lt;ref name = &quot;Gaastra&quot;/&gt;

===Asplenia===
[[Overwhelming post-splenectomy infection]] is associated with encapsulated organisms such as Capnocytophaga canimorsus.&lt;ref name=&quot;:0&quot; /&gt;

Of the cases presented in literature, 33% occurred in [[asplenic]] individuals, who have decreased [[IgM]] and [[Immunoglobulin G|IgG]] production.  They also have delayed macrophage assembly and produce less [[tuftsin]].&lt;ref name = &quot;Gaastra&quot;/&gt;  Tuftsin is responsible for the stimulation of [[phagocytosis]], so its decrease in the presence of bacterial infection poses a problem.  A functional spleen is important for the removal of pathogens.  Because this particular pathogen seems to flourish in asplenic patients,  both IgM antibodies and tuftsin may be critical in the process of marking this bacterium for destruction by phagocytosis.&lt;ref name = &quot;Lion&quot;/&gt;  People with asplenia are 60 times more at risk of developing fatal clinical manifestations of the bacterium.{{cn|date=July 2025}} Individuals with asplenia often experience symptom onset within a day of exposure.  The infection rapidly progresses toward multiple organ system failures and finally death. The mortality rate in individuals with asplenia is much higher than in any other at-risk category for ''C. canimorsus'' infections.&lt;ref name = &quot;Gaastra&quot;/&gt;

===Alcohol use disorder===
People who struggle with [[Alcohol use disorder|alcohol addiction]] represent around 24% of individuals presenting with ''C. canimorsus'' infections.&lt;ref name = &quot;Lion&quot;/&gt;  Alcoholism has been shown to result in decreased [[superoxide]] production in [[neutrophils]],&lt;ref&gt;{{cite journal | last=AW | first=Segal | title=How superoxide production by neutrophil leukocytes kills microbes | journal=Novartis Foundation Symposium | publisher=Novartis Found Symp | volume=279 | date=2006 | pages=92-8; discussion 98-100, 216-9 | issn=1528-2511 | pmid=17278388}}&lt;/ref&gt; as well as declines in [[neutrophil elastase]] activity.&lt;ref&gt;{{cite journal | last=Happel | first=K. I. | title=Alcohol, Immunosuppression, and the Lung | journal=Proceedings of the American Thoracic Society | volume=2 | issue=5 | date=2005-12-01 | issn=1546-3222 | doi=10.1513/pats.200507-065JS | pages=428–432| pmid=16322595 }}&lt;/ref&gt;  This results in an increase in predisposition to [[bacteremia]] (bacteria in the blood).  As a result, people suffering from alcoholism are more likely to suffer from the more dangerous aspects of ''C. canimorsus'' invasions.&lt;ref name = &quot;Lion&quot;/&gt;  Finally, people with alcohol addictions are associated with increased blood iron content.&lt;ref name = &quot;Gaastra&quot;/&gt;

===Immunosuppression===
[[Immunosuppressant]]s are often used to treat [[autoimmune diseases]], such as [[systemic lupus erythematosus]].  When individuals undergo treatment with immunosuppressants such as [[glucocorticoid]]s, their bodies' defenses are lowered. As a result, exposure to ''C. canimorsus'' is more infectious in these individuals than in healthy individuals. Immunosuppressed patients make up about 5% of individuals presenting with ''C. canimorsus'' symptoms.&lt;ref name = &quot;Lion&quot;/&gt;

==Symptom onset and clinical manifestations==
Symptoms appear within 1–8 days after exposure to ''C. canimorsus''&lt;ref name =&quot;Per&quot;/&gt; but usually present around day 2.&lt;ref name = &quot;Lion&quot;/&gt;  Symptoms range from mild, flu-like symptoms to full-blown [[fulminant]] sepsis.  Individuals often complain of any combination of: fever, vomiting, diarrhea, [[malaise]], abdominal pain, [[myalgia]], confusion, [[dyspnea]], headaches, and skin rashes such as [[exanthema]].  More severe cases of [[endocarditis]], disseminated intravascular coagulation, and [[meningitis]] have been reported.&lt;ref name = &quot;Per&quot;/&gt;  Prior treatment with methylprednisolone has been shown to prolong bacteremia in these infections, which enables the progression of endocarditis.{{citation needed|date=July 2022}}

==Differential diagnosis==
Diagnosing infections with ''C. canimorsus'' can be difficult.  Common practice for culturing isolates is to keep agar plates for one week; sometimes, cultures of ''C. canimorsus'' are not visible at that point due to slow growth or inappropriate media.  ''C. canimorsus'' requires very specific culture media and conditions; enriched media are necessary.  ''C. canimorsus'' displays enhanced growth in high concentrations of carbon dioxide, so culturing the bacteria in candle extinction jars or carbon dioxide incubators is necessary.&lt;ref name = &quot;Lion&quot;/&gt;  To diagnose this bacillus, certain reactions may be tested.  The bacterium should test positive for catalase and oxidase, arginine dihydrolase, maltose, and lactose.  It should test negative for nitrate reduction, urease, and H&lt;sub&gt;2&lt;/sub&gt;S production.  ''C. canimorsus'' can be distinguished from other Gram-negative bacteria by testing negative for inulin and sucrose.&lt;ref name = &quot;Lion&quot;/&gt;  Due to the relatively slow growth of this bacterium, diagnosis often relies upon the clinician knowing that the patient was previously in contact with a canine or feline.  Once aware of this, clinicians can request that agar plates be kept longer than one week to ensure proper isolation of the bacterium.  Sometimes, even these methods fail.  Cases have been noted where cultures repeatedly came up negative for ''C. canimorsus'', only to determine its presence with 16S rRNA gene sequencing.&lt;ref name = &quot;Gaastra&quot;/&gt;  [[Polymerase chain reaction|PCR]] assays of species-specific genes may also be beneficial.  For individuals presenting with meningitis, ''C. canimorsus'' can be diagnosed with a cerebrospinal fluid [[Gram staining|Gram stain]].&lt;ref name = &quot;Janda&quot;/&gt;  These methods are more costly, but are the best way to ensure species-level identification.  Isolates are usually obtained from blood cultures (88% of the time) and less frequently from bite wounds.  In incidents where the patient is in full septic shock, whole blood smears may be effective.&lt;ref name = &quot;Lion&quot;/&gt;

==Treatment==
Immediate cleansing of wounds caused by canines and felines can be successful in keeping ''C. canimorsus'' infections at bay. Irrigation of wounds with saline is recommended, and individuals are encouraged to seek medical help for the administration of antibiotics.  Antibiotics are recommended if wounds are deep or if individuals postpone seeking medical attention. Antibiotics that contain beta-lactamase inhibitors (''i.e.'', oral [[Augmentin]] or parenteral [[Unasyn]]) cover ''C. canimorsus'', as well as other organisms common in bites.{{citation needed|date=March 2017}}

Penicillin G is the drug of choice, although some isolates have been found to show resistance.&lt;ref name = &quot;Lion&quot;/&gt;  ''C. canimorsus'' is susceptible to ampicillin, third-generation [[cephalosporins]], [[tetracyclines]], clindamycin, and chloramphenicol.  It has shown resistance to gentamicin.&lt;ref name = &quot;Brenner&quot;/&gt;  Treatment is recommended for a minimum of three weeks.&lt;ref name = &quot;Lion&quot;/&gt;  Hospitalization is required in more severe infections.  For cases of sepsis, high doses of penicillin are required. Third-generation cephalosporins are often given before diagnosis because they cover a broad range of Gram-negative bacteria.  After diagnosis, provided the strain is not beta-lactamase-producing, medication should be switched to penicillin G.&lt;ref name = &quot;Lion&quot;/&gt; Presumably, penicillin G could be given with a beta-lactamase inhibitor combination, such as Unasyn, for patients with a beta-lactamase-producing strain.

Mortality of meningitis-related infections is much lower than the mortality associated with [[sepsis]].  Because ''C. canimorsus'' induces fulminant sepsis, earlier diagnosis is associated with greater survival.{{citation needed|date=July 2022}}

==Evasion of immune system==
''C. canimorsus'' has been observed to multiply in the presence of mouse J774.1 macrophages.  [[Macrophage]]s recognize and kill pathogens by engulfing them.  They also secrete cytokines necessary to begin the immune pathway cascade.  ''C. canimorsus'' bacteria are not internalized by macrophages; in fact, macrophage monolayers break down in their presence, suggestive of a [[cytotoxin]].&lt;ref name = &quot;Shin2&quot;&gt;{{cite journal | last1=Shin | first1=Hwain | last2=Mally | first2=Manuela | last3=Kuhn | first3=Marina | last4=Paroz | first4=Cecile | last5=Cornelis | first5=Guy R. | title=Escape from Immune Surveillance by Capnocytophaga canimorsus | journal=The Journal of Infectious Diseases | volume=195 | issue=3 | date=2007 | issn=0022-1899 | doi=10.1086/510243 | pages=375–386| pmid=17205476 }}&lt;/ref&gt;  In the presence of ''C. canimorsus'', cytokine activity is greatly downregulated, because the macrophages fail to produce TNF-α, IL-8, IL-6 and IL-1α, interferon-γ, and nitric oxide.&lt;ref name = &quot;Shin&quot;/&gt;  In addition, toll-like receptor 4 ([[TLR4]]) normally recognizes pathogens and begins a signalling cascade to induce production of pro[[Inflammation|inflammatory]] [[cytokines]] via the NF-κB pathway.  In cells infected with ''C. canimorsus'', TLR4 did not activate the signalling pathway, so did not elicit an inflammatory response by the immune system.&lt;ref name = &quot;Shin2&quot;/&gt;  Because this species does not elicit a strong inflammatory response, the bacteria have ample time for replication before detection by the host immune system.&lt;ref name = &quot;Shin&quot;/&gt;  [[Electron micrograph]]s of J774.1 monolayers infected with ''C. canimorsus'' have shown cells of the bacteria within the macrophage's [[vacuole]]s, surrounded by bacterial septa.  This suggests that ''C. canimorsus'' replicates intracellularly in macrophages.  ''C. canimorsus'' cells also show resistance to killing by complement and killing by [[polymorphonuclear leukocyte]]s (PNMs).  ''C. canimorsus'', when in the presence of PMNs, feeds on them by deglycosylating host glycans.  In fact, in the presence of PMNs, ''C. canimorsus'' experiences robust growth.&lt;ref name = &quot;Shin&quot;/&gt;  ''C. canimorsus'' can evade these necessary immune functions, and, therefore, must be taken seriously.  Greater knowledge about the pathogenesis of this bacterium is required to prevent and treat the diseases associated with it.{{citation needed|date=July 2022}}

==References==
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==External links==
* {{cite web |url= http://www.healthatoz.com/healthatoz/Atoz/common/standard/transform.jsp?requestURI=%2Fhealthatoz%2FAtoz%2Fency%2Fanimal_bite_infections.jsp |title= Animal bite infections |website= Health A to Z |publisher= Gale Encyclopedia of Medicine |date= Aug 14, 2006 |orig-year= 2002 |first= Julia |last= Barrett |url-status= dead |archive-date= February 26, 2007 |archive-url= https://web.archive.org/web/20070226145037/http://www.healthatoz.com/healthatoz/Atoz/common/standard/transform.jsp?requestURI=%2Fhealthatoz%2FAtoz%2Fency%2Fanimal_bite_infections.jsp }}
* {{cite web |url= https://www.ncbi.nlm.nih.gov/nuccore/CP002113 |id= CP002113 |title= Capnocytophaga canimorsus |date= 30 January 2014 |publisher= [[GenBank]] }}
* {{cite web |url= http://bacdive.dsmz.de/index.php?search=5493 |id= 5493 |title= Capnocytophaga canimorsus |website= Bacterial Diversity Metadatabase (BacDive) }}

{{Gram-negative non-proteobacterial bacterial diseases}}
{{Taxonbar|from=Q310984}}

[[Category:Flavobacteria]]
[[Category:Bacterial diseases]]
[[Category:Zoonoses]]
[[Category:Bacteria described in 1989]]
[[Category:Cat diseases]]
[[Category:Pathogenic bacteria]]