Capnocytophaga canimorsus
Encyclopedia
Capnocytophaga canimorsus is a Gram-negative
bacillus (rod-shaped) bacterium that causes a zoonotic disease
, most commonly in asplenic
patients. It is a member of the normal gingival flora
of dogs and cats. It causes fulminant sepsis
with disseminated intravascular coagulation
(DIC).
or plasmapheresis
in severe cases.
Following animal bites, co-amoxiclav
is often given to asplenic individuals to prevent disseminated infection; but in patients who are allergic to penicillins, the combination of doxycycline
and metronidazole
(to cover anaerobic organisms) may be used instead.
In patients with sepsis, treatment with imipenem
, clindamycin
, or a penicillin-β-lactamase inhibitor combination (e.g., co-amoxiclav
or piperacillin-tazobactam) should be used. Doxycycline
is active in vitro but there is little experience in using it in treating sepsis, and in many countries there is no intravenous form available, which suggests that it should be reserved for when no other options are available.
Capnocytophaga canimorsus was previously known as "dysgonic fermenter type 2" (DF2).
Gram-negative
Gram-negative bacteria are bacteria that do not retain crystal violet dye in the Gram staining protocol. In a Gram stain test, a counterstain is added after the crystal violet, coloring all Gram-negative bacteria with a red or pink color...
bacillus (rod-shaped) bacterium that causes a zoonotic disease
Disease
A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...
, most commonly in asplenic
Asplenia
Asplenia refers to the absence of normal spleen function and is associated with some serious infection risks. Hyposplenism is used to describe reduced splenic functioning, but not as severely affected as with asplenism.-Congenital:...
patients. It is a member of the normal gingival flora
Flora
Flora is the plant life occurring in a particular region or time, generally the naturally occurring or indigenous—native plant life. The corresponding term for animals is fauna.-Etymology:...
of dogs and cats. It causes fulminant sepsis
Sepsis
Sepsis is a potentially deadly medical condition that is characterized by a whole-body inflammatory state and the presence of a known or suspected infection. The body may develop this inflammatory response by the immune system to microbes in the blood, urine, lungs, skin, or other tissues...
with disseminated intravascular coagulation
Disseminated intravascular coagulation
Disseminated intravascular coagulation , also known as disseminated intravascular coagulopathy or consumptive coagulopathy, is a pathological activation of coagulation mechanisms that happens in response to a variety of diseases. DIC leads to the formation of small blood clots inside the blood...
(DIC).
Treatment
Treatment is via antibiotics with the possible aid of activated protein CProtein C
Protein C, also known as autoprothrombin IIA and blood coagulation factor XIV, is a zymogenic protein, the activated form of which plays an important role in regulating blood clotting, inflammation, cell death and maintaining the permeability of blood vessel walls in humans and other animals...
or plasmapheresis
Plasmapheresis
Plasmapheresis is the removal, treatment, and return of blood plasma from blood circulation. It is thus an extracorporeal therapy...
in severe cases.
Following animal bites, co-amoxiclav
Co-amoxiclav
Amoxicillin/clavulanic acid or co-amoxiclav is a combination antibiotic consisting of amoxicillin trihydrate, a β-lactam antibiotic, and potassium clavulanate, a β-lactamase inhibitor...
is often given to asplenic individuals to prevent disseminated infection; but in patients who are allergic to penicillins, the combination of doxycycline
Doxycycline
Doxycycline INN is a member of the tetracycline antibiotics group, and is commonly used to treat a variety of infections. Doxycycline is a semisynthetic tetracycline invented and clinically developed in the early 1960s by Pfizer Inc. and marketed under the brand name Vibramycin. Vibramycin...
and metronidazole
Metronidazole
Metronidazole is a nitroimidazole antibiotic medication used particularly for anaerobic bacteria and protozoa. Metronidazole is an antibiotic, amebicide, and antiprotozoal....
(to cover anaerobic organisms) may be used instead.
In patients with sepsis, treatment with imipenem
Imipenem
Imipenem is an intravenous β-lactam antibiotic developed in 1980. It has an extremely broad spectrum of activity.Imipenem belongs to the subgroup of carbapenems. It is derived from a compound called thienamycin, which is produced by the bacterium Streptomyces cattleya...
, clindamycin
Clindamycin
Clindamycin rINN is a lincosamide antibiotic. It is usually used to treat infections with anaerobic bacteria but can also be used to treat some protozoal diseases, such as malaria...
, or a penicillin-β-lactamase inhibitor combination (e.g., co-amoxiclav
Co-amoxiclav
Amoxicillin/clavulanic acid or co-amoxiclav is a combination antibiotic consisting of amoxicillin trihydrate, a β-lactam antibiotic, and potassium clavulanate, a β-lactamase inhibitor...
or piperacillin-tazobactam) should be used. Doxycycline
Doxycycline
Doxycycline INN is a member of the tetracycline antibiotics group, and is commonly used to treat a variety of infections. Doxycycline is a semisynthetic tetracycline invented and clinically developed in the early 1960s by Pfizer Inc. and marketed under the brand name Vibramycin. Vibramycin...
is active in vitro but there is little experience in using it in treating sepsis, and in many countries there is no intravenous form available, which suggests that it should be reserved for when no other options are available.
Capnocytophaga canimorsus was previously known as "dysgonic fermenter type 2" (DF2).