Pasteurella
Encyclopedia
Pasteurella is a genus
of Gram-negative
, facultatively anaerobic
bacteria
. Pasteurella species are non-motile
and pleomorphic. Most species are catalase
-positive and oxidase
-positive.
Many Pasteurella species are zoonotic pathogens, and humans can acquire an infection from domestic pet
bites. P. multocida
is the most frequent causative agent in human Pasteurella infection. Common symptoms of pasteurellosis in humans include swelling, cellulitis
, and bloody drainage at the site of the wound. Infections may progress to nearby joints where it can cause swelling and arthritis.
Pasteurella spp. are generally susceptible to chloramphenicol
, the penicillin
s, tetracycline, and the macrolide
s.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of Gram-negative
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...
, facultatively anaerobic
Facultative anaerobic organism
A facultative anaerobic organism is an organism, usually a bacterium, that makes ATP by aerobic respiration if oxygen is present but is also capable of switching to fermentation...
bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
. Pasteurella species are non-motile
Motility
Motility is a biological term which refers to the ability to move spontaneously and actively, consuming energy in the process. Most animals are motile but the term applies to single-celled and simple multicellular organisms, as well as to some mechanisms of fluid flow in multicellular organs, in...
and pleomorphic. Most species are catalase
Catalase
Catalase is a common enzyme found in nearly all living organisms that are exposed to oxygen, where it catalyzes the decomposition of hydrogen peroxide to water and oxygen...
-positive and oxidase
Oxidase
An oxidase is any enzyme that catalyzes an oxidation-reduction reaction involving molecular oxygen as the electron acceptor. In these reactions, oxygen is reduced to water or hydrogen peroxide ....
-positive.
Pathogenesis
- See: PasteurellosisPasteurellosisPasteurellosis is an infection with a species of the bacteria genus Pasteurella, which is found in humans and animals.Pasteurella multocida is carried in mouth and respiratory tract of several animals, notably cats. It is a small Gram negative bacillus with bipolar staining by Wayson stain...
Many Pasteurella species are zoonotic pathogens, and humans can acquire an infection from domestic pet
Pet
A pet is a household animal kept for companionship and a person's enjoyment, as opposed to wild animals or to livestock, laboratory animals, working animals or sport animals, which are kept for economic or productive reasons. The most popular pets are noted for their loyal or playful...
bites. P. multocida
Pasteurella multocida
Pasteurella multocida is a Gram-negative, non-motile coccobacillus that is penicillin-sensitive and belongs to the Pasteurellaceae family . It can cause avian cholera in birds and a zoonotic infection in humans, which typically is a result of bites or scratches from domestic pets...
is the most frequent causative agent in human Pasteurella infection. Common symptoms of pasteurellosis in humans include swelling, cellulitis
Cellulitis
Cellulitis is a diffuse inflammation of connective tissue with severe inflammation of dermal and subcutaneous layers of the skin. Cellulitis can be caused by normal skin flora or by exogenous bacteria, and often occurs where the skin has previously been broken: cracks in the skin, cuts, blisters,...
, and bloody drainage at the site of the wound. Infections may progress to nearby joints where it can cause swelling and arthritis.
Pasteurella spp. are generally susceptible to chloramphenicol
Chloramphenicol
Chloramphenicol is a bacteriostatic antimicrobial that became available in 1949. It is considered a prototypical broad-spectrum antibiotic, alongside the tetracyclines, and as it is both cheap and easy to manufacture it is frequently found as a drug of choice in the third world.Chloramphenicol is...
, the penicillin
Penicillin
Penicillin is a group of antibiotics derived from Penicillium fungi. They include penicillin G, procaine penicillin, benzathine penicillin, and penicillin V....
s, tetracycline, and the macrolide
Macrolide
The macrolides are a group of drugs whose activity stems from the presence of a macrolide ring, a large macrocyclic lactone ring to which one or more deoxy sugars, usually cladinose and desosamine, may be attached. The lactone rings are usually 14-, 15-, or 16-membered...
s.