Brucella abortus

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Brucella abortus
Scientific classification
B. abortus
Binomial name
Brucella abortus
(Schmidt, 1901) Meyer and Shaw, 1920

Bacteria Reaction

Brucella abortus is a Gram-negative alpha-proteobacterium in the family Brucellaceae and is one of the causative agents of brucellosis. The rod-shaped pathogen is classified under the domain Bacteria. [1] The prokaryotic B. abortus is non-spore-forming, non-motile and aerobic. [2]

Gram-negative bacteria group of bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation

Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the gram-staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wall sandwiched between an inner cytoplasmic cell membrane and a bacterial outer membrane.

Proteobacteria phylum of Gram-negative bacteria

Proteobacteria is a major phylum of Gram-negative bacteria. They include a wide variety of pathogenic genera, such as Escherichia, Salmonella, Vibrio, Helicobacter, Yersinia, Legionellales, and many others. Others are free-living (nonparasitic) and include many of the bacteria responsible for nitrogen fixation.

Brucellaceae family of bacteria

The Brucellaceae are a family of the Gram-negative Rhizobiales. They are named after Sir David Bruce, a Scottish microbiologist. They are aerobic chemoorganotrophes. The family comprises pathogen and soil bacteria



Brucella abortus enters phagocytes that invade human and animal innate defenses which in turn, cause chronic disease in the host. The liver and spleen are the mainly affected areas of the body. [3] Farm workers and veterinarians are the highest risk individuals for acquiring the disease due to their close proximity to the animals. Swine, goats, sheep, and cattle are a few of the reservoirs for the disease. [4] B. abortus causes abortion and infertility in adult cattle and is a zoonosis which is present worldwide. [5] Humans are commonly infected after drinking unpasteurized milk from affected animals or, less commonly, when coming into contact with infected tissues and liquids (afterbirth, etc.). [6]

Zoonosis infectious disease that is transmitted between species (sometimes by a vector) from animals other than humans to humans or from humans to other animals

Zoonoses are infectious diseases caused by bacteria, viruses and parasites that spread between animals and humans.

Pasteurization or pasteurisation is a process in which water and certain packaged and non-packaged foods are treated with mild heat, usually to less than 100 °C (212 °F), to eliminate pathogens and extend shelf life. The process is intended to destroy or deactivate organisms and enzymes that contribute to spoilage or risk of disease, including vegetative bacteria, but not bacterial spores. Since pasteurization is not sterilization, and does not kill spores, a second "double" pasteurization will extend the quality by killing spores that have germinated.

The incubation period for the disease can range from 2 weeks to 1 year. Once symptoms begin to show, the host will be sick anywhere from 5 days to 5 months, depending on the severity of illness. A few of the symptoms of brucellosis include: fever, chills, headache, backache, and weight loss. As with any disease, there can be serious complications; endocarditis and liver abscess are a couple of complications for brucellosis. [7] Although rare, B. abortus (and other Brucella spp.) can be transmitted between humans, usually via sexual transmission.

Endocarditis endocardium disease characterized by inflammation of the endocardium of the heart chambers and valves

Endocarditis is an inflammation of the inner layer of the heart, the endocardium. It usually involves the heart valves. Other structures that may be involved include the interventricular septum, the chordae tendineae, the mural endocardium, or the surfaces of intracardiac devices. Endocarditis is characterized by lesions, known as vegetations, which is a mass of platelets, fibrin, microcolonies of microorganisms, and scant inflammatory cells. In the subacute form of infective endocarditis, the vegetation may also include a center of granulomatous tissue, which may fibrose or calcify.

B. abortus also affects bison. [8]


Brucella has twelve different kinds of species, one being Brucella abortus. [9] Some of the other species are known as B. melintisis, B. canis, B. suis, B. ovis, B. neotomae, B. ceti, and B. pinnipediae. Each species displays an affinity for specific animals or groups of animals. [10] Cattle and other livestock are the major host species for the bacteria B. abortus. [9] It is usually found to colonize in the liver and spleen.

There are many different ways B. abortus can spread from the different animals and even to humans. Human infections can lead to what's known as Bang’s disease. [9] When cattle have still births and are carrying this disease, other animals nearby can get infected if they ingest it or otherwise come into contact with fluids containing the bacteria. It could also be passed by their semen and urine. [11] Ticks are another source of transmission for B. abortus. [11]


Temperature plays a huge role in the survival of B. abortus. [12] The bacteria can survive for a longer period of time if they are at a cooler temperature. This is why it can transmit through liquids like milk and tap water. [12] B. abortus can last a lot longer in animals if they aren’t watched closely and if the cattle aren’t getting treatment for it. In humans, it can be caught after noticing signs and the correct tests to determine the type of bacteria. [11]

Related Research Articles

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Brucellosis Human disease

Brucellosis is a highly contagious zoonosis caused by ingestion of unpasteurized milk or undercooked meat from infected animals, or close contact with their secretions. It is also known as undulant fever, Malta fever, and Mediterranean fever.

Glanders is an infectious disease that occurs primarily in horses, mules, and donkeys. It can be contracted by other animals, such as dogs, cats, goats and humans. It is caused by infection with the bacterium Burkholderia mallei.

Leptospirosis Human disease caused by Leptospira bacteria

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Fasciolosis A parasitic worm infection

Fasciolosis is a parasitic worm infection caused by the common liver fluke Fasciola hepatica as well as by Fasciola gigantica. The disease is a plant-borne trematode zoonosis, and is classified as a neglected tropical disease (NTD). It affects humans, but its main host is ruminants such as cattle and sheep. The disease progresses through four distinct phases; an initial incubation phase of between a few days up to three months with little or no symptoms; an invasive or acute phase which may manifest with: fever, malaise, abdominal pain, gastrointestinal symptoms, urticaria, anemia, jaundice, and respiratory symptoms. The disease later progresses to a latent phase with less symptoms and ultimately into a chronic or obstructive phase months to years later. In the chronic state the disease causes inflammation of the bile ducts, gall bladder and may cause gall stones as well as fibrosis. While chronic inflammation is connected to increased cancer rates, it is unclear whether fasciolosis is associated with increased cancer risk.

Diminazene chemical compound

Diminazene is an anti-infective medication for animals that is sold under a variety of brand names. It is effective against certain protozoa such as Babesia, Trypanosoma, and Cytauxzoon. The drug may also be effective against certain bacteria including Brucella and Streptococcus.

<i>Brucella melitensis</i> species of bacterium

Brucella melitensis is a Gram-negative coccobacillus bacterium from the Brucellaceae family. The bacterium causes ovine brucellosis, along with Brucella ovis. It can infect sheep, cattle, and sometimes humans, and it can be transmitted by the stable fly. It is zoonotic, unlike B. ovis, causing Malta fever or localized brucellosis in humans.

<i>Brucella suis</i> Bacterium that causes swine brucellosis

Brucella suis is a bacterium that causes swine brucellosis, a zoonosis that affects pigs. The disease typically causes chronic inflammatory lesions in the reproductive organs of susceptible animals or orchitis, and may even affect joints and other organs. The most common symptom is abortion in pregnant susceptible sows at any stage of gestation. Other manifestations are temporary or permanent sterility, lameness, posterior paralysis, spondylitis, and abscess formation. It is transmitted mainly by ingestion of infected tissues or fluids, semen during breeding, and suckling infected animals.

Bernhard Bang Danish veterinarian

Bernhard Lauritz Frederik Bang, was a Danish veterinarian. He discovered Brucella abortus in 1897, which came to be known as Bang's bacillus. Bang's bacillus was the cause of the contagious Bang's disease which can cause pregnant cattle to abort, and causes undulant fever in humans.

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Alice Catherine Evans American microbiologist

Alice Catherine Evans was a pioneering American microbiologist. She became a researcher at the US Department of Agriculture. There she investigated bacteriology in milk and cheese. She later demonstrated that Bacillus abortus caused the disease Brucellosis in both cattle and humans.

<i>Brucella canis</i> gram-negative proteobacterium in the family Brucellaceae that causes brucellosis in dogs and other canids

Brucella canis is a Gram-negative proteobacterium in the family Brucellaceae that causes brucellosis in dogs and other canids. B. canis is rod-shaped or a coccus, and is oxidase, catalase, and urease positive. The species was firstly described in United States in 1966 where mass abortions of beagles were documented. The disease is characterized by epididymitis and orchitis in male dogs, endometritis, placentitis, and abortions in females, and often presents as infertility in both sexes. Other symptoms such as inflammation in the eyes and axial and appendicular skeleton; lymphadenopathy and splenomegaly, are less common. Humans can be also infected, but occurrences are rare. Although there has been an increase in the international movement of dogs, Brucella canis is still very uncommon.

African tick bite fever spotted fever that has material basis in Rickettsia africae, which is transmitted by ticks

African tick bite fever (ATBF) is a bacterial infection spread by the bite of a tick. Symptoms may include fever, headache, muscles pains, and a rash. At the site of the bite there is typically a red skin sore with a dark center. Onset usually occur 4–10 days after the bite. Complications are rare, however may include joint inflammation. Some people do not develop symptoms.

Poll evil

Poll evil is a traditional term for a painful condition in a horse or other equid, that starts as an inflamed bursa at the anterior end of the neck between vertebrae and the nuchal ligament, and swells until it presents as an acute swelling at the poll, on the top of the back of the animal's head. The swelling can increase until it ruptures and drains. It can be caused by infection from Actinomyces bovis or Brucella abortus organisms, but may also occur due to parasite infestation, skin trauma, or badly fitting horse tack. Because of modern efforts to reduce the incidence of brucellosis in livestock, horses are less exposed to the Brucella abortus organism, and hence most modern cases of poll evil arise from trauma linked to a horse striking its head against poorly designed or low-clearance structures, or to improper use of equipment, particularly leaving a halter on the horse around the clock.

<i>Brucella ceti</i> species of bacterium

Brucella ceti is a gram negative bacterial pathogen of the Brucellaceae family that causes brucellosis in cetaceans. Brucella ceti has been found in both classes of cetaceans, mysticetes and odontocetes. Brucellosis in some dolphins and porpoises can result in serious clinical signs including fetal abortions, male infertility, neurobrucellosis, cardiopathies, bone and skin lesions, strand events, and death.


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