What is the Difference Between Brucella Abortus and Melitensis

The key difference between Brucella abortus and melitensis is that Brucella abortus is a gram-negative bacterium that causes brucellosis primarily in cattle, while Brucella melitensis is a gram-negative bacterium that causes brucellosis primarily in goats, sheep, and dromedary camels.

Brucella abortus and B. melitensis are two causative agents of brucellosis. Brucellosis is a bacterial infection that is normally transmitted from animals to people. Most commonly, brucellosis occurs in people due to eating raw or unpasteurized dairy products. Some Brucella strains can be identified in cows, while others are present in dogs, pigs, sheep, goats, and animals.

CONTENTS

1. Overview and Key Difference
2. What is Brucella Abortus  
3. What is Brucella Melitensis
4. Similarities – Brucella Abortus and Melitensis
5. Brucella Abortus vs Melitensis in Tabular Form
6. Summary – Brucella Abortus vs Melitensis

What is Brucella Abortus?

Brucella abortus is a gram-negative bacterium that primarily causes brucellosis in cattle. This bacterium belongs to the family of Brucellaceae. It is a rod-shaped, non-spore-forming, non-motile aerobic bacterium. B. abortus can cause abortion and infertility in adult cattle and is a zoonosis present worldwide. Generally, humans are infected with this bacterium after drinking unpasteurized milk from affected animals or coming into contact with infected tissues and liquids.

Farm workers and veterinarians are the highest risk individuals who can be infected with this disease. Other than cattle, swine, goats, and sheep can also be reservoirs for this disease. The incubation period for this disease can range from 2 weeks to 1 year. Once symptoms begin to appear, the host will be sick from 5 days to 5 months. The few symptoms of this disease include fever, chills, headache, backache, and weight loss. The serious complications of this disease are endocarditis and liver abscesses. This bacterial species can also be transmitted to humans via sexual transmission. Furthermore, the treatments for Brucella abortus infection include antibiotics such as doxycycline and rifampin for a minimum of 6 to 8 weeks.

What is Brucella Melitensis?

Brucella melitensis is a gram-negative bacterium that causes brucellosis, which primarily affects goats, sheep, and dromedary camels. This bacterium causes ovine brucellosis along with another bacterium known as Brucella ovis. B. melitensis primarily affects sheep and goats. But they have been reported on other animals such as cattle, yaks, water, buffalo, Bactrian, dromedary camels, alpacas, dogs, horses, and pigs. It infects humans when humans come into contact with infected animals and their by-products. On the other hand, animals are infected with this bacterium by venereal transmission and contact with the placenta, fetus, fetal fluids, and vaginal discharges from infected animals.

B. melitensis can be identified in blood, urine, milk, and semen. It is also a zoonotic bacterium. Furthermore, this bacterium causes inflammation of the epididymis with the formation of spermatoceles, fibrinous adhesions, and mastitis in animals like goats and sheep. Azithromycin and gentamycin antibiotics can be used for the treatment of human brucellosis.

What are the Similarities Between Brucella Abortus and Melitensis?

• Brucella abortus and melitensis are two bacteria that causes brucellosis.
• They are gram-negative bacteria of the family Brucellaceae.
• Both are zoonotic bacteria.
• Both cause similar symptoms in humans like fever, back pain, body-wide aches, weight loss, headaches, night sweats, weakness, abdominal pain, and cough.
• Both bacterial infections in humans can be treated through specific antibiotics.

What is the Difference Between Brucella Abortus and Melitensis?

Brucella abortus is a gram-negative bacterium that causes brucellosis that primarily affects cattle, while Brucella melitensis is a gram-negative bacterium that causes brucellosis that primarily affects goats, sheep, and dromedary camels. Thus, this is the key difference between Brucella abortus and melitensis.

The below infographic presents the differences between Brucella abortus and melitensis in tabular form for side-by-side comparison.

Summary – Brucella Abortus vs Melitensis

Brucellosis is a bacterial disease caused by Brucella species. They mainly affect animals like cattle, swine, goats, sheep, and dogs. Humans generally acquire the disease through direct contact with these infected animals, by eating or drinking contaminated products, or by inhaling airborne bacteria. Brucella abortus and B. melitensis are two bacteria causing brucellosis. Brucella abortus primarily affects cattle, while Brucella melitensis primarily affects goats, sheep, and dromedary camels. So, this summarizes the difference between Brucella abortus and melitensis.

Reference:

1. “Brucella Abortus.” Encyclopædia Britannica, Encyclopædia Britannica, Inc.
2. “Brucella Melitensis.” An Overview | ScienceDirect Topics.

Image Courtesy:

1. “Brucella abortus, brucella melitensis, brucella suis, brucella canis” By Megan Mathias and J. Todd Parker, USCDCP (CC0) via Pixino
2. “Brucella melitensis flagellum (fig. 2)” By Jonathan Ferooz, Jean-Jacques Letesson – Ferooz J., Letesson J. J. (2010). “Morphological analysis of the sheathed flagellum of Brucella melitensis. “BMC Res Notes 3: 333. DOI:10.1186/1756-0500-3-333. (CC BY-SA 2.0) via Commons Wikimedia