Proteus vulgaris

Proteus vulgaris

Proteus vulgaris colonies on MacConkey agar

Proteus vulgaris is a rod-shaped, Gram-negative bacterium that is part of the genus Proteus. It is known for its ability to swarm across agar plates and its role in various human infections.

Characteristics

Proteus vulgaris is a facultative anaerobe, meaning it can grow in both the presence and absence of oxygen. It is motile due to the presence of peritrichous flagella, which allow it to move in a characteristic "swarming" pattern on solid media. This bacterium is also known for its ability to deaminate amino acids, producing ammonia and other compounds.

Morphology

Proteus vulgaris is a Gram-negative bacillus, typically measuring 1-3 micrometers in length. It has a characteristic "swarming" motility on solid media, which can be observed as concentric rings on agar plates.

Biochemical Properties

Proteus vulgaris is capable of fermenting glucose with the production of acid and gas. It is urease positive, meaning it can hydrolyze urea into ammonia and carbon dioxide. This bacterium is also indole positive, indicating its ability to convert tryptophan into indole.

Pathogenicity

Proteus vulgaris is an opportunistic pathogen, commonly associated with urinary tract infections, wound infections, and bacteremia. It is part of the normal flora of the human gastrointestinal tract but can cause disease when it enters other parts of the body.

Infections

• Urinary Tract Infections (UTIs): Proteus vulgaris can cause UTIs, particularly in individuals with structural abnormalities of the urinary tract or those with indwelling catheters.
• Wound Infections: This bacterium can infect wounds, especially in immunocompromised patients or those with chronic wounds.
• Bacteremia: In rare cases, Proteus vulgaris can enter the bloodstream, leading to systemic infections.

Laboratory Identification

Proteus vulgaris can be identified in the laboratory using a variety of biochemical tests. It grows well on MacConkey agar, where it forms non-lactose fermenting colonies. The bacterium is also identified by its swarming motility and positive urease and indole tests.

Treatment

Infections caused by Proteus vulgaris are typically treated with antibiotics. However, the bacterium can exhibit resistance to multiple drugs, making susceptibility testing important for effective treatment.

Related Pages

• Proteus (bacterium)
• Urinary tract infection
• Gram-negative bacteria
• MacConkey agar