Characterization of indole-positive Proteus mirabilis

Area of Science:

• Microbiology
• Clinical Diagnostics
• Bacterial Identification

Background:

• Accurate identification of Proteus species is essential for effective clinical management.
• Proteus mirabilis and Proteus vulgaris are distinct species with differing clinical significance.
• Indole production is a key differentiator, but exceptions exist.

Purpose of the Study:

• To characterize indole-producing Proteus strains and determine their species.
• To evaluate the utility of biochemical tests, including ornithine decarboxylase, in differentiating Proteus species.
• To assess antibiotic susceptibility patterns of identified strains.

Main Methods:

• Isolation and biochemical characterization of thirteen indole-producing, swarming Proteus strains.
• Performance of 40 biochemical tests and antibiotic susceptibility testing against 11 antibiotics.
• Utilized indole and ornithine decarboxylase tests for species differentiation.

Main Results:

• All thirteen strains were identified as Proteus mirabilis.
• All identified P. mirabilis strains produced ornithine decarboxylase.
• Strains were susceptible to penicillin and cephalosporin antibiotics.
• Indole-positive P. mirabilis strains exhibited biochemical profiles distinct from P. vulgaris.

Conclusions:

• Indole-positive Proteus strains in this study were confirmed as P. mirabilis.
• Performing both indole and ornithine decarboxylase tests is recommended for accurate differentiation of P. mirabilis and P. vulgaris.
• This differentiation is critical for clinical relevance and appropriate patient treatment.