Proteus Mirabilis

Proteus mirabilis is a gram negative rod with swarming motility. It is facultative anaerobic bacterium having urease activity.

Pathogenesis

Route of entry
Proteus is responsible for community and hospitalized acquired urinary tract infection. It is present in colon and colonies urethra.

Virulence Factors

• Phenylalanine deaminase
• Urease
• O- antigen
• Pili
• Fimbriae for adherence
• Endotoxin

Predisposing factors
•    I/V injections
•    Urinary catheters
•    Poor hygiene
•    Malnutrition
•    Young and elderly

Clinical symptoms
•    UTI
•    Pneumonia
•    Wound infections
•    Septicemia

Lab-Diagnosis

Specimen
•    Urine
•    Pus
•    Sputum

Microscopy
•    Gram- negative rods
•    Facultative anaerobes
•    Motile – swarming motility
•    Non- encasulated
•    Fimbriae  

Culture

Blood agar     
Swarming motility on blood agar

MacConkey agar  
Non-lactose fermenting colonies, non-swarming because of bile salts

CLED                    
Non-lactose fermenting colonies, non-swarming because electrolyte deficient

Biochemical Tests

TSI Agar

• Slant                     Alkaline
• Butt                       Acidic
• Produces              Gas
• Produces              H2S

Catalase                                   positive
Oxidase                                    negative
Only ferments                         glucose, and sucrose
Reduces nitrate to nitrite
Urease                                       positive
Phenylalanine  deaminase    positive
B- galactosidose                      negative
Indole                                        negative

Serological Test
•    PCR

Treatment

•    Aminoglycosides
•    Trimethoprim- sulfamethoxazole