PSEUDOMONAS: Describe the pathogenicity of Pseudomonas aeruginosa
Definition
- Pseudomonas aeruginosa
- Gram-negative, rod-shaped bacterium
- Commonly found in soil, water, and on plants
- Can be found in the environment and on human skin
Causes
- Pseudomonas aeruginosa is an opportunistic pathogen
- Can infect people with compromised immune systems
- Can cause infections in people with cystic fibrosis, burns, and other conditions
Types of Infections
- Pneumonia
- Osteomyelitis
- Meningitis
- Septicemia
- Urinary tract infections
Pathogenesis
- Adherence to host cells โ Adhesins (e.g., Pseudomonas aeruginosa surface proteins) โ Host cell receptors โ Adhesion
- Invasion of host cells โ Type III secretion system โ Effector proteins โ Host cell invasion
- Toxin production โ Exotoxin A โ Exotoxin S โ Pyocyanin
Morphology
- Gram-negative, rod-shaped bacterium
- Size: 0.5-1.5 ฮผm x 1-5 ฮผm
- Motile with a single polar flagellum
- Has a lipopolysaccharide (LPS) outer membrane
Clinical Features
- Pneumonia: cough, fever, chest pain
- Osteomyelitis: pain, swelling, redness
- Meningitis: headache, fever, stiff neck
- Septicemia: fever, chills, rash
- Urinary tract infections: dysuria, frequency, urgency
Complications
- Pneumonia: respiratory failure, septic shock
- Osteomyelitis: bone damage, septic arthritis
- Meningitis: brain damage, hearing loss
- Septicemia: multi-organ failure
- Urinary tract infections: kidney damage, sepsis
Diagnosis
- Culture: Pseudomonas aeruginosa grows on agar plates
- Gram stain: Gram-negative, rod-shaped bacterium
- PCR: detects Pseudomonas aeruginosa DNA
- Serology: detects Pseudomonas aeruginosa antibodies
Management
- Antibiotics: ciprofloxacin, ceftazidime, tobramycin
- Supportive care: oxygen therapy, fluid resuscitation
- Surgery: may be necessary for osteomyelitis or abscesses
Memory Trick
- "Pseudomonas aeruginosa is a sly bacterium Adheres to host cells and causes trouble Infects the lungs, bones, and brain Makes toxins that cause pain and strain Be careful of this bacterium Use antibiotics and supportive care To treat infections and show it care"
Life Cycle
- Environmental reservoir
- Adherence to host cells
- Invasion of host cells
- Toxin production
- Infection
- Disease
- Recovery or complications