II-A. Systemic Bacteriology | 10. Proteus, Pseudomonas

Question 1

I. Proteus genus
1. What are the important species of Proteus genus?

Answer 1

Proteus vulgaris, P. mirabilis

Question 2

I. Proteus genus
2. What are the features of proteus?

Answer 2

• peritrhichous flagella→ able to move even on solid surfaces (phenomenon called swarming)
  => EMB agar contains a swarming inhibitor → colony formation is seen
• urease enzyme production (urease-positive)
• member of the normal intestinal flora

Question 3

I. Proteus genus
3. What are biochemical properties of Proteus?

Answer 3

Question 3

I. Proteus genus

Question 4

I. Proteus genus
4. What are the diseases caused by Proteus genus?

Answer 4

urinary tract infections nosocomial infections

Question 5

I. Proteus genus
5. What is the diagnosis for Proteus genus?

Answer 5

Culture of blood or urine for lactose-negative organisms with swarming motility

Question 6

I. Proteus genus
6. Describe empirical treatment for Proteus genus?

Answer 6

originally species of the genus are sensitive to a few penicillins and most cephalosporins, but has some intrinsic (natural) resistance

Question 7

I. Proteus genus
7. What are the hospital-acquired strains?

Answer 7

hospital-acquired strains tend to produce different beta-lactamases, hence tend to be resistant to different groups of beta-lactams
* ESBL production: resistance to penicillins and cephalosporins (quite common in hospitals)
* carbapenemase production: resistance to penicillins, cephalosporins and carbapenems

Question 8

II. Pseudomonas genus
1. What are the features of Pseudomonas genus?

Answer 8

• saprophytic, ubiquitous species (soil, water)
• Gram-negative rods with polar fimbriae
• obligate aerobic metabolism

Question 9

II. Pseudomonas genus
2. What are the important species of Pseudomonas genus?

Answer 9

Pseudomonas aeruginosa

Question 10

II. Pseudomonas genus - Pseudomonas aeruginosa
3. What are the features of Pseudomonas aeruginosa?

Answer 10

• opportunisic pathogen, usually seen in nosocomial infections
• could develop resistance against multiple antibiotic groups
• smells like grapes, green colonies (pioverdin, piocianin)
• beta-haemolytic on blood agar

Question 11

II. Pseudomonas genus - Pseudomonas aeruginosa
4. What are the virulence factors of Pseudomonas aeruginosa?

Answer 11

• A-toxin (inhibits protein synthesis)
• exoenzymes: elastase, phospholipase, haemolysin
• endotoxin
• biofilm production!

Question 12

II. Pseudomonas genus - Pseudomonas aeruginosa
5. What are the diseases caused by Pseudomonas aeruginosa?

Answer 12

1. superficial infections in healthy individuals
   - otitis externa, wound infections, conjunctivitis, hot-tub dermatitis
2. invasive infections in immunocompromised patients (burn patients, patients with diabetes, cystic fibrosis)
   - pneumonia, blood stream infection, UTI, meningitis

Question 13

II. Pseudomonas genus - Pseudomonas aeruginosa
6. What is the diagnoses for Pseudomonas aeruginosa?

Answer 13

• based on clinical signs and symptoms
• sampling: based on clinical disease
• laboratory: cultivation, PCR

Question 14

II. Pseudomonas genus - Pseudomonas aeruginosa
7. What is empirical therapy for pseudomonas aeruginosa?

Answer 14

• Multiresistant, based on antibiogram
• Antipseudomonal penicillin
• Aminoglycoside
• Fluoroquinolone

Question 15

II. Pseudomonas genus - Pseudomonas aeruginosa
7. How can we prevent pseudomonas aeruginosa?

Answer 15

• Pasteurize or disinfect water equipment
• Hand washing
• Removal of catheters

Question 16

II. Pseudomonas genus - Pseudomonas aeruginosa
8. What are the diseases caused by Pseudomonas aeruginosa?

Answer 16