Non-fermenting Gram negative rods (4)

Question 1

Name the non-glucose fermenting GNRs (4)

Answer 1

1) Pseudomonas aureginosa

2) Burkholderia cepacia and B. pseudomallei

3) Acinetobacter baumanni complex

4) Stenotrophomonas maltophilia

Question 2

What makes Acinetobacter baumanni complex culture features different from other NF GNs?

Answer 2

1. NLF GNR
2. Strict aerobe
3. Chunky Coccibacilli

Question 3

What diseases does the Acenitobacter baumanni complex cause?

Answer 3

Nosocomial infections

1. VAP
2. UTI in catheters
3. Wounds-Associated with contaminated soil.

Some soldiers that fought in the Iraq war had it.

Question 4

What are the culture characteristics of P. aureginosa?

Answer 4

1. NLF GNR
2. Grows metallic colonies on blood agar (pyocyanin)
3. Grows on MAC but does not ferment
4. Grows very well on humid surfaces

Question 5

Does P. aureginosa have intrinsic resistance?

Answer 5

Yes!

Question 6

Common P. aureginosa infections?

Answer 6

1. VAP (#1 agent)
2. Chronic lung infections (specially in CF)
3. Endotracheal tube infection
4. Skin infections (wounds/burns)
5. Eye infections (kerititis- inflammation of the cornea)
6. Otitis media- middle ear infection

Question 7

What are the culture characteristics of Stenotrophomonas maltophilia?

Answer 7

1. NLF, GNR, non-glucose fermenter
2. maltose oxidizer

Question 8

What are the diseases caused by Stenotrophomonas maltophilia?

Answer 8

Nosocomial pathogen in immunocompromied/debilitated patients

1. UTI (catheters)
2. Colonizes endoscopes (tube inserted through natural body openings)
3. Bacteremia
4. Pneumonia
5. Wounds

Question 9

What are the culture characteristics of the Burkholderia cepacia complex?

Answer 9

1. NLF, GNR, non-glucose fermenter
2. Grow well on the BCC selective agar because they are resistant to polymyxin B and gentamicin (aminoglycodise)

Question 10

Does Burkholderia cepacia complex have intrinsic resistance?

Answer 10

Yes.

Beta lactamase and aminoglycosides!

Question 11

Diseases associated with the Burkholderia cepacia complex?

Answer 11

1. Deadly to CF patients!!
2. VAP
3. Infects Nebulizers and Hospital cleaning products
4. Pneumonia
5. UTI
6. Bacteremia
7. Septic arthritis
8. Peritonitis (infection in peritoneum/abdomen)

Question 12

Burkholderia pseudomallei

Answer 12

1. NLF, GNR
2. resistant to polymyxin B
3. BSL 3 agent!!

Question 13

What disease does Burkholderia pseudomallei cause?

Answer 13

Melioidosis

*Spreads by contact with infected soil or water

*More common in Southeast Asia, Northern Australia

*Protean manifestation: Wide range of infections: cutaneous, pulmonary, bacteremia or asymptomatic

Question 14

What are the risk factors of Melioidosis?

Answer 14

immune suppression in general

diabetes
kidney, liver, blood disorders
thalassemia (genetic disorder that reduces hemoglobin carrying RBCs)
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