1. بسم الله الرحمن الرحيم 1 1 1

2. Head of Medical Microbiology Department
Gram Negative Bacilli
Dr. Manal El Said
Head of Medical Microbiology Department

3. Head of Medical Microbiology Department
Pseudomonas
Dr. Manal El Said
Head of Medical Microbiology Department

4. Pseudomonas aeruginosa
Diseases
Wound infection
UTI
Pneumonia
Sepsis.
Nosocomial infections, especially in burn patients and those with cystic fibrosis.
Causes endocarditis in intravenous drug users.

5. Pseudomonas aeruginosa Habitat and Transmission
Characteristics
Aerobic gram-negative rods.
Non–lactose-fermenting.
Pyocyanin (blue-green) pigment production.
Oxidase-positive
Habitat and Transmission
Habitat is environmental water sources.
Inhabits the skin, upper respiratory tract & colon.
Transmission is via water aerosols, aspiration & fecal contamination.

6. Pseudomonas aeruginosa
Pathogenesis
Endotoxin is responsible for fever and shock associated with sepsis.
Produces exotoxin A inactivates EF-2.
Pili and capsule mediate attachment and inhibit phagocytosis, respectively.
Glycocalyx-producing strains predominate in chronic infections in cystic fibrosis patients.
Severe burns & neutropenia are predisposing factors

7. Pseudomonas aeruginosa
Laboratory Diagnosis
Gram-stained smear and culture.
Non–lactose-fermenting colonies on MacConkey's agar. .
Oxidase-positive.

8. Pseudomonas aeruginosa
Laboratory Diagnosis
TSI agar shows an alkaline slant and an alkaline butt because the sugars are not fermented.

9. Pseudomonas aeruginosa
Treatment
Antibiotics must be chosen on the basis of antibiotic sensitivities because resistance is common.
Anti-pseudomonal penicillin & aminoglycoside are used.
Resistance is mediated by a variety of plasmid-encoded enzymes, e.g., β  -lactamases & acetylating enzymes.

10. Pseudomonas aeruginosa
Prevention
Disinfection of water-related equipment in the hospital
Handwashing,
Prompt removal of urinary and intravenous catheters.
There is no vaccine.

11. Burkholderia cepacia & Stenotrophomonas maltophilia
Gram-negative rod resembling P. aeruginosa.
Important cause of chronic infections in patients with cystic fibrosis.

12. Acinetobacter They are gram-negative coccobacillary rods
They found in soil & water
They can be part of normal flora.
They are opportunistic pathogens that colonize patients with compromised host defenses.

13. Acinetobacter

14. Acinetobacter
Acinetobacter baumannii causes disease in a hospital setting associated with respiratory therapy equipment & indwelling catheters.
Sepsis, pneumonia & urinary tract infections are the most frequent manifestations.
A baumannii is antibiotic resistant
& some isolates are resistant to all
known antibiotics.