Biology 216 - Lect 24
Pseudomonas/Opportunists
I. Pseudomonas - general
	A. Bacteriology - Family Pseudomonadaceae 
		(Gm- oxidative rods, TSI K/K, 
			some anaerobic respiration)
		Ox+, Cat+, pigments (yellow, green, blue); 
		ubiquitous
	B. Significant characteristics
		1. Metabolic diversity - catabolic pathways; 
				often plasmids (ex. Toluene)
			Petroleum degraders 
			(Chakrabarty; patent attempt 1972; awarded 1980)
			Molecular breeding for 2,4,5-T (agent orange)
		2. Ice minus - Ps. syringiae
		3. Resistance to antibiotics 
			(difficult to achieve effective in vivo levels)
			Resist disinfectants.
		4. Nosocomial disease 
			(becomes normal flora in hospital)
II. P. aeruginosa (P. cepacia becoming 
		significant also = Burkholderia)
	A. Bacteriology
		1. Products - Alginate (antiphagocytic mucoid 
			material from CF infection); Pili;
 			a. Proteases (hemorrhage, corneal damage);
				Elastase lung damage(30 % of lung protein) 
				Pigments (pyocyanin - blue chelates phosphates;
				pyoverdin and pyochelin - fluorescent 
						yellow siderophore; together green)
			b. Exotoxins - A - ADP-ribosyltransferase to EFII 
				(liver necrosis); Anti-A good prognosis.
				Exo S - Role unclear, important in burn 
				(impair phagocytes?)
			c. Hemolysins - lung damage
		2. Antibiotic resistance - R-plasmids; 
			Surface alterations (OMP-F); 
		3. Resist disinfectants - disinfectant test organism, 
			Found growing in disinfectants (phenolics).
	B. Pathogenesis and clinincal - 
		Opportunistic/Compromised host - Variety of diseases.
		Environmental organism: soil, water, vegetation, animals......
		Human: 10 % carriage in intestine 
			(up to 90 % carriage in hospital)
		Other: hot tubs, disinfectants, 
			contact solutions, respirator
		1. Neoplastic patients - systemic disease, 
				liver and internal organs.
		2. Burn patients (Ps and Staph) - 
				decrease vascularization (PMN can't reach site);
			Local high numbers (10(5)/gm tissue) -> 
				bacteremia, osteo, lung, endocard
			Burn mouse model.
		3. CF kids (chronic lung) - autosomal recessive, 
			single gene defect chr #7, 1/20 carriers
			in caucasian population; ionic transport -> 
				pancreatic enzymes, lung mucus, high salt.
			Lung - Progression: Enteric, Staph, Ps (life) - 
				ave life 26 years.
			Guinea pig model.
		4. Other compromised: Nocosomial (hospital) 
			- 10 % of nosocomial infections.
	C. Lab
		1. Isolation - Ps isolation agar, Mac (lac-, 
			but look dark from pigment), BAP, lung mucoid
		2. ID - pigment, odor, biochem (Biolog), 
			oxidative. (Vitek, Microscan)
		3. Antibiotic sensitivity profile.
	D. Treatment - combinations of antibiotics 
			(penicillin + aminoglycoside; quinolones; 
			imipenem - B-lactam)
		1. Get high level to site of infection: Burn, lung,
		2. Beware in vitro may not reflect in vivo effectiveness
		3. Passive transfer of anti-A in burn and
			 cancer has worked (experimental).
	E. Control
		1. Ubiquitous, so difficult to avoid;
			 Care of respirators
		2. Vaccine - Pseudogen (killed bugs) - 
				available, but questionable value
			Exptl vaccines - Toxin A toxoids; 
			ToxA/alginate conjugates; flagellin
III. Aeromonas hydrophila (Family Vibrionaceae); 
		Ox+, Glu+
	(Vibrio vulnificus, Plesiomonas similar)
	A. Ecology - fresh and salt water; 
		pathogens of cold blooded animals.
	B. Disease - Wound and diarrhea 
		(Cholera related enterotoxin)
		1994 - Enloe patient septic shock from cleaning Salmon