Biology 216 - Lect 26
Listeria/Actinomycetes
Does not produce Listerine
I. Listeria monocytogenes (Joseph Lister); 
	Originally associated w/ mono-like disease (flu-like).
    Now - disease in neonate (meningitis), 
	elderly and T-cell lymphoma
   A. Bact - small Gm+ coccobacilli; 
	Motile 25 C (peritrichous), 35 C monotrichous.
	X-mas tree motility at 25 C.
	Growth at low temps, so refrigeration 
		not effective prevention
	Stimulate phagocytosis (mechanism unknown)
	Facultative intracellular 
		(direct cell-cell spread in Macs) 
		- CMI important; Granuloma
	Actin tails - polymerizes host actin ->
		tails to move in cytoplasm (similar to Shigella)
	Hemolysin (Listeriolysin) Form pores 
		in host membrane (not enzyme)
		-> degranulate phago and lysosome -> 
		cytoplasmic location.
	Virulence genes clustered in 
		pathogenicity island on chromosome
   B. Pathos
	1. Reservoirs - nature, soil, plants, zoonosis 
		(shed in feces -> food)
	2. Transmission - Oral from contaminated vegies, 
		cheeses, meats.
		Usually transient colonization w/o disease.
		1981 outbreak in Canada - 41 cases (34 perinatal), 
			Cole slaw from cabbage fertilized by manure 
			from2 sheep which died of Listeria.
		1985 outbreak associated w/ Jalisco cheeze; 
			86 cases (29 death/21 infant), raw milk contam
			338 total cases; Became reportable in CA
			Pregnant Hispanics 
			(Isolated same serotype from patients/Cheese
			Cause - contamination after pasteurization; 
			Cheese taken off market.
	3. Invasion - through GI; CNS tropism
	4. Diseases: Usually asymptomatic to flu-like in 
		health adults (carried by 10 % adults). 
			Leukocytosis (monocytes and PMN)
		a. Compromised host (leukemic) - 
			Macs, granuloma -> tissue damage.
			Miliary foci - millet seed-like granules.
		b. Mother to fetus (before or during birth) - 
			1500/yr in US.
			- Mother asymptomatic (or flu-like)
			- Third trimester transplacental(one of few bacteria) -> 
				stillbirth, spontaneous abortion.
				Septicemia, miliary, liver, spleen..
			- During birth - 50 % fatality - meningitis.
   C. Diagnosis - fever during pregnancy, 
	usually diagnosed as stillbirth.
	1. Isolation and ID - CSF, blood, vaginal (colony 
			and cells look like diphtheroid, so ignored)
		Cold enrich - 4 C (releases intracellular)
		ID biochem (Coryn, Strept, Erysipelothrix)
		Catalase, B-hemolysis (beneath colony)
	2. Isolation from food (CA Dept Health)
		Food + selective broth -> 30 C/7 days, then plate
		Food + broth -> 4 C/4 weeks.
		New selective media.
   D. Prevention - tough, since vague symptoms by mother.
	1. Treatment of mother if detected (not routine).
	2. Avoidance of animals (which shed), avoid soft 
		cheeses and unpasteurized milk, 
	3. Cook meats, wash vegetables, reheat leftovers.
	4. Sporadic cases cannot be prevented; outbreaks can.
	5. Never will be vaccine due to number of cases.
II. Actinomycetales - Order with filamentous, 
	Gm+, dry growth, chronic disease.

	True branching	Acid fast	Disease
Streptomyces	Yes	No	Rare Mycetoma
Nocardia	No	Partial (with weak acid)	Lung
Actinomyces	Yes	No	Necrotic
Mycobacterium	No	Yes	TB/Leprosy/MAC

 
   A. Streptomyces
	1. General - common soil organisms; Soil odor; 
	Antibiotics (and resistance); Low virulence
	2. Disease - Mycetoma (fungal tumor) - 
		usually foot from large inoculum.
		- Transmission - traumatic implantation
		- Inflammation; Swelling; Edema; Discharge
		- Bone destruction - hyperplasia; 
			Vascular disruption; Amputation.
	3. Diagnosis - Direct smear for granules
		- Culture and ID - morphology, 
		extracellular enzymes, biochems, only from deep.
	4. Treat - Antibiotics; Debride; Amputation.
   B. Nocardia - N. asteroides most common; 
	partial acid fast (with HCl & H2SO4)
	1. Bact - filamentous and fragment;
		Colony - heaped, folded, dry, orange or yellow.
		Cell wall - mycolic acids 
		(long chain branched FA); Nocardic acids
C18 ---C32 (Coryne) --- C50 (Nocardia)---- C90 (Mycobact)
	2. Disease
		- Transmission - soil, normal 
			respiratory tract flora - inhalation
		- Never person to person
		- Colonization - compromised lung 
			(immunosuppressed, neoplasm, cavitation TB, 
			AIDS, transplant, decreased CMI
		- Chronic inflammation -> 
			lobar pneumonia (like S. pneumo)
			Pyogenic, consolidation, survive in Macs 
			(block phago/lyso fusion - cord factor)
			Necrosis, abscess, cough, fever, 
				hematogenous spread, CNS tropism.
			TB-like, however, no granuloma (pus)
	3. Lab - Lung infection usually diagnosed at autopsy
		- Clinical picture: Lobar, chronic, 
			unresponsive to Pen, compromised host
		- Sputum - L-cys as mucolytic agent; 
			Partial acid fast test (low sulfuric or HCl destain) 
		- Culture - Repeat isolation necessary, 
			since soil organism.
		- ID - Partial acid fast; casein-; xanthine-; 
			cell wall composition.
	4. Treat - antibiotics.
   C. Actinomyces ("actino" = ray)
	- Actinomycosis - slow progressive with 
		draining fistula - granules
	1. Bact - A. israelii (anaerobe); non-acid fast;
		 filamentous, normal flora on mucus
	2. Disease - 
		- Transmission - endogenous by (facial) 
			traumatic introduction (low O2)
			Ex. Dental extraction, rupture appendix, gingivitis
		- Colonize - necrosis, extension, PMN, 
			draining sinus/fistula (face, neck, abdomen)
		- Sulfur granules in pus (1 mm diameter) - 
			not really sulfur,
			(yellow from macrophage lipids) 
				- pathognomonic
			filamentous bacteria in 
				rosettes + liquified host tissue 
		- Most common cervicofacial (lumpy jaw); 
			genital from IUD.
			From poor dental hygiene, tooth extraction, 
				facial trauma
		- May extend to bone or meninges
		- Chronic, granuloma (CMI),
	3. Lab - Specimen is pus or sputum
		Granules - ray-like colonies (filaments),
			yellow, crush and examine.
		Culture - rich media anaerobically with CO2.
	4. Treat - Debride, drain, antibiotics.