KLEBSIELLA PNEUMONIAE: Gram (-) Rod
GRAM-NEGATIVE PNEUMONIAS
KLEBSIELLA PNEUMONIAE: Gram (-) Rod
Name-Derivation: Klebs was a researcher.
Epidemiology / At Risk: Male, malnourished, alcoholic pneumonia. "VA pneumonia."
Transient normal flora of throat.
Manifestations:
Pneumonia: Acute lobar pneumonia with highly productive cough.
Productive cough. Thick, mucinous, messy, bloody sputum.
Focal lung abscesses in late infection lead to bacteremia.
Bacteremia with secondary Meningitis
Wound Infections
UTI
Processing:
Culture:
Blood Agar: Difficult to define boundaries because the bugs are so mucinous.
Selective Medium: Used to inhibit Gram (+) growth; will yield smooth and mucinous colonies.
Identification:
Lactose (+)
Serotypes: 77
Virulence:
Capsule: THICK capsule is antiphagocytic.
Confers serum resistance ------> bacteremia.
beta-Lactamase
Enterotoxin: Plasmid-mediated. Causes vomiting and diarrhea.
Endotoxin: LPS, fever, hypotension.
Treatment: Penicillin-Resistant. Use cephalosporins and broad-spectrum.
LEGIONELLA PNEUMOPHILA: Faintly staining Gram (-) rods. Part of its own family, Legionellaceae.
Name-Derivation: Named after American Legion convention, site of initial outbreak.
Family classification based on unique lipid in cell wall.
Epidemiology / At Risk: Legionella are abundant in water, particularly at cool temperatures. They are natural intracellular parasites of non-pathogenic amoebae in rivers in lakes.
Aerosolized mist colonizes upper airways.
Associated with air conditioners.
Non-communicable
Manifestations: Legionnaire's Disease
Pneumonia: Non-productive cough.
Pulmonary fibrinous exudate. Multifocal necrotic lesions.
Pulmonary infiltrates on X-Ray.
Toxemia (toxin unidentified) gives us liver dysfunction and CNS toxicity. Also forms the basis for serology tests.
Pontiac Fever: Milder form of disease. Self-limiting, headache, myalgia, fever.
Processing:
Specimen: Trans-Tracheal Aspiration; Broncho-alveolar lavage.
Stain: Dieterle Silver Stain shows rod shaped bacteria within macrophages.
NO STAIN with Gram Stain, Acid-Fact Stain, or H&E.
Culture: CYSTEINE is absolutely required for growth. Must notify lab!
3-5 days required for growth.
Identification:
14 Serogroups
Group 1 accounts for the majority of cases.
Direct Fluorescent Antibody (FA) to Group-1 is diagnostic. If negative, must try to culture.
ELISA or RIA test for polysaccharide antigen in urine.
Serology: Backup tests when culture fails. Tested antibodies are non-protective.
Acute:Convalescent titer of 4X, or absolute titer of 1:256 is diagnostic. False negatives common; some never develop antibodies.
Can test for Serum antibody to heat-shock antigens.
Catalase (+)
Virulence:
Facultative Intracellular Parasite of macrophages and PMN's.
Inhibits phagolysosome formation. Catalase prevents killing once inside, similar to Francisella.
Macrophages take in the bug by a process known as Coiling Phagocytosis -- they wrap a finger around the bug.
Macrophage-Infectivity Potentiator (mip):
Lipids in Cell-Wall: gives organisms thermal resistance.
Catalase
Metalloprotease:
Hemolysin, sequestering iron for growth.
Degrades Fc receptors and complement receptors, impairing opsonization.
Cleaves IL-2, impeding cell-mediated response. Impedes T-Cell activation.
beta-Lactamase
Host Immune Response: It's an intracellular parasite, so cell-mediated immunity (activated macrophages) are required for protection.
Vaccine / Prevention: Hyperchlorination of tap-water.
Treatment: Erythromycin.
PSEUDOMONAS AERUGINOSA: See UTI's section.
KLEBSIELLA PNEUMONIAE: Gram (-) Rod
Name-Derivation: Klebs was a researcher.
Epidemiology / At Risk: Male, malnourished, alcoholic pneumonia. "VA pneumonia."
Transient normal flora of throat.
Manifestations:
Pneumonia: Acute lobar pneumonia with highly productive cough.
Productive cough. Thick, mucinous, messy, bloody sputum.
Focal lung abscesses in late infection lead to bacteremia.
Bacteremia with secondary Meningitis
Wound Infections
UTI
Processing:
Culture:
Blood Agar: Difficult to define boundaries because the bugs are so mucinous.
Selective Medium: Used to inhibit Gram (+) growth; will yield smooth and mucinous colonies.
Identification:
Lactose (+)
Serotypes: 77
Virulence:
Capsule: THICK capsule is antiphagocytic.
Confers serum resistance ------> bacteremia.
beta-Lactamase
Enterotoxin: Plasmid-mediated. Causes vomiting and diarrhea.
Endotoxin: LPS, fever, hypotension.
Treatment: Penicillin-Resistant. Use cephalosporins and broad-spectrum.
LEGIONELLA PNEUMOPHILA: Faintly staining Gram (-) rods. Part of its own family, Legionellaceae.
Name-Derivation: Named after American Legion convention, site of initial outbreak.
Family classification based on unique lipid in cell wall.
Epidemiology / At Risk: Legionella are abundant in water, particularly at cool temperatures. They are natural intracellular parasites of non-pathogenic amoebae in rivers in lakes.
Aerosolized mist colonizes upper airways.
Associated with air conditioners.
Non-communicable
Manifestations: Legionnaire's Disease
Pneumonia: Non-productive cough.
Pulmonary fibrinous exudate. Multifocal necrotic lesions.
Pulmonary infiltrates on X-Ray.
Toxemia (toxin unidentified) gives us liver dysfunction and CNS toxicity. Also forms the basis for serology tests.
Pontiac Fever: Milder form of disease. Self-limiting, headache, myalgia, fever.
Processing:
Specimen: Trans-Tracheal Aspiration; Broncho-alveolar lavage.
Stain: Dieterle Silver Stain shows rod shaped bacteria within macrophages.
NO STAIN with Gram Stain, Acid-Fact Stain, or H&E.
Culture: CYSTEINE is absolutely required for growth. Must notify lab!
3-5 days required for growth.
Identification:
14 Serogroups
Group 1 accounts for the majority of cases.
Direct Fluorescent Antibody (FA) to Group-1 is diagnostic. If negative, must try to culture.
ELISA or RIA test for polysaccharide antigen in urine.
Serology: Backup tests when culture fails. Tested antibodies are non-protective.
Acute:Convalescent titer of 4X, or absolute titer of 1:256 is diagnostic. False negatives common; some never develop antibodies.
Can test for Serum antibody to heat-shock antigens.
Catalase (+)
Virulence:
Facultative Intracellular Parasite of macrophages and PMN's.
Inhibits phagolysosome formation. Catalase prevents killing once inside, similar to Francisella.
Macrophages take in the bug by a process known as Coiling Phagocytosis -- they wrap a finger around the bug.
Macrophage-Infectivity Potentiator (mip):
Lipids in Cell-Wall: gives organisms thermal resistance.
Catalase
Metalloprotease:
Hemolysin, sequestering iron for growth.
Degrades Fc receptors and complement receptors, impairing opsonization.
Cleaves IL-2, impeding cell-mediated response. Impedes T-Cell activation.
beta-Lactamase
Host Immune Response: It's an intracellular parasite, so cell-mediated immunity (activated macrophages) are required for protection.
Vaccine / Prevention: Hyperchlorination of tap-water.
Treatment: Erythromycin.
PSEUDOMONAS AERUGINOSA: See UTI's section.
