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TORTORA  FUNKE  CASE
ninth edition
MICROBIOLOGY
an introduction
24
Part A
Microbial Diseases
of the Respiratory
System
PowerPoint® Lecture Slide Presentation prepared by Christine L. Case
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Microbial Diseases of the
Upper Respiratory System
 Laryngitis: S. pneumoniae, S. pyogenes, viruses
 Tonsillitis: S. pneumoniae, S. pyogenes, viruses
 Sinusitis: Bacteria
 Epiglottitis: H. influenzae
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Upper Respiratory System
 Upper respiratory normal microbiota may include
pathogens
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 24.1
Streptococcal Pharyngitis (Strep Throat)
 Streptococcus pyogenes
 Resistant to phagocytosis
 Streptokinases lyse clots
 Streptolysins are
cytotoxic
 Diagnosis by indirect
agglutination
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 24.3
Scarlet Fever
 Streptococcus pyogenes
 Pharyngitis
 Erythrogenic toxin
produced by lysogenized
S. pyogenes
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 24.4
Diphtheria
 Corynebacterium diphtheriae: Gram-positive rod
 Diphtheria membrane of fibrin, dead tissue, and
bacteria
 Diphtheria toxin produced by lysogenized C.
diphtheriae
 Prevented by DTaP and Td vaccine (Diphtheria toxoid)
 Cutaneous diphtheria: Infected skin wound leads to
slow healing ulcer
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Diphtheria
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 24.6
Otitis Media
 S. pneumoniae (35%)
 H. influenzae (20-30%)
 M. catarrhalis (10-15%)
 S. pyogenes (8-10%)
 S. aureus (1-2%)
 Treated with broad-spectrum
antibiotics
 Incidence of S. pneumoniae
reduced by vaccine
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 24.7
Common cold
 Rhinoviruses (50%)
 Coronaviruses (15-20%)
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Microbial Diseases of the
Lower Respiratory System
 Bacteria, viruses, and fungi cause
 Bronchitis
 Bronchiolitis
 Pneumonia
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Lower Respiratory System
 The ciliary escalator keeps the lower respiratory system
sterile.
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 24.2
Pertussis (Whooping Cough)
 Bordetella pertussis: Gram-
negative coccobacillus
 Capsule
 Tracheal cytotoxin of cell
wall damaged ciliated cells
 Pertussis toxin
 Prevented by DTaP vaccine
(acellular Pertussis cell
fragments)
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 24.8
Pertussis (Whooping Cough)
 Stage 1: Catarrhal stage, like common cold
 Stage 2: Paroxysmal stage: Violent coughing sieges
 Stage 3: Convalescence stage
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings