Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings PowerPoint ® Lecture Slide Presentation prepared by Christine L. Case Microbiology B.E Pruitt & Jane J. Stein AN INTRODUCTION EIGHTH EDITION TORTORA FUNKE CASE Medical Microbiology Ch. 16 Respiratory tract infections
Copyright © 2004 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 © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Upper respiratory normal microbiota may include pathogens Upper Respiratory System Figure 24.1
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Streptococcal pharyngitis (Strep throat) Figure 24.3 Streptococcus pyogenes Resistant to phagocytosis Streptokinases lyse clots Streptolysins are cytotoxic Diagnosis by indirect agglutination
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Streptococcus pyogenes Pharyngitis Erythrogenic toxin produced by lysogenized S. pyogenes Scarlet Fever Figure 24.4
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings 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 Diphtheria
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.6 Diphtheria
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings 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 © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Otitis Media Figure 25.7
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Rhinoviruses (50%) Coronaviruses (15-20%) Rhinoviruses attached to ICAM-1 on nasal mucosa Common cold
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Bacteria, viruses, & fungi cause: Bronchitis Bronchiolitis Pneumonia Microbial Diseases of the Lower Respiratory System
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Lower Respiratory System The ciliary escalator keeps the lower respiratory system sterile. Figure 24.2
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Pertussis (Whooping Cough) Figure 24.8 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 © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Stage 1: Catarrhal stage, like common cold Stage 2: Paroxysmal stage: Violent coughing sieges Stage 3: Convalescence stage Pertussis (Whooping Cough)
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Tuberculosis Figure 24.9 Mycobacterium tuberculosis: Acid-fast rod. Transmitted from human to human M. bovis: <1% U.S. cases, not transmitted from human to human M. avium-intracellulare complex infects people with late stage HIV infection
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Treatment of Tuberculosis: Prolonged treatment with multiple antibiotics Vaccines: BCG, live, avirulent M. bovis. Not widely used in U.S. Tuberculosis
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Tuberculosis Figure Diagnosis: Tuberculin skin test screening + = current or previous infection Followed by X-ray or CT, acid-fast staining of sputum, culturing bacteria
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Pneumomoccal Pneumonia Figure Streptococcus pneumoniae: Gram-positive encapsulated diplococci Diagnosis by culturing bacteria Penicillin is drug of choice „Lancet-shaped“
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Pneumomoccal Pneumonia α-hemolysis Optochin
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Gram-negative coccobacillus Alcoholism, poor nutrition, cancer, or diabetes are predisposing factors Second-generation cephalosporins Haemophilus influenzae Pneumonia
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Mycoplasmal Pneumonia Figure Mycoplasma pneumoniae: pleomorphic, wall- less bacteria Also called primary atypical pneumonia and walking pneumonia Common in children and young adults Diagnosis by PCR or by IgM antibodies
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Mycoplasmal Pneumonia Figure 11.19a, b
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Legionella pneumophila: Gram-negative rod L. pneumophila is found in water Transmitted by inhaling aerosols, not transmitted from human to human Diagnosis: culturing bacteria Treatment: Erythromycin Legionellosis
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Chlamydia psittaci: gram-negative intracellular bacterium Transmitted by elementary bodies from bird dropping to humans Reorganizes into reticulate body after being phagocytized Diagnosis: culturing bacteria in eggs or cell culture Treatment: Tetracycline Psittacosis (Ornithosis)
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Chlamydia pneumoniae Transmitted from human to human Diagnosis by FA test Treatment: Tetracycline Chlamydial Pneumonia
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Viral pneumonia as a complication of influenza, measles, chickenpox Viral etiology suspected if no cause determined Respiratory Syncytial Virus (RSV) Common in infants; 4500 deaths annually Causes cell fusion (syncytium) in cell culture Symptoms: coughing Diagnosis by serologic test for viruses and antibodies Treatment: Ribavirin Viral Pneumonia
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Chills, fever, headache, muscle aches (no intestinal symptoms) 1% mortality due to secondary bacterial infections Treatment: Amantadine Vaccine for high-risk individuals Influenza
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Hemagglutinin (H) spikes used for attachment to host cells Neuraminidase (N) spikes used to release virus from cell Influenza
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Influenza Figure 24.16
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Antigenic shift Changes in H and N spikes Probably due to genetic recombination between different strains infecting the same cell Antigenic drift Mutations in genes encoding H or N spikes May involve only 1 amino acid Allows virus to avoid mucosal IgA antibodies Influenza
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings A: causes most epidemics, H 3 N 2, H 1 N 1, H 2 N 2 B: moderate, local outbreaks C: mild disease Influenza serotypes
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Pneumocystis Pneumonia Figure Pneumocystis jiroveci (P. carinii) found in healthy human lungs Pneumonia occurs in newly infected infants & immunosuppressed individuals Treatment: Timethoprim- sulfamethoxazole
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Aspergillus Rhizopus Mucor Opportunistic fungi involved in respiratory disease: Mucor rouxii Figure 12.2b, 12.4