Medical Technology Department, Faculty of Science, Islamic University-Gaza MB M ICRO B IOLOGY Dr. Abdelraouf A. Elmanama Ph. D Microbiology 2008 Chapter 24 Microbial Diseases of the Respiratory System

2008 Microbial Diseases of the Upper Respiratory System Laryngitis: S. pneumoniae, S. pyogenes, viruses Tonsillitis: S. pneumoniae, S. pyogenes, viruses Sinusitis: Bacteria Epiglottitis: H. influenzae

2008 Upper respiratory normal microbiota may include pathogens Upper Respiratory System Figure 24.1

2008 Streptococcal pharyngitis (Strep throat) Figure 24.3 Streptococcus pyogenes Resistant to phagocytosis Streptokinases lyse clots Streptolysins are cytotoxic Diagnosis by indirect agglutination

2008 Streptococcus pyogenes Pharyngitis Erythrogenic toxin produced by lysogenized S. pyogenes Scarlet Fever Figure 24.4

2008 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

2008 Figure 24.6 Diphtheria

2008 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

2008 Otitis Media Figure 25.7

2008 Rhinoviruses (50%) Coronaviruses (15-20%) Rhinoviruses attached to ICAN-1 on nasal mucosa Common cold

2008 Bacteria, viruses, & fungi cause: Bronchitis Bronchiolitis Pneumonia Microbial Diseases of the Lower Respiratory System

2008 Lower Respiratory System The ciliary escalator keeps the lower respiratory system sterile. Figure 24.2

2008 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)

2008 Stage 1: Catarrhal stage, like common cold Stage 2: Paroxysmal stage: Violent coughing sieges Stage 3: Convalescence stage Pertussis (Whooping Cough)

2008 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

2008 Tuberculosis Figure

2008 Tuberculosis Figure

2008 Tuberculosis Figure

2008 Treatment of Tuberculosis: Prolonged treatment with multiple antibiotics Vaccines: BCG, live, avirulent M. bovis. Not widely used in U.S. Tuberculosis

2008 Tuberculosis Figure Diagnosis: Tuberculin skin test screening + = current or previous infection Followed by X-ray or CT, acid-fast staining of sputum, culturing bacteria

2008 Tuberculosis Figure 14.11c

2008 Tuberculosis Figure 24.12

2008 Pneumomoccal Pneumonia Figure Streptococcus pneumoniae: Gram-positive encapsulated diplococci Diagnosis by culturing bacteria Penicillin is drug of choice

2008 Pneumomoccal Pneumonia

2008 Gram-negative coccobacillus Alcoholism, poor nutrition, cancer, or diabetes are predisposing factors Second-generation cephalosporins Haemophilus influenzae Pneumonia

2008 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

2008 Mycoplasmal Pneumonia Figure 11.19a, b

2008 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

2008 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)

2008 Chlamydia pneumoniae Transmitted from human to human Diagnosis by FA test Treatment: Tetracycline Chlamydial Pneumonia

2008 Q fever 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

2008 Q fever Figure 24.15

2008 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

2008 Chills, fever, headache, muscle aches (no intestinal symptoms) 1% mortality due to secondary bacterial infections Treatment: Amantadine Vaccine for high-risk individuals Influenza

2008 Hemagglutinin (H) spikes used for attachment to host cells Neuraminidase (N) spikes used to release virus from cell Influenza

2008 Influenza Figure 24.16

2008 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

2008 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

2008 Histoplasmosis Figure Histoplasma capsulatum, dimorphic fungus (a) 37˚(a) >35˚

2008 Histoplasmosis Figure Transmitted by airborne conidia from soil Diagnosis by culturing fungus Treatment: amphotericin B

2008 Coccidioidomycosis Figure Coccidioides immitis

2008 Coccidioidomycosis Figure Transmitted by airborne arthrospores Diagnosis by serological tests or DNA probe Treatment: amphotericin B

2008 Pneumocystis Pneumonia Figure Pneumocystis jiroveci (P. carinii) found in healthy human lungs Pneumonia occurs in newly infected infants & immunosuppressed individuals Treatment: Timethoprim- sulfamethoxazole

2008 Pneumocystis Figure The mature cyst contains 8 intracystic bodies. The cyst ruptures, releasing the bodies. The bodies develop into trophozoites The trophozoites divide. 4 Each trophozoite develops into a mature cyst. 5 Cyst Intracystic bodies Trophozoite

2008 Blastomyces dermatitidis, dimorphic fungus Found in soil Can cause extensive tissue destruction Treatment: amphotericin B Blastomycosis

2008 Aspergillus Rhizopus Mucor Opportunistic fungi involved in respiratory disease: Mucor rouxii Figure 12.2b, 12.4