1. Airborne Bacterial Diseases
Chapter 10
Airborne Bacterial Diseases

2. 10.1 The Respiratory System Posses an Indigenous Microbiota
Upper respiratory defenses limit microbe colonization of the lower respiratory tract.
Microbial colonization is usually limited to the upper respiratory tract.
Figure 10.03: Respiratory System Anatomy.

3. Figure 10.05: Staphylococcus in the Ciliated Epithelium.
Mucociliary clearance traps microbes and particulates larger than 2 µm in a layer of mucus.
Ciliated epithelial cells move mucus to the pharynx where it is swallowed and sent to the stomach.
Figure 10.05: Staphylococcus in the Ciliated Epithelium.
Figure 10.04: Defenses of the Airway Epithelium.
© Juergen Berger/Photo Researchers, Inc.

4. 10.2 Several Bacterial Diseases Affect the Upper Respiratory Tract
Pharyngitis is an inflammation of the throat.
S. pyogenes causes streptococcal pharyngitis (strep throat).
It enters the upper respiratory tract through respiratory droplets.
Figure 10.07B: Scarlet Fever.
© imagebroker/Alamy Images

5. Figure 10.07A: Scarlet Fever. Rash.
Some patients with strep throat may develop scarlet fever, exhibiting a rash caused by erythrogenic exotoxins.
Strep throat and scarlet fever can be treated by antibiotics.
Figure 10.07A: Scarlet Fever. Rash.
© Medical-on-Line/Alamy Images

6. Rheumatic fever is a serious complication affecting the joints and heart.
It causes permanent heart damage called rheumatic (joint) and heart disease.
Acute glomerulonephritus is a rare inflammatory response to M proteins.
It may lead to renal damage.

7. Diphtheria is a life-threatening illness.
Diphtheria is a local infection of the throat caused by Corynebacterium diphtheriae.
C. diphtheriae bacilli remain in clumps after multiplying, forming a palisade layer.
Diphtheria is acquired by respiratory droplet transmission.
The bacteria produce an exotoxin that inhibits translation.
This results in the accumulation of a pseudomembrane on the tonsils or pharynx.

8. Figure 10.08: Diphtheria pseudomembrane.
Treatment requires antibiotics and antitoxins.
Injection of diphtheria toxoid is used for vaccination.
The epiglottis is subject to infection, especially in children.
Swelling of the epiglottis can block the trachea.
Figure 10.08: Diphtheria pseudomembrane.
© Medical-on-Line/Alamy Images

9. Sinusitis is inflammation of any of the sinuses
The nose is the most commonly infected part of the upper respiratory tract causing rhinitis.
Sinusitis is inflammation of any of the sinuses
Ear infections are common
illnesses in early childhood.
Otitis externa often called swimmers ear infects the ear canal
Otitis media is a middle ear infection
Figure 10.09: The Sinuses.
Figure 10.10: Ear Anatomy.

10. Acute bacterial meningitis is a rapidly developing inflammation.
Bacterial meningitis begins when a localized infection invades the blood and then the meninges around the brain and spinal cord.
Figure 10.13: Pathogenic Steps Leading to Meningitis.

11. Neisseria meningitidis causes meningococcal meningitis.
Neisseria meningitidis is the major cause of disease and mortality in infants.
90% of the cases occur in Africa’s meningitis belt.
Figure 10.12: African meningitis belt.

12. Other causes of Meningitis
Streptococcus pneumoniae causes pneumococcal meningitis, about 30% of the cases of meningitis.
Haemophilus influenzae Type b (Hib) is mostly prevented now in the US with the Hib vaccine.
A few species cause a rare neonatal meningitis in low weight newborns (Group B strep E. coli and Listeria)

13. Symptoms of Meningitis
It starts with an upper respiratory infection
Neisseria meningitis may have a rash
Fever and stiff neck
Headache, nausea and vomiting

14. Figure 10.15: Bordatella pertussis.
10.3 Many Bacterial Diseases of the Lower Respiratory Tract Can Be Life Threatening
Pertussis (Whooping Cough) is highly contagious.
Bordatella pertussis is spread by respiratory droplet transmission.
Toxin paralyzes ciliated cells in the respiratory tract.
Figure 10.15: Bordatella pertussis.
© NIBSC/Photo Researchers, Inc.

15. Figure 10.14: Pertussis Cases – United States, 1900-2010.
Patients experience multiple paroxysms of coughs, followed by an inhalation of breath that sounds like a “whoop.”
Erythromycin reduces the duration and severity of illness.
The newer vaccine (Tdap) contains B. pertussis chemical extracts rather than killed cells.
The number of cases in the United States has been rising since 1981.
Figure 10.14: Pertussis Cases – United States,
Reproduced from: Morbidity and Mortality Weekly Report, 58(53);1-100

16. Tuberculosis Is One of the Greatest Challenges to Global Health.
2 billion people are infected with TB globally.
Mycobacterium tuberculosis enters the respiratory tract in small aerosolized droplets.
About 90% of people who carry latent TB will never develop an active infection.
Clinical TB develops within 3 months and can be transmitted to others.
Figure 10.16: Estimated Global Incidence of TB, 2008.
Source: Global Tuburculosis Contro, 2011, WHO

17. Figure 10.18: The progress of tuberculosis.
Sputum coughed from the lower respiratory tract may contain blood.
Macrophages accumulate in the lung.
They form a tubercle that harbors M. tuberculosis.
If a tubercle breaks apart, bacteria spread throughout the body.
Figure 10.18: The progress of tuberculosis.

18. reaction in the Mantoux test can be used for early detection of TB
Miliary tuberculosis is the development of active tubercles throughout the body.
The tuberculin
reaction in the Mantoux test can be used for early
detection of TB
exposure.
Figure 10.19A: Pulmonary tuberculosis.
© James Cavallini/Photo Researchers, Inc.
Figure 10.20: Tuberculin Skin Test for Tuberculosis.
© Bart's Medical Library/Phototake/Alamy Images

19. Figure 10.19B: Acid-Fast stain.
Multidrug-resistant Mycobacterium tuberculosis is affecting which antibiotics are used to treat TB.
TB is a particularly the leading cause of death for co-infected AIDS patients.
Attenuated M.
bovis is used in
BCG immunization, but has limited effectiveness in adults.
Figure 10.19B: Acid-Fast stain.
© Manfred Kage/Peter Arnold, Inc.

20. Figure 10.21: Bronchus inflammation.
Infectious bronchitis is an inflammation of the bronchi.
Bronchitis produces excessive
mucus and a narrowing
of the bronchi.
Figure 10.21: Bronchus inflammation.
Adapted from Merck, "Acute Bronchitis: Lung and Airway Disorders", Merck Manual Home Edition, December 09, 2008,

21. Pneumonia Can Be Caused by Several Bacterial species
Healthcare-Acquired Pneumonia affects patients who have been on respiratory devices and can be caused by the following bacteria:
Staphylococcal pneumonia caused by Staphylococcus aureus
It may result in necrotizing pneumonia.
Klebsiella pneumoniae can be a primary or secondary infection in people with impaired pulmonary function.
Pseudomonas aeruginosa is seen in immunocompromised patients

22. Community-Acquired Pneumonia
Streptococcus pneumoniae called pneumococcal pneumonia
It is acquired through aerosolized droplets or contact.
Pneumococcal pneumonia can involve:
an entire lung lobe (lobar pneumonia).
both lungs (double pneumonia).
or patches in the respiratory passageways (bronchopneumonia).
vaccines available for children and elderly
Figure 10.22: Streptococcus pneumoniae.
Courtesy of Dr. Mike Miller/CDC

23. Figure 10.23: Mycoplasma pneumoniae.
Haemophilus influenzae can cause:
“typical” pneumonia.
otitis media sinusitis.
“Atypical” Pneumonia Can Be Caused by a Diverse Group of Bacterial Species.
Mycoplasma pneumoniae causes primary atypical pneumonia, often called walking pneumonia.
M. pneumoniae has no sensitivity to penicillin because it has no cell wall.
© Michael Gabridge/Visuals Unlimited
© ASM/Science Source/Photo Researchers, Inc.
Figure 10.23: Mycoplasma pneumoniae.

24. Legionella pneumophila causes Legionnaires’ disease.
It lives where water collects and becomes airborne in the wind (or ventilation system).
Disease develops within a week of inhalation of contaminated droplets.
Necrotizing pneumonia
may develop.
L. pneumophila also
causes Pontiac fever,
an influenza-like
infection.
Figure 10.24A: Legionella pneumophila.
© Collection CNRI/Phototake/Alamy Images

25. Figure 10.25: Coxiella burnetii.
Other Pneumonia-Causing Bacterial Species are Obligate, Intracellular Parasites.
Coxiella burnetii causes Q fever, a prevalent disease of livestock.
Humans can acquire
the disease by
consuming
contaminated raw
or improperly
pasteurized milk.
Figure 10.25: Coxiella burnetii.
Courtesy of Rocky Mountain Laboratories, NIAID, NIH

26. Zoonotic Respiratory Diseases
Chlamydia psittaci causes psittacosis (a.k.a. ornithosis).
It is a zoonotic disease humans can catch from infected birds.
Chlamydia pneumoniae causes chlamydial pneumonia.
Bacillus anthracis can be acquired from contaminated animal products or dust