this is a series of lectures on microbiology useful for undergraduate and postgraduate, medical and paramedical students

1. Diseases of the Respiratory System
Dr. Ashish V. Jawarkar

2. The Upper Respiratory System
Consists of:
Nose
Pharynx
(throat)
Middle ear
Eustachian
tubes
Dr. Ashish V. Jawarkar

3. The Lower Respiratory System
Consists of:
Larynx
Trachea
Bronchial
Alveoli
Pleura
Dr. Ashish V. Jawarkar
tubes

4. Upper Respiratory System defense
•Coarse hairs in the nose filter large
particles from air entering the respiratory
tract.
•The ciliated mucous membranes of the
nose and throat trap airborne particles and
remove them from the body.
•Lymphoid tissue, tonsils, and adenoids
provide immunity to certain infections.
Dr. Ashish V. Jawarkar

5. Dr. Ashish V. Jawarkar

6. Lower respiratory tract defense
The lower respiratory
system is usually sterile
because of the action of the
ciliary escalator.
Microorganisms hoping to
infect the respiratory tract
are caught in the sticky
mucus and moved up by the
mucociliary escalator.
Dr. Ashish V. Jawarkar

7. Upper Respiratory System Diseases
Most respiratory tract infections
are self-limiting.
Often caused by bacteria & viruses
in combination
Dr. Ashish V. Jawarkar

8. Upper Respiratory System Diseases
Pharyngitis: inflammation of the pharynx
Laryngitis: swelling and irritation (inflammation) of
the voice box (larynx)
Tonsillitis: inflammation of the tonsils
Sinusitis: inflammation of the sinuses
Dr. Ashish V. Jawarkar

9. Agents of URTi
S. pneumonia – pharyngitis/tonsillitis
S. Pyogenes – pharyngitis / tonsillitis
C. diphtheria - diptheria
B. pertussis – whooping cough
Common cold – rhino virus
Dr. Ashish V. Jawarkar

10. Streptococcal Pharyngitis
Also called strep throat
Streptococcus pyogenes /
strep. pneumoniae
Gram positive cocci
chains
Dr. Ashish V. Jawarkar

11. Corynebacterium Diphtheriae
Gram positive club shaped rod
Dr. Ashish V. Jawarkar

12. Dr. Ashish V. Jawarkar

13. Dr. Ashish V. Jawarkar

14. Diphtheria
Diphtheria membrane: Fibrin, tissue, bacterial
cells
••Leading infectious killer of children in U.S. in 1935
Leading infectious killer of children in U.S. in 1935
Dr. Ashish V. Jawarkar

15. Diphtheria
Still common in developing countries where
immunizations aren't given routinely.
Up to 40% to 50% of those who don't get
treated can die.
The exotoxin inhibits protein synthesis, and
heart, kidney, or nerve damage may result.
Prevented by DTP vaccine
Dr. Ashish V. Jawarkar

16. Lab diagnosis
Microscopy – Gram’s , Albert’s
Culture – selective media containing tellurite,
Loeffler’s serum slope
Dr. Ashish V. Jawarkar

17. Pertussis / whooping cough
Causes whooping
cough
Mostly in children
Coughing thru
strained vocal
cords produces
sound
Dr. Ashish V. Jawarkar

18. diagnosis
Mostly clinical
Bacteria does not grow on ordinary media
Prevented by vaccination – DPT
Dr. Ashish V. Jawarkar

19. Lower Respiratory System Diseases
Bacteria, viruses, and fungi cause
 Bronchitis
– S. pneumoniae
 Pneumonia – S. pneumoniae, Klebsiella,
Mycoplasma
 Tuberculosis - M. tuberculosis
Dr. Ashish V. Jawarkar

20. Mycoplasma
Bacteria with no cell walls
Gram negative, better stained with Giemsa stain
Dr. Ashish V. Jawarkar

21. Grow on media enriched with serum
Colonies give fried egg appearance
Dr. Ashish V. Jawarkar

22. Mycoplasmal Pneumonia
Primary atypical pneumonia; walking pneumonia


No physical signs/symptoms
X ray shows lower lobe pneumonia
Genitourinary infections
Dr. Ashish V. Jawarkar

23. Dr. Ashish V. Jawarkar

24. Viral Pneumonia
Viral pneumonia occurs as a complication of
influenza, measles, or chickenpox
Viral etiology suspected if no other cause is
determined
Dr. Ashish V. Jawarkar

25. Respiratory Syncytial Virus (RSV)
The most common viral respiratory disease in
infants; 4500 deaths annually
Causes cell fusion (syncytium) in cell culture
Symptoms: Pneumonia in infants
Diagnosis: Serological test for viruses and
antibodies
Treatment: Ribavirin, palivizumab
Dr. Ashish V. Jawarkar

26. Influenza (Flu)
Symptoms: Chills, fever, headache, and muscle
aches

No intestinal symptoms
1% mortality, very young and very old
Treatment: Zanamivir and oseltamivir inhibit
neuraminidase
Prophylaxis: Multivalent vaccine (currently grown
in Embryonated egg cultures
Dr. Ashish V. Jawarkar

27. The Influenza Virus
Hemagglutinin
(HA) spikes used
for attachment to
host cells
Neuraminidase (NA)
spikes used to
release virus from
cell
Dr. Ashish V. Jawarkar

28. Fungal Infections
Fungal spores are easily
inhaled; they may germinate in the
lower respiratory tract.
The incidence of fungal diseases has
been increasing in recent years.
The mycoses can be treated with
amphotericin B.
Dr. Ashish V. Jawarkar

29. Dr. Ashish V. Jawarkar