Matu is the best

1. Bacterial Respiratory Diseases

2. What makes the Respiratory system prone
to infections?
The air we
inhale
1. RT serves as Portal of entry for microbes
(pathogenic or non-pathogenic)
2. Lower RT provides moist and nutrient
rich region.

3. Such huge exposure!
How come we aren’t always down with respiratory diseases?
• Defensive Barriers are the answer.
1. Mucus and Mucociliary clearance
2. Pulmonary Surfactant Proteins
3. RT natural microflora
4. Antimicrobial peptides : lysozyme, human beta-defensin etc.
5. Secretory IgA antibodies

4. Paranasal Sinuses
Sinusitis
Streptococcus pneumoniae,
Haemophilus influenzae
Pharyngitis
Streptococcus pyogenes
Epiglottitis and Laryngotracheitis
Haemophilus influenzae type b
Bronchitis
H influenzae, S pneumoniae
Bacterial Pneumonias
Streptococcus pneumoniae,
Streptococcus pyogenes
Tuberculosis
Mycobacterium tuberculosis

5. Microorganisms we’ll study:
Streptococcus
Pyogenes
• Gram positive
bacterium
• Beta-haemolytic
group A
streptococcus
(GAS)
• Most pathogenic
in genus
• Strep throat,
scarlet fever,
necrotizing
fasciitis
Haemophilus
influenzae
• Gram negative
bacterium
• Facultative
Anaerobic
• Pneumonia,
epiglottitis, otitis
media,
meningitis
Mycobacterium
tuberculosis
• Acid fast
bacterium
• Highly aerobic,
requires high
level of oxygen
• Lipid rich
(mycolic acid)
unusual cell wall
• Tuberculosis (TB)

6. General Features
• Gram positive
• Catalase negative
• Arranged in chains
• Beta haemolytic
• Bacitracin sensitive
• PYR positive (Pyrriodonyl Arylamidase)

8. Virulence
Factors
CAPSULE made of
HYALURONIC ACID
M protein
STREPTOKINASE,
DNase,
STREPTOLYSINs
ERYTHROGENIC
EXOTOXIN A
M protein is strongly anti-phagocytic and binds
to serum factor H, destroying C3-convertase and
preventing opsonization by C3b, elementary
system.
.
plays critical roles in immune evasion,
prevents neutrophil-mediated clearance.
acts as a plasminogen activator to
generate the serine protease plasmin
which promotes bacterial metastasis,
lyse cell membrane e.g. RBCs
Super antigen, cross links T cell receptor to MHCII
apart from binding site, constant activation of T cell,
cytokine storm

9. Pyogenic
• Pharyngitis
• Impetigo
• Erysipelas
• Cellulitis
Immuno-genic
• Rheumatic Fever
• Glomerulonephritis
Toxigenic
• Scarlet Fever
• Toxic shock like syndrome
Diseases

10. Pharyngitis
(Sore Throat)
•Pain or a scratchy sensation in the throat.
•Pain that worsens with swallowing or
talking.
•Difficulty swallowing.
•Sore, swollen glands in your neck or jaw.
•Swollen, red tonsils.
•White patches or pus on your tonsils.
•A hoarse or muffled voice
SYMPTOMS
• respiratory droplets
• through contact with
secretions, such as saliva,
wound discharge, or nasal
secretions, from an infected
person.
• Cattles to human through raw
milk, contaminated food
• Pathogen can also be found in
carrier state (anus, vagina,
skin)
MODE OF
TRANSMISSION

11. DIAGNOSIS
•A throat culture is the gold standard for the diagnosis of
streptococcal pharyngitis, with a sensitivity of 90–95%.
• A rapid strep test (also called rapid antigen detection
testing or RADT) may also be used.
 quicker, it has a lower sensitivity (70%)
 Check GAS-specific antigens on a throat swab
•In adults, a negative RADT is sufficient to rule out the
diagnosis.
•However, in children a throat culture is recommended to
confirm the result.

12.  antibiotic: Phenoxymethylpenicillin
 To reduce the frequency of taking penicillin
tablets – amoxicillin is prescribed,
 If the above groups of antibiotics are not
possible – Josamycin, fewer other
macrolides or lincosamides are prescribed.
 The duration of treatment of pharyngitis
with antibiotics is 10 days, except for
Azithromycin, which is taken orally for 5
days.
 Soluble forms are convenient for antibiotic
therapy in children.
PROPHYLAXIS
 Hygiene helps prevent many cases of
pharyngitis.
 use only separate containers, only one
bottle of drinking water for yourself;
 Use mask in crowds
 Wash your hands often, especially
before eating and after coughing or
sneezing; disinfect hands with alcohol
wipes if soap and water are not
available;
 Avoid smoking and inhaling tobacco
smoke
PREVENTION

13. General Features
• Gram negative
• Catalase positive
• Oxidase positive
• Aerobes
• Blood Loving (as the name suggests), require
Hemin (Factor X), NAD (Factor V) present in
RBCs.

14. Haemophilus influenzae is not haemolytic
Cannot grow on blood agar media, as it cannot lyse
RBCs to get Hemin or NAD+
Blood Agar Media Chocolate Agar Media
In Chocolate Agar Media, the RBCs are
lysed. Now they can grow here.
In presence of haemolytic bacteria only,
H. influenzae can grow on Blood Agar
Media and project Satellitism.

15. IgA1 Protease
Breaks down IgA1
attacks mucosal surfaces
Polysaccharide Capsule
6types, a,b,c,d,e,f
Type b (Hib) most virulent
Provides resistance to complement
mediated phagocytosis
Virulence Factors

16. By encapsulated ( mostly Hib)
• Epiglottitis
• Meningitis (in children)
• Septic Arthritis (infants)
• Pneumonia
• Children with no spleen due to splenectomy or non-
functioning like SCD are at higher risk of getting
these.
Non-encapsulated
• Sinusitis
• Otitis Media
• Conjunctivitis
• No capsule= less invasive= local diseases
Diseases

17. DISEASE CAUSED BY DISEASE DETAILS & SYMPTOMS TREATMENT &
IMMUNIZATION
Strep throat Streptococcus
pyogenes
Streptokinase breaks down of fibrin clots, enlarged
lymph nodes, inflamed tissues, and pus on the
tonsils
penicillin antibiotics
Scarlet fever Streptococcus
pyogenes
erythrogenic toxin causes a skin rash, high fever,
inflamed throat tissue, strawberry tongue
Penicillin antibiotics
Diphtheria Corynebacterium
diphtheriae
Exotoxin destroys cells of the epithelial lining, sore
throat, neck swelling, and blockage of the
respiratory passageways
Antibiotic therapy, administration
of antitoxins to neutralize the
toxins, DPT vaccine
Pertussis
(whooping
cough)
Bordetella
pertussis
Organism multiplies in the trachea and bronchi and
causes paroxysms of cough. A rapid inrush of air
following a paroxysm results in whooping sound
erythromycin and other antibiotics,
DPT or DTaP vaccine
Bacterial Respiratory Diseases:
AT A GLANCE:

18. DISEASE CAUSED BY DISEASE DETAILS & SYMPTOMS TREATMENT &
IMMUNIZATION
Pneumococcal
pneumonia
Streptococcus
pneumoniae
fever, consolidation of the lung (filling of the air
spaces with bacteria, fluid, and debris), and severe
chest pains, with blood in the sputum
Aggressive penicillin therapy
Legionnaires'
disease
Legionella
pneumophila
high fever, lung consolidation, and pneumonia Erythromycin
Chlamydial
pneumonia
Chlamydia
pneumoniae
resembles influenza, fever, chills, muscle aches,
cough, runny nose, headache
tetracycline therapy
Mycoplasmal
pneumonia
Mycoplasma
pneumoniae
Mild pneumonia, often known as walking
pneumonia
Erythromycin
Tuberculosis Mycobacterium
tuberculosis
formation of tubercles, nodules on the lung tissue,
surrounded by layers of macrophages and T-
lymphocytes. When the lesions heal as calcified
bodies, they are called Ghon complexes. In some
individuals, the tubercles continue to grow, and the
lesion may rupture to release microorganisms into
the bloodstream for spread to other body organs.
This condition is called miliary tuberculosis.
isoniazid (INH), rifampin,
streptomycin, pyrazinamide,
ethambutol, and others.
BCG vaccine