Haemophilus influenzae.ppt................

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1. Haemophilus influenzaeHaemophilus influenzae

2. 
The genus haemophilus organisms are The genus haemophilus organisms are
small gram negative cocco-bacilli. small gram negative cocco-bacilli.

The commonest is Haemophilus The commonest is Haemophilus
influenzae.influenzae.

The other species of the genus are.The other species of the genus are.
1. H. ducreyi1. H. ducreyi
2. H. parainfleunziae2. H. parainfleunziae
3. H. aegyptius3. H. aegyptius

3. PropertiesProperties::

It is a gram negative rod ( coccobacillus).It is a gram negative rod ( coccobacillus).

A facultative anaerobe which grows best in A facultative anaerobe which grows best in
media enriched with comedia enriched with co
22..

Temperature requirements 32-37 Temperature requirements 32-37
00
C.C.

Has got a polysaccharide capsule.Has got a polysaccharide capsule.

Non capsulated forms also exist.Non capsulated forms also exist.

On the basis of type of capsule there are six On the basis of type of capsule there are six
serotypes numbered as a,b,c,d,e and f.serotypes numbered as a,b,c,d,e and f.

4. Haemophilus influenzae (electron micrograph) showing thick capsules..

5. Haemophilus influenzae—Gram stain

6. 
Serotype b is most virulent typeSerotype b is most virulent type

Organism found only in humans.Organism found only in humans.

PathogenecityPathogenecity::

Enters the body through respiratory tract Enters the body through respiratory tract
(through respiratory droplets)(through respiratory droplets)

Shows two types of behaviors.Shows two types of behaviors.
11. . Asymptomatic colonizationAsymptomatic colonization
2. Infections such as sinusitis, otitis media 2. Infections such as sinusitis, otitis media
or pneumonia.or pneumonia.

7. 
Organism produces IgA protease whichOrganism produces IgA protease which
neutralizes respiratory mucosal IgA.neutralizes respiratory mucosal IgA.

This helps in its attachment to This helps in its attachment to
respiratory mucosa.respiratory mucosa.

After attachment to respiratory mucosa it After attachment to respiratory mucosa it
can enter blood stream and cause can enter blood stream and cause
bacteremia and meningitis.bacteremia and meningitis.

8. 
95% of encapsulated forms 95% of encapsulated forms
(type b) responsible for these diseases.(type b) responsible for these diseases.

Non capsulated forms are responsible for Non capsulated forms are responsible for
otitis media, sinusitis and pneumonia.otitis media, sinusitis and pneumonia.

In children the age group 6 months -6 In children the age group 6 months -6
years is most prone to the infections years is most prone to the infections
caused by the organism.caused by the organism.

Virulence factors are polysaccharide Virulence factors are polysaccharide
capsule and endotoxin.capsule and endotoxin.

9. 
DiseasesDiseases::
1.Meningitis.1.Meningitis.

Commonest cause of meningitis in infants Commonest cause of meningitis in infants
and young children.and young children.
2.Otitis media and sinusitis.2.Otitis media and sinusitis.
3. Septic arthritis, cellulitis, and sepsis.3. Septic arthritis, cellulitis, and sepsis.
4. 4. Rarely, epiglottitis (which can obstruct
the airway) occurs.

10. 5.Pneumonia in elderly 5.Pneumonia in elderly
specially those with specially those with
chronic respiratory chronic respiratory
disease ( Untypeable disease ( Untypeable
strains).strains).
6. Conjunctivitis6. Conjunctivitis

11. 
Lab diagnosisLab diagnosis::

Gram stainingGram staining

Organism is grown on chocolate agar.Organism is grown on chocolate agar.

Chocolate agar is enriched with two Chocolate agar is enriched with two
factors.factors.
1. Factor X (hemin, derived from 1. Factor X (hemin, derived from
hemoglobin)hemoglobin)
2. Factor V (NAD), 2. Factor V (NAD), Nicotinamide adenine
dinucleotide.

12. 
Other species do not require both factorsOther species do not require both factors
The colonies will be greyish-white, small The colonies will be greyish-white, small
and mucoid. and mucoid.

Definitive diagnosis can be made with Definitive diagnosis can be made with
Quellung testQuellung test

14. 
TreatmentTreatment::

Ceftriaxone is drug of choice in Ceftriaxone is drug of choice in
meningitis and other serious infectionsmeningitis and other serious infections

Otitis media and sinusitis are treated with Otitis media and sinusitis are treated with
co-amoxiclav.co-amoxiclav.

PreventionPrevention::

It is by vacination.It is by vacination.

The vaccine given is called HibThe vaccine given is called Hib

It is in conjugated form. Conjugated with It is in conjugated form. Conjugated with
a carrier protein.a carrier protein.

15. 
Given in between 2-15 months.Given in between 2-15 months.

Conjugated is more effective than un- Conjugated is more effective than un-
conjugated one.conjugated one.

Rifampicin is given prophylactically in Rifampicin is given prophylactically in
close contactsclose contacts