This document provides information about the bacterium Haemophilus influenzae. It discusses the history of H. influenzae, identifying it was first isolated in 1890. It is a gram-negative coccobacillus that requires both a heme (X) factor and NAD (V) factors to grow. H. influenzae can cause systemic infections like meningitis in young children and is transmitted through respiratory droplets. Biochemical tests and serology can be used to identify and type H. influenzae. Vaccines are available to protect against H. influenzae type b, an encapsulated strain that commonly caused meningitis.

1. Sharq Elneil College
School of Medical Laboratory Sciences
Department of Microbiology
Medical Bacteriology course
Haemophillus
Mr.Mahadi Hassan Mahmoud
Bsc, Msc, MIBMS Microbiology

2. History
 Hib was found in a
group of patients
during an
influenza
outbreak in 1892

 Haemophilus
influenzae was
first isolated in
1890 by Richard
Pfeiffer

3. Medically important spp
q H. Influenzae q H.aegyptius (Koch.
q H.ducreyi q Weeks)
q H. haemolyticus. q H.Para Influenze
q H. phrophilus q H.para haemalyticus
q H.segnis q H.araphrophitus
 q
q

4. Morphology
Haemophilus influenzae is :
v a pleomorphic gram-negative coccobacillus.
v H.influenzae may be either encapsulated
(typeable) or unencapsulated
(nontypeable).
v There are six encapsulated serotypes
(designated a–f) that have distinct capsular
polysaccharides.


5. General properties
v Extracellular pathogen, does not
invade into cells
v Fastidious
vThismeans it is difficult to grow
vWe must give it lots of growth factors
vHaemophilus = blood loving
vHowever, this organism can not grow
on blood agar alone!
vRequires X factor (hematin)
vRequires V factors (NAD)
v

6. Culture:
Chocolate agar + CO2
Blood culture bottles

7. Blood agar plate culture of Haemophilus
influenzae

8. X and V factor:
 X factor is used by H. influenzae to produce essential
respiratory enzyme such as cyto chrome – catalase
and peroxidase.
 V Factor is used as electorn carriers in the organism
oxidation reduction system live culture on
chocolate (heated blood agar at 75Co - for few
minute).
 For extra V factor released from RBES on chocolate
agar after. Over night. Incubation, H. influenzae
strain produce mucoid colonies.


10. Species Growth Factor
Required
-------------------------------------
---
H. influenzae X+V
H. parainfluenzae V
H. ophrophilus X
H. ducreyi X
-------------------------------------
---

11. Satellitism
 satellitism test when we streak
staphaureus (produce V factor)
across the surface of on inoculated
blood agar plate.
 The colonies are largest nearest to
the staphylo cocous aureus column
of growth than those furthest from
it.


12. Satellitism

13. Levinthal agar (heated)
 The use of transparent media such as
levinthal agar (heated) or fildes agar
(Peptic digestion) after 24h at 37C
 colonies are fishy, seminal smell the
colonies of capsulate strain are larger
high convex in shape and mucoid and
we show ividencence consisting of
Red-orange – green blue shade which
alter with angle of observation.


14. H. influenzae typing
 H. influenzae can be divided into eight biotypes
on the basis of three biochemical test (indole
production – urease activity and ornithine de
carboxylase)
 this bio typing system is of limited use for
epidemiological studies
 the majority clinical isolate are distributed
between three bio type (I, II, III) invasive
type b strains are of biotype, I.


15. VIRULENCE FACTORS
i. Capsule:
ii. Outer membrane
components:OMP & LOS
iii. Adherence:
iv. IgA proteases:

16. Virulence Factors
v Fimbriae for attachment to respiratory tract
cells
v Capsule is produced to prevent phagocytosis
v Endotoxin which is part of ALL Gram-
negative cells
vHelps respiratory tract colonization by blocking
cilia clearance
vInduces inflammation at site of infection
v Causes disease by simply being in the
environment and sparking inflammation
through endotoxin
v

17. Transmission:
 Transmission occurs through direct
contact with respiratory droplets
from nasopharyngeal carrier or
case patient.
 Neonates can acquire infection by
aspiration of amniotic fluid or
contact with genital tract
secretions containing the bacteria.


18. Pathogencity of Haemophilus
 Is divided to capsulate and Non capsulate
 Capsulated strains could be differentiated
serological into 6.type labeled (a – F).
 The most serious strain is type b which
cause:
 Pyogenic (purulent) meningitis in young
children (2 month to 3 years) olds

19.  Acute epiglotitis (group) (2 – 7 years ols)
 Cellulitis – pyogemic ar thritis, osteitis)
conjunctivitis, middle ear infections, and
pneumonia.
 On Capsulated H. Influenzae strains are
associated with less severe but often persistent
infections such as
I. purulent exacerbations of chronic bron chitis
(Mainly in adult),
II. conductivities middle ear infection
III. paranasal sinusitis Non capsulated of H.
Influnzae and some other species form.


20. Haemophilus influenzae
v Systemic infections (meningitis)
v Caused by encapsulated strains
v Prior to the development of the new
conjugate vaccines, 1 in 200 children got the
disease
v 65% of cases were in kids <1 year
v 90% fatal untreated; 10% mortality treated
v 33% long-term neurological defects possible
even if properly treated
v

21. v Pathogenesis
vSpread via respiratory droplets
vEnters upper respiratory tract and throat
and attaches to cells using fimbriae
vEndotoxin stops respiratory tract cilia
from beating and clearing the bacterial
cells
vLocal spread (ears, sinuses, lungs)
vSystemic spread (blood and brain)
vEndotoxin and inflammation do the
damage

22. Biochemicals
tests to differentiate between species by
the production of:
 β haemolysis on blood agar (H.
haemolyticus
 Fermentation reactions to glucose with
acid production (sucrose, Xylose lactose
and mannose)


23. Serology
H. influenzae can be identification
in culture and specimen by
agglutination technique
 coagglutination – Latex
agglutination
 counter current immuno electro
phoresis (C/E

24. Antibiogram
H. Influenzae is sensitive for
 Chloramphenicol
 Ampicillin
 Tetracycline
 Erythromycin
 Contrimoxazole
Resistant to: Penicillin.

25. Haemophilus aegypticus (koch –
weeks bacillus)
 It grow more slowly than H.
influenzae
 Not ferment D-xylose
 It required X and V factor.
 It is sensitive to Troleandomycin.
 It is stronger haemo agglutinating
activity with human red blood cell
in tile test at 4Co.

26. Haemophilus Haemolyticus:
 It is forming zones of B-haemolysis around colonies
on blood agar.
 It required X2 V factor
Haemophilus Paro-Influenza:
 It required only V factor
 It ferment sucrose.
Haemophilus Parahaemolyticus:
 It required only V factor
 It do B-haemolysis

27. H. Aphrophilus:
 It required X factor only.
 It required extra CO2 for growth.
H.Segnis:
 It required V factor only.
 Grow very slowly.
H.ducreyi
 It required only X factor
 Not Ferment Xylose, sucrose.


28. Vaccine
 three monovalent conjugate Hib vaccines
and three combination vaccines that
contain Hib conjugate are available. An
infant primary series (2, 4, and 6 months
of age or 2 and 4 months of age,
depending on the vaccine type used) and
a booster dose at 12 through 15 months
of age is recommended

29. THANK YOU FOR ATTENTION