Hemophilus_influenzae.Hemophilus_influenzae.Hemophilus_influenzae.Hemophilus_influenzae.Hemophilus_influenzae.Hemophilus_influenzae.

1. Hemophilus influenzae
Dr Abid Hussain Chang
Associate.profesor

2. H. influenzae
H.Influenzae type b
is major cause of illness &
premature deaths in infants &
young children

3. Diseases
• Pyogenic Meningitis
in young children ( ie < 5 years)
• URTI, Pneumonia & Empyema
(mainly in adults)
• Acute Epiglotitis , Conunctivitis & Septic
arthritis

4. Important;
• Small, Non motile, Gram –ve, cocobacillus or
short rod
• Capsulated (polysacharide)—sero typing—6
serotypes
• type b – meningitis, sepsis.
• (heme & NAD)
• Most infections b/w ages of 6 mo to 6 yrs.( / IgG
• Only humans infected no animal reservoir
• IgA protease –degrades secretary IgA—
attachment to respiratory mucosa.

5. Important
• Enters body through,
upper resp tract then bacteremia &
spread.
• Six sero groups
a, b, c, d, e, f
• Meningitis mainly by sero group b

6. Important
• Best growth in carbon dioxide atmosphere
• Media used must contain,
Haemin/heme (iron containing porphyrin)
NAD (nicotinamide adenine dinucleotide)
used by organism to produce essential resp
enzymes ( cytochromes ,catalase,
peroxidase)

7. C/F;
• Meningitis;
.fever, hedache, neck stiffness & impaired
consciousness.
. Sinusitis/ Otitis media;
.pain, red, bulging tympanic memb
.Septic arthritis, cellulitis, sepsis.
• Epiglottitis ( inflammatory swelling of
epiglottis & neighbouring structures);
.fatal airway obstruction

8. Lab diagnosis
• Specimens: CSF, nasopharyngeal swabs blood
, pus, sputum
• Staining: Gram -ve cocobaillary rods
• Culture;
Organism grows on chocolate agar— mucoid
collonies
+Co2
. Quellung reaction
• Biochemical: not done routinely

9. Vaccine
• Containing capsular polysacharide of type
b
usually given B/w ages of 2-15 mo

10. H . Parainfluenzae
• Occasionally causes
resp infections, arthritis, conjunctivitis
.Do not require both
• Larger colonies on chocolate agar

11. H.ducreyi
• Causes chancroid & genital ulceration
• Transmitted sexually
• Requires haemin but not NAD
• Slow oxidase +ve

12. Bordetella pertusis
.A pathogen only for humans
•.Isolated by Bordet & Gengou in 1906
• causes,
pertusis
.Whooping cough
is a highly contagious esp prominent
disease of childhood
.Gram-ve aerobic coccobacilli
.arranged singly or in pairs
.B parapertusis causes mild disease

13. B. pertusis
.No growth on conventional media
.Growth requires enriched medium
.Selectively attaches to resp epith cells
decreased ciliary activity –death of cilia

14. Virulence factors
• Filamentous haemagglutinin; a protein
on pili mediates attachment to cilia
• Pertusis toxin; causes ADP ribosylation
also causes inhibition of entry of
lymphocytes into lymphoid tissue( spleen &
lymph nodes)
• also synthesizes adenylate cyclase which
can inhibit bactericidal activity of
phagocytes
• Tracheal cytotoxin + endotoxin induce
nitric oxide—kill ciliated epith cells

15. c/f; 3 sages-
• 1-Catarrhal stage:
• transmitted
• selectively attaches to resp epith cells
symptoms of URTI
• lasts for 1-2 wks
• 2-Paroxysmal stage-
. episodes of uncontrollable cough i.e 5-20 rapid
coughs+copious amounts of mucus
.Pt unable to breath even B/W cough
.A whooping sound
. lasts for 1-6 wks

16. c/f; 3 sages
• 3- Convalescent stage-may last for
several wks with some cough persisting
.Resp distress , 2ndary bacterial
pneumonia
.CNS also affected due to anoxia as a
result of severe coughing
.Restricted to resp tract
• 2nd attack is rare

17. Vaccine
• A killed vaccine
containing inactivated organism
is given in combination with tetanus &
diphtheria toxoids (DPT) as triple vaccine.
d/a
postvaccine Encephalopathy

18. Vaccine
• Acellular pertusis vaccine
Safer vaccine that do not react with brain
tissue.
Mainly inactivated pertusis toxin (toxoid) is
present.

19. Lab diagnosis
• Specimens; nasopharyngeal swabs
• Staining:
• Culture; Bordet-Gengou medium ( contains
high blood)
• Specific antisera- agglutination
• FAT
• PCR is highly selective & preferred
• Lymphocytosis is marked

20. THANKS