1. Hemophilus & Gardernella
Dr. Kanwal Deep Singh Lyall
M.D. Microbiology

2. Haemophilus
• Blood loving
• Catalase & oxidase positive
• 8 biotypes
• GNB, NM, non-sporing, require X/V or both
• Pfieffer – isolated – thought as causative agent
of influenza – hence named it influenzae
• Discovery of influenza virus – renamed

3. Haemophilus influenzae
• Delicate pleomorphic GNB
• GNCB in young cultures & in sputum
• Long filamentous bacilli in old cultures & CSF
• Culture: BA + S. aureus /CA/Leninthal’s/Field’s
• X – factor – haemin – heat stable protoporphyrin
IX or iron containg porphyrin- required for
synthesis of catalase, cytochrome oxidase &
Cytochrome C – enzymes required for respiration
• V – factor – (inside RBC) – Heat labile – NAD or
NADP – acts as hydrogen receptor

4. Species & their requirements
All PARA require only V , HAIN – both X & V,
DAP – Only X

5. Satellitism
• BA – only X is available – V inside RBCs – hence
small colonies
• S. aureus streak – provides V – large colonies
near the streak and smaller as we move farther
S. aureus
H. influenzae

6. Antigenic sturcture
• May be capsulated (virulent) or non-
capsulated
• Pitman divided H. influenzae in to 6 serotypes
– a to f
• Hib is the most invasive – capsule is polyribisyl
ribitol phosphate – induces protective
antibodies – hence used in vaccines
• Variation S to R (Virulent to non-virulent)

7. Virulence factors (COPI)
• Capsular polysaccharide – protects from
opsonization
• Pilli (fimbriae) – adhesion to Ep. Cells
• OMP – outer membrane proteins – adhesion
& invasion
• IgA1 proteases – cleave IgA

8. Pathogenesis
• Obligate human pathogens
• Droplets enter via resp. route
• m/c Hib
• Meningitis: 2 m – 2yrs, 90% untreated will die
• A. epiglottitis: > 2yrs, obstructive laryngeal
edema, always associated with bacteremia
• Bronchitis – acute exacerbations

9. Lab diagnosis
• Sample: CSF, blood, sputum, aspirate
• Never refrigerate sample – org dies @ low t°
• Direct microscopy: Gram stain – pleomorphic
GNCB, IF & Quellung reaction
• Antigen detection: LAT, Coagllutination, CIE
• Culture: CA or BA with S. aureus @ 37° C x 24
hrs + 5-10% CO2
• Satellitism, colony morphology, gram stain &
serotyping

10. Treatment & prophylaxis
• CTX or CTZ, AC etc.
• Hib vaccine: 6 wks - 10 wks – 14wks &
booster @ 12 – 18 months
• Rifampicin is given to contacts & carriers

11. H. aegypticus
• First observed by Koch in Egypt & 1st isolated
by Weeks in New York
• Hence Koch-Weeks bacillus
• Pink eye – highly contagious conjunctivitis
• Brazilian purpuric fever

12. H. ducreyi
• STD – Chancroid or soft sore
• Bipolar staining – gncb
• IN groups or parallel rows – school of fish, rail
road, tram line appearance
• Culture: requires X only – rabbit BA, fresh clotted
blood, CA with 1% Iso-Vitalex @ 35° C
• CAM of chick embryo
• Biochemicaly inert but reduces Nitrate
• Presence of cells with up-regulated HIV-1 co-
receptors
• Facilitates HIV transmission

14. Pathogenicity
• Chancroid or soft sore
• Highly contagious – tender non-indurated
irregluar ulcers on genitalia
• Enlarged, painful LAP
• Bubo – inguinal abscess
• Lab Dx: scrapings, aspirates – G/S – culture on
BA + Isovitalex @ 35° Cx 2 – 8 days – small,
grey colonies – agglutination
• Treatment: Cotri, ERY, CTX, CIP

15. • H. parainfluenzae: only V – pharyngitis, SABE,
Urethritis
• H. haemolyticus: both X & V, β-H’tic –
mistaken for β-HS. Similar strains requiring
only V are called parahaemolyticus.
• H. aphrophilus: X only – endocarditis, abscess,
pneumonia, require high CO2. Similar strains
requiring only V are called paraphrophilus

16. HACEK group bacteria
• Oral flora – severe endocarditis
• Haemophilus spp. (parainfluenzae, aprophilus
& paraaphrophilus)
• Actinobacillus actinomycetemcomitans
• Cardiobacterium hominis
• Eikenella corrodens
• Kingella kingae
• Take 7 – 30 days to grow, drug resistant

17. Gardnerella vaginalis
• May be normal flora in vagina & male
urethra
• GNB, NM
• Culture: BA / CA X 48 hrs – β-H’tic colonies
• Catalase – ve , oxidase – ve
• Pathogenicity: non-specific vaginitis &
cervicitis (along with anaerobic bacteria)

18. • Fishy odour – due to amines - intensifies
when mixed with KOH – amine test
• G/S – clue cells (Gardner & Duke’s cells)
• Treatment - Metronidazole

19. X