1. 4.8 HAEMOPHILUS

2. Scientific classification
Domain:Bacteria Kingdom:Eubacteria Phylum:Proteobacteria Class:Gammaproteobacteria Order:Pasteurellales Family:Pasteurellaceae Genus:Haemophilus Species:H. influenzae

3. Medical important species
Haemophilus influenzae
Haemophilus aegyptius
Haemophilus ducreyi

4. Normal habitat
H.influenzae (mostly non-capsulated strains), H. parainfluenzae and H.aegyptius is normal flora of the upper respiratory tract
Infections causing:
Pyogenic meningitis
Acute epiglottitis
Cellulitis, middle ear infection,etc

5. conjuctivitis

6. Laboratory diagnosis

7. Microscopy Small, non-motile, Gram negative rods or coccobacili
Long thread-like form in old csf culture

8. Microscopic observation

9. Culture of H.influenzae
H.influenzae grows better in aerobically compare to anaerobically
The optimum temperature for growth 35 – 37oC
The are X and V factor
Both represent in blood agar and permit the culture to grow
H.influenzae and H.aegyptius need X and V factor, H. parainfluenzae need V factor and H.ducreyi need X factor

11. Biochemical tests Not usually used to identify hemophilus
6 biovars of H.influenzae are recognized based on the indole, urease and ornithine decarboxylase (ODC) reactions of the diff strains

12. Serology Consist of 1 – f serotypes
Mostly causing meningitis belong to serogroup b
Most strains that cause chronic bronchial disease are non-capsulated
Antimicrobial sensitivity
Resistant towards chloramphenicol, ampicilin, tetracycline, erythromycin and cotrimoxazole
H. ducreyi is sensitive to sulphonamides
Ampicillin resistant are common

13. 4.9 STAPHYLOCOCCUS & STREPTOCOCCUS

14. Staphylococcus Staphylococcus aureus Staphylococcus epidermidis
Staphylococcus saprophyticus

15. Scientific classification
Kingdom:Bacteria Phylum:Firmicutes Class:Bacilli Order:Bacillales Family:Staphylococcaceae Genus:Staphylococcus

16. Introduction
Are microbial flora of the skin, upper respiratory tract and intestinal tract
S.aureus usually cause abscesses, boils, conjuctivitis, pneumonia, septicemia, food poisoning and scalded skin syndrome
S. epidermidis causing bactericaemia
S. saprophyticus causing cystitis and acute urethritis

17. Laboratory diagnosis Microscopy Non-motile Non capsulate
Gram positive cocci
Arrangement single or in pair
Size 1 µm diameter

19. Culture Grow well in aerobically and also in present of carbon dioxide
Temperature between 10 – 420C, optimum temperature are between C

20. S.aureus
Produce yellow to cream in blood and chocolate agar (heated agar)
Occationally produce white 1-2 mm in diameter colonies
Some strain produce beta-hemolytic when grown aerobically
Colonies are slightly raised and easily emulsified on a slide
Non- lactose fermenter in MacConkey agar
Mannitol salt agar is a useful differential and selective agar to identify S.aureus

21. On blood agar

22. S.epidermidis S. saprophyticus Colony is white
Non hemolytic in blood agar
Maybe white or yellow
There are non-hemolytic in BA
Not grow anaerobically
No growth in MacConkey agar
S. saprophyticus

23. Biochemical reactions
S.aureus
DNAse test will be positive for S.aureus but negative in other species
Catalase test will be positive in all staphylococcus but negative in all streptococcus
S. epidermidis and S. saprophyticus
Coagulase negative
DNAse negative
Catalase positive

24. Antimicrobial sensitivity
Erythromycin
Clindamysin
Fucidin
Vancomycin
Many strains of S.aureus are penicillin-resistant
S.epidermidis are more resistant than S.aureus to antibiotics
S. saprophyticus less resistant to antibiotics than S.aureus and S.epidermidis

25. Streptococcus sp.

26. Streptococcus Streptococcus pyogenes Streptococcus agalactiae
Enterococci

27. Lecture content Basic characteristics Classification
Grouping of species
Pathogenesis
Lab diagnosis

28. Scientific classification
Kingdom – Bacteria
Phylum - Firmicutes
Class – Bacili
Order – Lactobacillales
Family – Streptococcaceae
Genus - Streptococcus
Species – 22 sp.

29. Basic characteristics
Gram-positive
Lactic acid bacteria group
Spherical
Grow in chain (twisted) or pairs
Mostly are facultative anaerobes

30. Habitat Available in food such as Emmentaler (Swiss) cheese
Normal flora of the mouth, skin, intestine and upper respiratory tract of humans

32. Classification Beta hemolysis Alpha hemolysis Lancerfield serotyping
Based on carbohydrates in the bacterial cell wall
Beta hemolysis
Viridans groups
S.pneumoniae separated group
Alpha hemolysis

33. Alpha hemolysis Surrounded by an area of partial haemolysis
Green-brown colour (reduced haemoglobin)
Consist of pneumococci and viridans group( alpha hemolytic and no Lancerfield antigens

34. Pathogenicity

35. Pathogenicity S.pyogenes (Group A) Acute sore throat Scarlet fever
Ear infections
Peurperal sepsis
Septicemia and occasionally endocarditis
Skin infection such as celulitis and impetigo

36. Post-streptococcal disease
From the implication of pathogenesis, it will leads to a serious stage of diseases:
Acute glomerulonephritis
Rheumatic fever

37. Enzymes & toxin production
By S. pyogenes
Streptolysin O
Streptolysin S
Streptokinase (cause fibrinolysis)
Hyarulonidase
DNAses
DPNAse
Erythrogenic toxin

38. Other species S.Agalactiae (Group B)
Neonatal septicaemia, pneumoniae, meningitis
Septic abortion and peurperal sepsis
Enterococci (Group D)
Urinary tract infection
Infections of ulcer and wounds
Endocarditis and meningitis
Viridans
Endocarditis
Dental caries
Brain abscess

39. Laboratory diagnosis

40. Microscopy Gram positive (purple) Non-motile Long chains
Sometimes in pair

41. Culture Aerobically and anaerobically Temperature between (22 – 42o C)
And enterococci are between (15 – 45o C)
On BA, colony usually less than 1 mm in diameter
Grey – white or colourless
Dry / shiny, irregular outline
Most of the pathogenic streptococcus producing hemolysins

42. S. pyogenes Produce beta hemolysis
Sensitive to bacitracin (can’t rely 100% to it, coz not only group A sensitive to it) but for viridans it is resistance towards bacitracin
A selective BA containing crystal violet was suggested
Does not grow in MacConkey agar

43. S.agalactiae Optochin resistant but S.pneumoniae is sensitive
Beta hemolysis in BA
In serum starch agar, it produces orange pigment

44. Biochemical test Species Catalase Bacitracin Optochin Litmus Milk CAMP
S.pyogenes - +
S. agalactiae
Enterococci
Viridans streptococci
Pneumococci