GENUS: CORYNEBACTERIUM

1
??? ???? ?????? ??????

• GENUS CORYNEBACTERIUM
• Prof. Khalifa Sifaw Ghenghesh

2

• Diptheroides Coryneforms
• Gram ve,
• Nonmotile Rods.
• Arranged in V forms or Palisades
• Catalase ve

3
1. Corynebacterium diphtheriae

• Diphtheria.
• Pleomorphic Bacilli
• Cells Contain Metachromatic Granules.

Morphology
4
Corynebacterium diphtheriaeClub-shaped,
Gram-positive rods
5
Cultural Characteristics

• i. Loeffler's Serum Slope.
• ii. Tellurite BA.
• - Temp. 37oC,
• - Aerobic and Facultative AnO2.

6
Corynebacterium diphtheriae forms black colonies
on tellurit agar (left), on blood agar colonies
appear white (right)
7
PATHOGENICITY

• Diphtheria is a Toxaemia.
• Exotoxin M. wt 62000
• 2 Fragaments gtgt A B
• Inhibits Protein Synthesis.
• Has Special Affinity for Certain Tissues
  "Mycocardium, Adrenals, Nerve Endings".
• Toxin gtgt Toxoid.
• Site of Infection gtgt Faucial.
• Toxin gtgt Pseudomemebrane.

8
LABORATORY DIAGNOSIS

• Important gtgt Specific Treatment Should Be Started
  Immediately on Suspicion of Diphtheria.
• Specimen Two Swabs from the Lesion.
• Culture
• i. Loeffler's Serum Slope gtgt Albert Stain.
• ii. Tellurite BA.
• iii. BA gtgt Streptococcal or Staphylococcal
  Pharyngitis.

9
PATHOGENICITY TESTS

• In-vivo Tests
• i. Subcutaneous Test
• ii. Intracutaneuos Test
• In-vitro Test
• Elek Test ( Gel Precipitaion Test).
• Tissue Culture

10
TREATMENT

• i. Antitoxin gt Moderate Cases
• gt Severe Cases
• ii. Antibiotic
• i. Active Immunization gtgt PDT.
• ii. Passive Immunization
• iii. Combined

PREVENTION
11
SCHICK TEST

• gt Injection of 0.2 ml of Diphtheria Toxin
  Intradermally.
• gt Positive Reaction gtgt Erythema Swelling

12
SCHICK TEST

• __________________________________________________
  ____________________
• Result Test Arm Control Arm Interpretation
  Diphthri (Toxin) Inactivated Toxin
  Immunization
• 36h 120h 36h 120h
• __________________________________________________
  ____________________
• Negative -- -- -- -- Immune, Not
• Not Hypersensitive Required
• --------------------------------------------------
  --------------------------------------
• Positive -- -- Not Immune, Not
  Required
• Hypersensitive
• --------------------------------------------------
  --------------------------------------------------
  -----------------
• Negative -- -- Immune Not
• Hypersensitive Required
• --------------------------------------------------
  --------------------------------------------------
  -----------------
• Positive -- Not Immune Contra-
• Pseudo Hypersensitive indicated
• __________________________________________________
  ____________________

13
??? ???? ?????? ??????

• Listeria monocytogenes

14

• Listerosis.
• Gve Coccobacilli gt in Short Chains.
• Motile at 25oC But Not at 37oC.
• Aerobic to Microaerophilic.
• On BA gt Narrow Zone of b-Haemolysis.
• Listerolysin O gt

15
DISEASE

• Incidence and Transmission gt
• i. In Adults
• ii. Neonatal Infections
• a. Early Type
• b. Late Type

16
LABORATORY DIAGNOSIS

• i. Specimen Depend on Syndrome Blood,
  CSF, Genital Tract Secretions.
• ii. Media Selective Media.
• Penicillin, Ampicillin.

TREATMENT