5. An electron micrograph of spores fromAn electron micrograph of spores from
the Sterne strain ofthe Sterne strain of Bacillus anthracisBacillus anthracis
6. Bacillus anthracisBacillus anthracis McFaydean capsuleMcFaydean capsule
stain, grown at 35stain, grown at 35oo
C, in defibrinatedC, in defibrinated
horse blood.horse blood.
7. DISEASE:
• In Animals: >> Septicaemia.
• In Humans:
i. Cutaneous Anthrax > Malignant pustule
ii. Pulmonary Anthrax (Wool-Sorter'sDisease).
iii. Gastrointestinal Anthrax.
9. Anthrax lesion on the skin of theAnthrax lesion on the skin of the
forearm caused byforearm caused by Bacillus anthracisBacillus anthracis
10. PATHOGENESIS
• Capsule > Invasiveness
– D-glutamic acid
• Exotoxin (Plasmid mediated)
i. Protective Factor (Antigen).
ii. Oedema Factor.
iii. Lethal Factor.
Blocks the Adenyl Cyclase Pathway >
Increases vascular Permeability > Shock
11. LABORATORY DIAGNOSIS:
• Specimens obtained from:
a malignant pustule, sputum, blood.
- Gram stain + fluorescent-antibody stain.
- Motility
- Capsule formation: Sodium bicarbonate
+CO2
- String-of-pearls reaction:
- Mouse test:
- API
>> Demonstration of Abs to the organism:
12. Bicarbonate agar and blood agarBicarbonate agar and blood agar
plate cultures ofplate cultures of Bacillus anthracisBacillus anthracis
13. Negative encapsulation: Blood agar andNegative encapsulation: Blood agar and
bicarbonate agar plate cultures ofbicarbonate agar plate cultures of
Bacillus cereusBacillus cereus
14. • TREATMENT
– Penicillin, Ciprofloxacin
• IMMUNIZATION
–Animals > Live spore vaccine
(Sterne strain)
–Workers at Risk of Exposure >
Anthrax Vaccine Absorbed (AVA) >>
“Alum precipitated toxoid”
15. ii.ii. Bacillus cereusBacillus cereus
• Food Poisoning.
• Clinical Syndromes:
i. Severe Nausea &Vomiting.
ii. Abdominal Cramps & Diarrhoea.
16. PATHOGENICITY:
>> Due to an Enterotoxin.
• Also Causes Disease in Patients with
Underlying Disease.
• TREATMENT:
>> Tetracycline, Erythromycin.
• iii. B. subtilis:
• iv. B. stearothermophilus.
25. LABORATORY IDENTIFICATION
• In Chopped Meat - Glucose Medium:
• On BA:
• On Egg Yolk Agar:
>> Precipitation (Opalescence).
• Milk Media: Stormy Formation.
• Nagler Reacrion:
26. Blood agar plate withBlood agar plate with Cl. perfringensCl. perfringens
characteristic double zone of hemolysischaracteristic double zone of hemolysis
27. PATHOGENICITY & CLINICAL INFECTION
α-Toxin: Acts on Lecithin-Containing Lipo-
protein Complexes in the Cell Membrane.
• Predisposing Factors:
i. Trauma with Deep and Lacerated or Crush
Wounds of Muscle Etc.
ii. Require a Reduced Oxygen Tension and
Reduced Oxidation Reduction Potential
for Growth.
28. FOOD POISONING:
• Cl. perfringens Type A >> Enterotoxin.
> Acute Abdominal Pain and Diarrhoea.
29. LABORATORY DIAGNOSIS:
• Important: Diagnosis of Clostridium
Myonecrosis Should Be Rapid and Made on
Clinical Grounds.
i. Direct Smear and Gram Stain of Material
from Deep Within the Wound.
ii. Culture:
Tissue Aspirates or Deep Swabs Taken
from Affected Muscle.
30. TREATMENT:
• Clostridium Myonecrosis:
i. Surgical Removal of All Infected and
Necrotic Tissue.
ii. Antibiotic and Antitoxin Therapy.
iii. Adminstration of Hyperbaric Oxygen.
• Food Poisoning:
31. Clostridia That May Be Associated
with Gas Gangrene:
• Cl. perfringens Type A
• Cl. septicum
• Cl. novyi Type A
• Cl. histolyticum
• Cl. Sordellii
32. Human case of malignant edemaHuman case of malignant edema
caused bycaused by Cl. septicumCl. septicum
36. VIRULENCE FACTORS:
• Tetanus Toxin (Tetanospasmin) >
Neurotoxin.
i. An Intercellular Toxin Released by
Cellular Autolysis.
ii. Inhibits the Release of Inhibitory
Transmitters.
iii. Toxoid.
37. CLINICAL INFECTION & PATHOGENESIS
• "Tetanus is Generalized in Nature".
i. Unimmunized Rural Population.
ii. In Practice: Simple Puncture Wounds >
Nail, Splinter or Thorn.
iii. In Traumatic Wounds > Compound
Fractures, Dental Extractions, Etc.
iv. Tetanus Neonatrum:
v. Postoperative Tetanus:
38. Drawing of a Soldier dying ofDrawing of a Soldier dying of
Tetanus (Opisthotonos)Tetanus (Opisthotonos)
39. A patient presented with facial tetany.A patient presented with facial tetany.
Note the contraction of the masseter andNote the contraction of the masseter and
neck musclesneck muscles
40. LABORATORY DIAGNOSIS:
• > Diagnosis on Clinical Grounds.
TREATMENT:
• i. Antitoxin.
• ii. Debridement of Wound and Removal of
• any Foreign Bodies.
• iii. Pencillin >>> In Large Doses.
• iv. Mild Tetanospasm: >>> Barbiturates.
• v. Severe Cases:
• >>> Use Curare - Like Agents.
• >>> Tracheostomy.
• >>> Careful Control of the Environment.
43. Gram Stain ofGram Stain of Cl. botulinumCl. botulinum,,
Characteristic Long RodsCharacteristic Long Rods
44. A photomicrograph ofA photomicrograph of
Clostridium botulinumClostridium botulinum type Atype A
45. Blood Agar Plate withBlood Agar Plate with C. botulinumC. botulinum
46. VIRULENCE FACTORS
• Botulinum Toxin >>> Neurotoxin.
–Serologically 8 Toxins >>
A, B, C1, C2, D, E, F & G.
> Affect the Cholinergic System > Blocks
the Release of Acetylcholine (at Points
in Peripheral Nervous System).
47. DISEASE IN HUMANS
1. Food - Borne Botulism:
> Incubation Period: 12-36 Hours to 8 days.
2. Infant Botulism:
LABORATORY DIAGNOSIS
i. Diagnosis Made Clinically.
ii. Detection of Organism or Its Toxin in the
Suspected Food
iii. Samples of Stool or Vomit
48. TREATMENT & PREVENTION
Important: Specific Treatment Should
Begin as Quick as Possible.
>Polyvalent Antitoxin >>> Immediately.
>Physiological Support >>> ICU.
>NEVER Use a Swollen or Defective Can.
49. iv.iv. Clostridium difficileClostridium difficile
• Antibiotic Associated Colitis.
• Produce Two Major Protein Toxins
(A &B).
• Risk Factors:
–Antibiotic Exposure.
–Old Age.
52. Intestinal Smear- Close AssociationIntestinal Smear- Close Association
ofof Cl. difficileCl. difficile with Neutrophilswith Neutrophils
53. • Infection Can Be:
–Endogenous or Exogenous.
• Nosocomial Spread: Due to Spores.
LAB DIAGNOSIS:
1. Demonstration of Cytotoxin in Stool.
2. Isolation of the Microorganism.
TREATMENT:
–Discontinuing Treatment.
–Vancomycin.