[B] 1.13 Infectious agents/Bacteria, viruses and fungi as causes of disease

Question 1

Infection

Answer 1

Spreads from animal to animal through direct or indirect route

Question 2

Invasiveness

Answer 2

The pathogen is able to spread inside the organism

(But not all of them)

Question 3

Infectious pathogens: Examples

Answer 3

• Parasites
• Fungi
• Bacteria
• Viruses
• Prions

Question 4

Ectoparasites

Answer 4

Non-invasive, do not enter the organism

• Effect: Stress, weakening factor
• Vectors (may transfer other parasites/bacteria)

Question 5

Endoparasites (infectious) can be either…

Answer 5

• Multicellular
• Unicellular

Question 6

Multicellular endoparasites

Answer 6

Damage:

• Stress
• Weakening factor
• Tissue irritation
• Obturating effect
• Thromotisation
• Atrophy
• Autointoxication

Question 7

Unicellular endoparasites

Answer 7

• Intracellular (cell-damage e.g babesia)
• Extracellular (E.g toxoplasma → cytotoxic products)

Question 8

Fungal infections

Answer 8

• Mycotoxicosis
• Dermatomycosis
• Visceral mycosis

Question 9

Mycotoxicosis elicits…

Answer 9

No infection

Question 10

Dermatomycosis

Answer 10

• Superficial invasion: Skin, claw, hoof
• Loss of hair, irritation, stress

Question 11

Visceral mycosis

Answer 11

• Local inflammation
• Granuloma formation
• Thalus-formation
• Thrombotisation
• Metastasis

Question 12

Bacterial infections

Answer 12

Obligatory & Facultative pathogens

• IC bacteria
• EC bacteria
• Bacterial intoxications
• Enterosorption/Enterotoxaemia

Question 13

IC bacteria

Answer 13

• Chlamydophila
• Rickettsia
• Damage: ~virus

Question 14

EC bacteria

Answer 14

Exo- and endotoxins

• → Necrosis, inflammatory reaction

Question 15

Bacterial intoxication

Answer 15

No infection

E.g Botulism

Question 16

Enterosorption/Enterotoxaemia

Answer 16

1. Pathogen proliferated in the GI tract
2. Produces toxins → harmful effect

Question 17

Local bacterial infection

Answer 17

Pathogen enters body but doesn’t spread

• Wound infection
• Navel infection

Toxin production, local tissue destructive processes

Question 18

Systemic infections

Answer 18

Pathogen spreads in body

• Bacteraemia
• Pyaemia
• Septicaemia
• Sepsis
• Metastasis
• Bacterial thromboembolism

Question 19

Viruses cause loss…

Answer 19

Only after infection

Question 20

Obligatory intracellular pathogens

Answer 20

Modify the physiological metabolic processes of the infected cell

Question 21

Damage caused by viruses

Answer 21

• Cell destruction
• Inflammatory reaction
• Proliferative effect

Question 22

Prions

Answer 22

Cause losses after infection

• Modify cellualr metabolism
• Damage: Neuron degeneration; encephalosis

BSE