[A] 1.15 Spread of the pathological processes in the organism. Septicaemia, sepsis, bacteriaemia

Question 1

Infectious agents are found…

Answer 1

Spreading among animals and within the animal

Question 2

List the types of infectious agent

Answer 2

• Prion
• Virus
• Bacteria
• Chlamydia, Mycoplasma
• Fungi
• Protozoa
• Helminths
• Ectoparasites

Question 3

Infection

Answer 3

Entry ⇔ Shed of pathogen

• Can be horizontal/vertical
• Pathogen: Fights defensive mechanisms

Question 4

List the defensive mechanisms of the body that pathogens must overcome

Answer 4

• Physical barrier (skin)
• Innate immunity
  
  • PRRs (Toll-like receptors)
  • PAMPs
  • Phagocytes
  • NK cells
• Adaptive immunity
  
  • Faster/more effective response when needed
  • T- & B-Lymphocytes

Question 5

Give some brief defensive properties of the skin

Answer 5

• Cornifying squamous epithelium
• Thick keratin
• Low pH (5)
• Fatty acids (Ω3, Ω6)

Question 6

Transcutaneous infection occurs via…

Answer 6

• Intact skin:
  
  • Dermatophytosis (ringworm)(fungal)
  • Malassezia (fungal)
• Through lesions: Papilloma, rabies, tetanus
• Arbo-: Babesiosis, Lyme disease, infectious anaemia, West Nile Virus

Question 7

Give some brief defensive properties of the GI tract

Answer 7

• Gastric acidity (pH 1-2)
• Viscous mucus
• Digestive enzymes, detergents in the bile
• Defensins
• Normal intestinal flora
• Secreted IgA antibodies (MALT)

Question 8

Infection to the GI tract

Answer 8

• Per os / Oral(is) infection
• Virus
• Bacteria (Only toxins)
  
  • E. coli
• Fungi
• Parasites
  
  • Larva migrans visceralis

Question 9

Give the predisposing factors to GI tract infection

Answer 9

• Higher pH in the stomach
• Dysbacteriosis: → antibiotics
  
  • Horse: Linkomycin, tetracycline: Colitis-X, clostridial overgrowth
• ↓ Peristalsis, congestion
• ↓ Digestive enzymes
• ↓ Bile production
• Immunosuppression

Question 10

Microbiome

Answer 10

Commensalism, symbiotic and pathogen microorganisms

• Analysed by NGS methods (Next-generation sequencing)
• Involved in defence against:
  
  • Autoimmune disease
  • Muscle atrophy
  • Depression
  • Bipolar disorders

Question 11

Give some brief defensive properties of the respiratory tract

Answer 11

• Nasal cavity - Most inspired particles trapped here
• Mucociliary defence towards the pharynx
• Particles <5μm reach alveoli
• Phagocytes; IgA; neutrophils, B- & T-lymphocytes
• Type II pneumocytes

Question 12

Aerogen infections

Answer 12

Airborne

• Aerosol: Bacteria; viruses; mycoplasmae
  
  • Travels Kms by the wind; 1–5 μm
• Flying dust: Marek disease; Fungal spores

Question 13

Oronasal, conjunctival infections

Answer 13

• Bird flu
• Fowl cholera

Question 14

Urogenital infections

Answer 14

• Venereal
  
  • Semen; erosions on the mucous membranes
    
    • Brucellosis, AIDS, dourine
  • Urinary/genital infections: FLUTD, cystitis; pyometra

Question 15

Infection via the umbilicus

Answer 15

Omphalogen (the pathogen)

• E. coli
• Salmonella

Question 16

Transplacental/intrauterine infections (vertical)

Answer 16

• BVD
• PRRSV (Porcine reproductive and respiratory syndrome virus)

Question 17

Ovogen infection (vertical)

Answer 17

Salmonella

Question 18

Infections by the veterinarian

Answer 18

Iatrogenic infection

• PCV2
• EBL

Question 19

Factors affecting the spread of pathogens and the disease

Answer 19

• Infectivity
• Pathogenicity
• Virulence
• Host specificity
• Invasivity
• Immunological function
• Contagiousness
  
  • Temperature
  • Humidity

Question 20

Give the spread of pathological processes in the organism

Answer 20

Question 21

Metastasis

Answer 21

The development of secondary malignant growths (lesions)

• At a distance from the primary site
• Cancer; parasites*

Question 22

The spread of metastasis

Answer 22

Question 23

Distant metastasis

Answer 23

Question 24

Give the other forms of metastasis

Answer 24

• Metastasis by contact
• Implantation metastasis
• Pathogens spreading within the:
  
  • Peri-
  • Endoneurial lymphatic channels: Rabies, listeriosis, Herpesvirus

Question 25

Give the outcome of the spread of pathological processes in the organism

Answer 25

Generalisation

Question 26

Give the different forms of infection

Answer 26

• Bacteriaemia
• Septicaemia - sepsis
• Pyaemi
• Viraemia

Question 27

Bacteriaemia

Answer 27

• Bacteria in low number
• Only temporary

Question 28

Septicaemia -sepsis

Answer 28

• Lots of bacteria; prolonged time period
• Bacteria in the organs
• Settlement in the organs
• Pyogenic bacteria (sepsis)
• Rotting bacteria (Sapraemia)

Question 29

Septicemia - Settlement in the orans

Answer 29

• Bacterial-emboli
• Phagocytotic metastasis

Question 30

Septicaemia by mycoplasmas

Answer 30

Mycoplasmaemia

Question 31

Draw the process of SIRS

Answer 31

Systemic inflammatory response syndrome

Question 32

SIRS: Result

Answer 32

• High TNFα​ and LPS levels: DIC (Disseminate intravascular coagulopathy)
• Liver damage: Decreasing GNG
• High NO levels: Vasodialtion, ↓BP
• Septic shock

Question 33

Pathology of septicaemia

Answer 33

• Incomplete rigor mortis
• Dark red blood, incomplete PM coagulation
• Spleen enlargement
• Generalised lymphadenomegaly
• Acute catarrhal (MM) inflammation in the GI tract
• Haemorrhages everywhere
• Cloudy swelling in the parenchymatous organs