Mastitis - Intro + immunity Flashcards
Name a major mastitis pathogen which is environmental in origin but can become cow adapted and become contagious?
Strep Uberis
Which of these mastitis pathogens is Gram negative, environmental and is harboured inn poorly managed/damp sawdust?
1. E.coli
2. Staph aureus
3. Strep uberis
4. Klebisella
Klebsiella
Which pathogen is Gram positive, always contagious, associated with chronically high cell counts and lives intracellularly?
1. Staph aureus
2. Strep uberis
3. Strep dysgalactiae
4. Strep agalactiae
Staph aureus
What are consequences of mastitis infection?
- Chronic infection = spread of infection within herd
- Permanent damage = to udder - reduced milk yield
- Death = toxaemia
What does the innate immune system consist of?
- Resident leucocytes - macrophages, neutrophils, T lymphocytes
- Lactopreoxidase
- Lysozyme
- Lactoferrin
- Complement
What does the resident leucocytes do?
- Phagocytosis + killing of invading pathogens
- Trigger the acquired immune system by release of pro-inflammatory mediators + antigen presentation
What does the rest of the innate immune response do?
- Lactoferrin = inhibits growth of bugs requiring iron (E.coli)
- Lactoperoxidase = bacteriostatic agent
- Lysozyme = bacteriocidal protein
- Free complement = opsonisation of bacteria, activated it attracts phagocytes
What does the acquired immune system consist of?
- Invasion of circulating neutrophils + IgG2 antibodies
- B + T Lymphocytes
- Inflammatory cytokines
What do the B lymphocytes do?
*Circulate through lymphatic system
*Exposed to antigens in tissue fluids
*Initial response produce IgM , IgG1
*Repeated exposure produce IgG2 antibodies (“vaccination”)
*IgG2 antibodies then circulate and enter inflamed udder aiding opsonisation of pathogens by neutrophils
*Present antigen to T lymphocytes
What do the T lymphocytes do?
*T helper cells -production of cytokines following antigen recognition stimulates immune response
*T cytotoxic cells – eliminate host cells invaded by pathogens
What do the different antibodies do?
*IgG2 most important antibody response
*IgM fixates complement for opsonisation of pathogens, agglutinates bacteria, neutralizes toxin
*IgA agglutination of bacteria and neutralize toxins
*IgG1 opsonisation of bacteria