defence against repro pathogens Flashcards
Which area of the female repro tract is microbiologically sterile and how is this achieved?
uterus
cervix acts as a barrier
When in the female repro cycle could the uterus become unsterile?
oestrus or after parturition
cervix relaxes and opens allowing foreign bodies to enter
What are the common origins of micro-organisms found in the female repro tract?
mating
parturition
instrumentation
What are the consequences of bacteria contaminating the uterus?
Metritis - inflammation of uterus
endometritis - infection or inflammation of endometrium
ovaritis
pyometra - uterine infection
What factors can make bacterial contamination of the uterus more likely to occur?
Prolonged anoestrus/dioestrus - allows bacteria to remain in uterus and not be flushed out for longer
Progesterone exacerbates infection due to thickening of uterine lining and increased secretory activity and closed cervix
Can be environmental, retained foetal membranes, dystocia, vulval conformation
what is the most important opportunistic pathogens in the bitch, mare and cow female repro tracts?
Bitch - E.coli
Mare - streptococcus zooepidemicus
Cow - arcanobacterium pyogenes
What features of the female repro tract provide resistance to infection?
physical drainage via vagina and vulva
epithelial barrier
local mucosal glycosaminoglycan and IgA production
Anti-microbial peptides e.g., defensin
Immune cells
What immune cells are present in the female repro tract?
monocytes
neutrophils
macrophages
NK cells
T cells
B cells
What host receptors are involved in recognising pathogens and what do they recognise in inflammation of the female repro tract?
How does oestradiol affect immunity?
Promotes activity of macrophages and neutrophils
Enhanced immune response during follicular phase when oestradiol levels are high
What effect does progesterone have on immunity?
has immunosuppressive effects to create favourable environment for developing embryo
luteal phase - immune responses are suppressed
How does sperm survive as a foreign body in the female repro tract?
seminal plasma interacts with tract to protect sperm
progesterone protects the antigenic profile of sperm
contains prostalgandins to provide protection
What does semi-allogenic mean in the fetus?
Genetic material of the fetus is different to its mothers - this can pose immunological challenges as mothers immune system can recognise foetus as foreign
Why is pyometra more common in older bitches?
more cycles has led to thicker uterine walls -> more progesterone produced -> increased immunosuppression
