Bacteria of the Reproductive Tract Flashcards
What are the three transmission routes of bacterial infection?
Venereal transmission - Endogenous transmission - Environmental transmission
What bacteria cause bovine abortion?
Leptospira hardjo - Bacillus licheniformis - Salmonella dublin (and others) - Brucella abortus & B. melitensis - Mycoses
Which bacteria is the biggest cause of bovine abortion in the UK?
Leptospira (70-80% of herds in UK)
Why is it hard to detect leptospira infection in a herd?
Pathogen adapted to be mainly subclinical so reservoir in a herd
How is Leptospira diagnosed?
Sera samples examined by microscopic agglutination test
What bacteria cause non-specific bovine endometritis?
Arcanobacterium pyogens - E. coli - Streptococci
How does endometritis cause fertility problems?
Luteolysis prevented by inflammation - CL retained - Drainage prevented by closed cervix
What bacteria cause abortion in sheep?
Chlamydophila abortus - Campylobacter fetus
What is the pathogenesis of Chlamydophila abortus in sheep?
Obligate intracellular pathogen - Long-term persistent infection - Late term abortion - No infertility
How is Chlamydophila abortus transmitted and diagnosed?
Venereal or oro-faecal - Antigen detection by ELISA & Kosters stain (PCR)
What causes about 10% of ovine abortions?
Campylobacter fetus
Where is the reservoir of Campylobacter fetus? How does it cause abortion?
In the intestinal tract - oro-faecal ingestion - blood - bacteraemia - placenta - abortion
What bacteria cause canine pyometra & endometritis?
Coliforms (E. coli) - Beta-haemolytic streptococci (s. canis and s. zooepidemicus)
What bacteria is an environmental opportunist which causes sporadic abortion in cattle?
Bacillus licheniformis
How does Brucella abortus cause abortion in cattle?
Phagocytosed at mucosal surfaces - migrate via lymphatics to blood - localises in lymphatics, liver and spleen - attracted to placenta - placentitis - abortion
How does Brucella abortus avoid the immune system?
Facultative intracellular pathogen - Hides in liver cells
How was Brucella abortus eradicated from the UK?
Milk and serum testing - Slaughter of reactors - Vaccination with Attenuated and Killed whole cell vaccines
What allows identification of cows infected with Brucella abortus?
LPS is immunodominant antigen in all strains - Agglutination of bacteria
What types of Salmonella cause abortion? Give an example
Invasive serovars - S. Dublin
What is the most common form of fungal infection in cows which causes abortion?
Aspergillus sp.
How does mycotic infection cause abortion?
High inhalation/ingestion of bacterial spores - Haematogenous migration to placenta - Placentitis - Death of foetus
What bacteria causes infectious infertility in cows?
Campylobacter fetus (subsp venerealis)
Where does campylobacter fetus originate and how does it spread?
Mucous membrane and prepuce of mature bull - Infection of the cow at service
What is the pathogenesis of campylobacter fetus infection in cows?
Catarrhal infection of genital tract - Endometritis and inflammation - Death of foetus - Return to service = infertility
