Obligate intracellular bacteria

Question 1

Q fever - agent + habitat + source/route of infection + hosts

Answer 1

Coxiella burnetii

• Placenta, foetal fluids, GIT,
• Reservoir (bandicoots) > aerosol inhalation > infects ruminants/humans

Question 2

Rickettsiales - morphology + host cells + route of transmission

Answer 2

Gram - coccobacilli

• RBC, WBC, RES, ECs
• Arthropod/fluke vectors

Question 3

Rickettsiales - tx

Answer 3

Tetracyclines, chloramphenicol

Resistant to penicillin, aminoglycosides

Question 4

Rickettsiales - genera (5)

Answer 4

Rickettsia (ECs) 
Anaplasma
Ehrlichia 
Neorickettsia 
Aegyptionella

Question 5

Rickettsia - host cells + VF (1)

Answer 5

Infect endothelial cells

> destroy phagolysosome

Question 6

Rickettsia - species + dz

Answer 6

R. australis = Nth QLD tick typhus
R. typhi = murine typhus
R. prowazekii = endemic typhus

Question 7

Heartwater disease in cattle - agent + host cells

Answer 7

Ehrlichia ruminatium

> in ECs

Question 8

Heartwater disease in cattle - pathogenesis

Answer 8

Transtadial transmission in tick
> infects ECs = odema, haemorrhage, effusions
> recovery = immunity

Question 9

Canine monocytic ehrlichiosis/tropical canine pancytopaenia - agent + host cell

Answer 9

Ehrlichia canis in monocytes

Question 10

Canine granulocytic ehrlichiosis - agent + host cell

Answer 10

Ehrlichia ewingii in granulocytes

Question 11

Bovine petechial fever (Ondiri disease) - agent + host cell

Answer 11

Ehrlichia ondiri

> RES cells + WBCs + dmg’s ECs

Question 12

Salmon disease in dogs - agent + host cells + transmission

Answer 12

Neorickettsia helminthoeca
> RES cells
> ingestion of encysted fluke metacercariae in fish

Question 13

Potomac horse fever - agent + host cells

Answer 13

Neorickettsia risticii

> RES cells + GI epithelium (enteritis + diarrhoea)

Question 14

Anaplasmosis in rum - spp. + host cells

Answer 14

Anaplasma marginale - clinical dz in cows
Anaplasma centrale - subclin infection
Anaplasma ovis - mild dz in sheep

In RBCs > anaemia

Question 15

Anaplasmosis - clin signs + host factors (1)

Answer 15

Fever + anaemia (↑ destruction in spleen)

Cattle < 1yo resistant

Question 16

Anaplasmosis - transmission

Answer 16

Transtadial transmission in ticks

Poor hygiene on surgical/husbandry equipment (blood contam)

Question 17

Infectious canine thrombocytopaenia - agent + host cell

Answer 17

Anaplasma platys

> platelets

Question 18

Tick-borne fever - agent + host cells

Answer 18

Anaplasma phagocytophila

> WBCs

Question 19

Tick-borne anaemia of poultry - agent

Answer 19

Aegyptianella pullorum

Question 20

Chlamydiales - morphology + habitat

Answer 20

Gram –

RT, conjunctiva, serous membranes, repro tract, CNS, joints GIT

Question 21

Chlamydiales - life cycle

Answer 21

2 stage LC:

• transmitted by aerosols
• internalised > block lysosomal fusion
• form reticulate bodies > multiply
• mature into infectious elementary bodies

Question 22

Chlamydiales - tx

Answer 22

Tetracyclines (doxycycline)

Not susc to aminoglycosides

Question 23

Enzootic abortion - agent + host

Answer 23

Chlamydophila abortus - sheep + zoonosis

Question 24

Psittacosis - agent + host

Answer 24

Chlamydophila psittaci - birds + zoonosis

Question 25

Polyarthritis dt Chlamydia - agent + host

Answer 25

Chlamydophila pecorum - lambs/calves

Question 26

Sporadic bovine encephalomyelitis

Answer 26

Chlamydophila pecorum - calves

Question 27

Chlamydial repro tract dz - agent + host

Answer 27

Chlamydophila pecorum - koalas + others

Question 28

Chlamydiales - immunity

Answer 28

Anti-MOMP Ab

Question 29

Chlamydiales - dx

Answer 29

Giemsa stained tissue smears from lesions
ELISA
PCR