Spirochaetes + Mollicutes

Question 1

Spirochaete spp. (4)

Answer 1

Brachyspira
Borrelia
Leptospira
Treponema

Question 2

Brachyspira - habitat + metabolism

Answer 2

Oral cavity/GIT

Obligate anaerobes

Question 3

Swine dysentery - agent + manifestation

Answer 3

Brachyspira hyodysenteriae

- Necrosis/erosion of colonic mucosa = maladsorption + bloody diarrhoea

Question 4

Brachyspira pilosicoli - disease + host

Answer 4

mild persistent diarrhoea of pigs (post-weaning)

Question 5

Brachyspira intermedia
Brachyspira alvinipulli
- disease + host

Answer 5

Diarrhoea in adult chickens

Question 6

Swine dysentery - agent + origin + route of infection

Answer 6

Brachyspira hyodysenteriae

• asymptomatic Carrier animals
• Faeco-oral > ingestion

Question 7

Swine dysentery - agent + VFs (2)

Answer 7

Brachyspira hyodysenteriae

• Ag variation (9 serotypes)
• Cytotoxin (haemolysin)

Question 8

Borrelia - reservoir + spp./vectors

Answer 8

Tick reservoir

• B. anserina = Argus persicus
• B. burgdorferi = Ixodid ticks (Ixodes holocyclus)
• B. theileri = Boophilus/Rhipicephalus

Question 9

Avian spirochaetosis - agent + manifestation

Answer 9

Borrela anserina

> anaemia, fever, depression, diarrhoea

Question 10

Tick spirochaetosis - agent + host + manifestation

Answer 10

Borrelia theileri

> mild febrile dz in cattle + anaemia/weight loss

Question 11

Leptospirosis - source + route of infection

Answer 11

Maintenance host - each serovar w specific host

Shed in urine > direct contact

Question 12

Leptospirosis - host factors (2)

Answer 12

Maintenance host = mild/chronic dz (abortion, infertility, nephritis) + carrier state

Incidental host (dz depends on herd immune status)

• acute dz = sepsis, endotox., hepatitis, nephritis, agalactia
• chornic dz = aboriton, nephritis, infertility

Question 13

Leptospirosis - pathogenesis

Answer 13

Contact w contam environment/urine
> mucous membranes/dmg’d skin
> bacteraemia = endothelial dmg
> localisation/proliferation

Incidental host = tissue dmg + strong Ab response > recovery/elimination or death

Maintenance host = nephritis + leptospiruria

Question 14

Leptospirosis - serovars + hosts (4)

Answer 14

L. interrogans sv icterohaemorrhagiae = dogs
L. interrogans sv pomona = pigs, humans
L. borgpetersenii sv hardjobovis = cattle, humans
L. borgpetersenii sv tarrosovi = pigs

Question 15

Leptospirosis - VFs (2)

Answer 15

Haemolysin

Endotoxin

Question 16

Leptospirosis - host factors (1)

Answer 16

Herd immune status important in manifestation of disease (acute vs subclin)

Question 17

Leptospirosis - immunity (3)

Answer 17

Serovar-specific Ab
Vax available = protective + reduces shedding
Passive Ab = protective

Question 18

Mollicuttes - sp + morphology + habitat

Answer 18

Mycoplasma - don’t gram stain (no cell wall)
- Fried egg colony (fastidious requirements)

Obligate extracellular parasites of mucous membranes

Question 19

Mollicutes - VFs (4)

Answer 19

No cell wall = don’t gram stain (use Giemsa)
- susceptible to osmotic shock/dessication
Attachment organelle
Motile
Host damage dt immune response

Question 20

Mollicutes - AM use (3)

Answer 20

Sensitive to tetracyclines, macrolides, fluoroquinolones, aminoglycosides

Resistant to penicillins/cephalosporains (no cell wall)
Resistanat to sulphonamides/trimethoprim

Question 21

Mollicutes - dx (3)

Answer 21

PCR
Immunofluorescence
Serology (ELISA, agglutination)

Question 22

Mollicutes - general pathogenesis

Answer 22

Adhere to mucosa (attachment organelle)
> minor chronic infections (persistent)
> bacteraemia
> localisation in joints/tissues
> predisposition to secondary infections

Question 23

Mollicutes - source + transmission

Answer 23

Source = other animals of same sp. 
Transmit = aerosols, STI, milking, vertically in eggs

Question 24

Contagious bovine pleuropneumonia - agent

Answer 24

Mycoplasma mycoides ssp mycoides

Question 25

Contagious bovine pleuropneumonia - pathogenesis

Answer 25

Infection via aerosols from carrier cattle
> colonisation of LRT
> acute phase = neut exudation into airways, necrosis, oedema, serous pleural effusions
> chronic phase = lymphocytic inflamm
> bacteraemia
> localisation in joints/kidneys/placenta
> persistence in necrotic lung sequestrums = carrier animals

Question 26

Mycoplasma gallisepticum - hosts (2) + diseases

Answer 26

Chickens = tracheitis + airsacculitis
Turkeys = sinusitis + airsacculitis

Question 27

Mycoplasma gallisepticum - pathogenesis

Answer 27

Infection via aerosols/direct contact/vertical in egg
> attaches to sialic acid-R on RT epithelium (adhesins)
> disease exacerbated by concurrent infection, stress, high NH3 in env etc.
> immunity following disease (carrier + transmission)

Question 28

Enzootic pneumonia of pigs - agent

Answer 28

Mycoplasma hyopneumoniae

Question 29

Enzootic pneumonia of pigs - host factors (2)

Answer 29

Pigs > 6w old

Continuous mixed-age pig populations = cycle of infection

Question 30

Enzootic pneumonia of pigs - source + route + pathogenesis

Answer 30

Inf via inhalation of aerosols from infected pigs
> adheres to ciliated RT epithelium
> ciliostasis + loss of cilia
> low grade pneumonia + cough

Question 31

Enzootic pneumonia of pigs - dx (2)

Answer 31

Giemsa stained impression smears of pneumonic lungs

Confirmation by immunofluorescence

Question 32

Haemophilic Mycoplasmas

Answer 32

M. haemofelis = feline infectious anaemia
M. haemomuris
M. haemobovis

Question 33

Feline infectious anaemia - habitat + dz

Answer 33

Infects surface of erythrocytes
> haemolytic anaemia dt erthrophagocytosis
> fever

Question 34

Feline infectious anaemia - route of transmit (3)

Answer 34

Vertical
Bite wounds (young males)
Lice/ticks

Question 35

Feline infectious anaemia - host factors

Answer 35

Coinfection w FeLV/FIV > clinical disease

Question 36

Feline infectious anaemia - dx

Answer 36

Giemsa-stained blood smears