Curved and Spiral Bacteria (Spirochetes)

Question 1

Morphology of Spirochetes

Answer 1

Tightly coiled mini springs
Endoflagella
Corkscrew motility
Gram neg but stains poorly

Question 2

How do you detect spirochetes?

Answer 2

Impression smears
Dark-field microscopy
Silver, carbol fuchsin, giemsa

Question 3

Genus Borrelia transmission

Answer 3

Arthropod transmission –> ticks to skin for at least 48 hours and spread via CT

Question 4

Where do most Borrelia cases occur?

Answer 4

Wisconsin and Minnesota (80% of ticks carry)

Question 5

Which animals are most effected by Borrelia?

Answer 5

Canines –> horses, cattle and cats also
Only 5% of infected dogs show clinical signs

Question 6

What’s the causative agents of Borreliosis (Lyme’s disease)?

Answer 6

B. Burhdorferi

Question 7

Transmission cycle for B. burgdorferi

Answer 7

Deer or mice –> dogs and humans by bite of adults or nymphs of soft ticks of genus Ixodes

Question 8

Clinical signs in dogs with Borreliosis

Answer 8

Develops 2-5 months after exposure
Fever, swollen LNs
Polyarthropathy (shift leg lameness)
Renal failure
CNS symptoms

Question 9

Renal failure in dogs with Borreliosis

Answer 9

Protein losing glomerulopathy
Especially in Labs and goldens

Question 10

How do you diagnose borrelia

Answer 10

Serologic tests for Abs
ELISA and IFA Abs
C6 Ab test
PCR and culture to identify organisms

Question 11

ELISA and IFA Abs

Answer 11

Doesn’t differentiate between natural and vx infection
TIter increases within 4-6 weeks after exposure
+ = persist for years

Question 12

C6 Ab test

Answer 12

Recommended by the CDC
Detects the outer surface of protein Borrelia
Early detection before CS development

Question 13

PCR and culture

Answer 13

Best for skin biopsy from around tick bite

Question 14

Treatment and prevention for Borrelia

Answer 14

Doxycycline orally for dogs with CS
VX dogs @ risk
Tick preventative: topical fipronil, permethrin or amitraz

Question 15

Brachyspira

Answer 15

Intestine of pigs, wild rats and mice
B. hyodysenteriae (swine) and pilosicoli (swine, humans, primates, birds)
Uses Romanovsky’s stains

Question 16

B. hyodysenteriae

Answer 16

Highly motile in GIT mucus (flagella)
Colonization of colonic crypts
Invades goblet cells of the colonic mucosa

Question 17

Symptoms of B. hyodysenteriae

Answer 17

Swine dysentery (acute bloody diarrhea)
Chronic emaciation
Weight loss

Question 18

What increases the severity of B. hyodysenteriae?

Answer 18

Low in fiber and high in highly fermentable carbs

Question 19

Dysentery in swine

Answer 19

Cannot be produced in gnotobiotic (germ free animals) pigs
Older animals more susceptible

Question 20

B. hyodysenteriae diagnosis

Answer 20

Deep mucosal scrapping
Large intestine from dead pig
Rectal swabs and feces from affected pig

Question 21

Genus Lawsonia (Lawsonia intracellularis species)

Answer 21

Gram-neg, curved rods
Motile with darting motion (single flagella)
Intracellular pathogen in pigs and hamsters
Cultivation requires eukaryotic cells

Question 22

Where is the chronic form of Lawsonia intracellularis found?

Answer 22

Common on traditional, single-site farrow-to-finish farms (spreads easily)

Question 23

Lawsonia intracellularis is an etiologic agent of ______

Answer 23

Intestinal hyperplastic called Proliferative Enteropathy

Question 24

Proliferative Enteropathy

Answer 24

Horses, pigs, hamsters
Porcine proliferative enteritis, ileitis, intesinal adenomatosis, garden-hose gut

Question 25

Proliferative Enteropathy pathogenesis

Answer 25

Intracellular pathogen spread by comingling animals of different ages or sub-clinically infected sows

Question 26

4 forms of Proliferative Enteropathy

Answer 26

1. Proliferative hemorrhagic enteropathy (older naive animals)
2. Porcine intestinal adenomatosis
3. Necrotic enteritis
4. Regional ileitis (recovery stage of NE)

Question 27

Proliferative Enteropathy acute infection in pigs

Answer 27

Older, naive (4-12 months)
Intestinal hemorrhage, sudden death, pale carcass, petechial hemorrhage of intestinal mucosa

Question 28

Proliferative Enteropathy chronic infection in pigs

Answer 28

Manifests due to stress (1-3 weeks post weaning)
Lasts 1-3 weeks with mild enteritis (lasts 10-12 weeks)

Question 29

Proliferative Enteropathy subclinical infection in pigs

Answer 29

manifests with animals showing poor growth

Question 30

Proliferative Enteropathy in equine

Answer 30

Affects weanling foals (3-6 months)
Stress induced
Dullness, fever, weight loss, colic, diarrhea, hypoproteinemia
Leukocytosis, mild anemia

Question 31

Lawsonia intracellularis pathogenesis

Answer 31

1. Infection of tonsils, LN (macrophages)
2. Migration to GIT (enterocytes)
3. Hyperplasia
4. Crypts long and branched
5. Increased neutrophils, macrophages, and lymphocytes
6. Decreased goblet cells

Question 32

Epidemiology of Lawsonia intracellularis

Answer 32

Fecal matter from infected pigs (source)
Not K+ peroxy monosulphate, Na+ hypochlorite, penolics, H2O2, peracetic acid

Question 33

Diagnosis of Lawsonia intracellularis

Answer 33

Herd history + clinical signs
Gross + microscopic lesions
Fecal PCR + serology
Abdominal ultrasound in equine

Question 34

Control and treatment of Lawsonia intracellularis

Answer 34

All in all out
Modified life vaccine
Use Chlortetracycline, lincomycin-spectinomycin, tylosin, tiamulin

Question 35

Treatment for equine proliferative enteropathy

Answer 35

Fluid and electrocyte therapy
Erythromycin, azithromycin, rifampin