Curved and Spiral Bacteria (Spirochetes) Flashcards
Morphology of Spirochetes
Tightly coiled mini springs
Endoflagella
Corkscrew motility
Gram neg but stains poorly
How do you detect spirochetes?
Impression smears
Dark-field microscopy
Silver, carbol fuchsin, giemsa
Genus Borrelia transmission
Arthropod transmission –> ticks to skin for at least 48 hours and spread via CT
Where do most Borrelia cases occur?
Wisconsin and Minnesota (80% of ticks carry)
Which animals are most effected by Borrelia?
Canines –> horses, cattle and cats also
Only 5% of infected dogs show clinical signs
What’s the causative agents of Borreliosis (Lyme’s disease)?
B. Burhdorferi
Transmission cycle for B. burgdorferi
Deer or mice –> dogs and humans by bite of adults or nymphs of soft ticks of genus Ixodes
Clinical signs in dogs with Borreliosis
Develops 2-5 months after exposure
Fever, swollen LNs
Polyarthropathy (shift leg lameness)
Renal failure
CNS symptoms
Renal failure in dogs with Borreliosis
Protein losing glomerulopathy
Especially in Labs and goldens
How do you diagnose borrelia
Serologic tests for Abs
ELISA and IFA Abs
C6 Ab test
PCR and culture to identify organisms
ELISA and IFA Abs
Doesn’t differentiate between natural and vx infection
TIter increases within 4-6 weeks after exposure
+ = persist for years
C6 Ab test
Recommended by the CDC
Detects the outer surface of protein Borrelia
Early detection before CS development
PCR and culture
Best for skin biopsy from around tick bite
Treatment and prevention for Borrelia
Doxycycline orally for dogs with CS
VX dogs @ risk
Tick preventative: topical fipronil, permethrin or amitraz
Brachyspira
Intestine of pigs, wild rats and mice
B. hyodysenteriae (swine) and pilosicoli (swine, humans, primates, birds)
Uses Romanovsky’s stains
B. hyodysenteriae
Highly motile in GIT mucus (flagella)
Colonization of colonic crypts
Invades goblet cells of the colonic mucosa
Symptoms of B. hyodysenteriae
Swine dysentery (acute bloody diarrhea)
Chronic emaciation
Weight loss
What increases the severity of B. hyodysenteriae?
Low in fiber and high in highly fermentable carbs
Dysentery in swine
Cannot be produced in gnotobiotic (germ free animals) pigs
Older animals more susceptible
B. hyodysenteriae diagnosis
Deep mucosal scrapping
Large intestine from dead pig
Rectal swabs and feces from affected pig
Genus Lawsonia (Lawsonia intracellularis species)
Gram-neg, curved rods
Motile with darting motion (single flagella)
Intracellular pathogen in pigs and hamsters
Cultivation requires eukaryotic cells
Where is the chronic form of Lawsonia intracellularis found?
Common on traditional, single-site farrow-to-finish farms (spreads easily)
Lawsonia intracellularis is an etiologic agent of ______
Intestinal hyperplastic called Proliferative Enteropathy
Proliferative Enteropathy
Horses, pigs, hamsters
Porcine proliferative enteritis, ileitis, intesinal adenomatosis, garden-hose gut
Proliferative Enteropathy pathogenesis
Intracellular pathogen spread by comingling animals of different ages or sub-clinically infected sows
4 forms of Proliferative Enteropathy
- Proliferative hemorrhagic enteropathy (older naive animals)
- Porcine intestinal adenomatosis
- Necrotic enteritis
- Regional ileitis (recovery stage of NE)
Proliferative Enteropathy acute infection in pigs
Older, naive (4-12 months)
Intestinal hemorrhage, sudden death, pale carcass, petechial hemorrhage of intestinal mucosa
Proliferative Enteropathy chronic infection in pigs
Manifests due to stress (1-3 weeks post weaning)
Lasts 1-3 weeks with mild enteritis (lasts 10-12 weeks)
Proliferative Enteropathy subclinical infection in pigs
manifests with animals showing poor growth
Proliferative Enteropathy in equine
Affects weanling foals (3-6 months)
Stress induced
Dullness, fever, weight loss, colic, diarrhea, hypoproteinemia
Leukocytosis, mild anemia
Lawsonia intracellularis pathogenesis
- Infection of tonsils, LN (macrophages)
- Migration to GIT (enterocytes)
- Hyperplasia
- Crypts long and branched
- Increased neutrophils, macrophages, and lymphocytes
- Decreased goblet cells
Epidemiology of Lawsonia intracellularis
Fecal matter from infected pigs (source)
Not K+ peroxy monosulphate, Na+ hypochlorite, penolics, H2O2, peracetic acid
Diagnosis of Lawsonia intracellularis
Herd history + clinical signs
Gross + microscopic lesions
Fecal PCR + serology
Abdominal ultrasound in equine
Control and treatment of Lawsonia intracellularis
All in all out
Modified life vaccine
Use Chlortetracycline, lincomycin-spectinomycin, tylosin, tiamulin
Treatment for equine proliferative enteropathy
Fluid and electrocyte therapy
Erythromycin, azithromycin, rifampin
