Non-Spore-Forming Anaerobes

Front 1

Where are non-spore forming anaerobes usually found?

Back 1

As part of the normal flora on mucous membranes of animals and humans, particularly the digestive and urinogenital tracts.

Front 2

What enzyme allows these non-sporing anaerobes to tolerate oxygen for periods of time until conditions are more favorable?

Back 2

Superoxide dismutase

Front 3

Name some SPECIFIC diseases/infections associated with gram negative, non-spore-forming anaerobes. (Could be in conjunction with other organisms working synergistically.) (There are 6 mentioned in lecture)

Back 3

1) Foot rot in sheep
2) Foot rot in cattle (foul of the foot)
3) Liver abscesses in feedlot cattle
4) Calf diphtheria
5) Swine dysentery
6) Summer mastitis

Front 4

There are 5 NON-SPECIFIC infections mentioned in lecture associated with non-sporing anaerobes. What are they?

Back 4

1. abscesses
2. dental and oral infections
3. chronic pleuropneumonic conditions
4. infections of the female genital tract
5. cellulitis and wound infections

Front 5

What virulence factors are present for the following bacteria?
1. Fusobacterium
2. Dichelobacter
3. Gram pos. anaerobic cocci
4. Brachyspira

Back 5

1. Fusobacterium - leukotoxin, haemagglutinin, endotoxin
2. Dichelobacter - fimbriae and proteases
3. Gram + anaerobic cocci - exoenzymes and capsule
4. Brachyspira - cytotoxin

Front 6

What is the primary bacteria causing footrot in sheep?

What are some other bacteria that can also contribute?

Back 6

Dichelobacter nodosus

Fusobacterium necrophorum, Trueperella pyogenes, and treponeme-like spirochetes.

Front 7

True or False: different strains of Dichelobacter nodosus can cause different severity of footrot in sheep.

Back 7

True. Depending on the strain of Dichelobacter nodosus, footrot may be virulent, benign, or intermediate in severity.

Front 8

What are some environmental factors that play in to the development of footrot in sheep?

What is the source of footrot in sheep?

Back 8

-High moisture levels, lush pasture, temperatures greater than 10 degrees celcius.

Source is from chronic carriers.

Skin will become softened by water and faecal contamination will invade the stratum corneum, causing interdigital dermatitis which can then become more infected, extending the lesion and leading to destruction and inflammation of the tissue.

Front 9

Describe the pathogenesis of Dichelobacter nodosus in footrot.

Back 9

D. nodosus has type IV fimbriae which are required for adherence and protease secretion. Serine proteases inflict tissue damage and are critical for initial separation of the hoof from underlying tissue.

Front 10

Fusobacterium necrophorum has 3 virulence factors, explain how each of them contribute to it's pathogenicity.
1) Haemagglutinin
2) Leukotoxin
3) Endotoxin

Back 10

1) Haemagglutinin - promotes adherence to epithelial cells.
2) Leukotoxin - highly toxic to ruminant neutrophils, apoptosis of other immune cells, cytotoxic to liver and rumen epithelial cells at high conc, produced by all invasive strains.
3) Endotoxin - cytotoxic and necrotic effects.

Front 11

How is footrot in sheep diagnosed?

Back 11

Clinical signs, direct smears, cultures are difficult but possible, and PCR.

Front 12

What methods of treatment and control are used for footrot in sheep?

Back 12

Foot paring, foot bathing, parenteral antibiotics, vaccination....Cull if no response.

Front 13

What are some other foot conditions found in sheep?

Back 13

-Ovine interdigital dermatitis (scald) - F. necrophorum & T. pyogenes
-Foot abscess - F. necrophorum & T. pyogenes
-Contagious ovine digital dermatitis - Treponeme

Front 14

Foul of the foot causes about 10% of the lameness in cattle in Ireland. What non-sporing anaerobes contribute?

Back 14

Fusobacterium necrophorum, Porphyromonas levii, synergism with Prevotella melaninogenica.

(Causes inflammation with pus and necrobacillosis)

Front 15

What are some other foot conditions in cattle besides foul of the foot?

Back 15

Interdigital dermatitis, heel erosion (starts primarily at coronary band), and digital dermatitis.

Front 16

Injury plus infection with Fusobacterium causes what?

Back 16

Oral necrobacillosis, calf diphteria in calves up to 18 months, necrotic stomatitis in calves up to 3 months.
More common where animals are housed and if there is poor hygiene.

Front 17

What is Calf diptheria?

Back 17

Highly contagious bacterial disease that causes inflammation and necrosis of the larynx and pharynx.

Front 18

What non-sporing anaerobe causes liver abscesses?

Back 18

Fusobacterium necrophorum in conjunction with other organisms. Most occurs in feedlots where there is high grain diets causing increases in lactate levels. Higher lactate levels encourage growth of the Fusobacterium.

Front 19

Liver abscesses caused by Fusobacterium necrophorum causes production losses for farmers. How can you prevent liver abscesses occurring from this bacteria?

Back 19

Good feeding practices and antimicrobials (licensed for use in the USA).

Front 20

When collecting specimens for diagnoses of non-sporing anaerobes you should avoid contamination with normal flora. What are suitable specimens for collection?

Back 20

Pus, wound discharges, pleural or peritoneal aspirates, tissue specimens, joint fluids, and urine. Specimens should be transported in anaerobic transport medium.

Front 21

What laboratory tests can be used for diagnosing infection of non-spore-forming anaerobes?

Back 21

Enriched and selective media for culture, gram stain, biochemical tests, molecular tests, VFA profiles. Antimicrobial susceptibility testing can be used but is not routine.