bacteriology 8

Question 1

pyogranulomatous

Answer 1

mixture of acute and chronic inflammation
see a mixture of cells (PMN, macrophages, lympcytes)

Question 2

bacteria that cause pyogranulomatous inflammation by acting…..

Answer 2

as both extracellular and intracelluar

Question 3

gram positive rods rule of thumb

Answer 3

less frequently isolated than other groups of bacteria
tend to cause syndromes
definitive diagnosis

Question 4

gram positive, filamentous, branching rods

Answer 4

actinomyces (Facultative or Anerobic O2)
nocardia (strict aerobe)
dermatophilus (strict aerobe)
branching is distinctive morphological feature

Question 5

gram positive short club shaped rods

Answer 5

rhodococcus equi (Strict aerobe)

Question 6

actinomyces

Answer 6

normal flora of oral cavity and GIT of many species
opportunistic

Question 7

nocardia

Answer 7

saprophytes-soil and decaying vegetation
opportunistic but poor pathogen

Question 8

dermatophilus congolensis

Answer 8

obligate parasite of the skin-survive in the environment of a long time
reservoir are carrier animals (ruminant and horses) fomites
requires alteration in the skin-usually wetting

Question 9

dermatophilus

Answer 9

directly transferred from infected/carrier animal to susceptible animal
rub against each other (contagious)
transferred by insects
by contaminated fomites

Question 10

rhodococcus equi

Answer 10

saprophytes-soil, GIT of horses and animals manure
infections through inhalation or ingestion of bacteria

Question 11

virulence factors

Answer 11

actinomyces-little is known
nocardia-facultative intracellular parasite
due to mycolic acid and cell wall lipids
dermatophilus-motile zoospores aid invasion
rhodococcus-facultative intracelluar parasite

Question 12

lumpy jaw

Answer 12

actinomyces bovis
cattle
alteration to mucosa/skin to allow access of organism into site of disease-grass awns, sharp feeds, or impacted feed
invasion result in chronic, pyogranulomatous osteomyelitis of the mandible or maxilla
large lesion on mandible with discharging sinus and suphur granules

Question 13

abcesses

Answer 13

actinomyces spp
pyogranulomatous lesion
secondary to bite or traumatic injury
mixed flora
may extend to vertebrae
cats

Question 14

serositis

Answer 14

actinomyces spp
dogs and cats
thorax but may extend to abdomen
direct instillation(trauma, fighting, or migrating grass awns)

Question 15

pyothorax/peritonitis

Answer 15

norcarida spp
dogs and cats
immunocompromised individuals
thorax but may extend to abdomen
poor prognosis in cases
tomato soup consistency to exudate
beading branching filaments

Question 16

abscesses

Answer 16

nocardia spp
dogs and cats
immunocompromised individuals
pyogranulomotous lesions

Question 17

bovine mastitis

Answer 17

nocardia spp
economical important form of mastitis in cattle
assocaited with intramammary infusion
poor prognosis (cull

Question 18

dermatophilosis

Answer 18

dermatophilosis congolensis
rain scald/rot, greasy hell, lumpy wool, strawberry footrot
ruminants and horses
usually occurs in prolonged wet conditions
skin maceration
organisms to invade epidermis
exudative dermatitis
thick sabs-motile cocci, elongates into rod, divide in multiple planes, motile cocci

Question 19

rattles

Answer 19

rhodococcus equi
pyogranulomatous bronchopneumonia of foals
significant cause of morbidity and mortality in foals world wide
may disseminate to other sites
associated with hypersensitivity reaction

Question 20

cellulitis/lymphadentis

Answer 20

pyogranulomatous lesion particularly in cat
spread to local lymph node
rhodococcus equi

Question 21

obtain sample from lesion

Answer 21

pus, effusion(actinomyces/nocardia)
scabs (Dermatophilus)
transtracheal aspirate (rhodococcus)

Question 22

gram stain/diff quick

Answer 22

gram positive branching rods
definitive diagnosis for dermatophilus
short gram positive rods/coccobacilli (rhodococcus)

Question 23

if suspect either actinomyces or nocardia

Answer 23

to confirm culture aerobically and anaerobically to differentiate
actioymyces
nocardia-only O2 positive

Question 24

surgical debridement, excision or drainage

Answer 24

imperative

Question 25

topical therapy

Answer 25

rain rot, drying lesions get rid of scabs
daily application of topical antiseptics

Question 26

antibiotics

Answer 26

penicillin +/- strepomycin or tetratcyline are the drug of choice for actinomyces and dermatophilus
not nocardia (intracellular)
not rhodococcus (intracellular)