bacteriology 8 Flashcards
pyogranulomatous
mixture of acute and chronic inflammation
see a mixture of cells (PMN, macrophages, lympcytes)
bacteria that cause pyogranulomatous inflammation by acting…..
as both extracellular and intracelluar
gram positive rods rule of thumb
less frequently isolated than other groups of bacteria
tend to cause syndromes
definitive diagnosis
gram positive, filamentous, branching rods
actinomyces (Facultative or Anerobic O2)
nocardia (strict aerobe)
dermatophilus (strict aerobe)
branching is distinctive morphological feature
gram positive short club shaped rods
rhodococcus equi (Strict aerobe)
actinomyces
normal flora of oral cavity and GIT of many species
opportunistic
nocardia
saprophytes-soil and decaying vegetation
opportunistic but poor pathogen
dermatophilus congolensis
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
dermatophilus
directly transferred from infected/carrier animal to susceptible animal
rub against each other (contagious)
transferred by insects
by contaminated fomites
rhodococcus equi
saprophytes-soil, GIT of horses and animals manure
infections through inhalation or ingestion of bacteria
virulence factors
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
lumpy jaw
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
abcesses
actinomyces spp
pyogranulomatous lesion
secondary to bite or traumatic injury
mixed flora
may extend to vertebrae
cats
serositis
actinomyces spp
dogs and cats
thorax but may extend to abdomen
direct instillation(trauma, fighting, or migrating grass awns)
pyothorax/peritonitis
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
abscesses
nocardia spp
dogs and cats
immunocompromised individuals
pyogranulomotous lesions
bovine mastitis
nocardia spp
economical important form of mastitis in cattle
assocaited with intramammary infusion
poor prognosis (cull
dermatophilosis
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
rattles
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
cellulitis/lymphadentis
pyogranulomatous lesion particularly in cat
spread to local lymph node
rhodococcus equi
obtain sample from lesion
pus, effusion(actinomyces/nocardia)
scabs (Dermatophilus)
transtracheal aspirate (rhodococcus)
gram stain/diff quick
gram positive branching rods
definitive diagnosis for dermatophilus
short gram positive rods/coccobacilli (rhodococcus)
if suspect either actinomyces or nocardia
to confirm culture aerobically and anaerobically to differentiate
actioymyces
nocardia-only O2 positive
surgical debridement, excision or drainage
imperative
topical therapy
rain rot, drying lesions get rid of scabs
daily application of topical antiseptics
antibiotics
penicillin +/- strepomycin or tetratcyline are the drug of choice for actinomyces and dermatophilus
not nocardia (intracellular)
not rhodococcus (intracellular)
