Pathogenic non-spore forming anaerobes Flashcards
General characteristics of pathogenic non-spore forming anaerobes
gram-neg rods
anaerobes commonly found
mucous membrane
How are pathogenic non-spore forming anaerobes cultured?
anaerobic jars
blood agar + yeast + vitamin K + hemin
selective media
liquid media: cooked broth, thioglycollate medium + vit K + hemin
What disease does dichelobacter nodosus cause?
footrot in sheep
What diseases do fusobacterium necrophorum?
calf diptheria
footrot and liver abscesses in cattle
Dichelobacter nodosus distribution
worldwide
Mode of infection of dichelobacter nodosus
infected or carrier animals
present in the environment
skin abrasions, wounds, damage by larvae
damp pasture
Virulence factors of dichleobacter nodosus
pili
endotoxins
proteases
Colonization synergism of dichleobacter nodosus
trueperella pyogenes
fusobacterium necrophorum
Describe footrot in sheep and goats
seasonal in occurrence
infection of the epidermal tissue of the feet
lameness and loss of body weight
Treatment of footrot in sheep and goats
trim the affected hoof
foot baths
antibiotics
Prevention of footrot in sheep and goats
vaccination
General charcateristics of fusobacterium
gram-neg
rod shaped
non-spore forming
anaerobe
Characteristics of fusobacterium necrophorum
fusus - spindle shaped
pleomorphic
assocaited with necrotic lesions
“necrobacillosis”
Habitat of fusobacterium necrophorum
normal inhabitant of GIT, respiratory tract and urogenital tract
found in soil
Mode of infection of fusobacterium necrophorum
opportunistic infections - endogenous
soil - exogenous
Virulence factors of fusobacterium necrophorum
leukotoxins
LPS
hemolysins
hemagglutinin
adhesins
dermonecrotic toxin
platelet aggregating factor
proteases
Describe necrobacillosis
suppurative and necrotic infection in all animals
Describe calf diphtheria
aka necrotic laryngitis
calves up to 2 years of age affected
predisposing factor = break in mucus membrane
can be acute or chronic
necrosis of the mucus membrane and underlying tissues of the larynx
if untreated can develop into a fatal necrotizing pneumonia
Treatment for calf diphtheria
penicillin, tetracyclines, tylosin
Interdigital necrobacillosis aka
footrot in cattle
Bacteria that contribute to footrot in cattle
fusobacterium necrophorum
porphyromonas levii
dichelobacter nodosus
trueperella pyogenes
Treatment of footrot in cattle
penicillin + streptomycin injections
Control and prevention of footrot in cattle
trime hooves and foot baths
zinc sulfate in feed
fence animals, keep away from wet, marshy areas
vaccination
Diagnosis of bovine rumentitis-liver abscess complex
detected after slaughter
no clinical signs
normal liver function tests
Control of bovine rumentitis-liver abscess complex
proper feed management
antimicrobial feed additives
vaccine
Describe fusobacterium equinum
normal inhabitant of GI, respiratory and urogenital tract of horses
causes opportunistic infections - abscesses and necrotic infections
General characteristics of bacteriodes
gram-neg anaerobic rods
normal flora of the colon
cause abscesses and soft tissue infections
Virulence factor of B. fragilis
produces enterotoxin - fragilysin: zinc protease that stimulates fluid secretion causing enteritis in calves, piglets, foals, infant rabbits and children
Describe prevotella spp
largest single bacterial group from rumen of cattle and sheep undder most dietary
