Skin and Wound I Flashcards
treponema spp. general characteristics
- spirochete
- gram neg staining not true gram neg(w/ 2 membrenes outer no lps; have cell wall)
- flagella in periplasmic space
- anaerobes
treponema spp. found where
- environement
- mucosal surfaces and digestive tract
- feet of infected animals
treponema spp. spread how
- direct contact
- indirect contact
- effected when we underwood especially in fecally contaminated environment (bacteria from digestive tract into environment)
treponema spp. cause what
- bovine digital dermatitis “hairy foot” “hell wart”
treponema spp. see what
- ulcerative or proliferative lesions along coronary band typically affects hind feet
- lameness
treponema spp. affects who
diary cows > beef
treponema geography
in Europe more ulcerative lesions
in us more granulomatous/ proliferative type lesions
skin lesions can be spread to feet when its wet underfoot why
When wet underfoot -> masceration of skin -> tight juncitons between cells dec so this can get in
fusobacterium necrophorum general characteristics
- gram neg
- bacilli or fillamenous
- obligate anerobes
fusobacerium necrophorum natural inhabitation of
mucous membranes
fusobacteirum necrophorum spread how
- persistent soaking on wet pastures (breaks in skin make animal susceptible to foot infections)
fusobacterium necrophorum causes what in who
- affects cows -> interdigital dermatitis (foot rot) (not for this week but also causes calf diphtheria in GI tract)
- horses -> thrush (same kind of dx as cows diff name)
- foot dx small ruminants
fusobacteirum necrophorum see what in cows
- fissures in interdigital space
- foul smelling
- lameness
- starts btwn digits often stays there
- usually just one foot on animal effected, often mult animals in same environment effected at once
testing trephanimes
- pcr for trephanimes (usually dont test organism in foot dx)
testing for fusobacterium necrophorum
- culture and grow acerbically (usually dont test organism in foot dx)
tx bovine foot dxs (treponema and fusobacteirum necrophoru)
- trim hooves
- antibiotics (topical, foot bath)
- improve hygine
- fence wet areas
causative agents foot dx in small ruminants
- dichelobacter nodosus
- fusobacteirum necorphorum
- fusobacteirum necrophorum starts things off causing damage to interdigital epidermis persistent soaking on wet pasture then dichelobacter nodosus comes in -> damage
dichelobacter nodosus general characteristics
- gram neg
- obligate anaerobe
- bacillus
- swelling at end of bacilli can be helpful to ID
dichelobacter nodosus causes what in who
- footrot in small rumiants (interdigital swelling then invasion of epidermal structures)
dichelobacter nodosus see what
- lamness (loss of hoof sole)
- foul smelling lesions
foot rot in small ruminants diagonsis
- clinical presentation
- gram neg rods in exudates (dichelobacter nodosus)
foot rot small ruminants tx
- removal and exposure and diseased tissues (expose to o2)
- topical disinfectants or antibiotics
- ideally catch when early (just fusobacterium necrophorum) and segregate infected from non infected
- vac w/ bacteria helpful not totally preventable though
dermatophyte infections include
- ringworm
- tinea
- dermatophytosis
dermatophytes of interst
- trichophyton spp.
- microsporum spp.
- both in asexual forms
dermatophyte general characteristics
- obligate anaerobes
- macroconidia, microconidia formed off aerial hyphae in free living form (diff candid depending on where formed)
- arthrocondida in parasitic form
- ZOONOTIC
dermatophyte found where
- geophillic (soil)
- zoophlic
- antrhophillic (ppl)
- dnt like temps > 35 degrees c so keeps lesions superficial
dermatophyte spread how
direct and indirect contact
dermatophytes cause what broadly and how
fungal skin dxs by making keritinases so can live in keratinized tissues
ringworm see what
- erythema or vesicles or pustules
- usually circular lesions bc fungi move out radially from initial inoculation site; active fungal growth at edge of rings (this is also where host response to fungi is)
- alopecia with scaling or crusting
- self limiting
- generally infection in younger animals
- generally not pyritic (animal not itchy)
dermatophytoses pathogenicity
- conidia germinate in host after entering via breaks in stratum corneum mycelium grow along cornfield epithelium and w/ in hair
- grow in to hyphae after time hyphae differentiate into arthrocondida (repro form) which can be spread
- produce keritinase and other proteases allowing them to colonize keratinized tissues
- inflam response to fungi radiating form site of inoculation -> ring shaped lesion
dermatophytoses lesions
- lesions often circular
diagnosis of dermatophytoses
- woods lamp for Microsprum canis (doesn’t tell you for sure that its ring worm)
- examine hair/ scales in mineral oil
- tx hair/ scales w/ Koh for hyphae and arthrocondida
- fungal culture (dermatophyte test medium for up to 3 weeks, characteric macroconidia)
dermatophyte test medium works how
- 10 days see saprophytes (change color of media)
- dermatophytes grow slow so see slower change color or media
differentiation dermatophytes
- macrocondida from microsporum spp. and trichophyton spp. look v different so can tease off areas where there are hyphae and look at these in culture under microscope
- rRNA sequencing
tx dermatophytes
- topical antifingals
- systemic tx
- these are self limited but v contagious which = why treat
- vac for trichophyton verrucosum but not really used in us but yes used in Europe
staphylococcus pseudintermedius general characteristics
- gram pos
- fac an
- coccus
- clusters
staphylococcus pseudintermedis infections general
- primarily superficial
- humans can be transiently colonized w/this one but this is primarily in animals
staphylococcus pseudintermedius natural inhabitatng
mucusouls membranes of skin
staphylococcus pseudintermedius infeciton predisposing factors
- endogenous infection
- skin dx
- (normal flora overgrows -> staph infection)
staphylococcus psuedointermedius causes what in who
- pyoderma usually in dogs
- rarely also in cats
staphylococcus pseudintermedius usually see what
- papular lesions initially then pustules then folliculitis
- often also allopecia
- lesions usually start in moist areas (neck areas)
staphylococcus pseudintemedius outcome determinents
- host factors = key determinant
- confection w/ normal commensals of skin = possible
staphylococcus pseudintermedius diagonsis
- skin scarping
- direct impression smear (gram pos cocci in large numbers = indicative of this )
- culture if evidence mixed infection or if tx fails ot resolve signs in 6 weeks
staphylococcus pseudintermdis tx
- systemic ab therapy w/ topical ab shampoos
- bc pt of normal commensal point is to prevent underlying dx or whatever is -> overgrowth not get rid of this completely
