bacteriology 7 Flashcards
gram positive cocci that form chains
streptococci
facultative anaerobic
where are streptococci
widely distributed in nature
most commonly found on animal and humans
mucus membranes of URT, lower genitourinary tract and GIT
also on skin
may live in the environment as saprophytes
part of normal flora
strep zooepidemicus
carrier animals
strep equi
streptococci virulence factors
avoiding phagocytosis
killing phagocytes and causing inflammation
but species causing disease in animals do not have intracelluar survival
avoid phagocytosis
m protein-major virulence for strep
anti-phagocytic properties-PMN and macrophages
induces antibody production (currently used in vaccines)
capsules-only on some strains and species
killing phagocytes
wide range of different exotoxin
hemolysin-cytotoxic for RBC, WBC and platelets
beta-clear and kill RBC-horses,cattle, dog
alpha-green-cattle, human and dog
gamma-no hemolysis-non-pathogenic
streptococcal disease tend to be
acute (Short duration)-cleared with production of protective antibodies
type of hypersensitivity reaction
type III observed in streptococcal disease
strangles
strep equi equi
cervical lymphadenitis
contagious disease of horses
mastitis
cow
strep agalactiae-contagious in a carrier state
strep dysgalactiae
strep uberis
pneumonia
lower respiratory tract infections
normal flora of URT causes these infection
strep zooepidemicus-dog and pig (horse)
strep canis-dogs and cats
streph equisimilis-pig
neonatal septicemia
observed in range of species including foals, piglets, puppies and kittens
localization in many other body sites can occur
endometritis in mares
strep equi ss zooepidemicus
most common cause of endometritis which is a major disease in broad mared
necrotising fasciitis
grp g (strep canis) dogs and cats
grp a (strep pyogenes) human
treatment
ancillary therapy
antibiotic
ancillary therapy
drainage (thickened walled abscesses)
nursing care
antibiotics
beta-hemolytic strep are predictably sensitive to penicillin
but antimicrobial therapy may or may not be indicated
strep are frequently resistant to fluoroquinolones, aminoglycosides and tetracyclines
alpha-hemolytic and enterocci commonly have broader resistance to antibiotics including penicillin
gram positive, club shaped rods, facultative anaerobes
trueperella pyogenes
corynebacterium
c pseudotuberculosis
c renale
trueperella pyogenes
normal flora on mucus membranes and skin of ruminants and pigs
c pseudotuberculosis
nf skin and mucous membranes and git
environment (8 months)
lesions of infected animals-act as reservoirs
c renales
present in the genital tract of carrier cows and bulls
virulence factors
exotoxin-pyolsyin and phospholipase
trueperella pyogenes and c pseudotb
pili and urease production-c renale and t pyogenes
facultative intracelluar bacteria-c pseudotuberculosis
trueperella pyogenes
most common cause of pyogenic infections in cattle and pigs
lesions
initiated by trauma/viral infection
lesions may be localised, regional or metastatic
caseous lymphadentis (CLA) cheesy gland
corynebacterium pseudotuberculosis
economically important in sheep and goats
infection of superficial lymph nodes
requires break in skin
may disseminate (thin ewe)
pigeon breast/pigeon fever
corynebacterium pseudotuberculosis
disease of horses
thick walled abscesses
ulcerative lymphangitis
corynebacterium pseudotuberculosis
horse and cattle
hind limbs
spread via lymphatic with ulcerating lesions
infectious pyelonephritis
corynebacterium renale
disease in cows
ascending infection
hemorrhagic cystitis, ureteritis, pyelonephritis
pizzle rot (balanoposthitis)
corynebacterium renale
sheep-ram and whethers
increase protein in feed leads to increase urea in urine
produces urease with breaks down urea to ammonia which cause irritation of skin of preputial opening and which bacteria can invade
signalment(Species, history and clinical signs)
c renale
c pseudotuberculosis
obtain sample from lesion if in sterile site
pus, effusion (trueperella as for staph and strep)
perform a gram stain/diff quik
would see short rods (Streps)
culture
definitive diagnosis
surgical debridement/excision/drainage
important aspect of therapy
antibiotics
not effective in chronic cases as bacteria are inside abscess with a thick capsules which means poor penetration
if ruminants are involved, they may not be worth the cost of prolonged therapy
