bacteriology 6 Flashcards
Gram positive cocci
staphlococci
streptococci
Gram negative cocci
none
gram positive rods
actinomyces
nocardia
dematophilus
cortnebacterium
rhodococcus
trueperella
gram negative rods
oxidase negative
e. coli
salmonella
yersinia
klebsiella
pyogenic
acute inflammation
predominantly neutrophils
pyogranulomatous
mix of chronic and acute inflammation
see a mixture of cells
PMNs (eosinphils, basophil, neutrophil)
macrophages
lymphocytes
(eosinophils if fungal)
granulomatous
chronic inflammation where classically see central necrosis surrounded by giant epithelioid cells, macrophages, lymphocytes, some granulocytes and surrounded by a thick fibrous capsule
necrotizing
acute inflammation where classically see just cellular debris
potentially a few toxic, inflammatory cells and causative bacteria
pyogenic bacteria cause suppurative inflammation primarily….
by acting as extracellular bacteria
clusters
gram positive cocci
facultative anaerobes
can culture with or without O2
staph aureus
human and horses (other speices)
staph pseudintermedius
dogs
coagulase positive
staph pseudintermedius
staph aureus
Where are coagulase positive staphylococci found?
Normal flora-skin (mucocutaneous junctions-moist areas of the body) distal nasal passage, external nares and near rectum
may also be found in animal products and in the environment due to contamination
live long in environement
coagulase negative staphylococci may be found?
on skin (Also normal flora)
staphylococci are what kind of pathogen?
opportunistic
Staphylococci virulence factors
staph are good pathogen and require little host compromise
factors that help
capsule or pseudocapsule
exotoxin
intracellular survival
biofilm formation
others
capsule or pseudocapsule
anti-phagocytic properties
major defense mechanism
coagulase negative staph pathogenicity
non-pathogenic and are easily phagocytosed and killed easily
exotoxin
hemolysin/leukotoxin
cytotoxic (damage cells) and lethal
leucotoxin also kill phagocytes and evades immune system
facultative intracellular bacteria
allows staph aureus to
evade killing by phagocytes
evade immune system (Antibodies)
evade antibiotics which act extracellularly
underlying disease process is usually one of suppuration and abscess formation
pyogenic infection
bacteria that cause pyogenic infection
pyogenic bacteria
staphylococci
streptococci
corynebacteria
trueperalla
staph vs strep
staph can live intracellularly
abscesses involving staph may be more chronic
pyoderma in dogs
staph pseudintermedius is most common cause of pyoderma in dog
staph aureus causes pyoderma in other species (horses, birds(bumble foot))
mastitis
staph aureus in dairy cows, sheep and goats
musculoskeletal infection
discospondylitis
osteomyelitis
septic arthritis
urogenital tract infection (UTI)
cystitis
pyelonephritis
prostatitis
implant infection
coag negative and positive
staph spp may be involved
associated with significant host compromise
production of biofilms
treatment failure
treat underlying disease
treat staphylococcal infection and other organisms
must use appropriate antibiotics (may need susceptibility test)
treat for a long time
need owner compliance
