final exam 2 Flashcards
staphylococcus, streptococcus, bacillus, enterococcus, and clostridium are
gram +
gram positive disease is mostly from secreted
toxins
low amt of guanine-cytosine nucleotide base pairs versus adenin thymine nucleotide pairs
low G and C bacteria
high amount of guanine cytosine nucleotide base pairs versus adenine-thymine nucleotide base pairs
high g and c bacteria
prefer to grow in environments with oxygen for aerobic respiration but can grow and survive in environments without oxygen
facultative anaerobe
lack flagella
non-motile
which of staph is the most virulent strain
staph aureus
normal microbiotoa of the human skin but can cause opportunistic infections in very rare cases
staph epidermidis
what agar is used to identify between staph
MSA
which staph ferments mannitol
aureus and changes it to yellow
when is infection resulted in for stpah
when it breaches skin or mucous membrane to reach blood
extracellular enzymes of staph
cell-free coagulase, staphylokinase, hyaluronidase, lipases, and b-lactamase
reacts with prothrombin causing the inactive fibrinogen to convert to the active fibrin
cell free coagulase
dissolves fibrin causing blood clots to breakdown or dissolve
staphylokinase
this enzyme allows bacteria to pass between cells in the epidermis by breaking hyaluronic acid
hyaluronidase
breaks down lipids and oil for energy on the skin allowing staphylococci to grow on surface of skin and in cutaneous oil glands
lipases
gives antibiotic resistance as this enzyme breaks open and destroys beta lactam ring found in all beta lactam antibiotics such as penecillin
b-lactamase
binds to antibodies blocking the location where phagocytes grab onto the antibodies during phagocytosis
protein A
inhibit leukocyte chemotaxis and phagocytosis
slime layer
binds and weakens or destroys the plasma membrane
cytolytic toxin
specifically find to and destroy all leukocytes
leukocidin toxin
breakdown desmosomes causing skin cells to separate and slough off
exfoliative toxins
stimulate intestinal contraction nausea and intestine vomitting
enterotoxins
study of incidience, distribution and control of disease
epidemiology
which staph is found everywhere on human skin
staph epidermidis
which staph is only found on moist skin folds
staph aureus
staph grows in
UR, GI and urogenital tracts
how is staph transmitted
direct contact or fomites
you only need the toxin from the pathogen in your body to get the disease
noninvasive disease
blistering and peeling of the skin due to exfoliative toxins
scalded skin
formation of red sores that eject fluid and leave and amber colored scab, infectious and contagious
impetigo
impetigo and scalded skin are
cutaneous diseases
example of non invasive disease
food poisoning
diseases that are spread throughout the body
systemic disease
presence and spreading of the bacteria in the blood
bacteremia
the bacteria attack and damage the lining of the heart which causes the amount of blood pumped by heart to drop rapidly
endocarditis
inflammation of the lungs
pnuemonia
inflammation of bone and bone marrow
osteomyelitis
what are commonly used to treat staph
semisynthetic penicillin-methicillin or vancomyocin for those that do not respond
partially break down and green
alpha
completely breaks down clear
beta
no breakdown
gamma
characteristics of group a strep
white colonies, beta hemolysis, capsules
what represents the vast majority of group a
s. pyogenes
interferes with opsonization and digestion of bacteria by lysozome
m protein
act as camoflauge preventing detection by leukocytes
hyaluronic acid capsule
m protein and capsule are what features
antiphagocytic structures
kinases specifically produced by strep that break down blood clots allowing their rapid spread through infected and damaged tissue
streptokinases
unwind and destroys DNA released by dead cells in infection sites. reduces firmness of puss allowing for quick spread of the bacteria
deoxyribonucleases
a class of proteins that breakdown red blood cells, white blood cells and platelets
streptolysins
group a strep infects the
pharynx or skin
group a strep often causes disease when
normal microbiota is depleted
how does group a strep spread
through respiratory droplets
inflammation of the pharynx, most infections start this way and limited to this region of the body, when spread is can cause rheumatic and scarlet fever
streptococcal pharyngitis
this typically develops from untreated streptococcal pharyngitits, characterized by inflammation that damages heart valves and muscle
rheumatic fever
develops from untreated or secondary to streptococcal pharyngitis, characterized by rash on chest that spreads throughout body
scarlet fever
trigger rash and cause tounge to appear strawberry red
pyrogenics
characterized by bacterial infection in fascia
necrotizing fasciitis
sheet of connective tissue, primarily composed of collagen that rests beneath the skin
fascia
what is effective in group a strep treatment
peniccilin
what does rapid strep test look for
group a specific antigens
what represents majority of group b strep
strep agalctiae
can distinguish group B from group A by
group specific antigens, smaller zones of beta hemolysis, and resistant to bacitracin
group b strep typically infects
newborns
group b strep colonizes in
gi, urogenital tracts
diseases in adults usually follow
wound infections and childbirth
swelling in membranes covering the brain and spinal cord
meningitis
test used to identify group B step
enzyme linked immunosorbent assay
group b strep treated with
penicillin or ampicillin
