Lecture 9+10+DLA Flashcards
probability rule of one
informs us of the likelihood of it occurring, can range anywhere from 0 (indicating that the event will
never occur) to 1 (indicating that the event is certain).
probability rule of two
the sum of all the probabilities is one
probability rule of three
the probability that an event does not occur is 1 minus the probability that it does occur
P(A) = 1 - P(not A)
probability rule four
Events that cannot occur at the same time are called disjoint or mutually exclusive
If A and B are disjoint events, then P(A or B) = P(A) + P(B)
general addition rule
A and B are not mutually exclusive events
P(A or B) = P(A) + P(B) – P(A and B)
multiplication rule
the probability of two events happening at the same time
The general multiplication rule (has to do with conditional probability)
The specific multiplication rule:
The specific multiplication rule:
P(A and B) = P(A) * P(B), is only valid if the two events are independent
only works if one probability does not change the probability of the other event
power equals
power = 1 - beta
Power is the ability to correctly reject a null hypothesis that is indeed false.
Actinomycetes
bacteria that form long branching filaments
important genus:
actinomyces and nocardia
Actinomyces israelii
gram + branching filamentous
anaerobic, commensal oral and GI flora
Forms opportunistic abscesses in anoxic tissue
periodontal disease (can lead to lumpy jaw)
Foul-smelling, draining sulfur granules are notable
Can form slow granulomatous abscesses in any tissue
mycolic acids and acid fast stain (Ziehl-Neelsen stain)
form a thick lipid waxy layer that limits nutrient uptake and thus slow growth
the thick lipid wall interferes with staining and protects the bacteria
what species need to be stained by the acid fast
Mycobacterium species and Nocardia
Nocardia asteroides (Nocardiosis)
acid fast branching filamentous
weakly gram +
aerobic
Exogenous transmission via inhalation of dust particles
Forms opportunistic abscesses:
Pulmonary cavitation disease is more common
More severe in immuno-compromised patients
Mycobacterium tuberculosis (TB)
Transmission through air droplets originating from cough
In the lungs, M. tuberculosis is phagocytized by alveolar macrophages but they are unable to kill the bacterium due to its unique thick lipid cell wall (cord factor)
M. tuberculosis is facultative intracellular and poorly controlled in individuals with low Cell-Mediated Immunity
Granulomas are formed over weeks to months due to the production of cytokines and upregulation of proteins involved in recruitment, which also lead to host tissue damage.
Mycobacterium leprae (Leprosy)
obligate intracellular bacteria
replicates in the macrophages and nerve cells
Transmission is thought to involve coughing and sneezing or by prolonged contact
can have: both lead to loss of sensation
lepromatous leprosy: more severe
tuberculoid leprosy = less severe
M. marinum (skin infections)
found in bodies of fresh and salt water
usually uncommon, usually due to contact with fish
due to small cut or skin scrape
The first signs of infection with M. marinum include
a reddish or tan skin with a granuloma
Mycoplasma species general
do not have a cell wall
smallest prokaryote
sterols in membrane
Mycoplasma pneumoniae
transmission is by air droplets
Most common cause of “Walking pneumoniae” or
“atypical pneumonia”, associated with a dry persistent
cough over weeks
does not gram stain due to no cell wall; so cannot use beta lactams
Mycoplasma genitalium & Ureaplasma
STI’s
in women:
PID
painful sex
vaginal bleeding or discharge
in men:
urethritis
stinging and burning during urination
discharge
can cross placenta and lead to SA or premature birth
Chlamydia species
obligate intracellular
has a cell wall but no peptidoglycan
does not gram stain
resistant to beta lactams
depend on host for ATP
Elementary body (EB) : infectious form Reticulate body (RB) : replicative form
Chlamydia trachomatis
STI and trachoma
Chlamydia pneumoniae
pneumonia
human to human by aerosols
Chlamydia psittaci
(Psittacosis)
Zoonotic respiratory disease from birds
presents in the lungs and other organs
Chlamydia trachomatis Urethritis
most common bacterial STI/STD in the US
males are more likely to be symptomatic
pain from urination
clear discharge
Chlamydia trachomatis Cervicitis
most females are asymptomatic
untreated infection can lead to transmission to baby
PID
ectopic pregnancy
sterility
pap smear can detect intracytoplasmic inclusions
Rickettsia
obligate intracellular
does not stain and resistant to Beta lactams
transmitted by arthropod bite
Multiply at the site of arthropod attachment and often produce a local lesion
Penetrate the skin or mucous membranes, multiply in the endothelial cells of small blood vessels, causing vasculitis
Rickettsia rickettsii
Rocky Mountain Spotted Fever
onset is 7 to 14 days after a tic bite
high fever and lymphadenopathy
endovasculitis (rash on palms and soles)
Spirochaetes bacteria
unique structure with endoflagella
require special microscopy
Treponema pallidum
Causative agent of Syphilis
Transmitted by sexual contact or transplacental
Borrelia burgdorferi
Causative agent of Lyme Disease
Transmitted by tick bite
another name for null and alternative hypothesis?
Null = H0
Alt: H1 or HA
null hypothesis is rejected if
if the P value is less than alpha
if the P value is more than alpha the null is correct
Type I error
also known as a false positive
rejecting the null, when the null is true
Type II error
false negative
not rejecting the null when the null is not true
stat power
power = 1 - beta
