chapter 15/16 study questions Flashcards
examples of genotypic methods of identification
PCR and DNA sequencing
advantages of genotypic methods
affordable, fast, better patient outcome
agglutination is an __________ method
immunologic
examples of phenotypic
optimal pH for growth
enzymatic growth
susceptibility to tetracycline
currently, ______ methods are being used exclusively as a means to identify bacteria
genetic
what is not an advantage of genotypic methods
does not require sophisticated equipment of traingin
performing an assay for the presence of oxidase or determining susceptibility to antibiotics are _______ methods of bacterial identification
phenotypic
undesirable contaminant b/c of its large normal biota
saliva
common sampling sites
vein
mouth
throat
skin
aseptic technique to obtain a urine sample
catheter
washing the external urethra and collecting urine midstream is known as
clean catch
methods to collect saliva or mucus samples from oral and nasal cavities
expectoration
discharge by coughing
swabs
blood, tissue fluid, and CSF are considered
sterile
what is one of the most rapid ways of determining the general characteristics of a specimen
microscopic observation
best way to distinguish streptococcus from micrococcus
catalase assay
selective media should be used to enrich a patient sample for a suspected pathogen when _______
the pathogen is present in small numbers
the normal biota will grow faster then the pathogen
physiological reactions to nutrients and other substrates provide indirect evidence of the types of ________ expressed in a particular species
enzymes
best way to distinguish Neisseria from staphylococcus is
gram stain
The MGIT system is a phenotypic method used to detect
growth of mycobacterium tuberculosis
in differential media, the presence of an enzyme in an organism is often visualized by a change in
color of medium
biochemical testing to detect the presence of an enzyme is performed using
the enzyme substrate conjugated to a dye
tuberculosis needs MGIT system b/c
it is slow to grow in a lab
which microbes require the inoculation of cell culture to be cultivated in the lab?
Chlamydia
Influenza
Rickettsia
testing that is based on visualization of a specific antibody-antigen reaction, where the use of a known antigen can identify the presence of an unknown antibody, vice versa
serological testing
which of the following bacteria require the inoculation of specific animals for the microbes to be cultivated in the lab?
Mycobacterium leprae
Treponema tuberculosis
when the antigens are whole cells or organisms, antigen-antibody is observed as ________ in immunologic testing
agglutination
the formation of an insoluble aggregate when an antibody combines with a soluble antigen is termed
precipitation
what test matches with Weil-Felix test for rickettsial infection
agglutination
ABO blood typing is accomplished using a _______ test
agglutination
immunochromatography (lateral flow test) is often used for
point of care strep tests and rapid preg tests
technique that utilizes antigen-antibody reactions to cell parts such as flagella, cell wall capsules to group bacteria into categories
serotyping
immunologic method often used to differentiate between strains of salmonella, pneumococcus, streptococcus
serotyping
what diseases are diagnosed by determining antibody titer in the serum?
HINT: autoimmune diseases
lupus
rheumatoid arthritis
test that involves the separation of proteins in a gel, followed by immunoassay to detect the presence of specific protein antigens, is called
western blot test
in immunofluorescence testing, fluorescent ___ is combined with specific antibody to provide a sensitive test for the presence of a specific antigen or antibody
dye
test that uses fluorescent labeled antibodies to determine the presence of a specific microbe in a specimen, is called the ________ immunofluorescent test
direct
a test that employs an enzyme-antibody complex that can be used to produce a visual color change, indicating an antibody-antigen reaction, is called __________; is visualized with color change in substrate
ELISA
steps of Western Blot
electrophoresis of sample
transfer to a filter
incubation with radioactive or fluorescent labeled antibodies
Indirect ELISA detects ______ in a sample; DIRECT ELISA detects unknown ________ in a sample
antibody
antigen
what test is used to verify false positives in indirect ELISA test?
western blot
steps of indirect ELISA
- known antigen is adsorbed to surface of wall
- serum sample with unknown antibodies is added
- enzyme-antibody complex that is specific for Fc portion of antibody is added
- substrate for the enzyme is added
- color changes in well are observed
examples of in vivo test
allergen skin test
tuberculin test
which characteristic of an immunologic test insures that it will have a lot rate of false-positives?
specificity
indirect ELISA is commonly used to test for
helicobacter
hep a and c
rickettsias
HIV
PCR test that used fluorescent labeling during DNA amplification is
real time
rPCR
technique that matches complementary strands of nucleic acid to locate specific sites or types of nucleic acid is
hybidization
application of fluorescently labeled PROBES to intact cells within a pt specimen is known as _______ technique
FISH
microarrays for infectious disease diagnostics are chips that contain _____ from possible infectious agents
gene sequences
whole genome sequencing involves
sequencing nucleic acids from patient samples
PFGE advantage
accuracy in assessing microbial subtype
whole genome sequencing is particularly useful for rapid analysis of
drug resistant organisms
disease outbreaks
advantaged of labs on chips
can be used by technicians with little specialized training
require few supplies
________ is becoming common in many clinical laboratories for the identification of microbes b/c it can provide, rapid, precise, and cost-effective results
mass spec
lab on a chip tests
DNA and RNA sequencing and PCR
MALDI-TOF
mass spec
antibiotic testing (new testing method)
test host cells for seven genes in response to infection by bacteria (they express genes) BUT will NOT express genes for viruses
components of integ
hair
sweat and oil glands
skin
nails
bottom layer of cells in epidermis
stratum basale
bas= basement
list some components of dermis
nerves
blood vessels
lymphatic vessels
collagen fibers
separation of dermis and epidermis =
blister
___ charged antimicrobial peptides of the skin can disrupt the ___ charged membranes of bacteria to prevent infection
+
-
cells of stratum corneum are dead and packed with a protein called
keratin
how are oil (sebum) gland secretions antimicrobial in nature?
release antimicrobial fatty acids as the oil breaks down
primary type of tissue in the dermis?
hint: think collagen
connective
the _____ has a dense microbial population
groin
in addition to the skin, microbes can populate which of the following
glandular ducts
hair follicles
_________ is an enzyme found in sweat that breaks down peptidoglycan found in bacterial cell walls
lysozyme
describe S. aureus
nonmotile
destructiveness due to superantigens
sweat has a ____ pH, and a _______ salt concentration = antimicrobial
low
high
staphylococcus is found in
normal biota of many people
strains of MRSA are usually resistant to ________ antibiotics
multiple
under which conditions would S. aureus survive?
heating to 35C for 60 minutes
heating to 55C for 60 minutes
S. aureus is (traits)
G +
coccus
grows in grape like clusters
approx. __% of people have S. aureus in their normal skin biota
3-%
MRSA infection qualities
skin tends to be raided, red, tender. localized lesions, often with pus and are hot to touch
MRSA
can withstand high salt concentration
withstand extreme pH
very hardy, can remain viable for months in air
S. aureus has become troublesome in hospitals b/c
remains viable after drying
is resistant to many disinfectants
is resistant to many antibiotics
what enzyme is not produced by strains of S. aureus
streptokinase
microbial medium _______ _______ agar is often used to isolate staphylococcus species because of its high salt content that mimics the skin
mannitol salt agar
_____ is an enzyme that breaks down the hydrogen peroxide produced in oxidative metabolism
catalase
list some enzymes expressed by strains of S. aureus
Staphylokinase DNase Lipase Hyaluronidase Coagulase
which test is used to diagnose MRSA?
PCR
a diagnostic test for which of the following enzymes differentiates staphylococci from streptococci
catalase test
current antibiotic tx of MRSA
vancomycin
measles
syncytial; flat redness; main trans = resp droplets and direct contact; KOPLIK’S spots
some practices that would be likely to spread MRSA
not sanitizing gym equipment
sharing a razor
tx of MRSA may include
tx with more than one antibiotic
incision of the lesion to drain pus
measles is caused by a
virus
what is the cause of many deaths of measles world wide
low herd immunity
subacute sclerosing panencephalitis (progressive neurological degeneration of cerebral cortex - complication of measles)
initial s and s of measles
sore throat, dry cough, headache, conjunctivitis, lymphadenitis, and fever
measles starts at the ______ and spreads to
head
whole body
“slapped face” rash, spreads to limbs and trunk
fifth disease
rash not always present
roseola
in SSPE (measles) what areas of the body are degenerated
white matter, brain stem, cerebral cortex
measles virus contacts and infects skin by which method
travelling through the blood stream
the ______ virus tends to erase or diminish the immune system’s memory for other microbes
measles
steps in pathogenesis of measles virus
the virus infects cells in the resp mucosa
virus is carried in the blood stream
virus infects cells in the skil
what period is someone with measles not contagious
convalescent period
what aspects of immunity are often disabled by measles
cell-mediated immunity
delayed-type hypersensitivity
which antibody is detected in a patient with measles when ELISA is used?
IgM
typical age for first dose of measles
12-15 months
tx for measles may include vitamin
A
rubella/german measles “little red” (think minor rash)
- two doses of MMR confer protection for about 20 years
- rash of pink macules and papules first appears on face, and progressed down trunk
- resolving in about 3 days
- adult rubella = joint inflammation and pain rather than rash
what sign/symptom often differentiates postnatal rubella from adult rubella
mild rash
tx ofr measles
vitamin A
reducing sx
replacing lost fluid
normal modes of trans for fifth disease
resp droplets
direct contact
defects of congenital rubella
ocular lesions deafness cardiac abnorms mental/physical retardation miscarriage
causative agent of rubella
Rubivirus
rubella can spread through
resp secretions
urine
diagnosis of rubella
ELISA
latex agglutination card
common defect with congenital rubella
deafness
coongential rubella effects on fetus
stop mitosis
induce apoptosis
damages vascular endothelium
fifth disease rash
slapped face
confluent rash starting on the face and spreading to limbs and trunk
rubella virus is shed during _______ phase and up to a week after rash appears
prodromal
causative agent for fifth disease
Parvovirus-19
desrcibe Roseola rash
if rash appears, it is usually preceded by fever
roseola is usually caused by
Herpesvirus HHV-6
primary victims of impetigo
preschoolers
superficial bacterial infection that causes the skin to flake and peel off; highly contagious; caused by S. aureus or Streptococcus pyogenes or a mix
“honey colored scabs” itchy
impetigo
complication associated with untreated impetigo
glomerulonephritis
s. aureus impetigo toxins
exfoliative toxins A or B, coagulase, other enzymes (DNase, catalase, Staphylokinase…)
seen more often in adults and children
streptococcus pyogenes impetigo virulence factors
Streptokinase, plasminogen-binding ability, hyaluronidase, M protein
seen more often in newborns
S. pyogenes is a gram _____ bacterium that is _____-hemolytic on blood agar
+
beta
what infections does S. pyogenes cause besides impetigo
streptococcal pharyngitis (strep throat), scarlet fever, pneumonia, puerperal fever, necrotizing fasciitis, serious bloodstream infections, and poststreptococcal conditions such as rheumatic fever
common places for impetigo lesions
face, extrems
which skin regions are usually involved in cellulitis
dermis
subcutaenous tissue
sx such as pain, tenderness, swelling , fever, and LYMPHANGITIS are characteristic of
cellulitis
what do the exfoliative toxins A and B do in S. aureus impetigo infection
they attack cell to cell binding proteins in the epithelium
what can cause cellulitis
S. pyogenes
S. aureus
opportunistic bacteria
Group b streptococcus
most common age group to experience SSSS infections
infants
what percent of adults are asymp of SSSS
30%
where does S. aureus harbor on body
nasopharynx, axilla, perineum, and vagina
s and s of SSSS
bullous lesions (caused by exfoliative toxins A and B)
desquamation
split in skin within epidermis
SSSS is a ______ skin syndrome
dermolytic (damage/kills the skin)
SSSS is most effectively diagnosed through histological examinatino of tissue from a _____
lesion
s and s of chicken pox
centripetal lesions
superficial lesions
fever
itchy vesicles
which diseases present as generalized rashes with fluid-filled lesions
small pox
chicken pox
incubation period for chicken pox
10-20 days
chickn pox usually lasts dor
4-7 days
some cases of CP end up with complications leading to _______ (only 0.1% approx)
encephalitis
adolescents and adults have the _____ number of CP lesions
highest
shingles is characterized by an asymmetrical rash of the skin on the _____ or _______
trunk head
sx of shingles
tender persistent vesicles
Zostavax is intended fro adults aged ____ and over
60
small pox vaccine is based on ________ virus
vaccinia
cutaneous anthrax is normally transmitted by which of the following methods
direct contact with endospores
contact with infected animal hides
t or f
Leishmania only multiplies in macrophages
true
group of fungi responsible for a wide variety of skin and nail conditions
dermatophytes
general signs and sx of ringworm infections
itchiness and skin/nail lesions
causative agent for ringworm
vary with geographical region
general term for fungal infections of skin, hair, or nails
mycoses
what are not s and s of ringworm infections
macopapular exanthem
large pustular lesions
necrotic papules
properties that promote pathogenesis of dermatophytes
they can suppress immune system and invade and digest keratin
tinea versicolor is caused by
Malassezia furfur
