chapter 15/16 study questions Flashcards
1
Q
examples of genotypic methods of identification
A
PCR and DNA sequencing
2
Q
advantages of genotypic methods
A
affordable, fast, better patient outcome
3
Q
agglutination is an __________ method
A
immunologic
4
Q
examples of phenotypic
A
optimal pH for growth
enzymatic growth
susceptibility to tetracycline
5
Q
currently, ______ methods are being used exclusively as a means to identify bacteria
A
genetic
6
Q
what is not an advantage of genotypic methods
A
does not require sophisticated equipment of traingin
7
Q
performing an assay for the presence of oxidase or determining susceptibility to antibiotics are _______ methods of bacterial identification
A
phenotypic
8
Q
undesirable contaminant b/c of its large normal biota
A
saliva
9
Q
common sampling sites
A
vein
mouth
throat
skin
10
Q
aseptic technique to obtain a urine sample
A
catheter
11
Q
washing the external urethra and collecting urine midstream is known as
A
clean catch
12
Q
methods to collect saliva or mucus samples from oral and nasal cavities
A
expectoration
discharge by coughing
swabs
13
Q
blood, tissue fluid, and CSF are considered
A
sterile
14
Q
what is one of the most rapid ways of determining the general characteristics of a specimen
A
microscopic observation
15
Q
best way to distinguish streptococcus from micrococcus
A
catalase assay
16
Q
selective media should be used to enrich a patient sample for a suspected pathogen when _______
A
the pathogen is present in small numbers
the normal biota will grow faster then the pathogen
17
Q
physiological reactions to nutrients and other substrates provide indirect evidence of the types of ________ expressed in a particular species
A
enzymes
18
Q
best way to distinguish Neisseria from staphylococcus is
A
gram stain
19
Q
The MGIT system is a phenotypic method used to detect
A
growth of mycobacterium tuberculosis
20
Q
in differential media, the presence of an enzyme in an organism is often visualized by a change in
A
color of medium
21
Q
biochemical testing to detect the presence of an enzyme is performed using
A
the enzyme substrate conjugated to a dye
22
Q
tuberculosis needs MGIT system b/c
A
it is slow to grow in a lab
23
Q
which microbes require the inoculation of cell culture to be cultivated in the lab?
A
Chlamydia
Influenza
Rickettsia
24
Q
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
A
serological testing
25
which of the following bacteria require the inoculation of specific animals for the microbes to be cultivated in the lab?
Mycobacterium leprae
| Treponema tuberculosis
26
when the antigens are whole cells or organisms, antigen-antibody is observed as ________ in immunologic testing
agglutination
27
the formation of an insoluble aggregate when an antibody combines with a soluble antigen is termed
precipitation
28
what test matches with Weil-Felix test for rickettsial infection
agglutination
29
ABO blood typing is accomplished using a _______ test
agglutination
30
immunochromatography (lateral flow test) is often used for
point of care strep tests and rapid preg tests
31
technique that utilizes antigen-antibody reactions to cell parts such as flagella, cell wall capsules to group bacteria into categories
serotyping
32
immunologic method often used to differentiate between strains of salmonella, pneumococcus, streptococcus
serotyping
33
what diseases are diagnosed by determining antibody titer in the serum?
HINT: autoimmune diseases
lupus
| rheumatoid arthritis
34
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
35
in immunofluorescence testing, fluorescent ___ is combined with specific antibody to provide a sensitive test for the presence of a specific antigen or antibody
dye
36
test that uses fluorescent labeled antibodies to determine the presence of a specific microbe in a specimen, is called the ________ immunofluorescent test
direct
37
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
38
steps of Western Blot
electrophoresis of sample
transfer to a filter
incubation with radioactive or fluorescent labeled antibodies
39
Indirect ELISA detects ______ in a sample; DIRECT ELISA detects unknown ________ in a sample
antibody
| antigen
40
what test is used to verify false positives in indirect ELISA test?
western blot
41
steps of indirect ELISA
1. known antigen is adsorbed to surface of wall
2. serum sample with unknown antibodies is added
3. enzyme-antibody complex that is specific for Fc portion of antibody is added
4. substrate for the enzyme is added
5. color changes in well are observed
42
examples of in vivo test
allergen skin test
| tuberculin test
43
which characteristic of an immunologic test insures that it will have a lot rate of false-positives?
specificity
44
indirect ELISA is commonly used to test for
helicobacter
hep a and c
rickettsias
HIV
45
PCR test that used fluorescent labeling during DNA amplification is
real time
| rPCR
46
technique that matches complementary strands of nucleic acid to locate specific sites or types of nucleic acid is
hybidization
47
application of fluorescently labeled PROBES to intact cells within a pt specimen is known as _______ technique
FISH
48
microarrays for infectious disease diagnostics are chips that contain _____ from possible infectious agents
gene sequences
49
whole genome sequencing involves
sequencing nucleic acids from patient samples
50
PFGE advantage
accuracy in assessing microbial subtype
51
whole genome sequencing is particularly useful for rapid analysis of
drug resistant organisms
| disease outbreaks
52
advantaged of labs on chips
can be used by technicians with little specialized training
| require few supplies
53
________ 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
54
lab on a chip tests
DNA and RNA sequencing and PCR
55
MALDI-TOF
mass spec
56
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
57
components of integ
hair
sweat and oil glands
skin
nails
58
bottom layer of cells in epidermis
stratum basale
| bas= basement
59
list some components of dermis
nerves
blood vessels
lymphatic vessels
collagen fibers
60
separation of dermis and epidermis =
blister
61
___ charged antimicrobial peptides of the skin can disrupt the ___ charged membranes of bacteria to prevent infection
+
| -
62
cells of stratum corneum are dead and packed with a protein called
keratin
63
how are oil (sebum) gland secretions antimicrobial in nature?
release antimicrobial fatty acids as the oil breaks down
64
primary type of tissue in the dermis?
| hint: think collagen
connective
65
the _____ has a dense microbial population
groin
66
in addition to the skin, microbes can populate which of the following
glandular ducts
| hair follicles
67
_________ is an enzyme found in sweat that breaks down peptidoglycan found in bacterial cell walls
lysozyme
68
describe S. aureus
nonmotile
| destructiveness due to superantigens
69
sweat has a ____ pH, and a _______ salt concentration = antimicrobial
low
| high
70
staphylococcus is found in
normal biota of many people
71
strains of MRSA are usually resistant to ________ antibiotics
multiple
72
under which conditions would S. aureus survive?
heating to 35C for 60 minutes
| heating to 55C for 60 minutes
73
S. aureus is (traits)
G +
coccus
grows in grape like clusters
74
approx. __% of people have S. aureus in their normal skin biota
3-%
75
MRSA infection qualities
skin tends to be raided, red, tender. localized lesions, often with pus and are hot to touch
76
MRSA
can withstand high salt concentration
withstand extreme pH
very hardy, can remain viable for months in air
77
S. aureus has become troublesome in hospitals b/c
remains viable after drying
is resistant to many disinfectants
is resistant to many antibiotics
78
what enzyme is not produced by strains of S. aureus
streptokinase
79
microbial medium _______ _______ agar is often used to isolate staphylococcus species because of its high salt content that mimics the skin
mannitol salt agar
80
_____ is an enzyme that breaks down the hydrogen peroxide produced in oxidative metabolism
catalase
81
list some enzymes expressed by strains of S. aureus
```
Staphylokinase
DNase
Lipase
Hyaluronidase
Coagulase
```
82
which test is used to diagnose MRSA?
PCR
83
a diagnostic test for which of the following enzymes differentiates staphylococci from streptococci
catalase test
84
current antibiotic tx of MRSA
vancomycin
85
measles
syncytial; flat redness; main trans = resp droplets and direct contact; KOPLIK'S spots
86
some practices that would be likely to spread MRSA
not sanitizing gym equipment
| sharing a razor
87
tx of MRSA may include
tx with more than one antibiotic
| incision of the lesion to drain pus
88
measles is caused by a
virus
89
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)
90
initial s and s of measles
sore throat, dry cough, headache, conjunctivitis, lymphadenitis, and fever
91
measles starts at the ______ and spreads to
head
| whole body
92
"slapped face" rash, spreads to limbs and trunk
fifth disease
93
rash not always present
roseola
94
in SSPE (measles) what areas of the body are degenerated
white matter, brain stem, cerebral cortex
95
measles virus contacts and infects skin by which method
travelling through the blood stream
96
the ______ virus tends to erase or diminish the immune system's memory for other microbes
measles
97
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
98
what period is someone with measles not contagious
convalescent period
99
what aspects of immunity are often disabled by measles
cell-mediated immunity
| delayed-type hypersensitivity
100
which antibody is detected in a patient with measles when ELISA is used?
IgM
101
typical age for first dose of measles
12-15 months
102
tx for measles may include vitamin
A
103
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
104
what sign/symptom often differentiates postnatal rubella from adult rubella
mild rash
105
tx ofr measles
vitamin A
reducing sx
replacing lost fluid
106
normal modes of trans for fifth disease
resp droplets
| direct contact
107
defects of congenital rubella
```
ocular lesions
deafness
cardiac abnorms
mental/physical retardation
miscarriage
```
108
causative agent of rubella
Rubivirus
109
rubella can spread through
resp secretions
| urine
110
diagnosis of rubella
ELISA
| latex agglutination card
111
common defect with congenital rubella
deafness
112
coongential rubella effects on fetus
stop mitosis
induce apoptosis
damages vascular endothelium
113
fifth disease rash
slapped face
| confluent rash starting on the face and spreading to limbs and trunk
114
rubella virus is shed during _______ phase and up to a week after rash appears
prodromal
115
causative agent for fifth disease
Parvovirus-19
116
desrcibe Roseola rash
if rash appears, it is usually preceded by fever
117
roseola is usually caused by
Herpesvirus HHV-6
118
primary victims of impetigo
preschoolers
119
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
120
complication associated with untreated impetigo
glomerulonephritis
121
s. aureus impetigo toxins
exfoliative toxins A or B, coagulase, other enzymes (DNase, catalase, Staphylokinase...)
seen more often in adults and children
122
streptococcus pyogenes impetigo virulence factors
Streptokinase, plasminogen-binding ability, hyaluronidase, M protein
seen more often in newborns
123
S. pyogenes is a gram _____ bacterium that is _____-hemolytic on blood agar
+
| beta
124
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
125
common places for impetigo lesions
face, extrems
126
which skin regions are usually involved in cellulitis
dermis
| subcutaenous tissue
127
sx such as pain, tenderness, swelling , fever, and LYMPHANGITIS are characteristic of
cellulitis
128
what do the exfoliative toxins A and B do in S. aureus impetigo infection
they attack cell to cell binding proteins in the epithelium
129
what can cause cellulitis
S. pyogenes
S. aureus
opportunistic bacteria
Group b streptococcus
130
most common age group to experience SSSS infections
infants
131
what percent of adults are asymp of SSSS
30%
132
where does S. aureus harbor on body
nasopharynx, axilla, perineum, and vagina
133
s and s of SSSS
bullous lesions (caused by exfoliative toxins A and B)
desquamation
split in skin within epidermis
134
SSSS is a ______ skin syndrome
dermolytic (damage/kills the skin)
135
SSSS is most effectively diagnosed through histological examinatino of tissue from a _____
lesion
136
s and s of chicken pox
centripetal lesions
superficial lesions
fever
itchy vesicles
137
which diseases present as generalized rashes with fluid-filled lesions
small pox
| chicken pox
138
incubation period for chicken pox
10-20 days
139
chickn pox usually lasts dor
4-7 days
140
some cases of CP end up with complications leading to _______ (only 0.1% approx)
encephalitis
141
adolescents and adults have the _____ number of CP lesions
highest
142
shingles is characterized by an asymmetrical rash of the skin on the _____ or _______
trunk head
143
sx of shingles
tender persistent vesicles
144
Zostavax is intended fro adults aged ____ and over
60
145
small pox vaccine is based on ________ virus
vaccinia
146
cutaneous anthrax is normally transmitted by which of the following methods
direct contact with endospores
| contact with infected animal hides
147
t or f
| Leishmania only multiplies in macrophages
true
148
group of fungi responsible for a wide variety of skin and nail conditions
dermatophytes
149
general signs and sx of ringworm infections
itchiness and skin/nail lesions
150
causative agent for ringworm
vary with geographical region
151
general term for fungal infections of skin, hair, or nails
mycoses
152
what are not s and s of ringworm infections
macopapular exanthem
large pustular lesions
necrotic papules
153
properties that promote pathogenesis of dermatophytes
they can suppress immune system and invade and digest keratin
154
tinea versicolor is caused by
Malassezia furfur
