PC2 mod 1.1 lec 6-8

MIC is the lowest concentration of an antibiotic that inhibits ______ of microorganism and MBC is the lowest drug concentration which results in bacterial _______

- visible growth

- cell death

in broth macrodilution, each tube has varying antibiotic conc, and each tube has ____ conc or the previous one

1/2

in broth macrodilution ....

--> ______ is added to test tubes and _______

--> test tubes that remain clear are plated on ______ and _______

--> MBC is when there is ______

- standard inoculum

- intubated overnight

- solid medium

- intubated overnight

- zero growth

gold standard for MIC is...

broth microdultion

QUALITATIVE testing for S,I,R

does it give MIC?

disk diffusion (Kirby-Bauer)

no

QUANTITATIVE testing for S,I,R (3)

does it give MIC?

- broth dilution (macro and micro)

- agar dilution (less common)

- E test

most common quantitative test for MIC

E-test

broth microdilution is usually used in...

research

kirby bauer/disk diffusion test shows a diameter of zone of inhibition depending on

--> _____ of antibiotic

--> degree of ______ of the bacteria

--> ______ of bacteria

--> properties of antibiotic such as ______

- quantity

- susceptibility

- concentration

- molecular weight

HIGH/LOW molecular weight drugs are not optimal for disk diffusion/kirby bauer

high

advantage of disk diffusion test are ....

disadvantage is ...

- simple, cost-effective, several antibiotics

- interpreter variability

E-test technology has antibiotic impregnated _____ for preformed and stable ______ that are precise on a scale ______, incubated over ______

- plastic strip

- gradient dilutions

- MICs

- night

can E-tests be used for resistance detection?

yes

con of E-test is they are...

expensive

LOWER/HIGHER MIC means more susceptible

LOWER/HIGH diameter of E-test means more susceptible

- lower

- higher

automated system for MIC is small plastic cards containing multiple wells with dual function of ______ and _____ using ______ technology with results in ____h

- identification

- susceptibility

- colorimetric

- 2-18h

disadvantage of automated systems for MIC is ______ determines accuracy and there is ______ range of organisms that can be tested

- manual set up

- limited

MIC are _____ for a given pathogen to antibiotic and MICs ARE/ARE NOT comparable to one another and need to be interpreted against ______

- unique

- are not

- standardized concentrations

21st century cures act brought ______ and ____ together for breakpoints

- FDA

- CLSI

concentration of antibiotic that best predict clinical success

breakpoint

breakpoint is _______ of antibiotic that best predict clinical success

concentration

breakpoints are set by...

--> ______ outcomes

--> ______ data

--> _____ cutoffs (of wild type)

- clinical

- PK/PD

- epidemiological cutoffs

an ________ susceptibility accommodates technical variability through higher doses, prolonged infusions or combo therapy

intermediates

rapid diagnostic tests distinguish between _____ and _____ infection

- viral

- bacterial

4 immunologic detection antigen/antibody tests

- agglutination reaction

- immunochromatographic test

- immunofluorescent assay

- enzyme-linked immunosorbent assay (ELISA)

latex aggulation test process is _____ are bound to ______ which are mixed with _____ to expose antigen binding sites

--> positive test results is the presence of _____

- antibody

- latex beads

- serum

- cross linked aggregated

_______ test process is antibody are bound to latex beads which are mixed with serum to expose antigen binding sites

latex aggulation test

latex aggulation has a ______ differentiation for

to determine which classification it is

- streptococcus lancefield determination

(A-G)

advantages of latex aggulation are ____ result and ____ cost

- rapid

- low

latex aggulation test has ______ test that results in clumping due to ______ turning _____ to _____ to determine _____ from other of the same class

- coagulase test

- coagulase

- fibinogen --> fibrin

- staph auereus

coagulase negative staph IS/IS NOT staph aureus

is not (staph aureus coagulates)

two types of latex aggulation tests

- streptococcus lancefield classification test

- coagulase test

_______ test represent a well-established and appropriate technique for point-of-care and field-appropriate use that MINIMIZES the need for trained personnel

immunochromatographic

immunochromatographic test minimize need for _______ and provide ______ or ______ results

- personnel

- qualitative

- semi-quantitative

advantages of influenza immunoassay test

--> provide rapid result within ____ min

--> ______ to perform

--> approved for _____ use

- rapid (30min)

- simple

- bedside/office

disadvantage of influenza immunoassay test

--> sub-optimal test ______

--> false _____ may occur if procedure isnt followed

--> predictive value is reduced when prevalence is LOW/HIGH

--> difficulty in distinguishing between ______ or _____ viruses

--> cannot provide _____ subtype

- sensitivity (false negative)

- false positive

- low

- influenza A and B

- strain

influenza immunoassay test perform better with ____ quantity of infectious particles

10^4 to 10^6

______ assay is done with infected cells placed on slide and antigen specific antibodies fixed with a fluorophore are added to the slide and this is washed and viewed

immunofluorescent assay

immunofluorescent assay steps

--> ______ placed on slide

--> ______ fixed with______ and is added to the slide

--> following 15-30 mins incubation, preparation is washed and viewed under _______

- antigen (infected cells)

- antigen specific antibodies

- flurophore

- microscope

DELETE

- herpes and respiratory

- bordetella and legionella

enzyme-linked immunosorbent assay (ELISA) detect ______

(not used commonly)

antibodies

nucleic acid tests are highly _____ and _____ and these minimize waste, but challenge is ____

- sensitive

- specific

- costs

nucleic acid amplification method fall in 3 categories...

- target amplification systems

- probe amplification systems

- signal amplification

example of NAT target amplification...

PCR

PCR amplifies/detects small amounts of ______ to provide ______ and assist with antimicrobial selection by detecting specific genetic markers for ______

- target DNA

- organism identification

- resistance

does PCR give susceptibility profile?

NO, just resistance

example of rapid PCR test system

biofire filmarray

biofire filmarray is a _____

PCR

biofirre PCR steps

--> organisms are ____ and _____ are released

--> _____ creates DNA

--> _____ are added to amplify target DNA

--> ______ is added with these

--> sample is _____ and DNA ______, releasing dye

- lysed --> nucleic acid

- reverse transcriptase

- primers

- fluorescent dyes

-heated --> melts

PCR tells us about _____, NOT ______

- resistance

- susceptibility

biofire filmarray PCR advantages

--> results in ___h

--> several panels available for ____, ____, and _____

- 1h

- blood, respiratory, GI

biofire filmarray PCR disadvantage

--> less accurate in detecting individual pathogen in a ______ infection

--> detects _____ are limited

--> _____ not available

- polymicrobial

- resistance genes

- susceptibilities

probe amplification technique is done by _____

peptide-nucelic acid-fluoresence in situ hybridization (PNA FISH)

PNA FISH is a type of _______

probe amplification NAT

steps of PNA FISH

--> _____ labeled synthetic ______ mimicking DNA or RNA detects and binds to _______ directly from clinical specimens such as blood or tissue or culture

--> process occurs ______ within _____ of cell due to probes being HYDROPHILIC/HYDROPHOBIC

--> ______ is pairing of probe with rRNA

- fluorescently labeled

- oligomers

- RNA

- in situ

- nucleus

- hydrophobic

- hybridization

PNA fish advantages

--> short hybridization time in ____ min

--> _____ species can be detected simultaneously using _____ probes labeled with unique ______

--> visible detection of microorganism without the need for amplification is less likely to be _______

- 90min

- several

- specific

- fluorescent dyes

- contaminated

disadvantages of PNA FISH

--> ______

--> limited ____ detection

--> ______ not available

- cost

- resistance

- susceptibility

PNA-FISH available panels (5)

- candida

- staphylococcus

--> +mecA gene

- enterococcus

- gram-negative panel

NAAT test for sexually transmitted diseases uses _____ labeled probes to detect ______

- florescence labeled

- amplified DNA

NAAT test for detecting C.diff is done by using amplification to detect presence of _____ gene

toxin b gene

toxin B gene identifies ______ in NAAT test

c.diff

______ technology causes ionization and disintegration of a target molecule by bombarding it with electrons and the mass/charge ratio of the resulting fragments produce a molecule signature to identify

MALDI-TOF mass spec

MALDI-TOF mass spec works by causing ______ and _____ of a target molecule by bombarding it with ______

--> this results in a ______ ratio producing a _____ that can be identified compared to a database

- ionization and disintegration

- electrons

- mass/charge

- molecular signature

advantage of MALDI-TOF

--> rapid turnaround

--> can identify _____, _____, _____ and _____

- bacteria

- yeast

- filamentous fungi

- mycobacterium

which rapid diagnostic NAT test can identify bacteria, yeast, filamentous fungi and mycobacterium

MALDI-TOF MS

disadvantage of MALDI-TOF MS

--> _____

--> reference ______

--> _____ and _____ are not available

- cost

- database

- resistance and susceptibilities

does MALDI-TOF give resistance info? susceptibiltiy?

no

no

_____ test is used for identifying sexually transmitted diseases and c. diff

NAAT (nucleic acid amplification)

e-tests can be used for _______ detection

resistance

________ are available for viruses like herpes and respiratory viruses, as well as bacteria like bordetella or legionella

immunofluorescent assays

influenza immunoassay is a _______ test

immunochromatologic test

which test determines susceptibility?

automated system for MIC

______ has advantage of being able to detect multiple species simultaneously using unique probes with fluorescent dyes

PNA-FISH

______ is less accurate in detecting individual pathogens in polymicrobial infections

biofire filmarry

_______ has available panel for staphylococcus, enterococcus, candida, mecA and gram -

PNA-fish

immunologic tests rely on ______ detection

antibody-antigen