Diagnostic Microbiology Flashcards
Most importantly, you need an accurate clinical ___ and ____ ____ for diagnostic microbiology
History
Physical exam
Laboratory identification of microbial pathogens:
Growth dependent microbiology requires growing in the ___, and enriching it, isolating it and finally ___ it
Lab
Identifying
Antigen assays and molecular assays do not require ___ in the lab.
Growth
You can also use direct _____ examination.
Microscopic
Isolation of pathogens from a clinical sample must be ___ and ___ properly. Must be take for the ____ of infection. Sample must be taken ____. Sample size must be large enough to establish ____ in the lab. Metabolic requirements for the organism must be maintained during ___ and ___.
Obtained
Handled
Site
Aseptically
Growth
Storage
Transport
Direct microscopic examination can be done after the ___ stain or ____ stain. You can use ___ ___ for something like cryptococcus neoformans. ____ treatment is used for fungal forms. You can also use ____ antibodies or ____ microscope
Gram
Acid-fast
India ink
KOH
Fluorescent
Electron
Fungi are heterotrophs and feeding off of us, you have to use ___ which is potassium hydroxide to dissolve the human cells but not the fungal cells.
KOH
Table of direct microscopy examination:
Dark-field Microscopy is a flipped inversion of how the light normally moves through and highlights the ___ of the cell.
Edges
Direct and indirect immunofluorescence:
Immunofluorescence depends on the fact that the bacteria cell have ____ that are species specific
Antigens
Direct immunofluorescence is when the ____ antibody is fluorescently labeled.
Antibacterial
Indirect immunofluorescence is when the _____ antibody is fluorescently labeled.
Anti-rabbit
Indirect immunofluorescence is ____.
Cheaper
It is cheaper to make an indirect antibody in a ___ or other animal. It is a ____ antibody binding the primary antibody.
Rabbit
Secondary
Two rods that are distinguished using direct immunofluorescence:
Growth dependent diagnostic mechanisms:
___ ___ supplies the nutritional needs of the microorganism and it can be chemically defined (___ ___) or undefined (___ ___), usually yeast.
Culture media
Defined medium
Complex medium
____ media: contains compounds that selectively inhibit the growth of some microbes, but not others
Selective
____ media: contains an indicator, usually a dye, that detects chemical reactions occurring during growth
Differential
Successful cultivation and maintenance of ___ ____ of microorganisms can be done only if ___ ___ is practiced to prevent contamination by other microorganisms.
Pure cultures
Aseptic technique
Culture of ____ microorganisms can be complicated by the challenge of maintaining ____ conditions
Anaerobic
Anoxic
_____ require oxygen. ___ ___ can live with it without oxygen. ____ ____ can tolerate oxygen and grow in its presence even though they cannot use it. ____ are aerobes that can use oxygen only when it is present at levels reduced from that in air
Aerobes
Facultative organisms
Aerotolerant
Microaerophiles
Table of types of culture media:
Sheep’s Blood agar culture media is not ____ , it is differential. 5% sheep’s blood added. Used to cultivate _____ micro organisms along with a determination of their ____ capabilities.
Selective
Non-fastidious
Hemolytic capabilities
____ hemolysis: bacteria damages the red blood cells but not destroy them, internal components become oxidized
Alpha
____ hemolytic: they create toxins that are completely destroying the red blood cells. You get a halo
Beta
___ hemolysis: microorganisms that don’t produce a hemolytic toxin against red blood cells. They grow in the plate but the media does not change around them
Gamma
___ ____ ___ (___) agar is selective and differential. It is an enteric agar used to distinguish different forms of enteric ___ ___ pathogens, based on their ability ferment lactose. Lactose fermenters will produce a ___ ___ (left side in picture). It inhibits the growth of ___ ___ bacteria.
Eosin- methylene blue (EMB)
Gram negative
Metallic sheen
Gram positive
EMB agar table:
____ agar is selective and differential. Similar to EMB. Distinguishes between ___ ___, fermenters of lactose will turn deep ___ while non lactose fermenters remain ___ ___. Gram positive does not grow.
MacConkey
Gram negative
Purple
Light pink
___-____ media is used for isolating Neisseria bacteria and it inhabits the growth of most other microorganisms. Nutrients are chocolate ___ ___, beef infusion, casein hydrolysate, and starch. It contains the following antibiotics:
Thayer-Martin
Sheep’s blood
Example identification of N. gonorrhoeae:
It loves to grow inside our ____.
Neutrophils
Flow Chart
Neisseria gonorrhoeae characteristics:
____ ___ allows for us to run all these clinical tests for bacteria simultaneously.
API strip
Antibiotic drug susceptibility testing:
On a mill or hinter agar plate, looking for the growth of organisms around a disc that has been soaked with an ____. The halo around the disc is called the ___ of ___. The size of the halo Determines if that antibiotic can be used for ____ for that bacteria.
Antibiotic
Zone of inhibition
Treatment
____ is the study of antigen-antibody reactions in vitro. Serologic reactions are used for many diagnostic ____ tests.
Serology
Immunology
____ reactions: the visible clunking of a particular antigen when mixed with antibodies specific for the particular antigens. Used to identify ___ ___ antigens and many pathogens and pathogen products
Agglutination
Blood group
Direct agglutinations results when ____ antibody causes clumping due to interaction with an antigen that is an ___ part of the surface of a cell or other ____ particle. Used to classify antigens found on the surface of ___ ___ cells.
Soluble
Integral
Insoluble
Red blood
Passive agglutination is agglutination of antigens or antibodies that have been ___ or ___ ___ to cells or insoluble particles. Reacts can be up to 5 times more sensitive than ___ agglutination tests.
Absorbed
Chemically coupled
Direct
Passive agglutination is when you’re looking at something so ___ you can’t actually see agglutination with the naked eye. Or you’re looking at something that is ____.
Small
Colorless
Passive agglutination uses a ___ ___ with a bunch of antibodies on their surface. They bind to target pathogen. We are seeing the bead, not the pathogen itself
Latex bead
The direct Elisa Test:
Order a plate with wells of different antibodies. Then put a second antibody in the plate that causes a color change when it sticks to antigen. Wash phase removes anything that didn’t stick
Direct ELISA is also called ____ ELISA. Antibody-antigen-antibody
Sandwich
Picture of ELISA Test:
Usually a 16 fold dilution of ELISA shows ____ results. A 1 or 2 fold dilution is not reliable.
Reliable
The indirect ELISA test, instead of having antibody bound to the plate, we have ___ bound to the plate. We are looking for ___ from an immune response instead of pathogen itself. Use a secondary antibody that is ___ ___ to bind to the antigens.
Antigen
Antibodies
Anti-human
You can identify the ___ of antibody using indirect ELISA. Important when looking at the ____ of infectious disease.
Class
Serodiagnosis
Moving into searching for ____ ___ ___. Used in Covid.
Pathogenic nucleic acid
