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WEX 3B
Army 68K 05-09 Course
97
Microbiology
Undergraduate 2
02/02/2010

Additional Microbiology Flashcards

 


 

Cards

Term
Why is it necessary for RBs to reorganize into EBs before they are released from the host cell?
Definition
EBs are the extracellular form; RBs will not survive outside the host cell
Term
How do we culture for Chlamydia trachomatis?
Definition
Centrifugation enhances endocytosis into monolayer of cells, usually mouse fibroblasts (McCoy cells) then incubate 48-72 hrs at 35*C
Term
What is the life cycle of the genus Chlamydia?
Definition
1) Within 8 hrs of endocytosis, EB converts to RB
2) RB reproduces by binary fission
3) 18-24 hrs, RB reorganize to EB
4) Cycle complete 24-40 hrs after endocytosis
Term
What species of Chlamydia is zoonosis that causes cold or flu like upper respiratory illness?
Definition
Chlamydia psittaci
Term
What species of Chlamydia causes diseases of the eye and most frequent STD?
Definition
Chlamydia trachomatis
Term
What species of Chlamydia is an etiologic agent of walking pneumonia and brochitis?
Definition
Chlamydia pneumoniae
Term
What are 3 specimen sources for laboratory testing for Chlamydia?
Definition
1. Ocular and genital tract
2. Bubo pus (LGV)
3. Sputum and throat washings
Term
What are 4 detection methods for Chlamydia?
Definition
1. Fluorescent Antibody Technique (FA)
2. Enzyme Immunoassay (EIA)
3. Nucleic Acid Amplification
4. Nucleic Acid Probes
Term
What is the purpose of darkfield microscopy?
Definition
To permit observation of live, moving spirochetes that are unstained
Term
What are some of the general characteristics of the Genus Borrelia?
Definition
1. Loosely coiled spirochete
2. Gram-negative type cell wall
3. Wright's or Giemsa stain
4. Not easily or reliably cultured
Term
What does Borrelia recurrentis cause and how is it transmitted?
Definition
Causes epidemic louse-borne relapsing fever in humans, transmitted by lice from a smashed or scratched contaminate into the bite site
Term
What does Borrelia spp. causes and how is it transmitted?
Definition
Causes endemic tick-borne relapsing fever in humans transmitted by various species of soft-shelled ticks of the Genus Ornithodoros
Term
Describe the lesion that is seen in the initial phase of Lyme disease.
Definition
Skin lesion is called erythema chronicum migrans, a flat reddened area near the bite site that slowly expands with central clearing
Term
What are some of the general characteristics of the genus Leptospira?
Definition
1. Tightly coiled, thin, flexible spirochete
2. Resembles a "Shepherd's hook"
3. Gram-negative type of cell wall
4. Cultivated in protein-rich, semi-solid media (below surface of medium)
5. Primarily associated with occupational exposure
Term
Briefly describe the epidemiology for leptospirosis.
Definition
Organism carried by rodents in their urine, spread by direct exposure to infected animal urine or contaminated soil or water
Term
Briefly describe the mode of infection for leptospirosis.
Definition
Ingestion of contaminated water or food or through mucous membranes of the eye, mouth, genitals, or through abraded skin
Term
How can Leptospira biflexa be differentiated from other Leptospira spp?
Definition
Leptospira biflexa's ability to grow at 13*C
Term
What are some of the general characteristics of the Genus Treponema?
Definition
1. Moderately tightly coiled
2. Gram-negative type cell
3. Not culturable on laboratory media
Term
Give a brief description of the medical importance and epidemiology of Treponema pertenue.
Definition
Medical importance - infectious tropical skin disease
Epidemiology - non-venereal disease transmitted by direct contact
Term
Give a brief description of the medical importance and epidemiology of Treponema carateum.
Definition
Medical importance - contagious skin disease prevalent in tropical America
Epidemiology - non-venereal infection transmitted by direct contact
Term
What are the modes of infection for syphilis?
Definition
Acquired - contact with chancre or lesion
Congenital - infant is born with the disease (can cross the placenta)
Term
What are the clinical features for the primary stage of syphilus?
Definition
1. Chancre (usually heals spontaneously)
2. Enlarged lymph glands
Term
What is the method of diagnosis of syphilis during the primary stage?
Definition
1. Darkfield microscopic examination
2. Serological test (about 80% of untreated cases)
Term
What are the clinical features for the secondary stage of syphilis?
Definition
1. Secondary mucocutaneous rash
2. Fever
3. Malaise (feeling ill)
4. Alopecia (hair falls out)
Term
What are the methods of diagnosis during the secondary stage of syphilis?
Definition
1. Clinical features
2. Examination of rash scrapings
3. Serological tests
Term
What are the clinical features for the latent stage of syphilis?
Definition
NONE
Term
What are the methods of diagnosis during the latent stage of syphilis?
Definition
NONE
Term
What is the clinical significance of syphilis testing?
Definition
1. Control of venereal disease
2. Prevention or detection of congenital syphilis
3. Routine screening
4. Treatment will reduce non-treponemal test titers
Term
What are the contents of the "antigen ampoule" of the RPR test and what purpose do they serve?
Definition
1. Cardiolipin-lecithin-cholesterol (CLC) complex (antigen)
2. Charcoal carbon particles (indicator)
3. Choline chloride (deactivation of complement that may interfere with test)
Term
What kind of needle is used to dispense the antigen in the RPR test and how many drops should it be calibrated to deliver?
Definition
Blunt 20-gauge needle calibrated to deliver 60 drops of antigen per mL
Term
The rotator should be calibrated to how many rpms for the RPR test?
Definition
100 rpms
Term
How are both the specimen and antigen dispensed onto the 18 mm circle when performing the RPR test?
Definition
One "free falling" drop
Term
How long should the test card of an RPR test rotate?
Definition
8 mins (at 100 rpm)
Term
True/False? The RPR test is a "non-specific" or "non-treponemal" test used to detect the presence of reagin in a patient's serum or plasma.
Definition
True
Term
True/False? Results for the RPR test are reported as either positive or negative.
Definition
False. RPR test results are reported as either Reactive or Non-reactive
Term
True/False? The Fluorescent Treponemal Antibody Absorption Test (FTA-ABS) is a "specific" or "treponemal" test used to confirm a reactive RPR test.
Definition
True
Term
What is the definition of "antigen"?
Definition
A "foreign" substance that induces an immune response and reacts with antibodies or T-cell receptors.
Term
What is Indirect FA used for?
Definition
To detect the presence of a specific antibody to serum following exposure to a microorganism.
Term
ELISA concept is similar to FA, but uses an ____________ instead of a fluorochrome.
Definition
enzyme utilizing substrate
Term
Give one example of a membrane-bound EIA.
Definition
Home pregnancy tests
Term
True/False? Thermus aquaticus is heat labile.
Definition
False. Thermus aquaticus' Taq polymerase's optimal temperature is 72*C but can be stable at 94*C
Term
C-reactive protein is aptly named because it reacts with the C-polysaccharide of what bacteria?
Definition
Streptococcus pneumoniae
Term
In antigen-antibody testing, a __________________ test results when a cloudy line of reacted material appears in the area of the agar where an optimal ratio of antigen to antibody exists.
Definition
Precipitin ring
Term
The counter-immune electrophoresis, precipitin ring, and Ouchterlony diffusion tests are examples of antigen-antibody technology that use _____________________ reactions.
Definition
Precipitation
Term
This test detects antibodies against relatively large cellular antigens.
Definition
Direct agglutination
Term
This test detects antibodies against soluble antigens adsorbed onto large particles such as RBCs or latex beads.
Definition
Indirect agglutination
Term
These reactions are Antigen-Antibody reactions in which harmful effects of baterial toxins or a virus are blocked by specific antibodies found in the patient's serum.
Definition
Neutralization reactions
Term
These are fluorescent dyes that are attached to specific antibodies for detection.
Definition
Fluorescent antibody.
Term
Name 2 fluorochromes used to label antibody for fluorescent microscopy.
Definition
1. Auramine
2. Rhodamine
Term
Name 2 fluorochromes that are not antibody related and explain how they produce the fluorescence needed for fluorescent microscopy.
Definition
1. Acridine orange - binds directly to nucleic acid
2. Calcofluor white - binds to the polysaccaride in the fungal cell wall
Term
In _________________ FA testing the antibody is supplied by the patient serum
Definition
Indirect
Term
In _________________ FA testing the antibody to the antigen is tagged with a fluorochrome.
Definition
Direct
Term
In _________________ FA testing the fluorochrome is labeled to a specific antiserum.
Definition
Indirect
Term
What is the principle of the ELISA test?
Definition
An automated spectrophotometer reads the color change in the reaction which results from the enzyme utilizing substrate
Term
How is color developed in the ELISA test?
Definition
By the reaction which results from the enzyme utilizing substrate
Term
In direct ELISA testing, the microtiter plate suppplied by the test kit has the ___________ adsorbed to the wells.
Definition
antibodies
Term
In direct ELISA testing, the conjugate contains what two essential parts?
Definition
1. Enzyme
2. Antibody
Term
In indirect ELISA testing, the microtiter plate supplied by the test kit has the ___________________ adsorbed to the wells.
Definition
antigen
Term
The first step in DNA replication is to temporarily ___________ the double strand forming two moving fork replication sites.
Definition
unzips
Term
___________________ molecules move along each fork formed in the second step of DNA replication adding complimentary bases.
Definition
Polymerase
Term
Define Denaturation.
Definition
The process of disrupting the double helix to yield two molecules of single stranded DNA.
Term
Define Annealing.
Definition
Lowering the temperature slowly allows the strands (of DNA) to reassociate into the double helix with the proper base pairing
Term
Define Hybridization.
Definition
Annealing two strands derived from different types of sources.
Term
The principle behind ______________ is to use known fragments of DNA to detect complimentary sequences of DNA in an unknown specimen.
Definition
Nucleic Acid Probes
Term
What is the temperature used to denature?
Definition
94*C
Term
What is the temperature used to anneal?
Definition
50*C
Term
What is the temperature used to extend?
Definition
72*C
Term
What is the template/target for the probes or primers related to polymerase chain reaction technology?
Definition
Specimen DNA
Term
What reapeatedly heats and cools the sample in polymerase chain reaction technology?
Definition
Thermocycler
Term
What extends specific primers into a complementary strand of DNA in polymerase chain reaction technology?
Definition
Thermus aquaticus polymerase
Term
True/False? C-reactive protein is a non-specific antigen-like substance supplied by test kits that use latex agglutination testing to detect the presence of IgG immunoglobulins produced by the patient during an inflammatory response.
Definition
False. It detects C-Reactive Protein, an amino acid composition similar to that of IgG
Term
What are 3 general shapes of animal viruses?
Definition
1. Helical - rod-like
2. Icosahedral - ball-like
3. Complex
Term
Why are viruses considered to be "obligate intracellular parasites"?
Definition
Viruses replicate only in living cells and cannot replicate outside of a host cell. The host cell must provide the energy, synthetic machinery, precursors, enzymes, and ribosomes for the synthesis of viral protiens and nucleic acids
Term
What is the correct sequence of steps in the virus lytic replication cycle?
Definition
1. Attachment
2. Penetration and Uncoating
3. Eclipse or Synthesis Phase
4. Assembly/maturation
5. Release
Term
What is the correct sequence of steps in the virus lysogenic cycle?
Definition
1. Viral DNA is incorporated into the host DNA immediately upon entering the cell
2. Genes coded by the prophage are transcribed and replicated as if they were normal host DNA
3. Upon certain stimuli, the prophage/provirus is removed from the host DNA
Term
What are the characteristics of the acute phase of a virus infection?
Definition
1. Virus is detectable
2. IgM may be detectable
3. IgG is usually not detectable
Term
What are the visual effects or abnormalities seen in cells that are infected by a virus (Cytopathic effects)?
Definition
1. Inclusion body
2. Giant cells
Term
How many days after onset of symptoms should serum samples for acute and convalescent phases be collected?
Definition
Acute - 7 days after onset of symptoms
Convalescent - 14-30 days after onset of symptoms
Term
How long may a serum specimen for virology testing be stored at 4*C - 6*C?
Definition
Up to several weeks
Term
True/False? Virus specimens for virus isolation and growth are usually processed and inoculated onto cell cultures
Definition
True
Term
Which hepatitis viruses are transmitted fecal-oral?
Definition
Hepatitis A virus
Term
Which herpes family member causes recurring oral or genital lesions?
Definition
Herpes simplex viruses 1 and 2 (HSV-1 and HSV-2)
Term
Which herpes family member causes chicken pox and herpes zoster?
Definition
Varicella zoster virus (VZV)
Term
Which respiratory virus causes a disease in infants and young children and requires isolation of the patient?
Definition
Paramyxoviridae family, genus pneumovirus
Term
What virus family are Influenza viruses type A, B and C members of?
Definition
Orthomyxoviridae
Term
Which respiratory virus has caused outbreaks of Adult Respiratory Disease in military recruits?
Definition
Adenoviridae family, genus Mastadenovirus
Term
What type of immune cells does HIV infect?
Definition
CD4 (T-Cell) lymphocyte
Term
Although the Picornaviruses are best known for mild diseases such as the common cold, what is the most serious disease a member may cause?
Definition
Poliomyelitis
Term
Which family includes the virus which causes rabies?
Definition
Rhabdoviridae
Term
Are live virus vaccines "attenuated" or "inactivated" viruses?
Definition
Attenuated
Term
What aspect of viral growth do most of the currently prescribed antiviral drugs affect?
Definition
Inhibits viral activities within the host cells, but with minimal harmful side effects to the host.
Term
What direct preparation is used a CSF specimen?
Definition
India Ink
Term
What are the three macroscopic morphologies used mold culture?
Definition
Texture, Color and Reverse
Term
What is the causative agent of Black piedra?
Definition
Piedraia hortae
Term
Which thermally dimorphic fungal pathogens causes "rose handlers' disease"?
Definition
Sporothrix schenckii
Term
Name the three genera causin chromoblastomycosis.
Definition
Phialophora, Cladosporium, Fonsecaea
Term
Blastomyces dermatitidis is the etiological agent of what disease process?
Definition
North American Blastomycosis
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