Micro Module 1 Flashcards

Which scientist created the germ theory of disease?

Paul Ehrlich discovered the first antibacterial agent. It was effective against the spirochete responsible for which disease?

The cultivation of which infectious particles was especially important for vaccine development?

What are the five large groups of microbes?

Which type of microbe is considered the smallest infectious particle?

A microbe cannot replicate independently and must enter a host cell to reproduce. Which type of microbe is this?

Bacteria most commonly reproduce by which process?

A bacterial isolate has a cell wall with a thick peptidoglycan layer. Which classification best describes it?

A bacterial isolate has a cell wall with a thin peptidoglycan layer with an outer membrane. Which classification best describes it?

Which statement correctly compares bacteria and fungi?

A. Bacteria are eukaryotes, whereas fungi are prokaryotes

B. Both bacteria and fungi are prokaryotes

C. Bacteria are prokaryotes, whereas fungi are eukaryotes

D. Both bacteria and fungi are viruses

A unicellular fungal form replicates asexually. Which fungal form is being described?

A. Mold

B. Yeast

C. Hypha

D. Spore

A filamentous fungal form can replicate both asexually and sexually. Which fungal form is being described?

A. Yeast

B. Virus

C. Mold

D. Parasite

A physician suspects a parasitic infection. Which two parts of the history are especially useful for identifying possible exposure?

_____ and _____ history

Which organism is always considered pathogenic?

A. Staphylococcus epidermidis

B. Rabies virus

C. Lactobacillus species

D. Bifidobacterium species

Which organism is always considered pathogenic?

A. Bacillus anthracis

B. Candida albicans

C. Staphylococcus aureus

D. Escherichia coli

Which organism is always considered pathogenic?

A. Streptococcus viridans

B. Shigella

C. Clostridium difficile

D. Enterococcus faecalis

Which organism is always considered pathogenic?

A. Sporothrix schenckii

B. Saccharomyces cerevisiae

C. Aspergillus fumigatus

D. Candida albicans

Most human diseases are produced by organisms from which source?

A. Soil reservoirs

B. Arthropod vectors

C. The person’s own microbial flora

D. Hospital water systems

A single organism is able to cause endocarditis, pneumonia, wound infections, and food poisoning. Which organism is most likely responsible?

Which condition can be caused by viruses, bacteria, fungi, and parasites?

A. Meningitis

B. Tetanus

C. Gas gangrene

D. Scarlet fever

A patient has a bacterial infection with elevated serum inflammatory markers. Which two proteins are most likely increased?

A. Albumin and transferrin

B. C-reactive protein and procalcitonin

C. Hemoglobin and ferritin

D. Troponin and myoglobin

The ability of a bacterium to cause disease is usually determined by which microbial property?

A. Ribosomal size

B. Virulence factors

C. Host cell nucleus

D. Fungal morphology

Repetitive microbial structures are recognized by the immune system as which pattern?

A. MHC class I molecules

B. Pathogen-associated molecular patterns

C. Antibody constant regions

D. T-cell receptor domains

Pathogen-associated molecular patterns primarily induce which part of the immune system?

A. Innate immune system

B. Humoral memory system

C. Passive immune system

D. Allergic immune system

Extracellular bacterial and fungal structures commonly activate which immune pathway?

A. Complement system

B. Cytotoxic T-cell deletion

C. Somatic hypermutation

D. Central tolerance

Complement activation at an extracellular bacterial or fungal infection site mainly recruits which cells?

A. Eosinophils and basophils

B. Neutrophils and macrophages

C. B cells and plasma cells

D. Mast cells and erythrocytes

Human cells infected with intracellular microbes respond by shutting down cellular processes and activating which type of immune response?

A. Cytolytic cellular responses

B. IgE-mediated allergic responses

C. Antibody neutralization

D. Complement membrane attack

Which cells participate in the immune response to intracellular microbial infection?

A. NK cells, T cells, and macrophages

B. Neutrophils, eosinophils, and basophils

C. Plasma cells, mast cells, and platelets

D. B cells, erythrocytes, and fibroblasts

What is the best way to protect an individual from infection?

A. Broad-spectrum antibiotics

B. Prevent exposure or contact

C. Increase microbial flora

D. Activate complement directly

After preventing exposure or contact, what is the second-best measure for protecting an individual from infection?

A. Immunization against the microbe

B. Suppression of inflammation

C. Elimination of normal flora

D. Delayed antibiotic therapy

Which description best defines dimorphic fungi?

A. Yeast in the environment and mold in the body

B. Mold in the environment and spherical form in the body

C. Bacteria in the environment and fungi in the body

D. Parasites in the environment and viruses in the body

Which group contains examples of dimorphic fungi?

A. Candida, Aspergillus, Cryptococcus

B. Histoplasma, Blastomyces, Coccidioides

C. Staphylococcus, Streptococcus, Bacillus

D. Giardia, Entamoeba, Plasmodium

A unicellular organism lacks a nuclear membrane, mitochondria, Golgi complex, and endoplasmic reticulum. It reproduces asexually. What type of organism is this?

A. Eukaryotic organism

B. Prokaryotic organism

C. Dimorphic fungus

D. Multicellular parasite

Which feature is characteristic of a prokaryotic organism?

A. Well-defined nucleus

B. Mitochondria

C. No nuclear membrane

D. Endoplasmic reticulum

An organism contains a well-defined nucleus, mitochondria, Golgi bodies, and endoplasmic reticulum. What type of organism is this?

A. Prokaryotic organism

B. Eukaryotic organism

C. Virus

D. Prion

Which feature is characteristic of eukaryotic organisms but not prokaryotic organisms?

A. Asexual reproduction

B. Well-defined nucleus

C. Cell membrane

D. Ribosomes

Microbes in the Human Microbiome Project were identified using sequencing of targeted regions of which gene?

A. 23S ribosomal RNA gene

B. 16S ribosomal RNA gene

C. 16S messenger RNA gene

D. 23S messenger RNA gene

Which body site has the greatest taxonomic and genetic diversity of microbes?

Which body site has the least taxonomic and genetic diversity of microbes?

____ microbiome: Species present at a ____ ____ in 95% or more of individuals

Which function is provided by the normal microbiome?

A. Destroying all innate immune activity

B. Preventing colonization by unwanted pathogens

C. Eliminating the need for adaptive immunity

D. Preventing all bacterial growth

Which function is provided by the microbiome in its symbiotic relationship with the host?

A. Producing needed metabolic functions

B. Blocking mucin production

C. Preventing IgA production

D. Inhibiting all immune stimulation

The microbiome helps the host by stimulating which part of the immune system?

_____ immunity

Most body sites are colonized by which type of bacteria due to low oxygen availability?

A. Obligate aerobic bacteria

B. Anaerobic or facultative anaerobic bacteria

C. Acid-fast bacteria only

D. Intracellular bacteria only

Anaerobic and facultative anaerobic bacteria commonly colonize the mouth, intestine, and genitourinary tract because these sites have low levels of what?

What is now a major concern with broad-spectrum antibiotic use?

A. Increased oxygen delivery to tissues

B. Permanent elimination of viruses

C. Disruption of the microbiome

D. Increased fungal cell wall synthesis

Gut bacteria metabolize complex carbohydrates, including cellulose, into which products?

A. Long-chain triglycerides

B. Short-chain fatty acids

C. Bile acids

D. Ketone bodies

Which 3 short-chain fatty acids are produced by gut bacterial metabolism of complex carbohydrates?

Changes in the ratio of Bacteroidetes and Firmicutes can lead to higher efficiency in which process?

A. Destruction of short-chain fatty acids

B. Storage of metabolic by-products

C. Elimination of all carbohydrates

D. Suppression of bacterial metabolism

Microbiota prime innate immunity by stimulating production of which protective mucus component?

Microbiota prime innate immunity by stimulating production of which antibody at mucosal surfaces?

Microbiota prime innate immunity by promoting release of which protective molecules?

A. Antimicrobial peptides

B. Thyroid hormones

C. Complement inhibitors

D. Digestive bile salts

Clostridioides difficile overgrowth after antibiotic exposure causes disease by expressing what?

A. Enterotoxins

B. Exotoxins

C. Urease

D. Collagen cross-linking enzymes

Antibiotic-associated colitis is classically caused by proliferation of which bacteria after normal flora suppression?

A. Bacteroides fragilis

B. Clostridioides difficile

C. Helicobacter pylori

D. Streptococcus pneumoniae

A gut microbiota efficiently breaks down complex carbohydrates and allows more nutrients to be internalized rather than excreted. This increases susceptibility to what two conditions?

A patient has chronic relapsing C. difficile colitis despite treatment. Which therapy can restore a healthier microbiome?

A. Stool transplant

B. Broad-spectrum antibiotics indefinitely

C. Total colectomy as first-line therapy

D. IgE blockade

Necrotizing enterocolitis is an intestinal disease classically seen in which population?

A. Elderly adults

B. Adolescents

C. Infants

D. Pregnant patients

Early-onset necrotizing enterocolitis is associated with dominance of which organisms?

A. Enterobacteriaceae

B. Firmicutes, especially Staphylococcus

C. Saccharomyces species

D. Bacteroides fragilis

Late-onset necrotizing enterocolitis is associated with dominance of which organisms?

A. Enterobacteriaceae

B. Firmicutes, especially Staphylococcus

C. Lactobacillus species

D. Rabies virus

______ ______ is associated with increased bacteria that produce mucin-degrading sulfatases.

Production of which bacterial protein activity is responsible for degradation of the intestinal wall lining?

A. Mucin-degrading sulfatases

B. Hemolysin

C. DNA gyrase

D. Reverse transcriptase

Which toxic bacterium is a precursor to colonic hyperplasia and colorectal tumors?

______ ______

Which 2 organisms are among the most common probiotics?

Which gram-positive bacterial genera are commonly used as probiotics?

A. Staphylococcus and Streptococcus

B. Bifidobacterium and Lactobacillus

C. Bacillus and Clostridium

D. Corynebacterium and Listeria

Which yeast is commonly used as a probiotic?

A. Candida albicans

B. Aspergillus fumigatus

C. Saccharomyces

D. Cryptococcus neoformans

Which two bacterial phyla are especially efficient at breaking down complex carbohydrates in the gut?

A. Actinobacteria and Proteobacteria

B. Bacteroidetes and Firmicutes

C. Spirochetes and Chlamydiae

D. Cyanobacteria and Fusobacteria

Increased abundance of Bacteroidetes and Firmicutes in the gut microbiome improves the breakdown of which dietary component?

A. Complex carbohydrates

B. Nucleic acids

C. Heme iron

D. Steroid hormones

The microbiota can release which two cytokines?

Microbiota-induced IL-22 primarily helps protect the host by increasing what? _____ _____

Microbiota-induced IL-1β primarily promotes which immune response?

Recruitment of ______ cells

What is the role of Methanobrevibacter smithii in the gut?

Enhances dietary _____ digestion and promotes _____ accumulation

Which statement best describes the gut microbiome population?

A. Taxonomic diversity is low and functional redundancy is absent

B. Taxonomic diversity is great and functional redundancy is conserved

C. Taxonomic diversity is absent and functional redundancy is random

D. Taxonomic diversity is fixed and functional redundancy is impossible

Most of the approximately 200 unique bacterial species in the gut belong to which phyla?

A. Actinobacteria, Bacteroidetes, and Firmicutes

B. Proteobacteria, Cyanobacteria, and Spirochetes

C. Chlamydiae, Fusobacteria, and Rickettsiae

D. Archaebacteria, viruses, and fungi

Which organism is an example of Actinobacteria in the gut?

A. Bifidobacterium

B. Bacteroides

C. Ruminococcus

D. Faecalibacterium

Which organism is an example of Bacteroidetes in the gut?

A. Eubacterium

B. Bacteroides

C. Blautia

D. Bifidobacterium

Which set contains examples of Firmicutes in the gut?

A. Bacteroides and Bifidobacterium

B. Eubacterium, Ruminococcus, Faecalibacterium, Blautia

C. Shigella, Salmonella, and Vibrio

D. Histoplasma, Blastomyces, and Coccidioides

Short-chain fatty acids produced by gut microbiota help limit which organisms?

A. Undesirable bacteria

B. Host epithelial cells

C. Protective lymphocytes

D. Red blood cells

To kill bacterial spores, surgical equipment should be autoclaved by steaming at what temperature and duration?

A. 100°C for 5 minutes

B. 121°C for 15 minutes

C. 37°C for 30 minutes

D. 60°C for 60 minutes

Why is autoclaving required for surgical equipment contaminated with bacterial spores?

A. Spores are resistant and require steam sterilization

B. Spores are killed by room-temperature drying

C. Spores lack protective structures

D. Spores are destroyed by visible light only

Quaternary ammonium compounds act mainly by impairing what?

A. DNA replication

B. Cell membrane permeability

C. Ribosomal translocation

D. Peptidoglycan cross-linking

A disinfectant kills microbes by free radical oxidation. Which agent is being described? _____ _____

Chlorhexidine acts by ______ cell membranes and ______ intracellular components.

Saturated steam sterilization classically uses which temperature and duration?

____°C for ____ minutes

Which sterilizing agent is used for temperature- or pressure-sensitive items?

_____ _____ gas

Hydrogen peroxide acts as a sterilant through which mechanism?

A. Alkylation of sulfhydryl groups

B. Halogenation of nucleic acids

C. Free radical oxidation

D. Denaturation of proteins

What are the three levels of disinfection?

A. Sterile, aseptic, contaminated

B. High-level, intermediate-level, low-level

C. Aerobic, anaerobic, facultative

D. Chemical, physical, biologic

Bacterial spores may survive even after which level of disinfection?

Many microbes remain viable after which level of disinfection?

Which disinfectants are used for invasive-procedure items that cannot withstand sterilization?

A. High-level disinfectants

B. Low-level disinfectants

C. Quaternary ammonium compounds

D. Hand antiseptics

Intermediate-level disinfectants are used when contamination with which organisms is unlikely?

A. Enveloped viruses

B. Normal skin flora

C. Bacterial spores

D. Gram-positive bacteria

Which group contains examples of intermediate-level disinfectants?

A. Chlorhexidine, PCMX, triclosan

B. Ethylene oxide, formaldehyde, β-propiolactone

C. Alcohols, iodophors, phenolic compounds

Which item can be cleaned using intermediate-level disinfection?

A. Blood pressure cuff

B. Fiberoptic endoscope

C. Stethoscope

D. EKG electrode

Which item can be cleaned using intermediate-level disinfection?

A. Laryngoscope

B. Bed rail

C. Blood pressure cuff

D. Stethoscope

Which item can be cleaned using intermediate-level disinfection?

A. Hospital floor

B. EKG electrode

C. Bed sheet

D. Vaginal speculum

Which item can be cleaned using intermediate-level disinfection?

A. Blood pressure cuff

B. Anesthesia breathing circuit

C. Stethoscope

D. Patient gown

Quaternary ammonium compounds are classified as which type of disinfectant?

Which item can be cleaned using low-level disinfection?

A. Blood pressure cuff

B. Flexible endoscope

C. Surgical implant

D. Laryngoscope

Which item can be cleaned using low-level disinfection?

A. Surgical scalpel

B. Vaginal speculum

C. Fiberoptic endoscope

D. EKG electrode

Which item can be cleaned using low-level disinfection?

A. Surgical prosthesis

B. Laryngoscope

C. Stethoscope

D. Flexible endoscope

Alcohols have excellent activity against most groups of organisms except which form? ____

Alcohols tend to dry the skin surface because they remove what? _____

Alcohols lack which important antimicrobial property after application?

____ ____

Alcohols are inactivated by which substance?

____ ____

What increases the activity of alcohols as disinfectants?

Presence of _____

Why is 70% alcohol more active than 95% alcohol as a disinfectant?

A. Water improves alcohol activity

B. Higher alcohol concentration kills spores

C. Organic matter activates alcohol

D. Lipids prevent alcohol activity

Iodine and iodophors act mainly through which mechanism?

______ of DNA, RNA, and proteins

The efficiency of iodine and chlorine solutions is increased in what type of solution?

A. Alkaline solution

B. Neutral solution

C. Acidic solution

Which two factors decrease the effectiveness of chlorhexidine?

_____ material and _____ pH

The activity of para-chloro-meta-xylenol is limited mainly to which organisms?

____-____ ____

Triclosan is an antiseptic agent against _____ but not many other organisms

Triclosan is commonly found in which products?

A. Surgical implants and contact lenses

B. Autoclaves and gas chambers

C. Deodorant and some toothpaste

D. Blood agar and culture plates

Sterilization with ethylene oxide is optimal at approximately what relative humidity?

A. 30%

B. 5%

C. 70%

D. 95%

Ethylene oxide exerts sporicidal activity through which mechanism?

_____ of _____ _____ groups

Ethylene oxide blocks essential ____ processes by ____ terminal hydroxyl, carboxyl, amino, and sulfhydryl groups

Formaldehyde and β-propiolactone are strong examples of which type of gas?

The effectiveness of sterilization is monitored using which test organism?

A. Staphylococcus aureus

B. B. subtilis spores

C. Clostridioides difficile toxin

D. Bacteroides fragilis

Which class of compounds can be used as sterilants or high-level disinfectants?

_____

What concentration of hydrogen peroxide kills most bacteria?

A. 1-2%

B. 70-95%

C. 3-6%

D. 10-25%

What concentration of hydrogen peroxide can kill all organisms, including spores?

A. 1-2%

B. 3-6%

C. 70-95%

D. 10-25%

Hydrogen peroxide should be used to disinfect which item?

A. Plastic implants

B. Bed sheets

C. Wooden furniture

D. Blood agar plates

Hydrogen peroxide should be used to disinfect which item?

A. Blood pressure cuffs

B. Contact lenses

C. Paper charts

D. Cotton towels

Hydrogen peroxide should be used to disinfect which item?

A. Hospital floors

B. Patient gowns

C. Stethoscope tubing

D. Surgical prostheses

Phenolic compounds are active against mycobacteria because the mycobacterial cell wall has a high concentration of what?

_____

Which disinfectant class has activity against normally resilient mycobacteria?

A. Phenolic compounds

B. Quaternary ammonium compounds

C. PCMX

D. Alcohol-free detergents

Which halogenated bisphenol has activity against gram-positive bacteria?

A. Hydrogen peroxide

B. Hexachlorophene

C. Ethylene oxide

D. Formaldehyde

What is the mechanism of action of quaternary ammonium compounds?

Denature ____ ____ to release ____ components

At low concentrations, quaternary ammonium compounds have what effect?

A. Fungistatic

B. Fungicidal

C. Bactericidal

D. Bacteriostatic

At high concentrations, quaternary ammonium compounds have what effect?

A. Fungistatic

B. Fungicidal

C. Bactericidal

D. Bacteriostatic

Which 3 genera are resistant to quaternary ammonium compounds?

A) Staphylococcus, Streptococcus, Escherichia

B) Listeria, Shigella, Enterococcus

C) Pseudomonas, Mycobacteria, and Trichophyton

D) Salmonella, Proteus, Klebsiella

Sterilization vs disinfection?

An antiseptic agent is used to reduce the amount of ____ on the ____

Alcohols would be classified as an _____ agent

_____ _____ is used to sterilize heat-sensitive items. The sterilization process is relatively slow.

Aldehydes and ethylene oxide exert their effects through _____

peracetic acid and hydrogen peroxide exert their effects through _____

_____ act by disturbing lipid containing membranes and leaking cell contents

What is the most commonly used non-selective culture media?

____ ____

The _____ _____ pattern on blood agar is present with partial lysis of RBCs

The _____ _____ pattern on blood agar is present with full lysis of RBCs

The _____ _____ pattern on blood agar is present with lack of lysis of RBCs

Phase-Contrast Microscopy allows the ____ ____ to be examined by creating a ____ ____

What is the function of fluorochromes?

1. Absorb _____ wavelength UV or ultrablue light
2. Emit energy at a _____ visible wavelength

Why do organisms appear bright on a dark background in fluorescent microscopy?

The stained organisms emit _____ light while the background stays _____

Compared with the light absorbed by a fluorochrome, the light emitted by the fluorochrome has:

A. A shorter wavelength and higher energy
B. A longer wavelength and lower energy
C. The same wavelength and same energy
D. No wavelength because it is invisible

Which statement best describes the role of a fluorochrome?

A. It makes organisms visible by emitting light after excitation
B. It kills organisms before they are viewed
C. It increases the magnification of the microscope
D. It prevents antibodies from binding organisms

Why does electron microscopy have higher resolution than light microscopy?

A. It uses thicker specimens
B. It uses electrons with much shorter wavelengths
C. It stains organisms with fluorescent antibodies
D. It uses electrons with much longer wavelengths

Can viruses generally be visualized using electron microscopy?

A researcher wants to view the internal structure of a virus by allowing electrons to pass through the specimen. Which microscope should be used?

A. Transmission electron microscope
B. Scanning electron microscope
C. Fluorescent microscope
D. Dark-field microscope

A scientist wants a three-dimensional image of the surface of a bacterial cell. Which microscope is most appropriate?

A. Transmission electron microscope
B. Scanning electron microscope
C. Bright-field microscope
D. Phase-contrast microscope

Which statement best describes scanning electron microscopy?

A. Electrons pass directly through the center of the specimen
B. It is mainly used to view internal organelles in thin sections
C. It uses fluorescent dyes to label organisms
D. Electrons bounce off the surface of the specimen at an angle

The resolving power of a microscope refers to its ability to:

_____ the _____ of a specimen

Which factor improves the resolving power of a microscope?

A. Increasing the angle of light entering the retina
B. Decreasing the angle of light entering the retina
C. Increasing the angle of light entering the lens
D. Decreasing the angle of light entering the lens

Resolving power is mainly determined by the ______ of light used and the ______ of light entering the ______ lens

Why does oil immersion improve resolving power?

It _____ _____ /_____ of light

The India ink method is a classic _______ staining technique in which the background is _______ while the cells remain _______.

What two organisms can be detected using the India ink stain?

1. ______

2. Encapsulated ______ ______

What part of the organism does India ink stains dye?

1. The ______ rather than the cell
2. This creates a ______ ______ around the ______ cell

What is the advantage of darkfield microscopy?

Resolving power is significantly _____ compared to _____

Darkfield microscopy has a _____ that prevents transmitted light from illuminating the specimen

What is the disadvantage of darkfield microscopy?

Difficult to study the organism's _____ structure

The limitation of brightfield microscopy is the ______ of the image

Types of stains

The ____ stain is the best known and most widely used stain and forms the basis for the phenotypic classification of bacteria

The ____ ____ and ____ stains are invaluable for identifying protozoan parasites

____-____ stain is used to identify blood parasites

What is a mnemonic for 6 organisms that can be identified via Wright-Giemsa stain?

Which organism can be identified using a Wright-Giemsa stain?

A. Staphylococcus aureus
B. Enterococcus faecalis
C. Aspergillus fumigatus
D. Helicobacter pylori

Which organism can be identified using a Wright-Giemsa stain?

A. Chlamydia trachomatis
B. Neisseria gonorrhoeae
C. Treponema pallidum
D. Candida albicans

Which organism can be identified using a Wright-Giemsa stain?

A. Leptospira interrogans
B. Borrelia burgdorferi
C. Treponema pallidum
D. Clostridium tetani

Which organism can be identified using a Wright-Giemsa stain?

A. Bacillus anthracis
B. Mycoplasma pneumoniae
C. Rickettsia rickettsii
D. Legionella pneumophila

Which organism can be identified using a Wright-Giemsa stain?

A. Trypanosomes
B. Dermatophytes
C. Nontuberculous mycobacteria
D. Prions

Which organism can be identified using a Wright-Giemsa stain?

A. Toxoplasma gondii
B. Giardia lamblia
C. Plasmodium species
D. Entamoeba histolytica

In vitro cultures depend on 3 things for success
1. ____ of infection
2. Patient's ____ reponse
3. Quality of ____ media

MacConkey agar is a selective media for gram ______ bacteria which contains ______ ______ to inhibit growth of gram ______

What is the main difference between the Ziehl-Neelsen stain and the Kinyoun method?

A. Ziehl-Neelsen uses Gram stain, while Kinyoun uses India ink
B. Ziehl-Neelsen requires heat, while Kinyoun can be performed cold
C. Ziehl-Neelsen stains fungi, while Kinyoun stains viruses
D. Ziehl-Neelsen uses iodine, while Kinyoun uses crystal violet

Which acid-fast staining method is also called the hot acid-fast stain?

A. Kinyoun method
B. India ink stain
C. Ziehl-Neelsen stain
D. Wright-Giemsa stain

Which acid-fast staining method can be performed without heating the slide?

A. Ziehl-Neelsen stain
B. Kinyoun method
C. Gram stain
D. Silver stain

Why is heat used in the Ziehl-Neelsen stain?

A. To destroy bacterial endospores
B. To remove mycolic acids from the cell wall
C. To help carbolfuchsin penetrate the waxy cell wall
D. To make bacteria fluoresce

Acid-fast stains are especially useful for organisms with:

A. Thick peptidoglycan only
B. A capsule made of polysaccharide
C. No cell wall
D. Mycolic acid-rich cell walls

What makes chocolate agar brown?

A. Lactose fermentation
B. Heated hemoglobin
C. Bile salts
D. Crystal violet

Why is chocolate agar considered enriched?

It contains extra _____ from lysed _____ blood cells

MacConkey agar is differential because it separates bacteria based on their ability to:

A. Form spores
B. Ferment lactose
C. Produce mycolic acid
D. Invade red blood cells

A gram-negative rod grows pink colonies on MacConkey agar. What does this suggest?

A. It is acid-fast
B. It ferments lactose
C. It cannot ferment lactose
D. It is gram-positive

A gram-negative rod grows colorless colonies on MacConkey agar. What does this suggest?

A. It is a lactose nonfermenter
B. It is a lactose fermenter
C. It is inhibited by bile salts
D. It has heated hemoglobin

What type of agar is used to isolate Staphylococci? What color are the colonies in the presence of S. aureus?

_____ _____ agar

_____

Blood agar is commonly used to differentiate species of ______.

What are the magnifications of the following objective lenses?

Low power: [...]
High dry: [...]
Oil immersion: [...]

Can Light microscopy view viruses?

Which type of microscopy will allow you to see the internal details of a bacteria?
A. Light microscopy
B. Fluorescent
C. Electron
D. Phase-contrast
E. Dark

The iron hematoxylin and trichrome stains are invaluable for identifying ______ ______

What organisms are acid-fast bacteria?

1. M______
2. N______
3. C______

Xylose-lysine deoxycholate (XLD) agar is used to detect ______ and ______.

1. What color is Shigella on XLD agar? ____
2. What color is Salmonella on XLD agar? ____
3. What compound is added to Salmonella to create that color? ____ ammonium citrate

Shigella [does/does not] produce H₂S and Salmonella [does/does not] produce H₂S

_____-_____ agar is the recommended medium for antibiotic susceptibility testing of bacteria

Sabouraud dextrose agar is used to isolate _____.

Which type of microscopy would detect Treponema pallidum (etiologic agent of syphilis) and Leptospira spp. (leptospirosis)?

______

_____ microscopy involves a specimen that is brightly illuminated with a dark background

Brightfield microscopy uses which method to view a sample?

A. Electron reflection
B. Transillumination
C. Fluorescent emission
D. Magnetic resonance

What is the correct order of light movement in a brightfield microscope?

A. Ocular lens → objective lens → specimen → light source
B. Objective lens → ocular lens → light source → specimen
C. Specimen → light source → ocular lens → objective lens
D. Light source → specimen → objective lens → ocular lens

Why are stains often used in brightfield microscopy?

A. To make organisms glow on a dark background
B. To increase contrast between the specimen and background
C. To make electrons pass through the specimen
D. To make viruses visible without magnification

Thioglycolate broth is an enrichment broth used when there may be very few ______ in the sample. It helps recover both ______ and ______ bacteria.

Which medium is commonly used for the isolation of Mycobacterium tuberculosis?

A. MacConkey agar
B. Lowenstein-Jensen
C. Chocolate agar
D. Sabouraud agar

Middlebrook agar is used primarily to culture _______

The best brightfield microscopes have a resolving power of approximately 0.2 μm, which allows most _____, but not _____, to be visualized.

Which agar is used to isolate Corynebacterium diphtheriae?

A. Blood agar

B. Chocolate agar

C. Cystine-tellurite agar

D. MacConkey agar

What agar is used to isolate Bordetella pertussis?

_____-_____ agar

Selective media are designed to recover ____ organisms and ____ growth of unwanted organisms

Acridine orange is best classified as which type of stain?

A. Acid-fast stain
B. Fluorescent stain
C. Negative stain
D. Capsule stain

Acridine orange can be used to stain which organisms?

____ and ____

What is the function of a condenser?

______ the light on the specimen

How can you calculate the total magnification of an image?

(______ lens mag) * (______ lens mag)

____ ____ are used in electron microscopy to direct a beam of electrons from a tungsten ____ through a ____ and onto a screen

Yeasts are Gram-_____ organisms

What counterstain is retained by Gram-negative organisms?

_____

What two substances must be present in the media for Legionella to grow?

1. _____
2. _____

Which set includes the 3 types of acid-fast stains?

A. Gram, India ink, silver stain
B. Wright-Giemsa, PAS, methenamine silver
C. Ziehl-Neelsen, Kinyoun, auramine-rhodamine
D. Capsule stain, endospore stain, Lugol iodine

Which acid-fast stain is a fluorescent method?

A. Auramine-rhodamine method
B. Kinyoun method
C. Ziehl-Neelsen stain
D. Lugol iodine stain

Lugol iodine is used in microscopy to help differentiate:

_____ from host _____ _____ cells

A child with epiglottitis has Haemophilus influenzae. Which medium is classically used to culture it?

A. Chocolate agar

B. Sabouraud agar

C. Thayer-Martin agar

D. Lowenstein-Jensen agar

Inhibitory mold agar is selective for the isolation of:

_____ _____ other than dermatophytes

What are the 3 steps that are repeated in PCR?

1. ______- separates the ______ into 2 strands
2. ______- (annealing)- allows ______ to bind to the 2 strands
3. ______- temperature is increased and ______ ______ adds dNTPs to the strand

What is the most common nucleic acid amplification method?

The primary goal of RT-PCR (Reverse Transcription-Polymerase Chain Reaction) is to _____ and _____ RNA targets

A laboratory uses nested PCR to detect trace pathogen DNA in a clinical sample. Why does this technique provide greater sensitivity than standard PCR?

A. It performs two amplification rounds
B. It uses fluorescent nucleotide probes
C. It eliminates primer annealing steps
D. It directly sequences amplified DNA

Which strategy describes the selection and timing of the primers used during the two distinct amplification rounds of a nested PCR assay?

A. Utilizing the exact same primer pair for both the first and second rounds

B. Employing random hexamer primers to initiate amplification in each consecutive round

C. Utilizing two distinct, sequential primer pairs where the second pair binds internal to the first amplicon

D. Initiating the first round with RNA primers followed by DNA primers in the second round

Why is the nested PCR process described as a “funneling” approach?

A. It enriches the desired target
B. It converts RNA into DNA
C. It separates fragments by size
D. It measures fluorescence continuously

What happens to background material during nested PCR?

A. It becomes preferentially amplified
B. It is progressively diluted
C. It binds the second primers
D. It prevents target amplification

Which sequence best describes nested PCR?

A. Sequencing followed by amplification
B. Amplification followed by digestion
C. Reverse transcription followed by PCR
D. Traditional PCR then internal amplification

A RNA amplification test proceeds at a constant temperature (isothermal) without repeated heating and cooling cycles. Which method does this best describe?

A. Nested PCR
B. Standard PCR
C. Transcription-mediated amplification
D. Ziehl-Neelsen staining

Which enzyme first converts RNA into complementary DNA during transcription-mediated amplification?

_____ _____

In transcription-mediated amplification, RNA polymerase is mainly responsible for producing ______ copies from a ______ template

Why does single-stranded RNA simplify detection in transcription-mediated amplification?

It does not need to be ______ before detection

What is an isothermal amplification method for detection of specific RNA and DNA sequences?

_____ _____ _____ (_____)

When does amplification of the target sequence in SDA occur?

when the _____ creates a _____ at the _____ end and then _____ _____ binds to the _____ site

A rural clinic needs a rapid nucleic acid amplification test for a pathogen but lacks a thermocycler. The test uses multiple primers and runs at a constant temperature. Which method is being described?

____-____ amplification

Loop-mediated amplification is best described as which type of amplification method?

A. Isothermal variation of strand displacement amplification
B. Heat-cycled variation of nested PCR
C. Antibody-based detection of microbial antigens
D. Culture-based isolation of fastidious bacteria

Loop-mediated amplification can amplify which type of target sequence?

____ or ____

In loop-mediated amplification, amplified products can be monitored in real time by measuring:

_____ _____ turbidity

Which feature makes LAMP especially attractive for resource-limited settings?

A. It requires expensive fluorescence microscopy
B. It is rapid and does not require costly instrumentation
C. It requires repeated heating and cooling cycles
D. It only works after organisms are grown in culture

DNA fragments of different sizes or structures can be distinguished by their _____ _____ in an agarose or polyacrylamide gel

restriction fragment length polymorphism (RFLP) is the technique where specific strains of microorganisms can be distinguished by cutting ____ ____ with ____ that recognize specific DNA sequences

What do restriction endonucleases do during RFLP analysis?

A. Copy the DNA

B. Join DNA fragments

C. Translate viral proteins

D. Cut DNA at specific sequences

Two bacterial strains are digested with the same restriction enzyme but produce different DNA fragment patterns. What is the best explanation?

The strains have different _____ sequences affecting _____ sites

The pattern of DNA fragments produced in RFLP analysis is mainly used to determine:

A. Whether a bacterium ferments lactose
B. Whether a virus has an envelope
C. The relatedness of different microbial strains
D. The oxygen requirement of a microorganism

DNA can be visualized by staining with _____ _____

Standard gel electrophoresis does not separate the fragments well because they are too large. Which technique should be used?

A. Standard PCR
B. Pulsed-field gel electrophoresis
C. Gram staining
D. Transcription-mediated amplification

Pulsed-field gel electrophoresis is especially useful for separating large _____ fragments from _____.

What is the key feature of pulsed-field gel electrophoresis?

A. It uses antibodies to detect microbial antigens
B. It repeatedly changes the direction of the electric field
C. It uses heat cycles to amplify bacterial DNA
D. It stains acid-fast organisms with carbolfuchsin

A gel shows different banding patterns from bacterial isolates after large genomic DNA fragments are separated. What can these patterns help determine?

A. Whether the bacteria are lactose fermenters
B. Whether the bacteria are obligate aerobes
C. Whether the bacteria are closely related strains
D. Whether the bacteria have capsules

What occurs in a Western Blot?

1. Microbial proteins are _______ with a strong reducing agent
2. Microbial proteins are then ______ by size on a polyacrylamide gel by ______
3. Proteins are transferred onto a nitrocellulose ______ by "______" and then overlaid with the patient's serum (with antibodies)
4. Nitrocellulose is ______ and ______ to detect ______ binding to specific microbial protein

______ is a powerful diagnostic tool used to amplify a desired fragment of DNA

How many primers are needed for polymerase chain reaction (PCR)?

_____ (one for the _____ end of each DNA strand)

What type of primer is used in a polymerase chain reaction (PCR)?

In the body, _____ primers are used; in the test tube, _____ primers are used

PCR requires the addition of all _____ deoxynucleotide triphosphates (dNTPs) for DNA synthesis

Transcription mediated amplification is an _____ amplification method

What type of probe is used to bind protein when using a Western blot?

_____ _____

What disease would a western blot be useful for?

_____ _____

A lab wants to determine whether a bacterial isolate contains a specific antibiotic resistance gene. Which sequencing approach is most appropriate?

____ sequencing

A hospital is investigating whether several bacterial isolates from different patients are genetically related during an outbreak. Which sequencing method is most useful for subtyping/genotyping?

____ ____ sequencing

Scientists commonly sequence ribosomal RNA genes to identify ____ and ____

A titer is a measure of how much a sample can be ______ before ______ can no longer be detected.

_____ development is one of the more traditional methods used to generate _____ antibodies, enabling the production of highly sensitive binders.

Hybridomas are cells formed via fusion between a short-lived _____-producing B cell and an _____ _____ cell.

What are the disadvantages of monoclonal antibodies?

They are often ____ ____ - cannot identify two different strains of the ____ virus

The ____ ____ is the concentration range where antigen and antibody are in the right proportions to form a large cross-linked lattice.

That lattice becomes too large to stay dissolved, so it _____ and helps us detect antigen-antibody binding.

Single radial immunodiffusion measures ____ concentration by letting antigen diffuse outward into ____ -containing agar. A precipitin ____ forms at the equivalence zone, and the ring size ____ as antigen concentration increases.

What does the Ouchterlony double-diffusion test detect?

A. Antigen-antibody precipitation

B. Bacterial movement

C. Viral genome replication

D. Red blood cell size

Ouchterlony testing may help diagnose which infections?

A. Influenza and measles

B. Malaria and giardiasis

C. Histoplasma, Blastomyces, and Coccidioides

D. Staphylococcus and Streptococcus

In the immuno-double diffusion technique, a visible ____ ____ occurs when the concentrations of antibody and antigen reach equivalence

In an enzyme immunoassay, the _____ is linked to an _____.

That antibody binds the target _____.

Then you add a _____ for the enzyme.

If the antibody is bound to antigen, the enzyme acts on the substrate and produces a detectable signal, usually a ____ change.

Which enzyme can be conjugated to an antibody in an enzyme immunoassay?

A. DNA polymerase
B. Horseradish peroxidase
C. Reverse transcriptase
D. Restriction endonuclease

Which enzyme can be conjugated to an antibody in an enzyme immunoassay?

A. DNA polymerase
B. Alkaline phosphatase
C. Reverse transcriptase
D. Restriction endonuclease

_____ _____ _____ is used for population analysis of antigen-positive cells

What does flow cytometry analyze?

A. Cells fixed within solid tissue

B. Cells moving through suspension

C. Viruses growing on agar

D. Antibodies inside a test tube

Flow cytometry is especially useful for identifying which cells?

A. Red blood cells

B. Bone-forming cells

C. Skin cells

D. Lymphocytes

What 3 things does Flow cytometry assess for?

1. _______
2. _______
3. _______ expression

Which of the following cell types has the smallest size and is the least granular?

[Lymphocytes/Monocytes/PMNs]

Which of the following cell types has the largest size and is the most granular?

[Lymphocytes/Monocytes/PMNs]

What occurs in a direct ELISA

used to detect the presence of a _____ _____
1. _____ is placed at bottom of well
2. Primary _____ enzyme binds to _____
3. _____ is added to create a colorful solution (if antibody binds to antigen)

What occurs in an indirect ELISA?

used to detect the presence of an _____
1. _____ is placed at bottom of well
2. _____ _____ binds to antigen
3. _____ _____ enzyme binds to primary antibody
4. _____ is added to create a colorful solution (if antibody is present)

What type of analysis has been used to confirm ELISA results in patients who are suspected to have HIV?

____ ____

specific _____ antibody found is a good indicator of a recent primary infection

_____ or recurrence later in life causes an anamnestic (secondary or booster) response

What lab values indicate seroconversion or reinfection?

at least a _____ increase in _____ _____ between serum obtained during the acute phase of disease and that obtained at least 2-3 weeks later during the convalescent (recovery) phase

Early infection: antibodies often target accessible viral ____ antigens.

Later infection: cell lysis releases intracellular viral proteins, allowing antibodies to form against ____ viral antigens.

What is is an immunologic test used to detect the presence of either a specific antigen or antibody in a patient's blood sample

What is the main purpose of single radial immunodiffusion?

A. Determine antibiotic resistance genes
B. Detect and quantify antigen
C. Identify viral RNA sequences
D. Distinguish influenza strains

The Ouchterlony immuno-double-diffusion technique is primarily used to determine:

A. The concentration of antigen in serum
B. The relatedness of different antigens
C. The presence of viral nucleic acid
D. The oxygen tolerance of bacteria

Which statement best compares single radial immunodiffusion and Ouchterlony double diffusion?

A. Both involve antigen-antibody precipitin complex formation
B. Both are used mainly to amplify DNA
C. Both require fluorescent antibodies
D. Both measure antiviral antibody titers only

A clinician wants to detect and localize microbial antigens on the surface of infected cells. Which methods would be most appropriate?

A. RFLP and pulsed-field gel electrophoresis
B. Ouchterlony and thioglycolate broth
C. Immunofluorescence and enzyme immunoassay
D. Gram stain and acid-fast stain

How is protein expression detected during flow cytometry?

A. Fluorescently labeled antibodies

B. Restriction enzymes

C. Red blood cell clumping

D. Bacterial staining

What type of test is a home pregnancy test?

A. Western blot assay

B. Double-diffusion assay

C. Lateral-flow visual assay

D. Hemagglutination assay

What is done first in passive hemagglutination?

A. RBCs are coated with antigen

B. Antibodies are destroyed

C. Viruses are added to agar

D. Lymphocytes are separated

What causes clumping in passive hemagglutination?

A. Antigens destroy red blood cells

B. Complement dissolves the antigens

C. Patient antibodies cross-link coated RBCs

D. Viral proteins enter the RBCs

What does clumping indicate in passive hemagglutination?

A. The patient lacks antibodies

B. The patient has specific antibodies

C. The red cells are infected

D. The antigen has disappeared

What is seroconversion?

A. Loss of all antibodies

B. Conversion of RNA into DNA

C. Production of antibody after infection

D. Destruction of infected cells

During early viral infection, antibodies often target which antigens?

A. Accessible viral surface antigens

B. Hidden nuclear proteins

C. Host-cell ribosomes

D. Bacterial cell walls

Why may antibodies against internal viral proteins appear later?

A. Surface proteins become invisible

B. Cell lysis releases internal proteins

C. Viruses stop producing antigens

D. Antibodies enter the viral genome

What does hemagglutination-inhibition testing commonly measure?

A. Bacterial antibiotic resistance

B. Viral particle size

C. Antiviral antibody titers

D. T-cell granularity

How do antiviral antibodies affect hemagglutination?

A. They increase red-cell clumping

B. They inhibit red-cell clumping

C. They destroy all red cells

D. They coat red cells with antigen

Hemagglutination-inhibition testing can help distinguish strains of which virus?

A. Influenza virus

B. Hepatitis B virus

C. Herpes simplex virus

D. Human papillomavirus

How are monoclonal antibodies produced?

A. By many unrelated immune cells

B. By clones of one parent cell

C. By several different antigens

D. By complement proteins