Exam 2: Quizzes Flashcards
Which of the following structures would NOT be found in a prokaryotic cell:
- Ribosomes in the cytoplasm
- DNA
- A cell membrane composed of a phospholipid bilayer
- A cell wall composed of peptidoglycan
- Mitochondria in the cytoplasm
Mitochondria in the cytoplasm
The cell walls of gram-positive bacteria contain
- A very thin protective peptidoglycan layer
- An outer lipopolysaccharide layer
- Two unique antigenic components: teichoic acid and lipoteichoic acid
- All of the above are found in the cell walls of gram positive bacteria
Two unique antigenic components: teichoic acid and lipoteichoic acid
Streptococcus pyogenes would most likely have which morphology and arrangement?
- Clusters of spheres
- Single rods
- Chains of rods
- Chains of spheres
- Clusters of rods
Chains of spheres
**In regards to nomenclature guidelines, which of the following is written incorrectly:
**
1. Streptococcus pyogenes
- staphylobacillus
- Staphylococcus aureus
- Escherichia coli O157:H7
staphylobacillus
Which of the following lists the steps in the Gram Staining procedure correctly?
- Crystal violet, Iodine, Alcohol-Acetone, Safranin
- Safranin, Alcohol-Acetone, Crystal violet, Iodine
- Carbolfuchsin, Acid-Alcohol, Methylene Blue
- Methylene Blue, Acid-Alcohol, Carbolfuchsin
- None of these are correct
Crystal violet, Iodine, Alcohol-Acetone, Safranin
Corynebacterium diphtheria is the causative agent behind diphtheria. However, not all C. diphtheriae bacteria produce the toxin that causes this disease. To produce the toxin, the bacteria must first become infected with a bacteriophage. The process by which bacterial genes are transferred to new bacteria by a bacteriophage is called:
- Transduction
- Conjugation
- Replication
- Transformation
Transduction
**When bacteria are growing, they go through a stationary phase when:
**
1. the number of nonviable bacterial cells exceeds the number of viable cells.
- the bacterial numbers double with each generation time.
- nutrients are becoming limited and the numbers of bacteria remain constant.
- they are preparing to divide.
nutrients are becoming limited and the numbers of bacteria remain constant.
**Which of the following environmental factors influence the growth of bacteria in the laboratory?
**
1. pH
- Temperature
- Gaseous composition of the atmosphere
- All of the above
All of the above
**The anaerobic process carried out by both obligate and facultative anaerobes that uses an organic compound as the final electron acceptor is called
**
1. capnophilic
- fermentation
- microaerophilic
- anaerobic cellular respiration
fermentation
**All of the following statements are true about viruses except viruses:
**
can infect bacteria, plants, and animals.
are acellular but are surrounded by a protein coat.
do not need host cells to survive and grow.
have a genome that consists of DNA or RNA but not both.
do not need host cells to survive and grow.
**Microorganisms that participate in symbiosis where the microorganism lives at the expense of the host (the host is harmed)
**
mutualism
indigenous microbiota
commensalism
parasitism
host interactions
parasitism
**Which of the following “site - bacteria” combinations, would NOT be considered normal microbiota:
**
Gastrointestinal tract - Bacteriodes spp.
Oral cavity - Streptococcus mitis
Stomach - Escherichia coli
Skin - Staphylococcus epidermidis
Vagina - Lactobacillus spp.
Stomach - Escherichia coli
**Candida albicans is a member of the resident microbiota of many people, but it may overgrow when a person is taking an antibiotic. This type of infection is called:
**
sexually transmitted infection
an opportunistic infection
symbiosis
a carrier state
a parasitic infection
an opportunistic infection
A patient arrives at the emergency room exhibiting the following symptoms: a temperature of 102° F, low blood pressure, elevated white blood cell count, and abnormal blood clotting (DIC). Blood cultures reveal the presence of gram-negative rods. What is the likely cause of these symptoms?
Exotoxin
Endotoxin
Extracellular enzymes
Exfoliating toxin
Endotoxin
Innate immunity consists of which of the following components?
Physical and chemical barriers, such as the skin and mucous membranes
Blood proteins that act as mediators of infection
Cells capable of phagocytosis
All of the above are part of the innate immune system.
All of the above are part of the innate immune system.
Which of the following is NOT a virulence factor found on/in at lease some pathogenic bacteria?
Fimbriae
Protein A
Cilia
Capsules
Ability to resist phagocytosis
Cilia
Indirect routes of transmission of infectious disease include all of the following EXCEPT?
Airborne - aerosols suspended in the air
Water
Fomites
Sexual contact
Food
Sexual contact
Health care-associated infections are commonly associated with:
foodborne illness.
respiratory aerosol transmission.
preexisting infections.
breaks in aseptic technique.
breaks in aseptic technique.
What process helps public health and health care officials recognize outbreaks, increasing trends of infections, and positive effects of interventions?
Intervention
Handwashing techniques
Antimicrobial resistance
Surveillance
Surveillance
**How quickly would rabies need to be reported as a disease of major public health concern? (this is true for MN and OH like the chart)
**
By the end of the next business day
Immediately
During a monthly report
By the end of the work week
It doesn’t need to be reported at all
Immediately
Methods used to destroy all life are called
bacteriostatic
sterilization
bactericidal
disinfection
sterilization
The most resistant microbes to heat, chemicals, and radiation are:
parasites
viruses
prions
bacteria
prions
After working in the microbiology lab, the laboratory scientist sprayed the bench top with a chemical spray. This process will not kill all microbes, but will reduce the number of microbes, including pathogens, on this non-living surface. What is this called?
Sterilization
Antiseptic
Bactericidal
Bacteriostatic
Disinfection
Disinfection
Which type of gas has commonly been used for gas sterilization of heat sensitive material in a hospital setting?
oxygen
nitrous oxide
ethylene oxide
carbon dioxide
ethylene oxide
What is the most common iodophor used in the U.S. for preoperative skin preparation?
calcium iodophor
95% ethanol and iodine
tincture of iodine
povidone iodine
povidone iodine
**Which of the following is NOT contained on a SDS
**
Disposal recommendations
Precautions to take while using chemical and control measures
Directions for using the chemical experimentally
Spill cleanup procedures
Name, address, and telephone of manufacturer
Directions for using the chemical experimentally
Which Biosafety Level is used in most hospital labs, where there is a moderate potential for encountering hazardous material?
1
2
3
4
2
Which of the following is NOT considered a major source of biological hazard for people working in clinical microbiology?
Patient samples during processing and handling
Actively growing culture materials
Appropriately disposed of infectious waste
None of these are sources of biological hazard
Appropriately disposed of infectious waste
**Why is quality control important?
**
ensures that the correct BSL is used.
ensures that incidence of emerging infectious diseases is decreasing.
ensures that standard precautions are followed.
ensures the medical reliability of laboratory data.
ensures the medical reliability of laboratory data.
Select the answer that best fills in the blank: 100 patients who have gonorrhea are tested for that disease and the test yields positive results in 95 and is negative in the other 5. Five of these 100 patients had false-negative (FN) test results. The _of the test is 95%
Clinical specificity
Incidence
Analytic specificity
Clinical sensitivity
Clinical sensitivity
Which of the following is NOT TRUE of correct specimen collection?
label the specimen accurately with the specific anatomic site and the patient information.
select the correct anatomic site to collect the specimen.
pack the specimen to maintain viability and prevent leakage
collect the appropriate quantity of specimen.
it is acceptable to collect specimens after antibiotics are administered on a routine basis.
it is acceptable to collect specimens after antibiotics are administered on a routine basis.
Why are bone marrow, synovium, and blood specimens mixed after collection with anticoagulants?
Anticoagulants dissolve part of the bacteria’s cell wall and congeal many bacteria into groups.
It ensures the specimen will work when using an automated spreader device.
Prevent organisms from becoming bound up in the clotted material, making them difficult to isolate.
It kills all the normal microbiota and only leaves the pathogens in the specimen.
It breaks down eukaryotic nuclear material, but not bacterial for nucleotide amplification tests.
Prevent organisms from becoming bound up in the clotted material, making them difficult to isolate.
Which of the following normally has the highest level of specimen prioritization?
Feces
Cerebrospinal fluid
Urine
Bone
Sputum
Cerebrospinal fluid
**Which of the following is NOT a normal reason to reject a specimen?
**
Specimen is received in the wrong preservative.
The transport time was 30 minutes.
All of these are normal reasons to reject a specimen
The transport container is leaking.
Requisition information does not match specimen label
Specimen is dried up.
The transport time was 30 minutes.
You receive a specimen through the mail from a smaller lab. The package has a small watertight vial in a larger watertight tube. The smaller tube has absorbent material around it. No other packaging is present. What was wrong with this?
The primary container does not need to be watertight.
It is not necessary to have a second watertight tube to enclose the smaller vial.
Absorbent material should be around the larger tube not the primary receptacle.
Secondary container should be enclosed in a outer container made of fiberboard.
Specimen was placed in a small watertight vial.
Secondary container should be enclosed in a outer container made of fiberboard.
Which of the following media would be classified as nonselective and enriched?
Mannitol salt agar
Eosin methylene blue agar
MacConkey agar
Chocolate agar
CNA agar
Chocolate agar
Which of the following media / classification pairings is incorrect?
Sheep’s blood agar / Differential media
CNA / Selective media
MacConkey agar / Selective Media
Sheep’s blood agar / Selective media
MacConkey agar / Differential Media
Sheep’s blood agar / Selective media
A common method to isolate individual colonies of bacteria on a culture plate is called a _plate. It allows grading of a relative concentration of organisms using four quadrants.
Streak
Cotton swabs are the best specimen collection devise.
True False
false
Both written and verbal instructions are necessary to provide patients expected to collect a clean catch urine sample.
True False
true
Which of the following is NOT a critical value in microbiology?
Positive blood culture
Positive cerebrospinal fluid culture
Positive acid-fast smears
Streptococcus agalactiae from genital site of pregnant women at term
Streptococcus pyogenes from a sterile site
All of these are examples of critical values in microbiology
All of these are examples of critical values in microbiology
If you are looking at a specimen under the 100X oil objective of a compound microscope with a 10X ocular magnification, what would be the total magnification?
10X
60X
110X
500X
1,000X
1,000X
Which type of microscope is usually used in the clinical microbiology lab?
Darkfield compound
Fluorescent
Brightfield compound
Dissecting
Brightfield compound
In the Gram stain technique, Safranin functions as the
Mordant
Decolorizer
Counterstain
Primary stain
Counterstain
**Which of the following staining procedures would be used as a differential stain of infected materials to stain infected materials suspected of containing bronchoalveolar fungi?
**
Leifson stain
Acid-fast stain
Calcofluor white stain
Methylene blue stain
Wright-Giemsa stain
Calcofluor white stain
When making slides of thin materials such as urine and cerebrospinal fluid (CSF)
use the two-slide pull method to ensure evenly distributed material over the slides
spread the material once, let the specimen dry, then spread another layer on top to ensure enough specimen to stain
mark the area of the sample drop on the reverse side with a wax pencil and then place a drop of the specimen into the marked area
dip a swab into the specimen, then roll the swab over the glass slide to ensure adequate coverage for staining
mark the area of the sample drop on the reverse side with a wax pencil and then place a drop of the specimen into the marked area
What elements should be included in the direct examination of a microbial smear?
Only those elements pertaining to the amount of gram-positive cocci present in the specimen
Only those elements useful in characterizing the specimen
Only those elements of contaminating material present in the specimen
Only elements pertaining to the necrosis present in the specimen
Only those elements useful in characterizing the specimen
A cytocentrifuge is an excellent method for preparing nonviscous fluids, because
it deposits cellular elements and microorganisms from the specimen onto the surface of a glass slide as a monolayer.
the sediment is mixed with 70% albumin before spreading it on the surface of a slide.
the cytocentrifuge not only spreads the specimen over the surface of a slide but also stains the specimen.
it concentrates the protein evenly throughout the slide surface.
it deposits cellular elements and microorganisms from the specimen onto the surface of a glass slide as a monolayer.
You prepare cerebrospinal fluid (CSF) cultures and read the results. You notice no growth on sheep blood agar (BAP) or MacConkey (MAC) agar, but that there is growth on chocolate agar (CHOC). The Gram stain showed a gram-negative bacillus. What organism should be suspected?
Haemophilus influenzae
Streptococcus pneumoniae
Escherichia coli
Staphylococcus aureus
Haemophilus influenzae
If a symptomatic patient presents to a physician with a bacterial infection, the physician will treat the patient with antibiotics. What role does the laboratory play in antibiotic selection if the physician has already treated the patient before receiving the laboratory results?
**
The physician has only given the patient antibiotic samples, and they will only last for a couple days—until the culture results are ready and a proper prescription can be written.**
Physicians will only write antibiotic prescriptions for patients who are infected with a large number of bacteria, so the laboratory needs to tell the physician which antibiotic to use to treat the patient infected with a small number of bacteria.
The physician can treat the patient for bacterial infections, but if the patient has a fungal infection, the physician relies on the laboratory to tell her or him if the patient has a fungal infection.
The physician expects the laboratory to affirm or reject the antibiotic choice made after the presumptive diagnosis.
The physician expects the laboratory to affirm or reject the antibiotic choice made after the presumptive diagnosis.
Plate reading is:
a comparative examination of bacteria growing on a variety of culture media.
examining the colonial morphology of bacteria on slants.
determining if the inoculum is mixed.
setting up biochemical tests to identify bacteria.
a comparative examination of bacteria growing on a variety of culture media.
A commonly used medium containing lactose and bile salts that is a selective and differential medium for the isolation of gram-negative bacteria is .
Sabouraud dextrose agar
Anaerobic blood agar
MacConkey agar
Chocolate agar
MacConkey agar
β-Hemolysis is:
when organisms have no lytic effect on the erythrocytes in the blood agar plate.
partial lysing of erythrocytes in a blood agar plate around and under the colony.
complete clearing of erythrocytes in a blood agar plate around and under the colony.
a pink “halo” around a colony.
complete clearing of erythrocytes in a blood agar plate around and under the colony.
Which of the following is not used to describe the edge of colonies?
filamentous
umbonate
rough
rhizoid
irregular
smooth
umbonate
Which bacterial species is said to smell like a musty basement?
Haemophilus spp.
Nocardia sp.
Proteus mirabilis
Pseudomonas aeruginosa
Staphylococcus aureus
Haemophilus spp.
Which of the following organisms form scumlike growth when grown in thioglycollate broth?
Gram-negative rods (Enterobacteriaceae)
Pseudomonas spp.
Yeast
Streptococcus spp.
Pseudomonas spp.
**Why should laboratory professionals look for contamination of a specimen by normal microbiota?
**
Normal microbiota always preclude the possibility of a pathogen infecting the area where they reside.
Contamination of specimens with normal flora that are not collected from sterile sites diminishes the value of the culture studies.
The normal microbiota will be found in clumps, and any pathogenic bacteria will be found with the normal flora.
Contaminated specimens will have much amorphous debris that also goes with them.
Contamination of specimens with normal flora that are not collected from sterile sites diminishes the value of the culture studies.
When reading stool culture plates, a microbiologist observes an organism that has a dry, pink colony with a surrounding halo of pink on MAC. What organism are they likely observing?
Klebsiella/Enterobacter-like organism
Haemophilus influenzae
Escherichia/Citrobacter-like organism
Enteric pathogen
Escherichia/Citrobacter-like organism
When examining colony size on culture plates, what organisms generally have larger colonies y comparison?
Gram-positive rods
Gram-negative rods
Gram-negative diplococci
Gram-positive cocci
Gram-negative rods
When examining a vaginal culture, a microbiologist observes very white colonies that are non-hemolytic on BAP but appear to have feet. What organism is likely present?
Gram-negative rods
Yeast
Haemophilus influenzae
Gram-positive cocci
Yeast
All of the colors below are commonly used to describe bacteria, except
buff
gray
white
orange
orange
Biochemical tests are based on microbial .
mitochondria
phenotype characteristics
plasmid number
antibiodies
lysogeny formation
phenotype characteristics
Arguably the most important carbohydrate determination, screening of gram-negative rods is first performed by testing for the use of _.
glucose
mannitol
sucrose
lactose
lactose
**When performing the O/F test two tubes are used. Why is one tube covered with mineral oil?
**
To create an asaccharolytic environment
To create an anaerobic (fermentative) environment
To create a reductive environment
To create an aerobic (oxidative) environment
To create an anaerobic (fermentative) environment
Semi-solid medium that is helpful in differentiating gram-negative bacteria in the Enterobacteriaceae family. Used to determine motility, production of H2S, and indole production.
Urease agar
SIM agar
Citrate agar
LIA slant
SIM agar
Commercial identification systems fall into all of the following categories, except
enzyme-based reactions
use of nitrogen and sulfur sources
visual detection of bacterial growth
pH-based reactions
molecular assays
use of nitrogen and sulfur sources
**The identification system for gram-negative fermentative bacteria that has a series of 20 cupules attached to a plastic strip. Inside the cupules are lyophilized pH-based substrates. What is the name of this system?
**
Enterotube II
Microbact
None of the other answers are correct
API 20E
ID Tri-Panel
API 20E
What result is shown for the TSI agar slant below?
Ferments glucose, lactose (or sucrose), no gas is produced, but hydrogen sulfide is produced.
The ONPG test is used to test for
ornithine decarboxylation vs deamination
delayed lactose fermenters vs nonlactose fermenters
sucrose fermenters vs nonfermenters
citrate utilization vs unable to utilize citrate
delayed lactose fermenters vs nonlactose fermenters
**Why is zinc added during the nitrate reduction test?
**
To determine if nitrate was reduced to nitrite and then further reduced to a product like nitrogen gas
To determine if nitrite is reduced completely to nitrate and the further reduced to a product like nitrogen gas
To determine the presence of urease within the media
To determine the presence of the cytochorome oxidase system within the bacteria
To determine if nitrate was reduced to nitrite and then further reduced to a product like nitrogen gas
Enterics use two separate pathways for glucose metabolism within the Embden-Meyerhof pathway. Which test determine whether the bacterium uses the butylene glycol pathway for this type of metabolism?
Voges-Proskauer (VP)
Methyl Red (MR)
Phenylalanine deaminase (PAD) test
Motility-Indole-Ornithine (MIO) test
Voges-Proskauer (VP)
