MLT – Microbiology with comprehensive questions and answers
What term describes the morphology of organisms that vary in size and shape?✔️✔️ pleomorphic
Capsules are the basis of which test?✔️✔️ serotyping
A mucoid colony on blood agar medium indicates that which characteristic may be present?✔️✔️
organism has a capsule
What are dark staining granules called?✔️✔️ metachromatic
Which organisms are non motile?✔️✔️ Shigella and Klebsiella
In the bacterial growth cycle, growth ceases because nutrients are exhausted or toxic metabolic
products have accumulated in what phase?✔️✔️ stationary phase
What genera of bacteria form spores?✔️✔️ Bacillus, Clostridium
What term is used to describe bacteria that grow in the absence of atmospheric oxygen and
obtain oxygen from oxygen-containing compounds?✔️✔️ anaerobes
What is the temperature at which bacteria grow best known as?✔️✔️ optium
On blood sugar plates a small zone of alpha hemolysis surrounded by a zone of beta hemolysis
after refrigeration is known as what type of hemolysis?✔️✔️ alpha-prime
,What is the most effective method of sterilization?✔️✔️ autoclaving
What is used for quality control for the dry heat oven?✔️✔️ Bacillus subtilis
Media that cannot be heated can be sterilized by what alternate method?✔️✔️ filtration
What disinfectant is the most effective germicide against bacteria, spores tubercle bacilli, fungi,
and viruses?✔️✔️ chlorine bleach
What term describes a process or treatment that renders a medical device, instrument, or
environmental surface safe to handle?✔️✔️ decontamination
What color do Gram-positive bacteria stain?✔️✔️ purple/ dark blue
Acid-fast bacteria appear what color microscopically?✔️✔️ red
Acid-fast organisms in tissue are best stained by what method?✔️✔️ Kinyoun
What should be used to remove antimicrobials before culturing?✔️✔️ antimicrobial removal
device
Name some characteristics concerning sodium polyanethol sulfonate (SPS)-✔️✔️ prevents blood
from clotting, prevents phagocytosis, neutralizes the bactericidal effect on human serum
What is the most abundant normal flora in throat culture?✔️✔️ alpha-hemolytic streptococci
What is the most common pathogen in throat cultures?✔️✔️ Streptococcus pyogenes
, Why is it recommended to stab the blood agar plate when setting up throat cultures?✔️✔️ some
streptococci may not produce beta hemolysis under aerobic conditions
Nasopharyngeal swabs are recommended for the detection of which carriers✔️✔️ H. influenzae,
N. meningitidis, B. pertussis
Why is a first morning urine specimen preferred for urine cultures?✔️✔️ specimen is more
concentrated
What indicates vaginal or urethral contamination of urine?✔️✔️ greater than 10 squamous
epithelial cells per hpf
How are smears of cerebrospinal fluid prepared?✔️✔️ centrifuged CSF sediment
Smears of cerebrospinal fluid are usually stained with which stain?✔️✔️ Gram stain
Which test for bacterial antigen on cultures isolated from CSF is more sensitive and faster?✔️✔️
latex agglutination tests
What is not the cause of venereal disease?✔️✔️ Haemophilus aegyptius
A positive coagulase test is observed for what?✔️✔️ clotting of plasma
What is the preferred method of differentiating S. aureus from S. epidermidis?✔️✔️ coagulase test
A colony of nonhemolytic, catalase-positive, coagulase-negative, GPC is most likely to be what
organism?✔️✔️ S. epidermidis
What term describes the morphology of organisms that vary in size and shape?✔️✔️ pleomorphic
Capsules are the basis of which test?✔️✔️ serotyping
A mucoid colony on blood agar medium indicates that which characteristic may be present?✔️✔️
organism has a capsule
What are dark staining granules called?✔️✔️ metachromatic
Which organisms are non motile?✔️✔️ Shigella and Klebsiella
In the bacterial growth cycle, growth ceases because nutrients are exhausted or toxic metabolic
products have accumulated in what phase?✔️✔️ stationary phase
What genera of bacteria form spores?✔️✔️ Bacillus, Clostridium
What term is used to describe bacteria that grow in the absence of atmospheric oxygen and
obtain oxygen from oxygen-containing compounds?✔️✔️ anaerobes
What is the temperature at which bacteria grow best known as?✔️✔️ optium
On blood sugar plates a small zone of alpha hemolysis surrounded by a zone of beta hemolysis
after refrigeration is known as what type of hemolysis?✔️✔️ alpha-prime
,What is the most effective method of sterilization?✔️✔️ autoclaving
What is used for quality control for the dry heat oven?✔️✔️ Bacillus subtilis
Media that cannot be heated can be sterilized by what alternate method?✔️✔️ filtration
What disinfectant is the most effective germicide against bacteria, spores tubercle bacilli, fungi,
and viruses?✔️✔️ chlorine bleach
What term describes a process or treatment that renders a medical device, instrument, or
environmental surface safe to handle?✔️✔️ decontamination
What color do Gram-positive bacteria stain?✔️✔️ purple/ dark blue
Acid-fast bacteria appear what color microscopically?✔️✔️ red
Acid-fast organisms in tissue are best stained by what method?✔️✔️ Kinyoun
What should be used to remove antimicrobials before culturing?✔️✔️ antimicrobial removal
device
Name some characteristics concerning sodium polyanethol sulfonate (SPS)-✔️✔️ prevents blood
from clotting, prevents phagocytosis, neutralizes the bactericidal effect on human serum
What is the most abundant normal flora in throat culture?✔️✔️ alpha-hemolytic streptococci
What is the most common pathogen in throat cultures?✔️✔️ Streptococcus pyogenes
, Why is it recommended to stab the blood agar plate when setting up throat cultures?✔️✔️ some
streptococci may not produce beta hemolysis under aerobic conditions
Nasopharyngeal swabs are recommended for the detection of which carriers✔️✔️ H. influenzae,
N. meningitidis, B. pertussis
Why is a first morning urine specimen preferred for urine cultures?✔️✔️ specimen is more
concentrated
What indicates vaginal or urethral contamination of urine?✔️✔️ greater than 10 squamous
epithelial cells per hpf
How are smears of cerebrospinal fluid prepared?✔️✔️ centrifuged CSF sediment
Smears of cerebrospinal fluid are usually stained with which stain?✔️✔️ Gram stain
Which test for bacterial antigen on cultures isolated from CSF is more sensitive and faster?✔️✔️
latex agglutination tests
What is not the cause of venereal disease?✔️✔️ Haemophilus aegyptius
A positive coagulase test is observed for what?✔️✔️ clotting of plasma
What is the preferred method of differentiating S. aureus from S. epidermidis?✔️✔️ coagulase test
A colony of nonhemolytic, catalase-positive, coagulase-negative, GPC is most likely to be what
organism?✔️✔️ S. epidermidis
