Microbiology and Parasitology
When was the term microbiology first used - ANS 1860s
What four areas of study are encompassed by clinical microbiology - ANS Viruses, fungi,
bacteria, and parasites
What is the difference between a pathogen and an opportunistic pathogen - ANS Pathogen: a
bacteria capable of causing a disease
Opportunistic pathogen: microorganisms that invade the body and cause illness only when the
body's immune defense are impaired or absent
How do bacterial pathogens cause host damage - ANS The damage is caused by bacterial
growth in tissues or y the toxins bacteria produce
What are the morphological types of bacteria - ANS Coccus, bacillus, and spirochete
What are the morphological forms of fungi - ANS Molds and yeast
What is a gram stain? - ANS A test that uses a series of stains to differentiate the composition
of their cell walls
Gram positive- violet (retain the crystal violet stain)
Gram negative- pink (lose the crystal violet and retain the safranin)
What is the difference between aerobic and anaerobic bacteria - ANS Aerobic bacteria grow in
the presence of oxygen
Anaerobic bacteria grow in the absence or decreased levels of oxygen
How are viruses different from microorganisms? Name 3 viral diseases - ANS Viruses are not
living cells, and can only replicate by invading a cell, viruses can only contain either a DNA or
RNA not both
Epstein-Barr virus (mono), rubella, rhinoviruses
What type of specimen is used to detect malaria and giardia - ANS Malaria requires blood
specimen
Giardia requires fecal specimen
Five methods used to help identify bacteria - ANS microscopic morphology- coccus, bacillus,
spirochete
colony morphology- how the colony grows on the plate
reactions with Gram stain and other stains,
, biochemical reactions,
gene probes
antibody reactions- antibiotic susceptibility testing
antibiotic susceptibility testing - ANS can be routine like strep
only works for bacteria
finding the minimum inhibitory concentration (MIC) to inhibit the bacterial growth
fastidious bacteria - ANS bacteria that require special nutritional factors to survive
immunoassay - ANS a diagnostic method using antigen-antibody reactions
Diagnostic Testing - ANS The standard method for isolating and identifying viruses have been
cell culture. As well as serum testing for anti-viral antibodies using enzyme immunoassays.
What can cause contamination of a throat swab during collection? - ANS Touching the tongue
and inside of the mouth will contaminate the swab with normal flora
What mistakes can occur in the collection of urine for culture? - ANS The patient can
insufficiently cleanse the area around the urethral opening and contaminate the urine with skin
microorganisms, epithelial cells and mucus
Why stool specimens in an infants disposable diaper may not grow microorganisms - ANS
because diapers often contain bacteriostatic chemicals inhibiting microorganisms from growing
Why should the patient rinse their mouth with water before collecting sputum sample? - ANS to
reduce the number of oral bacteria present that can contaminate the sputum sample
why is an aspirate of a wound preferred over a swab? - ANS the swab is more prone to drying
and in addition may not pick up sufficient bacteria for culture
why are both alcohol and iodine used in preparation for a blood culutre - ANS if cleansing is not
thorough, skin bacteria or fungi can contaminate the culture and produce false-positive results
3 important properties of transport systems for bacteriology specimens - ANS A container
capable of providing the correct environment until the bacteria can be inoculated, the test
requisition form and specimen label
What type of culture performed to determine MRSA - ANS nasal swab specimen
carrier - ANS an individual who harbors an organism and is capable of spreading the organism
to others, but has no symptoms or signs of disease
When was the term microbiology first used - ANS 1860s
What four areas of study are encompassed by clinical microbiology - ANS Viruses, fungi,
bacteria, and parasites
What is the difference between a pathogen and an opportunistic pathogen - ANS Pathogen: a
bacteria capable of causing a disease
Opportunistic pathogen: microorganisms that invade the body and cause illness only when the
body's immune defense are impaired or absent
How do bacterial pathogens cause host damage - ANS The damage is caused by bacterial
growth in tissues or y the toxins bacteria produce
What are the morphological types of bacteria - ANS Coccus, bacillus, and spirochete
What are the morphological forms of fungi - ANS Molds and yeast
What is a gram stain? - ANS A test that uses a series of stains to differentiate the composition
of their cell walls
Gram positive- violet (retain the crystal violet stain)
Gram negative- pink (lose the crystal violet and retain the safranin)
What is the difference between aerobic and anaerobic bacteria - ANS Aerobic bacteria grow in
the presence of oxygen
Anaerobic bacteria grow in the absence or decreased levels of oxygen
How are viruses different from microorganisms? Name 3 viral diseases - ANS Viruses are not
living cells, and can only replicate by invading a cell, viruses can only contain either a DNA or
RNA not both
Epstein-Barr virus (mono), rubella, rhinoviruses
What type of specimen is used to detect malaria and giardia - ANS Malaria requires blood
specimen
Giardia requires fecal specimen
Five methods used to help identify bacteria - ANS microscopic morphology- coccus, bacillus,
spirochete
colony morphology- how the colony grows on the plate
reactions with Gram stain and other stains,
, biochemical reactions,
gene probes
antibody reactions- antibiotic susceptibility testing
antibiotic susceptibility testing - ANS can be routine like strep
only works for bacteria
finding the minimum inhibitory concentration (MIC) to inhibit the bacterial growth
fastidious bacteria - ANS bacteria that require special nutritional factors to survive
immunoassay - ANS a diagnostic method using antigen-antibody reactions
Diagnostic Testing - ANS The standard method for isolating and identifying viruses have been
cell culture. As well as serum testing for anti-viral antibodies using enzyme immunoassays.
What can cause contamination of a throat swab during collection? - ANS Touching the tongue
and inside of the mouth will contaminate the swab with normal flora
What mistakes can occur in the collection of urine for culture? - ANS The patient can
insufficiently cleanse the area around the urethral opening and contaminate the urine with skin
microorganisms, epithelial cells and mucus
Why stool specimens in an infants disposable diaper may not grow microorganisms - ANS
because diapers often contain bacteriostatic chemicals inhibiting microorganisms from growing
Why should the patient rinse their mouth with water before collecting sputum sample? - ANS to
reduce the number of oral bacteria present that can contaminate the sputum sample
why is an aspirate of a wound preferred over a swab? - ANS the swab is more prone to drying
and in addition may not pick up sufficient bacteria for culture
why are both alcohol and iodine used in preparation for a blood culutre - ANS if cleansing is not
thorough, skin bacteria or fungi can contaminate the culture and produce false-positive results
3 important properties of transport systems for bacteriology specimens - ANS A container
capable of providing the correct environment until the bacteria can be inoculated, the test
requisition form and specimen label
What type of culture performed to determine MRSA - ANS nasal swab specimen
carrier - ANS an individual who harbors an organism and is capable of spreading the organism
to others, but has no symptoms or signs of disease
