Identification of Unknown Bacteria Notes:
Which of the following would be most valuable to confirm the identification of microorganisms isolated
during a food poisoning outbreak? Identification of microorganisms using microscopic, cultural, and
physiological characteristics.
What three main approaches can be used by microbiologists to identify microorganisms? Genetic,
immunologic, phenotypic.
Which method used to identify a microorganism causing an infection rely on the response of the host,
rather than observation of the microorganism’s properties? Immunologic methods
Genotypic identification methods examine the sequence of an organism, whereas Immunologic
identification method uses antibody-antigen reactions to identify microorganisms.
Which of the following is an example of a morphological characteristic that could be used in the
bacterial identification process? Cell shape
A particular microorganism can be distinguished from several closely related microorganisms by
determination of its preferred growth temperature. This is an example of a cultural characteristic that
can be used for identification.
Which of the following are examples of physiological (biochemical) characteristics that could be used in
the bacterial identification process? Ability to ferment glucose, ability to break down lipids, presence of
specific enzyme.
FALSE: Bergey’s Manual is an excellent resource for the identification of fungi and viruses as well as
bacteria.
TRUE: Bergey’s Manual contains information on the identification of bacteria only.
FALSE: Bergey’s Manual of Determinative Bacteriology contains information related to the identification
of only pathogenic bacteria.
Bergey’s Manual of Determinative Bacteriology contains information regarding the identification of all
types of culturable bacteria.
Which of the following methods could be used to isolate bacteria from a mixture? Serial dilution
followed by spread plating, loop dilution pout plating, streak plating
Bergey’s Manual of Determinative Bacteriology first categorizes bacteria based upon which of the
following characteristics? Cell shape, gram stain reaction
TRUE: Multiple bacterial species can have similar staining reactions and microscopic morphology.
What is the internationally recognized reference for bacterial classification and identification? Bergey’s
Manual
The ninth edition of Bergey’s Manual of Determinative Bacteriology was designed solely for identifying
bacteria that have already been cultured and phenotypically examined.
, Which of the following types of media might be particularly helpful in the isolation of a single bacterial
species from mixed bacterial culture? Differential, selective
Which of the following is the quickest way to isolate bacteria from a mixture? Streak plating
Which of the following would be a good starting point for identifying an unknown bacterium? Gram
staining
Identification of a bacterium can not be made on microscopic morphology alone because many
microorganisms have a similar microscopic morphology.
The name of the reference book that provides information about staining properties, morphology, and
biochemical reactions of all known bacterial species is Bergey’s Manual.
FALSE: A standard set of biochemical tests is used to identify all types of bacteria, regardless of
morphological and cultural characteristics.
Which of the following are advantages of using multi-test media or systems? Reduction in media usage,
improved efficiency, reduction in time required for identification.
A dichotomous key is a flowchart that can be used to identify an organism by making a series of choices
until you arrive at one possibility.
According to this flowchart, what test is most useful for distinguishing between Escherichia coli and
Vibrio cholerae? Oxidase test
How do you determine the strain of an sd? You use multiple biochemical tests and pre-existing
knowledge to classify the bacteria.
When choosing a biochemical test to perform on an unknown bacterium, you should consider which of
the following? Choose an easy, rapid test that is applicable for its main group of bacteria
Which of the following media tests can provide information on more than one biochemical
characteristic? Kligler’s iron agar (KIA), SIM tubes
Which of the following biochemical tests can be performed on a well-isolated colony and can provide
immediate results without further incubation? Oxidase test
Which of the following biochemical tests involve growth of an organism in a specific broth medium?
Nitrate reduction test, phenol red, methyl red
Which of the following media allows for the observation of multiple biochemical properties? SIM
Inoculation of which tests involves stabbing the organism into the medium with an inoculating needle?
SIM, KIA
Which of the following is an agar plate that can indicate whether an organism ferments lactose?
MacConkey medium
Which of the following media allows for observation of several different biochemical properties? KIA
The oxidase test determines the presence of cytochrome oxidase enzyme. This enzyme functions as
part of the electron transport chain.
Which of the following would be most valuable to confirm the identification of microorganisms isolated
during a food poisoning outbreak? Identification of microorganisms using microscopic, cultural, and
physiological characteristics.
What three main approaches can be used by microbiologists to identify microorganisms? Genetic,
immunologic, phenotypic.
Which method used to identify a microorganism causing an infection rely on the response of the host,
rather than observation of the microorganism’s properties? Immunologic methods
Genotypic identification methods examine the sequence of an organism, whereas Immunologic
identification method uses antibody-antigen reactions to identify microorganisms.
Which of the following is an example of a morphological characteristic that could be used in the
bacterial identification process? Cell shape
A particular microorganism can be distinguished from several closely related microorganisms by
determination of its preferred growth temperature. This is an example of a cultural characteristic that
can be used for identification.
Which of the following are examples of physiological (biochemical) characteristics that could be used in
the bacterial identification process? Ability to ferment glucose, ability to break down lipids, presence of
specific enzyme.
FALSE: Bergey’s Manual is an excellent resource for the identification of fungi and viruses as well as
bacteria.
TRUE: Bergey’s Manual contains information on the identification of bacteria only.
FALSE: Bergey’s Manual of Determinative Bacteriology contains information related to the identification
of only pathogenic bacteria.
Bergey’s Manual of Determinative Bacteriology contains information regarding the identification of all
types of culturable bacteria.
Which of the following methods could be used to isolate bacteria from a mixture? Serial dilution
followed by spread plating, loop dilution pout plating, streak plating
Bergey’s Manual of Determinative Bacteriology first categorizes bacteria based upon which of the
following characteristics? Cell shape, gram stain reaction
TRUE: Multiple bacterial species can have similar staining reactions and microscopic morphology.
What is the internationally recognized reference for bacterial classification and identification? Bergey’s
Manual
The ninth edition of Bergey’s Manual of Determinative Bacteriology was designed solely for identifying
bacteria that have already been cultured and phenotypically examined.
, Which of the following types of media might be particularly helpful in the isolation of a single bacterial
species from mixed bacterial culture? Differential, selective
Which of the following is the quickest way to isolate bacteria from a mixture? Streak plating
Which of the following would be a good starting point for identifying an unknown bacterium? Gram
staining
Identification of a bacterium can not be made on microscopic morphology alone because many
microorganisms have a similar microscopic morphology.
The name of the reference book that provides information about staining properties, morphology, and
biochemical reactions of all known bacterial species is Bergey’s Manual.
FALSE: A standard set of biochemical tests is used to identify all types of bacteria, regardless of
morphological and cultural characteristics.
Which of the following are advantages of using multi-test media or systems? Reduction in media usage,
improved efficiency, reduction in time required for identification.
A dichotomous key is a flowchart that can be used to identify an organism by making a series of choices
until you arrive at one possibility.
According to this flowchart, what test is most useful for distinguishing between Escherichia coli and
Vibrio cholerae? Oxidase test
How do you determine the strain of an sd? You use multiple biochemical tests and pre-existing
knowledge to classify the bacteria.
When choosing a biochemical test to perform on an unknown bacterium, you should consider which of
the following? Choose an easy, rapid test that is applicable for its main group of bacteria
Which of the following media tests can provide information on more than one biochemical
characteristic? Kligler’s iron agar (KIA), SIM tubes
Which of the following biochemical tests can be performed on a well-isolated colony and can provide
immediate results without further incubation? Oxidase test
Which of the following biochemical tests involve growth of an organism in a specific broth medium?
Nitrate reduction test, phenol red, methyl red
Which of the following media allows for the observation of multiple biochemical properties? SIM
Inoculation of which tests involves stabbing the organism into the medium with an inoculating needle?
SIM, KIA
Which of the following is an agar plate that can indicate whether an organism ferments lactose?
MacConkey medium
Which of the following media allows for observation of several different biochemical properties? KIA
The oxidase test determines the presence of cytochrome oxidase enzyme. This enzyme functions as
part of the electron transport chain.
