CHAPTER 2: METHODS OF STUDYING BACTERIA AND CULTURE ASEPTIC TECHNIQUES

Question 1

Two types of preparations for microscopic exams:

Answer 1

Wet mounts and Bacterial smears

Question 2

Valuable for demonstrating motility in
microorganisms

Answer 2

Wet mounts

Question 3

– movement seen is
due to molecules of the solvent medium
bombarding with the organism’s surface;
occurs in all microscopic bodies
suspended in water

Answer 3

Brownian motility

Question 4

– movement of a bacteria
in a given direction

Answer 4

True motility

Question 5

in wet mount, No stain is employed since most stains kill the organisms except

Answer 5

vital stains

Question 6

Features which may be particulate, such as spores
of fungi and ferns, and pollen grains may be best
obsserved during this technique

Answer 6

Wet mounts

Question 7

in Normal wet mount, what is dropped in the slide

Answer 7

dH20

Question 8

inn normal wet mount, for
greater volume of sample, or hanging
drop method preparations, use a
.

Answer 8

depression slide

Question 9

difference of normal wet munt and hanging drop method

Answer 9

in normal wet mount
o Small size is okay
o It is short-term use
o uses dh20

in hanging drop mount
o Large sample size
o Long-term use
o uses vaseline or petroleum jelly

Question 10

o Allows microbes to freely move around
o Allows to distinguish true motility from
Brownian motion

Answer 10

➢ Hanging drop method

Question 11

The best smears are made from bacteria that have

Answer 11

grown on a solid surface such as an agar slant or
plate

Question 12

The aim is to place an
appropraite concentration of cells on the slide

Answer 12

smear prepartion for bacterial smear

Question 13

– producing a culture

Answer 13

Inoculation

Question 14

creating the proper temperature and other
conditions to promote the growth of microbes

Answer 14

incubation

Question 15

separating microbes from one another, grow
colonies (pure culture

Answer 15

isolation

Question 16

observing characteristics of colonies and
cultures (color, texture, size, shape, motility)

Answer 16

Inspection

Question 17

– main purpose is to determine the type of
microbe using biochemical, immunologic, serologic tests,
and DNA analysis

Answer 17

Identification

Question 18

his describes the “side view” of a colony.
These are the most common

Answer 18

Elevation

Question 19

edge of a colony (or any growth)
may be an important characteristic in identifying
organisms.

Answer 19

margin

Question 20

provide the preparations of the antigen and the use of serum of the patients is to detect if their sample contains the antibodies specific to the antigen in the kit

Answer 20

Latex kits

Question 21

Purpose of Serologic testing

Answer 21

• In vitro antigen-antibody reactions (detectability and
  specificity).
  o Latex kits provide the preparations of the antigen
  and the use of serum of the patients is to detect if
  their sample contains the antibodies specific to the
  antigen in the kit.
• Confirmation of identification results from other tests.
  o It can detect the serotype through serologic
  testing.
• Determine a patient’s immune status.
  o A patient is immune to a certain bacteria if the
  antigen-antibody reaction is positive. (There is a
  presence antibody in the patient’s serum).
• Follow the course of a disease (antibody increase).
  o It can be seen through serologic testing if
  antibodies are increasing or decreasing in terms of
  the reaction in the serological test.
• Serotyping for epidemiological purposes.

Question 22

t provides rapid and accurate data when it comes to dealing
with results

Answer 22

Molecular techniques

Question 23

how bacteria evolves

Answer 23

Phylogenetic studies

Question 24

for stain typing of
epidemiologically related organisms.

Answer 24

Pulsified gel electrophoresis

Question 25

To separate molecular components such as DNA,
RNA and Protein in the electric field.

Answer 25

Pulsified gel electrophoresis

Question 26

Direct detection of genes related to resistance
mechanisms such as mecA gene in Staphylococcus aureus.

Answer 26

Molecular techniques

Question 27

– bacteria possess diverse proteins and RNA that
can sense change to their intracellular and extracellular
movement

Answer 27

Signaling

Question 28

To detect important and unusual proteins in order
to identify bacteria and the characteristics that
were altered.

Answer 28

Signaling

Question 29

to detect genetic
material from a specific organism such as virus, to amplify
DNA sequences

Answer 29

Polymerase Chain Reaction (PCR) –

Question 30

– separate double-stranded DNA

Answer 30

Denutration

Question 31

➢ – complementary sequence is attached

Answer 31

Annealing

Question 32

– extending the gene to amplify the
genes

Answer 32

Extension

Question 33

– specificity and quantification
of the targer organism

Answer 33

Quantitative PCR

Question 34

is used routinely in microbiology to
separate DNA, RNA, or protein molecules using an electric
field by virtue of their size, shape, or electric charge.

Answer 34

Gel electrophoresis

Question 35

Southern blotting, northern blotting, western blotting,
and eastern blotting are molecular techniques for
detecting the presence of microbial:

Answer 35

o DNA sequences (Southern)
o RNA sequences (Northern)
o Protein molecules (Western)
o Protein modifications (Eastern).

Question 36

are used in microbiology as the modern
alternative to the “blotting” techniques

Answer 36

DNA microassays

Question 37

permit the exploration of thousands
of sequences at one time.

Answer 37

Microassays

Question 38

Used in molecular microbiology to detect the
presence of pathogens in a sample

Answer 38

DNA microassay

Question 39

were the first to be completely analysed by DNA
Sequencing

Answer 39

viral genomes

Question 40

was discovered as a cellular
gene regulation mechanism in 1998, but several RNAibased applications for gene silencing have already made it
into clinical trials

Answer 40

RNA interference (RNAi)

Question 41

Leading uses for nucleic acid-based tests

• Nonculturable agents
• Fastidious, slow-growing agents
• Highly infectious agents that are dangerous to culture

Answer 41

• Nonculturable agents
  o Human papilloma virus
  o Hepatitis B virus
• Fastidious, slow-growing agents
  o Mycobacterium tuberculosis
  o Legionella pneumophilia
• Highly infectious agents that are dangerous to culture
  o Francisella tularensis

Question 41

To transfer living microbes from one place to another
without contamination of the culture or the sterile medium
or the surroundings

Answer 41

Aseptic Transfer

Question 42

In order to prevent contamination of the sample, inoculating
instruments must be sterilized prior to use, immediately
before use in an incinerator or Bunser burner flame

Answer 42

Aseptic Transfer

Question 43

• Preventing contamination of a culture with environmental
  microbes

Answer 43

Aseptic Technique