BACTE part 1 Flashcards
Science of classifying groups of biological organisms – descriptions,
identification, and nomenclature
taxonomy
father of taxonomy
carlolus linnaeus
2 main taxonomy ranks used in hospital setting
genus and species
size of prokaryotes
0.5 to 5 um
reproduction of prokaryotes
transverse binary fission
reproduction of eukaryotes
mitosis
true or false
bacteria has true nucleus
false, only nucleoloid
site for energy production in
a. prokaryotes
b. eukaryotes
a. cytoplasm
b.mitochondria
2 non chromasomal element of bacteria
plasmid
transposons
2 types pf transposons
insertion sequence
composite transposons
true or false
bacteria are double, unpaired chromosomes
false, only single stranded
describe as jumping genes
transposons
• Autonomously replicating extrachromosomal gene
• Determinant of antimicrobial resistance
plasmid
Pieces of DNA that move from one genetic element to another, mobile
genetic material
transposons
enzyme neede for genetic recombination
bacterial recombinase protein A
Bacterial cell uptake of free DNA when another
bacterial cell dies
transformation
bacterial dna transported via bacteriophage
transduction
Two bacteria join together and exchanges genetic
material thru a sex pilus
conjugation
2 Major metabolic pathway of the bacteria where they derived their energy in the form of ATP
Embden-Meyerhof-Parnas Pathway
Tricarboxylic Cycle / Krebs Cycle
– energy production in the presence of oxygen
Aerobic respiration
energy production without the presence of
oxygen; less efficient
Anerobic respiration
true or false
Most of the ATP molecules (36 ATP ) are derived which makes it more efficient in energy production compared to anaerobic respiration
true
Absolute requirement
for O2 for growth
Pseudomonas, Neisseria,
Francisella, Brucella,
Bordetella
Obligate
Aerobes
Requires reduced O2
(2-10%) for growth
Yersinia, Neisseria,
Campylobacter
Microaerophilic
Can grow under both
aerobic/anaerobic
conditions, prefers
using O2 for growth
Facultative
Anaerobes
Obligate
Anaerobes Cannot grow when O2
is present
Obligate
Anaerobes
Principally anaerobic
but are not killed by
presence of O2
Aerotolerant
Anaerobes
Requires 5-10% CO2
for growth
Capnophilic
Cold-loving bacteria (10-20C)
Can grow inside the refrigerator
Psychrophile
Grows on moderate temperature (20-40C)
MOST Pathogens/pathogenic bacteria are considered mesophilic
because they usually grow on body temperature (37C)
Mesophilic
Heat-loving bacteria (50-60C)
Thermophile
Can survive above 100C
Thermoduric
FOUR PHASES OF BACTERIAL GROWTH
lag
log
stationary
death
phase of bacterial growth werein Bacterial multiplication begins in which bacterial numbers increase
logarithmically through transverse binary fission
* Most active metabolism of bacteria
log
phase of bacterial growth werein Nutrients are becoming limited/exhaust
* The numbers of bacteria remain constant
stationary
Adaptation period
* Bacteria are preparing to divide
* NO BACTERIAL MULTIPLICATION yet
lag phase
Found only in Gram-negative bacteria
* Contains LPS – Lipopolysaccharide which acts as??
endotoxin
true or false
Thinnwe in Gram-positive, Thicker in Gram-negative
false
Long chain fatty acid
§ Can be seen in Mycobacterium tuberculosis
Mycolic acid
binds Mg ions and protect bacteria from thermal
injur
teichoic acid
EXCLUSIVE ONLY FOR Gram Negative:
® Outer membrane (LPS, Endotoxin)
® Periplasmic space
Deepest layer of the cell envelope
Cytoplasmic (Inner) Membrane
Flagellum on one pole
Monotrichous
Single flagellum on both poles
Amphitrichous
Flagella at both poles
Lophptrichous
Flagella all over the organism
Peritrichous
Primarily for Bacterial attachment
pili or fimbriae
protein component of pili
pilin
® Used for bacterial Conjugation
® Present only in cells that produce the protein- F factor
Sex Pilus
nucleoid is Attached to a ???, a saclike structure in the cell membrane
mesosome
Cytoplasmic Inclusions that Serves as nutrient storage and is found on Corynebacterium diphtheriae
Metachromatic Granules
other name for Metachromatic Granules
volutin granules or Babes-Ernst granules
® Demonstrated by Yersinia pestis
® Nutrient storage is found on both sides or terminal sides of the bacillus
Bipolar Bodies
Bipolar Bodies has what kind of apperance
“safety-pin
Able to grow simply, using carbon dioxide as the sole source of carbon
* Obtain energy either photosynthetically or by oxidation of inorganic
compounds
autotrophs
Require an organic source of carbon such as glucose
* Obtain energy either by oxidizing or fermenting organic compounds
heterotrophs
Exotoxins are made only of proteins and contribute to the virulence
factor.
* They are created with bacterial lysis
true or false
false 2nd statement
- Used to detect endotoxins in body fluids
Limulus Lysate Test
Limulus Lysate Test reagent used
Blood of Horseshoe Crab (Limulus polyphemus)
All cocci are Gram-POSITIVE
except:
Neisseria
Moraxella
Veillonella
which bacilli are gram positive
I. Erysipelothrix
Arcanobacterium
II. Lactobacillus
Actinomyces
III. Neisseria Bacillus
Moraxella
a. all of the above
b. none of the above
c. only II and I
d. only III and I
e. II only
c. only II and I
Resulting Color in omission of Crystal Violet
pink
Resulting Color in omission of mordant
pink
Ziehl-Neelson other name
hot method
provide the following information abour Ziehl-Neelson stain
primary stain:
mordant:
decolorizer:
counterstain:
acid fast result
non acid fast result:
Carbolfuchsin
Steam
Acid-alcohol Acid-alcohol Acid-alcohol
Methylene blue
Bright red
Blue
Fluorochrome dye which binds to the nucleic acid and produce bright
orange fluorescence
Acridine orange
Traditionally has been used to stain C. diphtheriae for observation of
metachromatic granules which acts as nutrient storage
Methylene blue
Uses tannic acid and a dye to stain flagella
Leifson stain
Stain for bipolar bodies; colours only the two opposite poles of the
microorganism in question
Wayson
Use for staining endospores; utilizes malachite green (primary stain) &
safranin (counterstain
Schaeffer fulton
Negative stain used to visualize capsules surrounding certain yeasts, e.g.
Cryptococcus spp
India ink
Fluorochrome that binds to chitin in fungal cell walls, fluoresces as applegreen or blue-white
Calcofluor white
Used to stain the cell walls of medically important fungi grown in slide
culture
Lactophenol blue
Autoclave
(moist heat) calibration
121C / 15 psi / at least
15 mins
Autoclave
(moist heat) indicator
B.
stearothermophilus
Dry heat
(oven) calibration
160-180C / 1.5-3 hrs
Dry heat
(oven) Indicator
Indicator: B. subtilis var niger
Ethylene
oxide (gas) calibration
Chamber space @ 55C
/ 2 hrs
sterilization Used in syringes, gloves,
catheters
Ionizing
radiation
Used in parenteral solutions,
vaccines
Used in laboratory hoods
and isolation rooms
Filtration
Kills vegetative
forms
Boiling
Long wavelength, low
energy
Non-ionizing radiation
composition of aldehyde
Formalin 8%,
Glutaraldehyde 2%
Disinfects hands of surgical
personnel
a. Chlorhexidine
gluconate
b. halogen
c. alcohol
d, iodine
Chlorhexidine
gluconate
A device that encloses a workspace in such a way as to protect workers from
aerosol exposure to infectious disease agents
. BIOLOGICAL SAFETY CABINET
Allows room air
(unsterilized) to
pass and circulate
into the cabinet,
and exhaust air is
filtered by a HEPA
filter.
Class I BSC
A percentage of
the remaining air is
HEPA filtered
before reaching
the environment
* Most hospital
microbiology
laboratory uses this class
Class II BSC
- Provides the
highest level of
safety all air
entering/leaving
the cabinet is
sterilized by a
HEPA filter
Class III BSC
– HEPA filter: air entering, recirculated, and exhaust air
Class III BSC
HEPA filter: recirculated & exhaust air
® A.k.a Vertical Laminar Flow Cabinet
Class II BSC
Blood culture Anticoagulant: ?
Anticoagulant: 0.025% Sodium Polyanethol Sulfonate
Blood culture adult volume sample
20 ml
based on the following gram stain of sputum, is it suitable for culture?
® >25ECs / LPF
® <2 PMNS / LPF
no. PMNs should be greater than ECs
preservative used for urine culture
boric acid
transport medium used for stool
(Cary-Blair medium
At least ? bacteria per milliliter of broth are needed for turbidity
to be detected with the unaided eye
10^6 (1,000,000)
agarose melts at what tempt?
95C
media Recommended for fastidious bacteria
enrichment media
Recommended for non-fastidious bacteria
® Bacteria that don’t require specific nutrients
Nutritive
There is presence of inhibitors
* Contain one or more agents that are inhibitory to all organisms except those
“selected” by the specific growth condition or chemical
Selective
agar that inhibit the growth of gram negative bacteria
Phenylethyl Alcohol (PEA) agar and Colistin-Nalidixic Acid
(CNA) agar
TRANSPORT media contains ?
charcoal
Small area of intact RBCs around colony surrounded
by a wider zone of complete hemolysis
alpha prime hemolysis
Kills target microorganisms, resulting to cell lysis
Bactericidal agent
Inhibits bacterial growth but does not kill the organism
Bacteriostatic agent
which broth is often used as major component for blood culture
Brain-Heart Infusion
Differentiation of microorganisms relies on the expression of the pathway for
fermentation of lactose
Macconkey Agar
You can determine the atmospheric requirement of the bacteria by observing
the appearance of this broth
Thioglycolate Broth
Antimicrobial agent in question may be an appropriate choice for
treating the infection
Susceptible
Antimicrobial agent in question may not be an appropriate choice
for treatmen
® Resistant
Altering dosing (e.g., higher doses) results in higher drug
exposure
Susceptible-Dose Dependent (SDD)
Inoculum is too light causes false sensitive or false resistant?
false sensitive
Too much moisture on the agar cause false sensitive or false resistant?
false resistant
> 15 mins delay after seeding the
plate and before antibiotic disks are
applied
false resistant
> 15 mins delay after seeding the
plate and before antibiotic disks are
applied
Principle: Turbidimetry
® Have the advantage with large number of samples
VITEK System
Substrate used in Beta-lactamase Production
Cephalosporin
If the organism produces this enzyme, it is effective to prescribe betalactam drugs
true or false
false
refers to the concentration resulting to a 99.9% reduction in CFU
per milliliter compared with the organism concentration in the original
inoculum.
MINIMAL BACTERICIDAL CONCENTRATION
Involves exposing a bacterial isolate to a concentration of antibiotic n a broth
medium and measuring the rate of killing over a specified time period
TIME-KILL STUDIES
Analogous to the MIC-MBC test except that the test medium used is the
patient’s serum containing the therapeutic antimicrobial agents the patient
has been receiving.
SERUM BACTERICIDAL TEST (SCHLICTER TEST)
- Two serum samples are required
Trough specimen
Peak specimen
collected just before the patient is to receive the
next antimicrobial dose
Trough specimen
collected after the antimicrobial agent is given (30
minutes for IV, 90 minutes for oral)
Peak specimen
standard medium for any type of
susceptibility tes
Mueller-Hinton Agar)
0.5 McFarland standard composition
® 1% H2SO4 sulfuric acid (99.5 mL)
® 1.175% BaCI2 barium chloride (0.5 mL
