MTAP CHAP 1 Flashcards
1
Q
leeuwenhoek called microorganisms as
A
wee beasties and animacules
2
Q
are unicellular organisms that are classified as prokaryotes
A
bacteria
3
Q
size of bacterial ribozomes
A
70S - 50S and 30S
4
Q
it appears as highly refractile bodies in the cell and are visualized with gram stain as unstained areas in a cell because of thick protein coat
A
spores
5
Q
the most commonly used endospore stain
A
schaeffer-fulton stain
6
Q
primary stain and counterstain in schaeffer-fulton stain
A
primary stain for spores - malachite green
safranin stain for bacterial cells - appearing red
7
Q
the prokaryotic plasma membrane of a bacteria is made of phospholipids and proteins, and do not contain sterols except for what family
A
mycoplasmaceae
8
Q
is a rigid structure that maintains the shape of the cell and prevents bursting of the cell from the high osmostic pressure inside it
A
cell wall
9
Q
is a phospholipid bilayer eith embedded proteins that surrounds the cytoplasm
A
plasma cell membrane
10
Q
cell walls in bacteria can be traditionally categorized according to their staining characteristics, this stain is called
A
gram stain
11
Q
primary component of gram positive cell wall
A
thick peptidoglycan layer (murein layer )
12
Q
penicillin targets what gram ____ bacteria
A
gram positive - targets the peptidoglycan synthesis
13
Q
what are the components of gram positive cell wall aisde from the peptidoglycan
A
teichoic acid - anchored to peptidoglycan
lipoteichoic acid - anchored to plasma membrane
14
Q
2 layers of gram negative cell wall
A
inner peptidoglycan layer which is much thnner than the gram positive
an and additional outer membrane unique to the gram negative cell wall
15
Q
the outer membrane of gram negative cell wall is sometimes called as ____
it contains proteins, phospholipids, and lipopolisaccharide
A
envelope
16
Q
The 3 layers of lipopolysaccharide of gram negative cell wall
A
antigenic O specific polysaccharide
core polysaccharide
inner lipid A
17
Q
inner lipid A is also called as
A
endotoxin
18
Q
endotoxin or lipid A is responsible for
A
producing fever and shock in animals infective with gram negative bacteria
19
Q
functions of the outer membrane
A
acts as a barrier to hydrophobic compounds and harmful substances
acts as a sieve, allowing water-soluble molecules to enter through protein-lined channels called porins
provides attachment sites that enhance attachment to host cells
20
Q
the space or area between the outer and inner membrane and encompassing the thin peptidoglycan layer is an area referred to as the
A
periplasmic space
21
Q
what is inside the periplasmic space
A
gel-like matrix containing nutrient-binding proteins and degradative and detoxifying enzymes
22
Q
is periplasmic space present in gram positive cell wall?
A
nope, wala naman kasing outer membrane si gram positive
23
Q
certain genera such as __ and ___ have a gram positive cell wall structure and are classified as gram positive bacteria. However, they stain poorly in gram stain, why is it so?
A
because they contain a waxy layer of glycolipids and fatty acids (mycolic acid) bound to the exterior of the cell wall
24
Q
this fatty acid is a component of mycobacteriym and nocardia, which is a strong hydrophobic molecule that forms a lipid shell around the organism and affects its permeability
low permeability to water
A
mycolic acid
25
prokaryotes that belong to the genera __ , ___ and ___ are unique in that they lack a cell wall an contain sterols in their plasma membranes
acholeplasma
mycoplasma
ureaplasma
26
acholeplasma
mycoplasma
ureaplasma
since they lack the rigidiity of the cell wall, they are seen in various shapes microscopically rferred to as
pleomorphic
27
various pathogenic bacteria produce a discrete organized covering called as
capsule
28
capsules are usually made of
polysaccharide polymers, although may also be made of polypeptides
29
acts as virulence factors in helping the pathogen evade phagocytosis
capsules
30
capsule removal is accomplished by ___
boiling a suspension of the microorganism
31
capsule appears as _____ in a direct snear frin a clinical specimen
halo like between or surrounding the stained organism
32
are similar to capsules but are more diffuse layers surounding the cell
glycocalyx
33
are exterioir protein filaments that rotate and cause bacteria to motile
flagella
34
flagella that occur singly at one end is called as
monotrichous
35
flagella that occur at both end is called as
amphitrichous
36
flagella that occur at multiple tuffts at one end is called as
lophotrichous
37
flagella that occur at all over the bactrium is called as
perithrichous
38
are nonflagellar, proteinaceous, hairlike appendages extending a short distance from the surface of some bacterial cells that adhere to one another and to host cells
pili and fimbriae
39
are protein tubes that connect two bacterial cells and mediate dna exchange
conjugation pili
40
what is the largest bacterium known which is found in ocean sediment and generally has a diameter of 0.1 mm to 0.3 mm
thiomargarita namibiensis
41
bacilli with tapered, pointed ends are termed as
fusiform
42
cocci in chains are called as
streptococci
43
cocci in clusters are called as
staphyloccoci
44
the microscopic staining characteristics such as shapes and groupings are used in the
classification and identifictaion of microorganisms
45
the most commonly used stain in the clinical microbiology lab
gram stain
46
color of gram positive
blue to purple
47
color of gram negative
pink or red
48
gram stain processes
heat fixing (methyl alcohol may be used instead of fixation)
primary stain - crystal violet - 1 mn
mordant - iodine 1 mn
decolorizer - alcohol or an alcohol-acetone solution - just quick rinse
counter stain - safranin 30 seconds
rinsing with water each step is important
49
cells in a direct smear from a patient specimen such as epithelial cells, white blood cells, red blood cells, and amorphous background material, should appear ____ if the gram stain procedure was performed correctly
pink
50
are used to stain bacteria that have a high lipid (mycolic acid ) and wax content in their cell walls and do not stain well with traditional bacterial stains
acid fast stain
51
a primary stain used for acid fast stains
carbol fuchsin, red dye
52
principle in acid fast staining
carbol fuchsin is used as primary stain of acid fast bacteria
their cell wall is resistant to decolorization thus they will be able to retain the stain
53
the cell wall of acid fast bacteria is treated to allow penetration of the dye either by
heat or by a detergent
heat - ziehl-neelsen method
detergent - kinyoun method
54
what is used as decolorizer
acidified alcohol
55
acid fast staiing
primary stain
mordant
decolorizer
counter stain
carbol fuchsin
heat or detergent
acidified decolorizer
methylene blue/malachite green
56
this stain selective is selective for the cell wall of acid fast bacteria
fluorochrome - will appear yellow or orange under a fluorescent microscope
57
a more sensitive staining method than carbol fuchsin stain and the non acid fast bacteria remained unstained
fluorochrome staining method
58
a fluorochrome dye that stains gram positive and gram negative bacteria, living or dead.
it binds to the nucleic acid of the cell and fluoresces a bright orange when a fluorescent microscope is used
acridine orange
59
a stain or dye that is used to locate bacteria in blood cultures and other speciments in which discerning bacteria might otherwise be difficult
acridine orange
60
acridine orange will stain ___ cells as well
eukaryotic
61
is a fluorochrome that binds to chitin in fungal cell walls
calcofluor white
62
color of calcofluor white
bright apple green or blue-white
63
was the original "bluing" used in high-volume laundries to whiten yellow-appearing white cotton and other fabrics
calcofluor white
64
this stain is traditionally has been used to stain cornebacterium diphtheriae for the observation of metachromic granules
methylene blue
65
sometimes used as a simple stain to detect WBC in stool samples
methylene blue
66
is used to stain the cell walls of medically important fungi grown in slide cultures
it utilizes the blue dye aniline
lactophenol cotton blue
67
are negative stains used to visualize capsules surrounding certain yeasts, such as the yeast cryptococcus
india ink
68
is used to stain bacterial spores
endospore stain
69
process of endospore staining
primary stain - malachite green - flooded
heat fixed smear and heated to steaming for about 5 mns
washed for about 30 seconds to remove the primary stain
counterstain 0 safranin
70
in the endospore staining, spores will appear as
pink or red appearing bacterial cells
71
3 major nutritional needs for growth
carbon source for making cellular constituents
carbon represents 50% of the dry weight of a bacterium
a nitrogen source for making proteins and nucleic acids
nitrogen makes up 14% of the dry weight
energy source ATP for performing cellular functions
72
this make up additional 4% of the bacterial weight
phosphate for nucleic acids
phospholipids of cell membranes
sulfur for protein synthesis
73
are able to grow simple, using carbon dioxide as the sole source of carbon, in addition to the required water and inorganic salts
autotrophs (lithotrophs )
74
this group of bacteria requires a more complex substance for growth. Using organic source of carbon, such as glucose and obtain energy by oxidizing or fermenting organic substances
heterotrophs
75
what type of bacteria are those inhabiting the human body
autotrophs or heterotrophs
heterotroph
76
those media that contain nutrients that support the growth of most non fastidious organisms are called as
non selective or nutritive type of media
77
examples of nutrient media
trypticase soy agar or broth
nutrient agar
78
a growth medium that contains added growth factors such as blood vitamins and yeast extract is referred to as
enriched medium
79
79
enriched medium examples
blood agar
chocolate agar
80
media that contain additives such as dyes, bile salts, alcohols, acids, and antimicrobial agents that inhibit the growth of some bacteria but allow others to grow are called as
selective media
81
MacConkey agar is an example of what type of media
selective
selective for gram-negative bacteria
82
columbia agar with colistin and nalidixic acid, is selective for
gram positive bacteria
83
McConkey agar contains
bile salts and crystal violet
84
media that contain ingredients that allow visualization of metabolic differences between groups are called as
differential media
85
MAC agar is also a differential medium , what is the color of the colonies of non lactose and lactose fermenters
lactose fermenters - pink
nonlactose fermenters - clear
86
how come that the sheep blood agar is an enriched, non selective and also a differential medium
it can distinguished between hemolytic and non hemolytic organisms
87
transport media examples to preserve bacterial viability
stuart broth and amies
cary blair transport media
88
3 important environmental factors influencing the growth rate of bacteria and must be considered when bacteria are cultured in the lab
pH
temperature
gaseous composition of the atmosphere
89
psychrophiles optimal growth
10*-20*C they are cold loving
90
mesophiles optimal growth
moderate temp
20*-40*C
91
thermophiles optimal growth
50-60*C - heat lover
92
this type of bacteria must be grown in an atmosphere wither devoid of oxugen or with significantly reduced oxygen content
obligate anaerobes
93
can survice in the presence of oxygen but grow poorly and do not utilized oxygen for growth
aerotolerant anaerobes
94
can grow either with or withought oxugen
if oxygen is present, it will utilzie it
if no oxygen, it will grow much better
facultative anaerobes
95
this bacteria require a reduced level of oxygen to grow
microaeropholic
96
____ organisms are those that require an atmosphere enriched with carbon dioxide
capnophilic
97
bacteria replicate by ___ with one cell dividng into 2 cells
binary fission
98
the time required for one cell to divide into 2 cells is called
generation time or
doubling time
99
with enough nutrients and no toxic products, the increase in abcterial numbers is proportipnal to the increase in
other bacterial properties such as mass, protein content, and nucleic acid content
100
4 phases of growth
lag phase - bacteria prepares to divide
exponential phase - bacteria increase logarithmically
stationary phase - limited nutrients constant numbers of bacteria
death phase - non viable bacteria > viable bacteria
101
this method can be used to estimate the number of bacteria present in a specimen
direct counting under the microscope
102
by growing dilutions of broth cultures on agar plates, one can determine the nmber of CFY
direct plate count
103
this method provides a count of viable cells only and used in determining bacterial cell count in urine cultures
direct plate count
104
the density referred to as turbidity of a bacterial broth cilture can be correlated to the number of CFU of the culture.
density measurement
105
this method is used to prepare a standard inoculum for antimicobrial susceptibility testing
density measurement
106
is an anaerobic process carried out by obligate facultative, and aerotoilerant anaerobes
fermentation
107
In fermentation, the electron acceptor is an
organic compound
108
is an efficient energy generating process in which molecular oxygen is the final electron aceptor
aerobic respiration
109
is a disaccharide consisting of one molecule of glucose and one molecule of galactose
lactose
110
the utilization of lactose by a bacterium requires 2 step, what are they
1. needs an enzyme called b galactoside permease for the transoirt of lactose across the cell wall into the cytoplasm
2. occurs inside the cell and rrqyures enzyme b-galactosidase to break the galatoside bond, releasing glucose which then can be fermented.
for easy understanding, b-galactoside permease taga deliver sa cell wall ni bacteria, galactosidase to breakdown para marelease si glucose
111
the bacterial chromosome is also called as
genome
112
are specific DNA sequences that code for the amino acid sequence in one protein, but this may be sliced or combined with other polypeptides to form more than one protein
genes
113
in addition to the genetic information encoded in the bacterial chromosome, many bacteria contain additional information on `small circular pieces of extrachromosomal dsDNA` called
plasmids
114
genes that code for antimicrobial resistance are often located on __
plasmids
115
plasmids are located in ____ of the cell and are self replicating and passed to daughter cells, similar to chromosomal DNA
cytoplasm
116
some fragments of DNA are mobile, and can jump from one place in the chromosome to another place, they are called as
jumping genes
117
are changes that occur in the DNA code and often result in a change in the coded protein or in the prevention of its synthesis
mutations
118
a gene sequence must be read in the right frame or series of how many codons for the correct protein to be produced
3 codons
119
is a method by which genes are transferred or exchanged beyween homologous regions on two dna moleciles
genetic recombination
120
genetic material may be transferred from one bacterium to another in 3 ways
transformation
transduction
conjugation
121
is the uptake and incorporation of free or naked DNA into a bacterial cell
transformation
122
cells that can take up naked DNA are referred to as
competent
123
is the transfer of bacterial genes by a bacteriophage from one cell to another
transduction
124
is the transfer of genetic material from a donor bacterial strain to arecipient strain
conjugation
125
explain how conjugation works
the donor strain produces a hollow surface appendage called a `sex or conjugation pilus` which mbinds to the recipient F - cell and brings the two cells in close contact
126
this method of transfering dna and genes can transfer both plasmids and chromosomal genes
conjugation
127
when the F factor is integrated tinto the bacterial chromosome rather than a plasmid, there is a higher frequency of transfer of adjacent bacterial chromosome genes. These strains are known as ___
high-frequency recombination strains
128
bacteria gave evolved a system to restrict the incorporation of foreign DNA into their genomes, these are called
restriction enzymesh
129
these enzymes are used in the field of biotechnology to create sites for insertion of new genes
restriction enzymes
130
is the growth of microbiota in or on a body site without the production of damage or notable symptoms
colonization
131
microorganisms that are commonly found on or in body sites of healthy person are called
normal or indigenous microbiota
132
microorganism that colonize an area for months or years represent what microbiota
resident microbiota
133
microorganism that are present at a site temporarily for a shorter period represent what type of microbiota
transient microbiota
134
this type of microbiota come to visit but do not stay
transient microbiota
135
these type of microbiota tend to be be eliminated either by the host inherent immune defenses or by competition with the resident biota
transient microbiota
136
the bacteria that can withstand lipids and fatty acids
bactericidal kasi dapat yan pero kaya niya through breaking down of skin lipids to fatty acids
propionibacterium spp
137
pH of a female genital tract
4-5.0 pH
138
human milk has a high lactose concentration and maintains a pH of 5-5.5, an environment supportive of ____ spp
bifidobacterium spp
139
is the ability of a microbe to produce disease in an individual
pathogenicity
140
conditions compromising host defenses
foreign bodies - catheters, shunts, prosthetic heart valves
what are the related opportunistic microorganisms
staphylococcus epidermidis
cutibacterium acnes
viridans streptococci
aspergillus spp
candida albicans
141
conditions compromising host defenses
alcoholism
what are the related opportunistic microorganisms
streptococcus pneumoniae
klebsiella pneumoniae
142
conditions compromising host defenses
burns
what are the related opportunistic microorganisms
pseudomonas aeruginosa
acinetobacter baumannii-calcoaceticus complex
143
conditions compromising host defenses
hematoproliferative disorders
what are the related opportunistic microorganisms
cryptococcus neoformans
varicalla-zoster virus
144
conditions compromising host defenses
cystic fibrosis
what are the related opportunistic microorganisms
pseudomonas aeruginosa
burkholderia cepacia
145
conditions compromising host defenses
immunosuppression
what are the related opportunistic microorganisms
aspergillus
candida albicans
pneumocystis jitovecii
diphtheroids
pseudomonas
staphylococcus
cytomegalovirus
herpes simplex virus
varicella zoster vius
146
the first step in initiating an infection is for the infectious agent to ___
gain access to the host
147
a very small particles called ____ are the residue from the evaporation of fluid from larger droplets and are light enough to remain airborne for long periods
aerosols
148
which infection is more serious, upper or lower respiratory tract
lower
upper respi infection is usually self limiting
149
the most common microorganism causin lower respiratory tract infection in an individuals older than 30 years of age is
streptococcus pneumoniae
150
most common cause of community-acquired pneumonia
S.pneumoniae
151
organisms that can cause disease by means of a preformed toxin, produced outside the body includes /________ which one is fatal as welll
clostridium botulinum - fatal and life threatening
Bacillus cereus
Staphylococcus aureus
152
a commonly seen cause of diarrhea and intetsinal infection is
escherichia coli
153
the strains of E.coli referred to as ____ are a common cause of traveler's diarrhea and other intestinal problems
diarrheagenic
154
is the relative ability of a microorganism to cause disease or the degree of pathogenicity
virulence
155
usually measured by the number of microorganisms necessary to cause infection in the host
virulence
156
shigella is a definition of a virulent agent, how many organism it can infect a host
as few as 100 organisms
157
the most common mechanism for evading phagocytosis used by microorganisms is a
polysaccharide capsule
158
another bacterial structure to avoid phagocytosis is a protein found in the cell wall of staphyococcus aureus by interferin with the binding of the host's antibodies to the surface of the organism
protein A
159
the main adhesins in bacteria are
surface proteins and polysaccharides
160
bacteria that can grow inside even aftr phagocytized and is called as intracellular parasites
chlamydia
mycobacterium
brucella
listeria
161
endotoxins and exotoxins,
which one is exclusive only to gram negative
endotoxins
eNdotoxins
N= negative
162
