unit 9 (antimicrobial methods and eukaryotic microorganisms) Flashcards
1
Q
two factors that influence the level of cleanliness required for a particular fomite
A
application for which the item will be used, level of resistance to antimicrobial treatment by potential pathogens
2
Q
sterilization definition
A
the complete removal or killing of all vegetative cells, endospores, and viruses from the targeted item or environment
3
Q
sterilization can be accomplished through
A
physical means: high heat, pressure, or filtration and chemical means
4
Q
sterilants definition
A
chemicals that can be used to achieve sterilization
5
Q
aseptic technique definition
A
involves a combination of protocols that collectively remain sterility, or asepsis, thus preventing contamination of the patient with microbes and infectious agents
6
Q
antisepsis definition
A
reduces microbial load on skin or tissue through application of antimicrobial chemical
7
Q
sepsis definition
A
a systemic inflammatory response to an infection that results in high fever, increased respiratory and heart rates, shock, and possibly death
8
Q
sterile field definition
A
a designated area that is kept free of all vegetative microbes, endospores, and viruses
9
Q
disinfection definition
A
reduces or destroys microbial load of an inanimate object through application of heat or antimicrobial chemicals
10
Q
ideal characteristics for disinfectants/antimicrobials
A
fast acting, stable, easy to prepare, inexpensive, and easy to use
11
Q
disinfection is not sterilization because
A
some microbes remain, endospores tend to survive even when all vegetative cells have been killed
12
Q
what are antiseptics
A
chemicals safe for use on living skin or tissues
13
Q
critical items definition
A
must be sterile because they will be used inside the body, often penetrating sterile tissues or the bloodstream
14
Q
semi-critical items definition
A
items that do not need to be sterilized but require a high level of disinfection because they come in contact with mucous membranes or nonintact skin but do not penetrate tissues
15
Q
noncritical items definition
A
items that need to be cleaned but not highly disinfected because they come in contact with, but to not penetrate, intact skin
16
Q
degerming definition
A
microbial numbers are greatly reduced by gently scrubbing living tissue with a mild chemical
17
Q
sanitization definition
A
cleansing of fomites to remove enough microbes to achieve levels deemed safe for public health.
18
Q
-cide or -cidal refers to
A
physical and chemical methods of microbial control that kill the targeted microorganism
19
Q
-stat or -static refers to
A
physical or chemical methods that do not kill the organism, but stop their growth
20
Q
factors that determine whether a particular treatment is -static or -cidal
A
types of microorganisms targeted, the concentration of chemicals used, and the nature of the treatment applied
21
Q
microbial death curve
A
how degree of microbial control is evaluated, describes the progress and effectiveness of a particular protocol
22
Q
decimal reduction time (DRT) definition
A
the amount of time it takes for a specific protocol to produce a one-order-of-magnitude decrease in the number of organisms, or death to 90% of the population
23
Q
factors that contribute to the effectiveness of an antimicrobial protocol
A
length of exposure, amount of microbes, susceptibility of microbe to antimicrobial, concentration of antimicrobial, temperature, conditions that limit the contact between the agent and the microbe
24
Q
physical methods of control examples
A
heat, cold, pressure, desiccation, radiation, sonication, filtration
25
thermal death point (TDP) definition
the lowest temperature at which all microbes are killed in a 10 minutes exposure
26
thermal death time (TDT) definition
length of time needed to kill all microorganisms in a sample at a given temperature
27
boiling kills
kills vegetative cells and some viruses
28
boiling mode of action
moist-heat control that denatures proteins and alters membranes
29
categories of heating protocols
dry-heat sterilization and moist-heat sterilization
30
dry-heat sterilization examples
aseptic technique of inoculating loops, incineration
31
moist-heat sterilization example
autoclave
32
most effective heat sterilization category is __ because
moist-heat sterilization because it can penetrate cells better than dry heat does
33
autoclaves function by
raising temperatures above the boiling point of water (steam) and pressure to sterilize items
34
autoclaves kill
vegetative cells, viruses, and endospores (everything except for prions basically)
35
autoclave mode of action
moist-heat control that kills cells by denaturing proteins and alters membranes
36
autoclave tape function
indicates when appropriate temp is reached: white strips turn black when appropriate temp is achieved
37
biological indicator spore test function
uses strip of paper of endospores to determine whether endospores were killed or not during the autoclave process
38
Diack tube function
indicates when proper sterilization temperature is reached in an autoclave; a temperature sensitive pellet melts at proper sterilization temp
39
traditional pasteurization kills
pathogens and reduces the number of spoilage causing microbes
40
pasteurization mode of action
denatures proteins and alters membranes
41
high-temp short-time (HTST) pasteurization
exposes milk to 72 degrees for 15 secs, which lowers bacteria numbers while preserving quality
42
ultra-high-temp (UHT) pasteurization
milk is exposed to 138 degrees for 2 seconds, causing slight change to taste and smells
43
refrigeration mode of action
inhibits metabolism, slows or arrests cell division
44
freezing mode of action
stops metabolism, may kill microbes
45
high-pressure processing kills
vegetative bacteria (not endospores), yeast, molds, parasites, and viruses (not endospores)
46
high-pressure processing mode of action
denatures proteins and can cause cell lysis
47
hyperbaric oxygen treatment mode of action
inhibits metabolism and growth of anaerobic microbes
48
desiccation kills
can kill all types of cells because all cells require water, except endospores
49
simple desiccation (drying) mode of action
inhibits metabolism
50
reduce water activity (addition of solute) mode of action
inhibits metabolism and can cause cell lysis
51
lyophilization (freeze-drying) mode of action
inhibits metabolism
52
ionizing radiation types
x-rays, gamma rays, and high-energy electron beams
53
ionizing radiation mode of action
sterilizes by altering molecular structures, introduces double strand breaks into DNA
54
ionizing radiation is used on
packaged items that cannot be autoclaved (plastic)
55
what is nonionizing radiation
ultraviolet light that sterilizes but does not penetrate cells or packaging
56
nonionizing radiation mode of action
introduces thymine dimers, leading to mutation that eventually kill the cell
57
sonication definition
use of high frequency sound waves to disrupt cell structures
58
sonication mode of action
cavitation disrupts cells, lysing them
59
cavitation definition
formation of bubbles inside the cell
60
filtration mode of action
physically removes microbes from air or liquid
61
high efficiency particulate air (HEPA) filters trap
bacterial cells, endospores, viruses, nearly sterilizing the air
62
membrane filters remove __ from ___
microbes from liquid samples
63
factors to consider when choosing chemical antimicrobials
type of microbe targeted, how clean the item needs to be, the disinfectant's effect on item integrity, its safety, its expense, and its ease of use
64
chemical antimicrobial examples
phenolics, heavy metals, halogens, alcohols, surfactants, bisbiguanides, alkylating agents, peroxygens, supercritical fluids, and chemical food preservatives
65
phenol mode of action
inhibit microbial growth by denaturing proteins and disrupting membranes
66
phenols are used in
mouthwash and toothpaste, lysol, agriculture, impregnated into products
67
phenolics characteristics
tend to be stable and persistent on surfaces
68
heavy metals mode of action
kill microbes by binding to proteins, thus inhibiting enzymatic activity
69
oligodynamic definition
very small concentrations show significant antimicrobial activity
70
heavy metals examples
mercury, silver, copper, nickel, zinc
71
mercury mode of action
bacteriostatic; bind to sulfur-containing amino acids within proteins, inhibiting their functions
72
silver is used as __ in __
antiseptic in antibiotic creams, making them thousands of times more effective
73
copper sulfate is a common
algicide used to control algal growth in pools and fish tanks
74
halogen examples
iodine, chlorine, and fluorine
75
iodine mode of action
disinfects by oxidizing cellular components
76
chlorine mode of action
disinfects by producing a strong oxidant that is uncharged and enters cells easily
77
chloramine characteristics
disinfect, stable, release chlorine over long periods of time
78
fluorine mode of action
accumulates in plaque-forming bacteria, interfering with their metabolism
79
alcohol mode of action
disinfect and antiseptic by rapidly denaturing proteins, inhibiting cell metabolism, disrupting membranes, leading to cell lysis
80
alcohols effective against
bacteria, fungi, enveloped viruses
81
surfactant definition
group of chemical compounds that lower the surface tension of water
82
surfactant mode of action
degerm by physically lifting away dirt and microbes from surfaces and skin
83
quaternary ammonium salts (quats) mode of action
insert into the bacterial phospholipid bilayer and disrupt membrane integrity
84
characteristic of quats
stable, nontoxic, inexpensive, colorless, odorless, and tasteless
85
quats kill
fungi, protozoans, bacteria, enveloped viruses (not endospores or nonenveloped)
86
bisbiguanide (chlorhexidine) mode of action
disrupts cell membranes and causes cell's cytoplasmic contents to congeal and is bacteriostatic at lower concentration, bactericidal at higher
87
bisbiguanide (chlorhexidine) kills
yeasts, gram+ and - bacteria, enveloped viruses
88
alkylating agents mode of action
replace a hydrogen atom within a molecule with an alkyl group, thereby inactivating enzymes and nucleic acids
89
alkylating agents examples
formaldehyde, glutaraldehyde, o-phthalaldehyde (OPA), ethylene oxide, beta-propionolactone
90
formaldehyde kills
bacteria, viruses, fungi, and endospores
91
formaldehyde leads to
sterilization at low temperatures
92
ethylene oxide
highly penetrating, gaseous sterilizer
93
peroxygen examples
hydrogen peroxide, peracetic acid, benzoyl peroxide, carbamide peroxide, ozone gas
94
hydrogen peroxide mode of action
produces free radicals that damage cellular macromolecules
95
hydrogen peroxide kills
gram- and + bacteria (more effective against gram+), fungi, viruses, endospores, decreased efficacy against bacteria that produce catalase and peroxidase
96
peracetic acid characteristics
can be used as a liquid or plasma sterilant, readily kills endospores, more effective than hydrogen peroxide, immune to inactivation by catalase and peroxidase, and breaks down into environmentally innocuous compounds
97
ozone gas characteristics
disinfectant used to clean air or water supplies
98
supercritical fluid definition
carbon dioxide that is brought to 10 times atmospheric pressure and gains physical properties between those of liquids and gases
99
supercritical carbon dioxide mode of action
penetrates cells and forms carbonic acid, which lowers cell pH considerably
100
supercritical carbon dioxide kills
vegetative cells, can kill endospores when combined with peracetic acid
101
characteristics of supercritical carbon dioxide
nonreactive, nontoxic, nonflammable, effective at low temps, preserves object's integrity
102
chemical food preservative examples
sorbic acid, benzoic acid, propionic acid and their soluble salts potassium sorbate, sodium benzoate, calcium propionate; sulfur dioxide, nitrites
103
sorbic acid mode of action
inhibits various cellular enzymes (those in Krebs cycle, catalase, peroxidase)
104
benzoic acid mode of action
decreases intracellular pH, interfering w/ mechanisms such as oxidative phosphorylation and the uptake of molecules such as amino acids into cells
105
propionic acid mode of action
inhibits enzymes and decreases intracellular pH, working similarly to benzoic acid
106
sulfur dioxide (sulfites) mode of action
may interfere w/ the disulfide bond formation in proteins, inhibiting enzymatic activity. they may reduce cell pH, interfering w/ proton motive force
107
nitrite mode of action
reacts w/ enzyme ferredoxin in bacteria, this electron transport chain carrier is destroyed, preventing ATP synthesis
108
natural chemical food preservative examples
nisin, natamycin
109
nisin mode of action
disrupts cell wall production, leaving cells prone to lysis
110
high level germicide definition
have the ability to kill vegetative cells, fungi, viruses, and endospores, leading to sterilization
111
intermediate-level germicides
less effective against endospores and certain viruses
112
low-level germicides
kill only vegetative cells and certain enveloped viruses, ineffective against endospores
113
disk-diffusion method for testing antimicrobial effectiveness
chemicals are applied to separate, sterile, filter paper disks. the disks are then placed on a plate w/ the target bacterium and the chemicals form a zone of inhibition based on their effectiveness against the target bacterium
114
use-dilution test
cylinder of stainless steel is dipped into culture of target microorganism, cylinder is dipped in solutions of disinfectant at various concentrations for specific amount of time, cylinder is transferred to a medium to see if bacteria grow
115
in-use test determines
whether disinfectant solutions are being used correctly in clinical settings
116
protist definition
informally refers to a diverse group of microscopic eukaryotic organisms: "animal-like" protozoans, "plant-like" algae, and "fungus-like" protists such as water molds
117
algae basic characteristics
photosynthetic organisms that can be unicellular or multicellular
118
protozoa basic characteristics
non-photosynthetic, heterotrophic, motile organisms that are always unicellular
119
plankton definition
microorganisms that drift or float in water, moved by currents
120
types of plankton
zooplankton, which are motile and non-photosynthetic, and phytoplankton, which are photosynthetic
121
trophozoites
protozoans that are beneficial symbionts that feed on small particulate food sources like bacteria
122
cyst definition
a cell with a protective wall
123
encystment definition
the process by which a trophozoite becomes a cyst when environmental conditions are too harsh
124
excystment definition
process by which cysts are triggered by environmental cues to become active again
125
protozoans reproduce sexually, asexually, or both
reproduce both sexually and asexually
126
modes of asexual reproduction in protozoans
binary fission, budding, or schizogony
127
schizogony process
nucleus of the cell divides multiple times before the cell divides into many smaller cells
128
merozoites definition
the products of schizogony
129
schizonts definition
structures that merozoites are stored in
130
modes of sexual reproduction in protozoans
syngamy, conjugation
131
syngamy definition
production of haploid gametes that fuse
132
conjugation (protozoan sexual reproduction)
exchange genetic material by joining to exchange DNA (different than bacterial conjugation)
133
protist conjugation definition
refers to a true form of eukaryotic sexual reproduction between two cells of different mating types
134
all protozoans have a
plasma membrane, or plasmalemma
135
pellicle formed from
bands of proteins just inside the plasma membrane that add rigidity that some protozoans have
136
ectoplasm definition
outer gel layer of the cytoplasm under the plasma membrane that some protists have
137
endoplasm definition
inner layer and sol (fluid) region of the cytoplasm that some protists have
138
cytosome definition
specialized structure for taking food in through phagocytosis that some protozoans have
139
cytoproct definition
specialized structure for the exocytosis of wastes that some protozoans have
140
holozoic definition
protozoans that ingest whole food particles through phagocytosis
141
saprozoic definition
protozoans that ingest small, soluble food molecules
142
protozoan motile structures
flagella or cilia made of microtubules, pseudopodia
143
contractile vacuoles definition
organelles that can be used to move water out of the cell for osmotic regulation that are found in some protozoans
144
mitochondria in parasites
may be absent or altered to kinetoplastids or hydrogenosomes
145
polyphyletic group definition
group that lacks a shared evolutionary history
146
domain Eukarya six supergroups
Excavata, Chromalveolata, Rhizaria, Archaeplastida, Amoebozoa, Opisthokonta
147
Amoebozoa includes
protozoans that used amoeboid movement
148
amoeboid movement
actin microfilaments produce pseudopodia, into which the remainder of the protoplasm flows, thereby moving the organism
149
Amoebozoa subgroup examples
slime molds, Entamoebas
150
slime mold types
cellular slime mold and plasmodial slime molds
151
cellular slime mold exist as
exist as individual amoeboid cells that periodically aggregate into a mobile slug, which then forms a fruiting body that produces haploid spores
152
plasmodial slime mold exist as
large, multinucleate amoeboid cells that form reproductive stalks to produce spores that divide into gametes
153
Chromalveolata is united by
similar origins of its members' plastids and includes the apicomplexans, ciliates, oomycetes, diatoms, and dinoflagellates
154
apicomplexans
intra- or extracellular parasites that have an apical complex at one end of the cell
155
apical complex
concentration of organelles, vacuoles, and microtubules that allows the parasite to enter host cells
156
apicomplexan life cycle
complex life cycles that include an infective sporozoite that undergoes schizogony to make many merozoites
157
examples of apicomplexan
the genus Plasmodium, Toxoplasmosis gondii, Cryptosporidium parvum
158
ciliates (Chromalveolata) characterized by
the presence of cilia on their cell surface
159
ciliate nucleus comes in the form of
a micronucleus and macronucleus
160
micronucleus
diploid, somatic, and used for sexual reproduction by conjugation
161
macronucleus
derived from the micronucleus, becomes polyploid, and has a reduced set of metabolic genes
162
polyploid definition
multiple sets of duplicate chromosomes
163
reproduction by conjugation produces
two cells that are genetically different from each other and from their previous versions
164
oomycetes are called
water molds
165
oomycetes characteristics
cell walls of cellulose, generally diploid
166
Excavata members characterized by
depression on the surface of the cell called an excavate
167
Excavata subgroups
Forincata, Parabasalia, Euglenozoa
168
Forincata characteristics
lack mitochondria but have flagella
169
Parabasalia characteristics
frequent animal endosymbionts, basal bodies, modified mitochondria (kinetoplastids), large complex cell structure w/ an undulating membrane, often have many flagella
170
Euglenozoa characteristics
cells have two flagella, a pellicle, a stigma to sense light, and chloroplasts for photosynthesis
171
major groups of parasitic helminths
roundworms (Nematoda) and flatworms (Platyhelminthes)
172
monoecious definition
having both male and female reproductive organs in a single individual
173
dioecious definition
having either male or female reproductive organs
174
Phylum Nematoda worms are
unsegemented worms that have a full digestive system even when parasitic
175
Nematoda are parasites of what area of the body
common intestinal parasites, their eggs can sometimes be identified in feces or around the anus of an infected individual
176
Nematoda parasite examples
Ascaris lumbricoides, Enterobius vermicularis (pinworm), Toxocaria canis and T. cati (toxocariasis), Necator americanus (hookworm), Trichinella spiralis (trichinosis), Dirofilaria immitis (heartworm)
177
Phylum Platyhelminthes includes
flukes, tapeworms, and turbellarians
178
flukes (trematodes) are characterized by
nonsegmented flatworms that have an oral sucker and attach to inner walls of intestines, lungs, large blood vessels , or the liver
179
important examples of flukes
liver flukes, intestinal flukes, oriental lung fluke, and schistosomiasis
180
tapeworms (cestodes) characterized by
segmented flatworms that may have hooks or suckers at the scolex (head region)
181
proglottids
what body of tapeworm is made up of, contains reproductive structures that detach when the gametes are fertilized, releasing gravid proglottids w/ eggs
182
tapeworm intermediate host function
consumes the eggs, which then form into larval form called oncosphere that travels to a particular tissue or organ to form a cysticerci
183
after cysticerci are consumed by definitive host
they develop into adult tapeworms in the host's digestive system
184
tapeworm examples
Taenia saginata (beef tapeworm), Taenia solium (pork tapeworm), Diphylobothrium latum (fish tapeworm), Echinococcus granulosus (dog tapeworm)
185
fungi characteristics
heterotrophic, saprozoic, unicellular and multicellular
186
mycoses definition
illnesses caused by fungi
187
hyphae
filaments that make up most multicellular fungal bodies
188
Hyphae can form
tangled network called a mycelium and form the thallus (body) of fleshy fungi
189
septate hyphae
hyphae that have walls between the cells
190
nonseptate (coenocytic) hyphae
hyphae that lack walls and cell membranes between the cells
191
unicellular fungi are
yeasts
192
budding yeasts
reproduce asexually by budding off a smaller daughter cell
193
pseudohyphae
budding yeast cells that sometimes stick together as a short chain
194
example of a common yeast that forms a pseudohyphase
Candida albicans
195
dimorphic fungi definition
having more than one appearance during their life cycle, appearing as yeasts or molds
196
example of a dimorphic fungi
Histoplasma capsulatum, the pathogen that causes histoplasmosis
197
fungal cell wall have
chitin and ergosterol
198
fungi reproduce sexually through either
cross-fertilization or self-ferilization
199
plasmogamy (fungi sexual reproduction)
cytoplasms of the + and - type gametes fuse, producing a cell w/ two distinct nuclei
200
karyogamy (fungi sexual reproduction)
the two nuclei fuse to create a diploid zygote, which undergoes meiosis to form spores that germinate to start the haploid stage, which eventually creates more haploid mycelia
201
sexually produces spores are known as
zygospores (in Zygomycota), ascospores (in Ascomycota), or basidiospores (in Basidiomycota)
202
fungi can reproduce asexually by
mitosis, mitosis w/ budding, fragmentation of the hyphae, and formation of asexual spores by mitosis
203
seven major groups of Fungi
Urediniomycetes and Ustilagomycetes, Glomeromycota, Chytridiomycetes, Zygomycota, Ascomycota, Basidiomycota, Microsporidia
204
Urediniomycetes and Ustilagomycetes include
plant rusts and smuts, respectively
205
Glomeromycota includes
mycorrhizal fungi, obligate symbionts associated w/ plant roots: fungi receives carbs from plant roots, plant benefits by increased ability to take up nutrients and minerals from the soil
206
Chytridiomycetes characteristics
small fungi that are generally aquatic and have flagellated, motile gametes
207
Zygomycota characteristics
mainly saprophytes with coenocytic hyphae and haploid nuclei; they use sporangiospores for asexual reproduction
208
zygospores
what Zygomycota uses for sexual reproduction, have hard walls formed from the fusion of reproductive cells from two individuals
209
Ascomycota characteristics
septate hyphae, cup-shaped fruiting bodies called ascocarps, use sexually produced ascospores, use asexual spores called conidia
210
medically important ascomycota
Trichophyton, Microsporum, Epidermophyton, Blastomyces dermatitidis, Histoplasma capsulatum, Candida albicans
211
unicellular Ascomycota examples
Saccharomyces
212
Basidiomycota characteristics
have basidia (club-shape structures) that produce basidiospores within fruiting bodies called basidiocarps
213
Basidiomycota disease example
Cryptococcus neoformans can cause serious lung infections when inhaled by individuals w/ weakened immune systems
214
Microsporidia characteristics
unicellular fungi that are obligate intracellular parasites; lack mitochondria, peroxisomes, and centrioles; spores release a unique polar tubule that pierces host cell membrane to allow the fungus to enter
215
microsporidiosis definition
human infections w/ microsporidia pathogen
216
algae are
autotrophic protists that can be unicellular or multicellular
217
algae are found in supergroups
Chromalveolata (dinoflagellates, diatoms, golden algae, and brown algae) and Archaeplastida (red and green algae)
218
harmful algal bloom occur when
algae grow too quickly and produce dense populations, can produce high concentrations of toxin
219
pyrenoids
structures inside of algal chloroplasts that synthesize and store starch
220
primary chloroplasts membranes
have two membranes, one from original cyanobacteria that the ancestral eukaryotic cell engulfed, and one from the plasma membrane of the engulfing cell
221
seaweeds differ from plants because
they do not have true tissues or organs like plants do, they do not have a waxy cuticle to prevent desiccation
222
algal reproduction
may be asexual by mitosis or sexual using gametes
223
algae that fall in Chromalveolata
dinoflagellates and stramenopiles
224
dinoflagellates nutritional types
may be phototrophic, heterotrophic, or mixotrophic
225
photosynthetic dinoflagellates use what chlorophylls
chlorophyll a, chlorophyll c2, and other photosynthetic pigments
226
dinoflagellates have how many flagella
two flagella that cause them to whirl
227
theca on dinoflagellates
cellulose plates that form a hard outer covering as armor
228
dinoflagellates neurotoxin causes
paralysis in humans and fish
229
red tide
a harmful algal bloom created by a dense population of dinoflagellates
230
stramenopiles include
golden algae, brown algae, and the diatoms
231
stramenopiles photosynthetic pigments
chlorophyll a, chlorophyll c1/2, and fucoxanthin
232
stramenopile storage carbohydrate
chrysolaminarin
233
diatom characteristics
have flagella and frustules, which are outer cell walls of crystallized silica; their fossilized remains are used to produce diatomaceous earth; can reproduce sexually or asexually
234
brown algae characterisitics
multicellular marine weeds; have leaf-like blades, stalks, and structures called holdfasts that are used to attach to substrate
235
brown algae photosynthetic pigments
chlorophyll a, chlorophyll b, beta-carotene, and fucoxanthine
236
brown algae storage carbohydrate
laminarin
237
Archaeplastids include
green algae (Chlorophyta), red algae, another group of green algae, and the land plants (Charophyta)
238
Charaphyta are most similar to land plants because
they share a mechanism of cell division and an important biochemical pathway, among other traits
239
like land plants, Charaphyta and Chlorophyta have
chlorophyll a and b as photosynthetic pigments, cellulose cell walls, and starch as a carbohydrate storage
240
Chlamydomonas is a green alga that has
a single large chloroplast, two flagella, and a stigma
241
red alga characteristics
mainly multicellular but have some unicellular forms, rigid cell walls containing agar or carrageenan
