final exam Flashcards
1
Q
sepsis
A
decay, putrid
bacterial contamination
2
Q
asepsis
A
absence of significant contamination
3
Q
aseptic surgery
A
prevent microbial contamination of wounds
4
Q
sterilization
A
destroying all microbial life
5
Q
disinfection
A
destroys harmful microorganisms on surfaces and environments
5
Q
commerical sterilization
A
kills clostridium botulism endospores in canned goods
(not completely sterilized to keep the flavor but also reduces endospores)
6
Q
sanitization
A
lowering microbial counts on eating utensils
6
Q
antisepsis
A
destoys harmful microorganisms from living tissue
6
Q
degerming
A
mechanical removal from limited area (injection)
7
Q
biocide (germicide)
A
treatments that kill microbes
8
Q
bacteriostasis
A
stop, inhibit but not kill microbes
9
Q
disinfectant must be
A
-fast acting in presense of organic materials (blood, feces, vomit)
-effective against all microorganisms without destroying tissue or acting as a toxin if ingested
-no discoloration or damage
-stable in environment
-inexpensive
No such thing as a perfect disinfectant
10
Q
microbial exponential death rate
A
0 min: 1million survivors (x90%)
6 min 1 survivor
*each minute the treatment is applied, 90% of the pop (remaining) is killed
11
Q
effectiveness of treatment depends on
A
of microbes
environment
time of exposure
microbial characteristics (endospore, cell wall)
12
Q
when the rate of killing is the same it takes
A
longer to kill all members in a larger population than smaller
13
Q
damage to plasma membrane
A
cellular content leakage
interfered cell growth
14
Q
actions of microbial control agents
A
damage to protiens and nucleic acids
15
Q
heat
A
inhibit protein growth so it denatures enzymes
16
Q
thermal death point (TDP)
A
lowest temp at which cells are killed in 10 min
17
Q
thermal death time (TDT)
A
minimal time for all bacteria to be killed at particular temp
18
Q
decimal reduction time (DRT)
A
minutes to kill 90% of specific pop of bacteria at given temp
19
Q
moist heat sterilization
A
moist heat coagulates/ denatures protiens
boiling
free-flowing steam
20
Q
autoclave
A
steam under pressure
121 c at 15 psi for 15 min
kills alls organisms (except prions) and endospores
21
Q
autoclave works by
A
steam rushes inside, air moves out until old air moves out so steam can build
-steam is passed through inlet
22
container sizes on autoclave sterilization times for liquid solutions
smaller containers take less time/ quicker
23
sterilization indicators
indicator lines wrapped in aluminum foil was not sterilized bc steam couldnt penetrate the foil
24
pasteurization
reduces spoilage organisms and pathogens
-M bovis cattle
25
High temperature short time (HTST)
72 c for 15 sec
26
Thermoduric organisms
survive but unlikely to cause disease or to spoil refrigerated milk
27
heat
ultra high temp treatments
will sterilize and can be stored without refrigeration ex. milk, creamer, juice
shelf life of many months
rapid heated to 140C for 4 sec followed by rapid cooling
28
dry heat sterilization
kills by oxidation
-flaming loop
-incineration: paper cups, bags, dressings
-hot air sterilization
29
filitration
used for heat sensitive stuff
-membrane filters remove microbes >22 mM
-small pore sizes filter out viruses and large protiens
30
low temperature has bacteriostatic effect (psychotropic)
refrigeration
deep freezing
lyophilization: freeze drying
31
high pressure
-denatures protiens
-alters carb structure
32
dessication
absense of water prevents metabolism
33
osmotic pressure uses high conc of salt and sugars to
create hypertonic environment, causes plasmolysis
34
ionizing radiation (x rays, gamma rays, electron beams)
-ionizes water to create reactive hydroxyl radicals
-damages DNA -> lethal mutations
35
gamma ray
penetrate deep but takes a long time to sterilize (hours)
36
high energy electron beams
less penetration, but fast (seconds)
37
non-ionizing radiation (UV, 260 nm)
damages DNA by creating thyme dimers
UVC "germicidal" lamps
must avoid contact with eyes or skin
effective but doesn't penetrate
38
visible blue light (470 nm)
kills wide range of bacteria due to formation of single oxygen
39
microwaves
kill by heat, not antimicrobial
40
sonication
high frequency ultrasound waves to disrupt cell structures
*rapid changes in pressure
41
selective toxicity
selectively destroying pathogens without damaging host
-bacteria -> targets cell wall
42
chemotherapy
use of chemicals to treat a disease
43
antibiotic
substance produced by microbe that inhibits the other
44
antimicrobial drugs
synthetic substance that interferes with growth of microbes
45
history of chemotherapy
-fleming discovered penicillin produced by penicillium
-prontosil red dye (type of sulfanilamide) used for strep infections
46
narrow spectrum of microbial activity
drugs that affect a narrow range of microbial types
47
broad spectrum antibiotics
affect broad range of gram positive and negative bacteria
48
superinfection
overgrowth of normal microbiota that is resistant to antibiotics
-candida albicans
-c. dificile
49
development of superinfections
-normal microbiota keeps opportunistic pathogens in check
-broad spectrum antibiotics kill nonresistant cells
-drug resistant pathogens proliferate and can cause a superinfection
50
dosage
amount of meds given during a certain time interval
-children: based on mass
-adult: standard dosage not based of mass
51
half life of antibiotic
rate at which 50% of drug is eliminated from the plasma
52
intravenous administration of a drug
peaks very quickly
53
orally or intramuscularly administered drugs
take longer for concentration to reach its peak
54
bactericidal
kills microbes directly
55
bacteriostatic
prevent microbes from growing
56
major action modes of antibacterial drugs
inhibition of cell wall synthesis
inhibition of protien synthesis
inhibition of nucleic acid replication and transcription
57
penecillins
prevent the synthesis of peptidoglycan
-inhibit cell wall synthesis
-against growing cells from mold
58
inhibiting protien synthesis
target bacterial 70S ribosomes
-chloramphenicol: binds to 50S portion and inhibits formation of peptide bond
-streptomycin: changes shape of 30S, causing code on mRNA to be read incorrectly
59
polypeptide antibiotics
change membrane permeability
60
antifungal drugs
combine w membrane sterols
61
ionophores
antibiotics that allow uncontrolled movt of cations
-cattle feeds (digestive and growth)
62
polymyxin
changes permeability
63
inhibiting nucleic acid synthesis
blocks topoisomerase (interferes with dna replication)
block RNA polymerase (interferes with transcription)
64
inhibiting the synthesis of essential metabolites
antimetabolites compete with normal substrates
-Sulfanilamide: competes with Para-aminobenzoic acid (PABA) stopping the synthesis of folic acid
65
PABA
substrate formation of folic acid
-similar structure as sulfanilamide
66
penecillin binding protiens
enzymes that produce peptide cross links in peptidoglycan
67
penicillin
natural
inhibits PBP (narrow spectrum)
no cross links
weak
burst
lysis
contain B lactam ring
chemical side chains are attached to the ring
68
G- outermembrane consists of
porins
69
cycloserine
inhibits part of peptide side chain on NAM
70
bacitracin
binds to bactoprenol lipid carrier
-transport of dissacharide units of peptidoglycan across cell membrane to the growing chain inhibited
71
penecillin, vancomycin, cephalosporins inhibit
activity of enzymes that cross-link the peptide side chains
72
natural penicillins
from penicillium fungi cultures
-pencillin G (injected) and penicillin V (oral)
-narrow spectrum of activity
-susceptible to penicillinases (B- lactamases)
73
cephalosporins
similar to penecillins
b lactam ring differs from penicillin
74
4th generation of cephaloporins
pseudonomas
good gram positive
75
5th generation of cephaloporins
MRSA+
staph aureus
good: gram positive/ negative
76
bacitracin
b. subtilis and b. lichenform
topical application works against gram positive
77
vancomycin
streptomyces
resistant to vancomycin
vancomycin resistant enterococcus: nosomial oppurtunistic pathogen
78
teixobactin
kills some gram positive bacteria (M. tuberclosis, S. aureus, VRE)
79
isoniazid (INH)
anti-mycobacterial antibiotic
inhibits mycolic acid synthesus in mycrobacteria
80
ethambutol
secondary drug to avoid resistance
-only acts against mycrobacterium
81
nitrofurantoin
-attack bacterial ribosomal protiens
-treatment for UTIs
82
chloramphenicol
inhibits peptide bond formation
-binds to 50S subunit
83
how does chloramphenicol inhibit protien synthesis
suppresses bone marrow and affects blood cell formation (aplastic anemia)
84
aminoglycosides
-changes shape of 30S
-auditory and kidney damage
-streptomycin: tuberculosis
85
tetracylines
produced by streptomyces
interfere with tRNA attachment to ribosome
broad spectrum
against ricketsias and chlymadias
suppress C. albicans
86
glycyclines (inhibitor of protien synthesis)
broad spectrum
bacteriostatic
30S ribosomal
inhibit rapid efflux
intravenous
useful against MRSA
87
multi drug resistant glycylcycline
acinetobacter baumannii
88
macrolide (inhibitors of protein synthesis)
lactone ring
narrow spectrum against gram positive: eryhthomycin
azithromycin
89
streptogramins
attach to 50S subunit
work against gram positives (penecillin, mold, PBP)
synercid: multiple targets/ sites on 50S subunit
90
NAG-NAM
cell wall - prevents cross link
91
porins are found
outer membrane
92
b lactimase
resistant
93
b lactam ring
cidal
94
oxazolidinone
bind to 50S/30S interface
synthetic: combat MRSA (linezolid)
95
pleuromutilin
mushroom
retapamulin: topical and effective against gram positives
96
lipopeptide (inhibits protien synthesis)
daptomycin: produced by streptomyces, used for skin infections
polymyxin B: against gram negative
polymyxin E (colistin): against gram negative
97
rifamycin (rifampin)
nucleic acid synthesis inhibitor
-penetrates tissues; antitubercular activity
-mycobacteria, tuberchlosis, leprocy
98
quinolone and fluoroquinolones
nalidixic acid: synthetic; inhibits DNA gyrase
norflaxin and ciproflaxin: broad spectrum; relatively nontoxic
gemifloxacin, moxifloxcin: newer versions
problem: ruptures tendons
99
sulfonamides
inhibit synthesis of folic acid needed for nucleic acid and protien synthesis
-structurally similar to PABA (folic acid precursor)
100
PABA
sulfa drug
structurally similar
101
antifungal drugs
fungal steroids
-interrupt synthesis of ergosterol, making membrane excessively permeable
102
polyenes
fungal sterols
interrupts ergosterol synthesis, making membrane excessively permeable
nystatin: most commonly used
-thrush, candida
amphtotericin B: systemic fungal infections; toxic to kidneys
103
azoles
imidazoles: topical; treat cutaneous mycoses
triazole: treat systemic fungal infections; toxic to the kidneys
104
allylamines
fungal; azole resistant infections
105
echinocandins
inhibit synthesis of B-glucan
106
flucytosine
inteferes with rna synthesis, inhibit nucleic acids
107
griseofulvin
produced by penicillium
inhibits microtubule formation: mitrosis -> fungal reproduction
active against superficial dermatophytes
108
what antifungal drug is used to treat tolnafate
tolnaftate
109
pentamidine
anti- pneumocystis
may bind to dna
immunocompromised
110
antiviral drugs
entry and fusion inhibitors
-block receptors on host cell that bind to virus
-block fusion of virus and cell
-uncoating, genome integration, nucleic acid synthesis inhibitors
-prevent viral uncoating
-inhibit viral dna integration into host genome
111
protease inhibitors
block cleavage of protien precursors
example: Paxlovid, used to treat covid19
112
exit inhibitors
inhibit neuraminidase: enzyme required for viruses to bud from the host cell
113
interferons
immune signaling molecule, defense
-viral infected cells to inhibit further spread of infection
Imiquimod: promotes interferon production
114
antiretrovirals
to treat HIV/AIDs
HIV: RNA virus
115
quinine and chloroquine (antiprotozoan)
treats malaria
bark of cinchona
116
artemisinin (antiprotozoan)
kills plasmodium that causes malaria
117
metronidazole, tinidazole, nitrazoxanide
interferes with anaerobic bacteria
-treats trichomonas, giardiasis, amebic dysentry
118
miltefosine
inhibits cytochrome oxidase in mitochondria
treats amebic encephalitis and leishmaniasis
vectoe: sandfly
119
niclosamide (antihelmic)
treats tapeworms
prevents ATP production
120
praziquantel (antihelmic)
alters membrane permeability
treats tapeworms and flukes
121
mebendazole and albendazole
interfere with nutrient absorption
treat intestinal helminths
122
ivermectin
treats roundworms and mites
123
disk diffusion method (kirby bauer test)
paper disks with chemotherapeutic agent placed on agar inoculated with test organism
-zone of inhibition around disk determines sensitivity of organism to the antibiotic
124
E test
minimal inhibitory concentration (MIC)
lowest antibiotic conc preventing bacterial growth
125
broth dilution tests
determine MIC and MIB (minimal bactericidal conc) of antimicrobial drug
-99% of cells of inoculation added are killed
-test organism is placed into wells of tray containing dilations of drug; growth is determined
-antibiograms: susceptibility of organisms
126
if cells grow it means that it is
not cidal
127
broth dilution tests measure
turbidity
-cells are viable, dead or not growing
128
MBC is determined by using
tube dilution test and removing antibiotic
-further plating to see if cells survived 3 to 5 times above the MIC
129
if cells grow in fresh medium without antibiotic
drug is bacteriostatic
130
if cells dont grow in fresh medium
drug is bacteriocidal
131
persister cells (resistance to antimicrobial drugs)
microbes with genetic characteristics allowing for their survival when exposed to an antibiotic
132
superbugs
resistant genes spread horizontally among bacteria on plasmids or transposons
133
bacterial pathogens
resistant to nearly all antibiotics; cause HIAs
-acinetobacter baumannii
-p. aeroginosa
134
mechanisms of resistance
-enzymatic destruction or inactivation of drug
-prevent penetration to the target site within microbe
-alters drugs target site
-rapid efflux (ejection) of antibiotic
-variations of mechanisms of resistance
135
beta lactamse
break B lactam ring of penicillins and cephalosporins
136
gram negative bacteria
porins in outer membrane may be modified and prevent access of antibiotic to periplasm
137
MRSA
modified penicillin binding protien (PBP)
-B lactam antibiotics can no longer bind and halt cross linking of peptidoglycan
138
therapeutic index
risk vs benefit
139
clinical considerations
drug concentration > MIC during treatment
-half life depends on how quickly the antibiotic is removed from body via excretion
how long a drug stays in tissue
140
therapeutic dose
minimum dose per kg of body weight that stops growth
141
toxic dose
maximum dose tolerated by pt
142
chemotherapeutic index
ratio of toxic to therapeutic dose
143
higher the chemotherapeutic index
safer the drug
144
synergistic drugs
greater effectiveness when used together
ex. aminoglycoside (access to inside the cell) and vancomycin (cell wall)
145
antagonistic drugs
interfere with each other, decrease effectiveness
ex. penicillin (acts of growing cells) and macrolides (bacteriostatic: inhibits growth)
146
antimicrobial agents
target virulence factors
sequester iron which feeds pathogens
drugs combat dormant persister cells (antibiotic resistant cells)
target gram negative bacteria (porins outermembrane)
antimicrobial sensitivity
bacteriocins:peptides produced by bacteria (kills other bacteria)
phage therapy: using bacteriophage to treat infection
147
microbiome
growth of MRSA (resistant S. aureus)
lactobacillus spp grew
148
phenol and phenolics
plasma membranes, causing leakage
active in presense of organic matter
reduced irritation, increased effectiveness
ex. O-phenylphenol
149
Bisphenols
two phenol groups connected by a bridge
disrupt plasma membranes
hexachlorophene: control skin infections
triclosan: antibacterial soaps
150
biguanides
effective against gram positive, gram negative bacteria, enveloped viruses
ex.
Chlorhexidine: surgical hand scrubs
Alexidine: works faster
151
iodine
impairs protien synthesis and alters membranes
tincture: solution in alcohol
iodophor: combined with organic molecules
povidone-iodine: skin antisepsis
152
Essential oils
peppermint, pine and orange oil
strong against gram positive bacteria, effectiveness against viruses not studied
tree and pine oil: broad spectrum that includes gram positive and negative bacteria and fungi
153
chlorine
bleach: hypochlorous acid (HOCL) neutral
chloramine: chlorine and ammonia
municipal water disinfection: compressed chlorine gas
154
if the water is cloudy/ not clean
2-3 drop bleach
1 L of H2O
30 mins
155
alcohols
denture protiens and dissolves lipids
require water
alcohol based hand sanitizers: above 62% alcohol
not effective against endospore producers and nonenveloped viruses
-not effective against C. dificile or Norovirus
156
best alcoholic action
around 65-70%
100% = growth of bacteria
157
oligodynamic action (heavy metals)
very small amounts
denature protiens
158
silver nitrate
prevents opthalmia neonatorium
159
copper sulfate
algicide
swimming pools
160
Cu2+ and Ag+ ions
used in water disinfection
161
zinc chloride
mouthwash
antidandruff shampoos
162
soap
acid anionic sanitizers
-emulsification
break oil film -> soalather and water
phosphoric acid
163
quaternary ammonium compounds (quats)
cations denature
broad spectrum
except ineffective against endospores and mycobacteria
exception: pseudomonas
164
organic acids to prevent molds in some foods
sorbic acid
benzoic acid
calcium propionate
165
nitrites and nitrates
prevent endospore germination (clostridium botulism)
-nitrosamines
166
bacteriocins
one bacterium that inhibits another
-nisin and natamycin prevent spoilage of cheese
167
aldehydes
inactivate protiens by cross linking with functional groups
-formalin preserve specimen
-glutaraldehyde: sporicidal in 3-10 hours; used in respiratory therapy equipment, endoscopes, other equipment that can be autoclaved
168
gaseous chemosterilants
cross links nucleic acids and protiens
heat sensitve material
169
ethyl oxide
sealed chamber
sterilizes large equipment and furniture depending on chamber size
170
chlorine dioxide
enclosed building areas or water treatment
surface disinfection
171
supercritical fluids
supercritical state in both gas and liquid properties
uses:
-food industry
-medical implants including bone, tendons, ligaments removed from donors
172
peroxygens
oxidizing agents
-hydrogen peroxide:
good disinfectant
asceptic food packaging
disinfection of food processing and medical equipment
173
benzoyl peroxide
topical acne medications
174
ozone
water disinfection
175
effecive disinfectant principles
concentration of disinfectant
organic matter
176
disk diffusion method
look for zone of inhibition around disks
177
gram negative bacteria
more resistant to biocides due to lipopolysaccharide (porins in OM)
-pseudonomas and burkholderia are unusually resistant
178
mycrobacteria
tuberculocides must undergo special testing
179
bacterial endospores
resistant to biocides
180
nonenveloped viruses
more resistant than enveloped viruses
180
prions
immerse in NaOH and autoclave at 121 ceclius for 1 hour
181
bukholderia (gram negative)
moist soil -> septic shock
181
BSL (biological safety levels)
BSL 1 - low risk microbes
BSL 5 - high risk microbes
181
BSL 1
healthy hosts
ex. E coli
182
BSL 2
diseases of varying severity
moderate risk to workers and environment
ex. S aureus
183
BSL 3
serious or lethal diseases through respiratory transmission
ex. Mycobacterium tuberclosis
184
BSL 4
pose high risk of aerosol transmitted infections
fatal
Ebola, Marburg
185
symptoms
subjective changes felt by pts
186
signs
objective changes measured or observed
187
syndrome
signs and symptoms
-labratory tests
188
pathology
study of disease
189
etiology
cause of disease
190
pathogenesis
manner in which disease develops
191
infection
invasion or colonization by pathogens
192
infectious disease
infection results in any change in state of health
-infection may exist in absence of disease
-could occur in a type of microorganism locates in a part of body where its normally not found
193
communicable disease
spread from one host to another
ex. covid
194
contagious disease
diseases that easily and rapidly spread from one host to another
195
noncommunicable diseasee
disease that is not spread from one host to another
ex. tetanus (clostridum tetani)
196
duration
average time individuals have a disease from diagnosis until they are either cured or die
197
acute disease
symptoms develop rapidly but has a short duration
ex. influenza
198
chronic disease
symptoms develop slowly
199
subacute disease
between chronic and acute
ex measles
200
latent disease
causative agent that is inactive for a time but then activates and produces symptoms
ex. asymptomatic at first; shingles, chickenpox, coldsores
201
sepsis
extreme inflammatory syndrome in response to severe infection
202
local infection
pathogens are limited to a small area of the body
ex. boils, abcess
203
systemic (generalized) infection
infection spread throughout the body by blood and lymph
204
focal infection
systemic infection that began as a local infection
-teeth, tonsil, sinus
205
septicemia
blood poisoning; growth of bacteria in the blood
206
toxemia
toxins in blood
207
viremia
viruses in blood
208
primary infection
acute infection that causes initial illness
209
secondary infection
opportunistic infection after primary infection
210
subclinical infection
no noticeable signs of symptoms
(inapparent, asymptomatic)
ex. hepatitis A
211
kochs postulates
-specific infection disease is caused by specific microbe
-etiology of disease: first step in treatment and prevention
212
exceptions to kochs postulates
-some pathogens cause several diseases, cause disease only in humans
-some microbes have never been cultured
213
phenotype (sign or symptom) should be associated with pathogen strains of a species - enterogemorrhagic e coli
EHEC causes intestinal inflammation and diarrhea
214
inactivation of suspected genes are a measurable loss of pathogenicity
one of the genes in EHEC codes for shiga toxin and inhibits protien synthesis
215
reversion of the inactive gene should restore the disease phenotype
by adding the gene that encodes the toxin bck into the genome, ehec's ability to cause disease is restored
216
incubation period
no signs or symptoms
-interval btw initial infection and first signs and symptoms
217
prodromal period
early, mild signs or symptoms
218
period of illness
disease is most severe
219
period of decline
signs and symptoms subside
220
period of convalescence
body returns to its pre-diseased state; recovery
-could still spread disease ex. vibrio, typhoid fever
221
continual sources of infections
human reservoirs: ppl with signs or symptoms; carriers may have inapparent infections or latent diseases
-aymptomatic, incubating, convalescent, chronic and passive carriers
222
animal reservoirs
zooneses are diseases in wild and domestic animals
223
nonliving reservoirs
soil and water
foods
pet waste
consuming infected animal products
antropod vectors
rabies, lyme disease
224
direct contract transmission
close association btw infected and a susceptible host
225
congenital transmission
mother to fetus
syphallis
226
indirect contact transmission
spreads to host by nonliving "fomite"
ex. AIDs, hepatitis B
227
droplet transmission
transmission via airborne droplets
ex. flu, pneumonia
228
vehicle transmission
transmitted by an inanimate reservoir
-airborne: histoplasmosis
-waterborne: cholera
-foodborne: tapeworm; may involve cross contamination
229
vectors
anthropods (fleas, ticks, mosquitos)
mechanical: by feet
biological: reproduces in vector; transmitted via bite or flea
230
hospitals
nosocomial infections
-certain normal microbiota are oppurtunistic and pose a risk
-antimicrobial resistance (S aureus MRSA) are high among HAIs
231
compromised host
individual whose reistance to infection is impaired by disease, therapy, burns
232
infect contact through fomites and hospital ventilation system
urinary catheters (fomite transmission)
intravernous catheters
respiratory aids
needles
surgical dressings
233
pseudonomas aeroginosas is
highly resistant nosocomial pathogen
234
infection control committee
oversee and monitor infection control
235
emerging infectious disease
new or changing, increasing in incidence or showing a potential to increase in near future
236
contributing factors of emerging infectious diseases: genetic recombination between organisms
E coli O157:H7 and avian influenza (H5N1)
O antigen
H7: flagella
237
contributing factors of emerging infectious diseases: evolution of existing organisms
vibrio cholerae
O139 - cholera toxin
238
contributing factors of emerging infectious diseases: widespread use of antibiotics and pesticides
antibiotic resistant strains
-superbugs, R plasmids
239
240
changes in global climate and weather patterns
Hantavirus: rodents - saliva -urine - feces - respiratory syndrome
240
antigenic shift
two strains of influenza virus infect the same cell and genomes get mixed
*dramatically makes a different virus
-pandemics, outbreaks
241
antigenic drift
random mutations that occur within cell that a virus infects, creating small changes in virus protiens
241
contributing factors of emerging infectious diseases: inherant genetic instability of some microbes
rna viruses: lack proofreading of dna viruses, mutations
antigenic shirt and drift
242
modern transportation
zika virus and chikungonya: joint pain
west nile encephatlitis: birds, mosquitoes: vectors
243
insect vectors transported to new areas where they become established
aedes aegypti
a albopictus: asian tiger
244
public health failure
diptheria -> corynebacterium dipthaie
244
ecological diseas
coccidioimycosis
244
zika virus
congenitial
-mother to fetus causes microencephaly
245
pathogenecity
ability to cause disease
246
virulence
degree of pathogenecity -> genetic element
247
attenuation
weakening of disease producing ability of pathogen
-attenuated vaccines contain crippled viruses or bacteria that iject into a host to stimulate an immune response
248
portals of entry
mucous membranes
skin
parental route: deposited directly into tissues when barriers are penetrated
injections, barriers, wounds, cuts, surgery
249
ID50
infectious dose (cause disease) for 50% of a sample population
-measures virulence of a microbe
-causes disease
249
LD50
lethal dose for 50% of a sample population
-potency of a toxin
250
virulence factors
pili, detection enzymes, capsule, enzymes that inactivate antibiotics, protiens that disrupt normal cellular function
251
pathogenecity island
genomic island that contains virulence factors
252
adherence
all pathogens attach to host tissues
253
adhesions (ligands) on pathogen
bind to receptors on host cells
254
glycocalyx
in S. mutans, made of dextran, enabling the bacteria to adhere to teeth
255
fimbrae
in actinomyces, adheres to glycocalyx of S. mutans
256
viral spikes
spikes of SARS-COV-2 adhere to ACE2 receptor on host cells
257
capsules
resistance
glycocalyx around cell wall
impair phagocytosis:
-S. pneumonae: pneumonia
-H. influenza; pneumonia, meningitis
-B. anthracis: anthrax
-Y. pestis: plague
258
M protien in cellwall
resists phagocytosis
-S. pyogenes
259
Opa protien in cell wall
allow attachment to host cell
-N. gonorrhae
260
Waxy lipid (mycolic acid)
resists digestion by phagocytosis
mycobacterium tuberculosis
261
kinase
digest fibrin clot
261
coagulase
coagulate fibrinogen forming fibrin
262
hyaluronidase
digests hyaluronic acid, a host polysaccharide that holds cells together
263
collagenase
breaks down collagen
264
IgA protease
destroy IgA antibodies
265
protozoan pathogenesis
immune avoidance by protozoa`
266
antigenic variation
pathogens alter their surface antigens
antibodies that a host made against antigens are rendered ineffecive
example:
-influenza virus
-N. gonorhea
-Trypanosome brucei gambiense
267
antigenic masking
some protozoans coat themselves in host antigens to avoid detection by the immune system
268
invasins
surface protiens produced by bacteria that rearrange actin (cytoskelaton of eukarya) filmanents of the cytoskelaton
269
what do invasins cause
membrane ruffling resulting in bacteria being engulfed
270
shigella and listeria
use actin to move from one cell to the next
271
survival inside phagocytes
require low pH in phagolysosome
escape from phagosome before lysomal fusion
prevention of fusion of lysosome with phagosome
272
how is pathogen excreted as waste`
pathogen
phagocyte
lysozome
phagolysozome
digestive enzymes
superoxide radicals
residual
excreted as waste
273
biofilms
resist antibiotics and disinfectants
involved in 65% of all infections
evade phagocytes
resistant to phagocytosis, shielding by extracellular polymeric substance (EPS) of biofilm
274
iron
required for most pathogenic bacteria
-siderophores: secreted by pathogens, bind iron more tightly than host cells and host iron binding protiens
275
direct damage
disrupts host cell function
uses host cell nutrients
produce waste products
multiplies in host cells and causes ruptures
276
endotoxins
G- outermembrane
lipid A of LPS of gram negative bacteria
*released during bacterial multiplication and when gram negative bacteria die
fever, activation of clotting factors, vasodilation, shock, and death may result
277
toxins
produced by microorganisms
-produce fever, cardiovascular problems, diarhea, shock
278
toxigenicity
produce toxin
279
toxemia
presense of toxin in hosts blood
280
intoxications
presense of toxin without microbial growth
281
exotoxins
released outside - metabolism - protiens
protiens secreted and produced by bacteria
highly specific for their targets
highly lethal
282
antitoxins
antibodies against exotoxins that provide immunity
-neutralize
283
toxoids
inacinvolved in biochemical reactions
enzymatic nature
small amt is lethal
can be used again
284
AB type exotoxins
AB toxins
cytolytic toxins: membrane disrupting toxins
superantigen toxins
285
potent exotoxins
AB toxins
-include: diptheria, tetanus, botulism, cholera
286
diphtheria exotoxin
blockage of protien synthesis
287
the A domain in AB toxin adds
ADP- ribosyl group to EF-2
288
elongation factor 2
key factor in translation
289
neurological exotoxins
C tetani and C botulism produce potent AB exotoxins that affect nervous tissue
290
enterotoxins
massive secretion of fluid into intestinal lumen, results in vomitting and diarhea
291
plasmids and bacteriophage
cause waterborne disease cholera
292
membrane disrupting toxins (exotoxins)
lyse host cells by disrupting plasma membranes
293
leukocidins
kill phagocytic leukocytes
294
hemolysins
kill erythcrocytes by forming protien channels
295
streptolysins
hemolysins produced by streptococci
296
superantigens
excessive activation of immune response - lots of T cells
-strong immune and inflammatory response: shock and death
-pyrogenic (fever producing) toxins of staph A such as shock syndrome
-food poisoning by entereotoxins`
297
bacterial source
endotoxins: gram positive and negative
exotoxin: gram negative in outer membrane
298
relation to microorganism
exotoxin: metabolic product of growing cell; excreted outside host CM
endotoxin: outer membrane of cell wall during cell division (within)
299
chemistry
exotoxin: AB protiens
endotoxin: lipid portion (A)
300
pharmacology
exotoxin: specific; gastrointestinal
endotoxin: general
301
high stability
exotoxin: toxid
endotoxin: stable
302
toxicity
exotoxin: high
endotoxin: low
303
fever producing
exotoxin: no
endotoxin: yes
304
immunology
exotoxin: converted to toxoids (vaccine)
endotoxin: not easily neutralized by antitoxin
305
lethal dose
exotoxin: small
endotoxin: larger
306
representative diseases
exotoxin: gas gangrene, tetanus, botulism, diphtheria, scarlet fever, cyanobacterial intoxication
endotoxin: typhoid fever
307
viral mechanisms for evading host defenses
-intracellular prevents immune response from detecting or accessing the virus
-use host cell surface molecules to attach and gain entrence to host
-attack components of immune system
-antigenic variation: antigenic changes on infected cell
308
cytopathic effects
visible effects of viral infections
-viruses multiply inside host
-create inclusion bodies (cytoplasm of cell diagnostic)
syncytium ex. measles, mumps
transformation of host cells - contact inhibition - unregulated cell growth resulting in cancer
309
cytocidal effects
cytopathic effects that kill the host cell
310
noncytocidal effects
cell damage but not cell death
311
fungi
virulence facots
toxic metabolic products
allergic response
312
trichothecene (fungi)
toxins inhibit protien synthesis in eukarya
313
proteases
modify host cell membranes
-break protiens to attach
ex. C albicans
314
capsules
prevent phagocytosis
-Cryptococcus neoformans
-soil fungus, pigeion, chicken, meningitis
315
ergot
alkaloid toxins
-Claviceps purpurea
316
alflatoxin
carcinogenic toxin produced by aspergillus flavus
317
mycotoxin
mushroom
neurotoxic
318
protozona and waste produces avoid defenses by
digesting tissue and cells
-Giardia intestinalis
-Toxoplasma gondii
antigenic variation: surface components
-Trypanosoma
319
portals of exit
respiratory tract: cough, sneeze
GI tract: feces, saliva
Genitourinary tract: urine
skin
blood: anthropods that bite; needles or syringes
320
epidemiology
where and when diseases occur, how they are transmitted in populations
321
john snow
father of evolution
-tracked source of cholera outbreak to water from a specific well
-broke chain of transmission
322
ignaz sammelweis
handwashing as sepsis
323
florence nighingtale
improved sanitation decreased incidence of epidemic typhus
324
reproductive number
average number of people who will contract a disease from one infected individual
325
descriptive epidemiology
analysis of data
-retrospective study: already happened
326
analytic epidemiology
particular disease to determine cause or risk factors
-Nightingale's work -> soliders, cilivians, cohort groups
327
experimental epidemiologu
hypothesis
clinical trial -> test or control
328
case reporting
enables researchers to establish chain of transmission
report specific diseases to officials
Notifiable infection diseases list
provide early warning of possible outbreaks
329
CDC
epidemiological information in the US
publishes Morbidity and Mortality Weekly Report
330
morbidity
incidence of specific notifiable disease
331
mortality
deaths from notifiable diseases
332
notifiable infectious diseases
physicians are required to report occurance
333
morbidity rate
number of people affected in relation to total population
334
mortality
number of deaths in a given time period
335
spoardic disease
Neisseria meningitis, typhoid fever
-occurs only occassionally
336
endemic disease
constantly present
ex. common cold
337
epidemic disease
disease scquired by many ppl in a given area in a short time
ex. influenza
338
pandemic disease
worldwide epidemic
339
incidence
number of people who develop a disease during particular time period
-new cases
340
prevalence
number of ppl who have a disease at a specific time, regardless of when it first appeared
-takes into account both old and new cases
341
common source epidemic
contamination of food or water
ex. cholera
342
host to host epidemic
disease that shows a slow progressive and gradual decline
ex. flu, chickenpox
343
Borrelia burgdorferi
lyme disease
ixodes tick
increase in deer and human populations in wooded areas
344
Mycobacterium tuberclosis
tuberclosis
sputum dprolets
multi-drug resistant
345
Clostriodes difficile
antibiotic associated enterolitis
person to person
gut dysbiosis due to long term use of antibiotics
346
Vibrio cholerae
cholera: severe diarrhea
water contaminated with feces of infected persons
poor sanitation and hygiene via infected travelers and commerce
347
dengue
infected mosquito Aedes aegypti
poor mosquito control
increased travel and shipping - modern transportation
348
influenza H5N1
direct contact with infected animals or humans, not spread by respiratory aerosols
antigenic shift
349
zika
asymptomatic
bite of infected mosquito
poor mosquito control
increased urbanization in tropics
350
candida
microbiota becomes oppurtunistic pathogen
catheters: compromised host
351
disease tracking
index case or patient zero
(1st person with the disease)
352
specimen collection sites
blood
CSF (lumbar puncture, direct microscopy and culture)
pleural fluid: lungs
synovial: oral cavity
peritoneal: abdominal cavity
aspectically
353
cerebrospinal fluid
turbid leukocytes
354
labratory identification of microbial pathogens
1. isolate bacteria from pt
2. pure culture - cell and colony morpholoy
3. gram stain
4. biochemical pathways
355
selective media
allow some organisms to grow, while inhibiting others
356
differential media
allow identification of organisms based on their growth and appearance on the medium
357
colonies of MRSA on chromogenic agar medium
appear pink
others appear blue
358
biochemical alogrithms to identify bacteria
identify gram positive pyogenic cocci
359
specificity
recognize the target pathogen
360
sensitivity
minimum amount of pathogen needed for this test to detect it, minimizing false negatives
361
immunoassays
measure pt antibody levels
serology and titers
-antigen antibody reactions in vitro
-individual is infected, antigens to that pathogen should become elevated
362
anitigen
foreign agents to body provoke an immune response
363
antibody
produced by B cells
bind antigens for which they are specific
364
enzyme immunoassay (EIA)
very sensitive
rapid tests
detect antigen antibody complexes
365
direct elisa
detects antigens
complex of antigen- antibody
adding a substrate for linked enzyme produces a color
366
indirect elisa
detects antibodies
367
sandwich EIA
target antigen detected via anchoring between two antibodies
368
rapid tests
point of care diagnostics
matrix contains soluble antibodies that are specific to antigen and conjugated to a colored molecule called a chromophore
as liquid sample diffuses through matrix, pt antigens bind the chromophore labeled antibodies
369
pregancy test
detects levels of human chronic gonadotropin hormone (HCG)
370
test line area
fixed antibodies
2nd body antibody fixed
371
control line area
fixed antibodies
372
polymerase chain reaction (PCR)
-amplify small quantities of dna for analysis
-make billions of copies of a target dna within a few hours
used for diagnostic tests for genetic diseases and detecting pathogens
373
dna primers
made for specific pathogens
complimentary to target dna
374
cycles
0 cycle - 2 copies
1 cycle - 4 copies
20 cycles - 2 million
375
reverse transcription pcr
uses mrna as template
-can make cDNA from small amount of viral rna
-detect presense of rna viruses
-complimentary, pcr
376
RT- qPCR (quantitative reverse transcription pcr)
involves detection and quantification of RNA
combines effects of reverse transcription and quantative pcr or real time pcr to amplify and detect specific targets
377
flourescent signal
measures quantity of dna in real time
-hydrolysis probes
-detect pathogens such as viruses for the diagnosis of infectious diseases
378
influenza (flu)
negative sense
segmened rna genome
envelope
external glycoporotiens
avian, swine and mammalian strains
379
Hemagglutinin spikes
recognize and attach to hosts
bind to sialic acid
respiratory epithileum
380
neuramadase spikes
seperate from the infected cell
-assembly
381
H1N1
each virus has one type of HA and one type of NA on its viral capsid and is named for the antigens it contains
382
3 genera of human influenzaviruses
influenza A (alphainfluenzavirus): found in different animals
influenza B: epidemics
influenza C: mild sickness
383
influenza A
identified by variation in the HA and NA spikes
16 subtypes HA; 9 subtypes NA
384
influenza antigenic drift
minor antigenic changes in HA and NA
385
influenza antigenic shift
two different species infect the same person
-lead to pandemics
-reassortment of the 8th rna segments
386
1918-1919 pandemic
lethal for young adults
cytokine storm
lethal hemorrhaging
avian influenza viruses
387
H5N1 is detected in
birds
388
H1N1
"bird flu"
389
streptococcus spp.
invasive infections
nonsporulating
gram positive
cocci
aerotolerent anaerobes
390
how does strep transmit
respiratory pathogens transmitted by airborne droplets or direct contact
391
risk of a microbe
oppurtunistic pathogens cause disease in immunocompromised hosts
392
s pyogenes
spread by respiratory droplets and contact w fomites
skin infections
minor skin irritation
rectal carriers
food borne
393
pyogenes subgroup
form pus
strep throat
b hemolysis
hemolytic enzyme
inactivated by oxygen
394
viridans subgroup
strep mutans: denta; caries
incomplete hemolysis on blood agar
395
superantigen exotoxins of strep
recruit large numbers of T cells
secrete cytokines that activate large numbers of macrophages and neutrophils
toxic shock syndrome
hypotension - systemic shock
fatal in some individuals
weakened from cancer, drug treatments, hiv infection or old age
396
streptococcal pharyngitis (strep throat)
contagious spread via person to person contact
indrect contact with items contaminated
symptoms: high fever, sore throat, tonsils, absense of cough
treat w antibiotics
397
streptococci
non-sporulating
gram positive cocci
aerotolerant anerobes
398
streptococci can cause disease in immunocompromised hosts bc it is
oppurtunitstic
399
s pyogenes is spread by
respiratory droplets
contact with fomites
400
pyogenes subgroup undergo what type of hemolysis
beta
401
viridans subgroup of strep
mutans: dental carries
incomplete blood agar hemolysis
402
streptococci go through
lysogenic conversion
403
s. pharyngitis produce
eryhtrogenic toxin
-encoded by temperate bacteriophage (bacterial virus)
404
s. pharyngitis unique characteristic
strawberry tongue (red rash on tongue) -> scarlet fever
405
erysipelas (strep)
involves dermis
local tissue destruction causing sepsis
406
erythema nodosum
inflammation of hypodermis
red nodules on skin
407
post-streptococcal includes
acute rheumatic fever
acute glomerulonephritis
408
gonnorhea
gram negative
diplococcus
obligate aerobe
409
what does gonorhea have on its outer membrane
lipooligosaccharide
410
opthalmia neonaturum
conjuctivitis of newborn
-gonnorhea can cause this
411
what is needed in atmosphere for gonorhae to survive
carbon dioxide
412
HIV family
retroviridia
413
HIV genus
lentivirus
414
structure of HIV
enveloped with ssRNA
415
virion of HIV contains
2 identical + stranded rna
416
HIV results in decrease in
CD4 T cells
417
what test detects HIV sooner than other types
nucleic acid test (NAT)
-looks at actual virus in the blood
418
treatment for HIV
anti-retroviral drug
419
re-emerging disease from HIV
mycobacterium tuberclosis
420
