idk exam Flashcards
(368 cards)
1
Q
pathogen
A
an organism that causes disease
2
Q
pathogenicity
A
ability to cause disease
3
Q
virulence
A
degree of pathogenicity
- virulence factors like capsules, fimbriae, toxin
4
Q
pathology
A
the study of disease
5
Q
etiology
A
the study of the cause of a disease
6
Q
pathogenesis
A
the development of disease
7
Q
infection
A
growing and multiplying of pathogens in the host
8
Q
disease
A
an abnormal state in which the body is not functioning normally
9
Q
infection _____ always cause disease
A
doesn’t
10
Q
primary pathogens
A
have the ability to penetrate host defenses
11
Q
opportunistic pathogens
A
cause disease only in compromised hosts
12
Q
what can allow in an opportunistic pathogens? (3)
A
- immune system is defective
- break in tissue allows organisms to access to new site
- loss of other microflora allows organisms to bloom
13
Q
ID50
A
infectious dose for 50% of the test opoulation
14
Q
LD50
A
lethal dose (of a toxin) for 50% of the test population
15
Q
which of the following strains most easily causes an infection?
strain A - ID50 = 200
strain B - ID50 = 5000
strain C - ID50 = 50
strain D - ID50 = 500
A
strain c - 50
16
Q
reservoirs of infection: humans
what infections find their home in humans?
A
AIDS, gonorrhea, other STDs
17
Q
reservoirs of infection: animal
A
rabies, lyme disease
18
Q
reservoirs of infection: nonliving
what diseases?
A
botulism, tetanus, anthrax, in soil
19
Q
portals of entry (3)
A
- skin
- mucous membranes (respiratory, digestive, genitourinary tracts)
- parenteral: injection (tick, mosquito, needle punctures)
20
Q
transmission of disease: direct
A
requires close association between infected and susceptible host
- touching, kissing, sexual intercourse
21
Q
transmission of disease: indirect
A
fomites: tissues, towels, bedding, diapers, drinking cups, toys, moeny, etc
22
Q
transmission of disease: droplet
A
transmission via airborne droplets
23
Q
transmission of disease: vehicle
A
transmission by an inanimate reservoir like food and water
24
Q
transmission of disease: vectors
A
arthropods, especially fleas, ticks, and mosquitos
25
mechanical vectors
carry the pathogen on them
- arthropods carry on feet, flies transfer pathogens from feces of infected to food
26
biological vectors
pathogen reproduces in the vector
- like lyme disease
27
acute disease
symptoms develop rapidly
28
chronic disease
disease develops slowly
29
subacute disease
symptoms between acute and chronic
30
latent disease
disease with a period of no symptoms when pathogen is inactive
- herpes aka cold sores
31
what must all pathogens do to cause disease? (4)
- enter a host
- find their unique niche
- avoid, circumvent, or subvert normal host defenses (immune evasion)
- multiple and eventually be transmitted to a new susceptible host (transmisison)
32
immune evasion
the ability to avoid, circumvent, or subvert normal host defenses
33
pathogens can be distinguished from their avirulent counterparts by the presence of _____ _____ that help accomplish these goals
virulence factors
34
molecular Koch's postulates (3)
1. the phenotype under study should be associated with pathogenic strains of a species
2. specific inactivation of the suspected virulence gene should lead to a measurable loss in virulence or pathogenicity
3. reversion or replacement of the mutated gene should restore pathogenicity
35
virulence genes may be found on _____ _____ in the chromosome
pathogenicity islands
36
pathogenicity islands (3)
- section of the genome containing multiple virulence genes
- often flanked by phage or plasmid genes
- often have GC content different from the rest of the genome
37
how does the human body expel invaders? (4)
- mucosa, dead skin constantly expelled
- liquid expelled from bladder
- coughing, cilia in lungs
- expulsion of intestinal contents
38
bacterial adhesion strategies (2)
- pili (fimbriae): hollow fibrils with tips to bind to host cells
- adhesins: surface proteins that bind to host cells
39
how do viruses attach to host cells?
using their capsid or envelope proteins to attach to receptors
40
how do biofilms play an important role in chronic infections?
they enable persistent adherence and resistance to bacterial host defenses and antimicrobial agents
41
virulence factors: toxin
substances that contribute to pathogenicity
42
virulence factors: toxoid
inactivated toxin used in a vaccine
43
virulence factors: antitoxin
antibodies against a specific toxin
44
exotoxtins
proteins produced by various types of bacteria to kill hosts and unlock their nutrients
45
endotoxins
part of LPS of gram-negative bacteria that can hyperactivate the host immune systems to harmful levels
46
exotoxin functional categories (9)
1. plasma membrane disruption
2. cytoskeleton alterations
3. protein synthesis disruption
4. cell cycle disruption
5. signal transduction disruption
6. cell-cell adherence
7. vesicular traffic
8. inhibit exocytosis
9. superantigens
47
hemolysins
toxins that lyse red blood cells
48
leukocidins
toxins that lyse white blood cells or leukocytes
49
alpha toxin of staphylococcus aureus (2)
- classic example of a pore-forming exotoxin
- forms a transmembrane, seven member pore in target cell membranes
50
pore forming toxins (2)
- alpha toxin of Staphylococcus aureus
- listeriolysin O of Listeria monocytogenes
51
phospholipase toxins
| what is the toxin called and what bacteria releases it?
phospholipase C of Clostridium perfringens
52
two subunit AB exotoxins
the generally shared structure of exotoxins; A and B subunits, where B is designed to get A (the one that has toxic activity) into the cell
53
one major subclass of AB exotoxins have ADP-ribosyltransferase activity, meaning....
the toxin enzymatically transfers the ADP-ribose group from NAD
54
cholera toxin
| what does it do?
colonizes the brush border of the small intestine, and causes the cells to secrete water and NaCl into the intestinal lumen (the opposite of what is normally does) causing diarrhea
55
diphtheria toxin (2)
| what is this a classic example of?
classic example of a toxin that targets protein synthesis
- kills cells by ADP-ribosylating eukaryotic protein synthesis elongation factor 2 (eEF-2) blocking ribosome function
56
Bacillus anthracis plamid-encoded tripartite toxin: name the parts (3)
- protective agent (PA)
- edema factor (EF)
- lethal factor (LF)
57
Bacillus anthracis: protective agent
binds membrane receptor and forms a pore
58
Bacillus anthracis: edema factor
raises cAMP levels, causing fluid secretion and tissue swelling
59
Bacillus anthracis: lethal factor
cleaves protein kinases, blocks immune system from attacking
60
type III secretion
uses a molecular syringe to inject proteins from the bacterial cytoplasm directly into the host cell
61
where is type II secretion found? (3)
Salmonella, Yersinia, Shigella
62
who are endotoxins made by?
only gram-negative bacteria
63
_____ _____ is released as bacteria die
Lipid A
64
what does Lipid A do? (3)
- is a MAMP, which binds to certain TLRs on macrophages or B cells
- causes massive cytokine release from host cells
- can trigger fever, shock, and death
65
survival inside a host: some pathogens use hemolysins to break out of phagosomes (2)
| S...L...
Shigella dysenteriae
Listeria monocytogenes
66
survival inside a host: some pathogens secrete proteins to prevent fusion of lysosomes (4)
| S.C.M.L.
Salmonella
Chlamydia
Mycobacterium
Legionella
67
survival inside a host: some pathogens mature in acidic environments
Coxiella burnetii - Q fever
68
survival outside the host: some pathogens secrete thick capsules to avoid antibodies (2)
Streptococcus pneumoniae
Neisseria meningitidis
69
survival outside the host: some pathogens make proteins to bind antibodies (1)
Staphylococcus aureus - Protein A
70
what does Staphylococcus aureus's Protein A do? (4)
- binds Fc fragments
- antibodies attach "upside down"
- prevents opsonization
- used to purify Abs
71
how do bacteria recognize the host environment? (3)
- two component signal transduction
- detect magnesium concentration (pH)
- quorum sensing
72
what does quorum sensing do? (2)
- detect exotoxins made by other cells
- delays toxin synthesis until many bacteria are present
73
Endotoxins include which of the following?
a. diphtheria toxin
b. lipopolysaccharide
c. tetanus toxin
d. botulinum toxin
b. lipopolysaccharide
LPS contains Lipid A which is an endotoxin only secreted by gram-negative bacteria when they die
74
Bacterial exotoxins can...
a. cause host cell membrane leakage
b. interfere with host second messenger pathways
c. block host protein synthesis
d. do all of these
e. do none of these
d. do all of these
75
The final outcome of most host-parasite relationships depends on...
a. the number of organisms present in or on the host
b. the virulence of the organism
c. the host's defenses
d. all of the choices
d. all of the choices
76
epidemiology
the study of where and when diseases occur
77
endemic
low frequency, and normally present
- influenza (the flu)
78
epidemic
"outbreak"
- high frequency over a short period of time
79
common-source epidemic
- disease spread from one source
- little transmission from infected
think food poisoning
80
propagated epidemic (2)
- disease continuously transmitted infected
- higher numbers, longer-lasting epidemic
81
pandemic
spreads all over the world
82
what can identifying "patient zero" do?
- can allow for identification of those in contact with ZERO
- can identify the reservoir and potentially stop the outbreak
83
John Snow
Father of Epidemiology
- first to methodically investigate the source of a disease
- cholera outbreak in 1850's London
84
certain disease are called _____ _____, because of their severity and transmissibility
reportable diseases
85
who are physicians required to notify?
central health organizations like the CDC and WHO
86
nosocomial infections
hospital-acquired infection; any infection that is acquired during the course of stay in a hospital, nursing home, or other health care facility
87
what percent of hospitalized patients acquire nosocomial infections?
5-15%
88
what are nosocomial infections often caused by?
bacterial that are members of normal microbiota
- many hospital strains are also antibiotic resistant
89
emerging infectious diseases (EID)
refer to new infectious diseases that crop up in the world
| like Sars-CoV-2
90
reasons for the increase of EID (5)
- world population growth
- increased international travel
- habitat disruption
- microbial evolution and development of resistance
- inadequate public infrastructures
91
examples of climate change affecting epidemiology (3)
- rising air temps can extend the habitat of mosquito and tick vectors
- melting of glacier may expose pathogens
- increased rain and flooding promote the breeding of mosquito vectors
92
three types of epidemic control measures
1. reduce or eliminate the source or reservoir
2. break connection between source and susceptible individuals
3. reduce number of susceptible individuals
93
reduce or eliminate source or reservoir (4)
- quarantine and isolation of cases and carriers
- destruction of animal reservoir
- treatment of sewage
- therapy that reduces or eliminates infectivity of cases
94
break the connection between the source and susceptible individuals (5)
- chlorination of water supplies
- pasteurization of milk
- supervision and inspection of food and food handlers
- destruction of insect vectors with pesticides
- masking and social distancing ?
95
reduce the number of susceptible individuals (3)
- raises herd immunity
- passive immunity following exposure
- active immunity for protection
96
categories of bioterrorism agents: category A - "the killer" (3)
- are relatively easy to disseminated or transmitted person to person
- cause high mortality with potential for major public health threat
- cause public panic and social disruption
97
categories of bioterrorism agents: category B - "the disablers" (3)
- moderately easy to disseminate, moderate morbidity, low mortality, require enhanced diagnostic capability and disease surveillance
- C. burnetti, Brucella spp, Ricin toxin
- subset includes food and waterborne agents
98
categories of bioterrorism agents: category C - "the disablers" (2)
- emerging pathogens with potential for mass dissemination because of availability, easy of production, potential for high morbidity/mortality
- hantavirus, yellow fever, MDR TB
99
biological safety level 1
normal sterile techniques
100
biological safety level 2
limited lab access, biosafety cabinets, agents with little risk of aerosol transmission
101
biological safety level 3
labs with negative air pressure, agents can cause disease via inhalation
102
biological safety level 4
complete isolation, high risk of aerosol transmission
103
John Snow is considered the Father of Epidemiology for his work on....
a. malaria
b. gonorrhea
c. cholera
d. influenza
e. chlamydia
c. cholera
he found the tap handle where the outbreak originated and the subsequent removal resolved the epidemic
104
Which of the following viruses has been linked to microcephaly in newborns?
a. Ebola
b. Marburg
c. Yellow fever
d. Zika
e. Dengue
d. Zika
105
normal skin flora includes (4)
- staphylococcus (low GC gram+)
- streptococcus (low GC gram+)
- diphtheroids (high GC gram+)
- some yeasts
106
staphylococcus
gram positive (low GC) cocci in clusters
107
staphylococcus secretes coagulase...
which is an enzyme that clots fibrin in the blood
108
are skin flora coagulase positive or negative?
negative
109
staphylococcus aureus can cause (4)
- folliculitis, furuncles (boils), carbuncles
- toxemias
- scalded-skin syndrome
- toxic shock syndrome
110
folliculitis
infections of the hair follicles
111
sty(e)
folliculitis of an eyelash
112
furuncle
abscess; pus surrounded by inflamed tissue
113
carbuncle
inflammation of tissue under the skin
114
streptococcus
gram positive (low GC) cocci in chains
115
streptococcus secrete _____
hemolysins
116
streptococcus virulence factors (3)
M protein, extracellular enzymes, toxins
117
streptococcus M protein (3)
key virulence factor, anti-phagocytic, anti-compliment
118
streptococcus can cause (2)
impetigo
erysipelas
119
group A streptococcal infections
rare,not very contagious
- flesh eating bacteria
120
pseudomonas
gram negative rods
121
what is unusual about Pseudomonas?
their metabolism; they grow on traces of organic substances in soap
122
where are Pseudomonas found?
soils and water
123
what do Pseudomonas cause? (4)
- dermatitis
- wound and skin infections
- otitis externa (swimmer's ear)
- burn patient infections
124
infections of Pseudomonas are characterized by what?
blue-green pus
125
viral skin infections: warts
| what is it caused by?
papilloma virus
126
viral skin infections: fever blisters
| what is it caused by?
herpes simplex
127
viral skin infections: chicken pox - shingles
| what is it caused by?
herpes virus
128
viral skin infections: smallpox
| what is it caused by?
variola virus
129
Herpes simplex virus 1 (2)
| what is it, where does it hide?
cold sores
- can remain latent in trigeminal nerve ganglia
130
Herpes simplex virus 2 (2)
genital herpes
- can remain latent in sacral nerve ganglia
131
what may lessen symptoms of the Herpes Simplex Viruses?
| what medication?
Acyclovir
132
Varicella-zooster virus
chickenpox
- transmitted by respiratory route, very contagious
- virus remains dormant in dorsal root ganglia
133
shingles
a reactivation of latent VZV, moves along peripheral skin nerves
134
Paramyxoviruses (2)
| what is this virus called?
Measles
- transmitted via respiratory route, very contagious
135
Togavirus
Rubella
- macular rash and fever
136
Neisseria gonorrhoeae (2)
gram negative cocci
- eye infection in babies, ophthalmic ointment given at birth for prevention
137
Chlamydia trachomatis: inclusion conjunctivitis (3)
- at birth
- swimming pool conjunctivitis
- treated with erythromycin ointment
138
Chlamydia trachomatis: trachoma (3)
- leading cause of blindness worldwide
- sever conjunctivitis, nodules, scarring of the cornea
- scars abrade the cornea leading to blindness
139
where can bacteria grow in the CNS?
cerebrospinal fluid in the subarachnoid space of the CNS
140
what prevents antimicrobial drugs from entering the CNS?
the blood brain barrier
140
menigitis
inflammation of the meninges
140
encephalitis
inflammation of the brain
141
bacterial meningitis symptoms (3)
- fever, headache, stiff neck
- nausea and vomiting
- later, convulsions and coma
142
how is bacterial meningitis diagnosed? (2)
gram stain or latex agglutination
143
how is bacterial meningitis treated?
| what drug?
cephalosporins
144
Haemophilus influenzae - meningitis (4)
- occurs mostly in children
- gram negative aerobic bacteria, normal throat microbiota
- capsule antigen type B
- prevented by Hib vaccine
145
Neisseria meningitidis (3)
- gram negative aerobic cocci
- begins as a throat infection/rash
- serotype B is most common in US
146
Streptococcus pneumoniae meningitis (3)
- gram positive cocci
- most common in children
- mortality is 30% in children and 80% in elderly
147
where does tetanus grow?
puncture wounds where it interrupts blood flow and tissue becomes anaerobic
147
Clostridium tetani
anaerobe, gram positive rod, (Low GC), endospore-forming
148
what does tetanus toxin do?
block release of neurotransmitters, causing muscles to contract uncontrollably, leading to lethal spasms
149
what is the treatment for tetanus?
antibiotics and an antitoxin
150
Clostridium botulinum
anaerobe, gram positive rod, low GC
151
where does Clostridium botulinum grow?
| prior to infection
canned food
152
endospores of Clostridium botulinum survive unless...
autoclaved
153
what does the Clostridium botulinum toxin do?
blocks the release of acetylcholine preventing muscle movement
154
symptoms of Poliomyelitis (3)
- initial sore throat and nausea
- infection and disease
- viral syndrome to progressive paralysis
155
Rhabdovirus
causes rabies
156
where does rabies multiple?
in skeletal muscle before moving to nerves, up the spinal cord, to the brain
157
Which of the following microbes can cause toxic shock syndrome?
a. E. coli
b. M. tuberculosis
c. S. aureus
d. N. meningitidis
c. S. aureus
158
Skin warts are caused by...
a. papillomavirus
b. poxvirus
c. herpesvirus
d. parvovirus
e. S. aureus
c. herpesvirus
159
The tetanus vaccine is a...
a. conjugate vaccine
b. toxoid
c. attenuated whole-agent vaccine
d. inactivated whole-agent vaccine
b. toxoid
160
a vaccine can be used for post-exposure treatment for...
a. polio
b. smallpox
c. rabies
d. Creutzfeldt-Jakob disease
c. rabies
161
diseases of the upper respiratory tract: laryngitis (2)
| what bacteria cause this?
S. pneumoniae, S. pyogenes
162
diseases of the upper respiratory tract: tonsillitis (2)
| what causes these?
S. pneumoniae, S. pyogenes, and some viruses
163
diseases of the upper respiratory tract: sinusitis
bacteria
164
diseases of the upper respiratory tract: epiglottitis
H. influenzae
165
Streptococcal Pharyngitis - strep throat is caused by...
streptococcus pyogenes
166
strep throat (4)
- resistant to phagocytosis
- streptokinases lyse clots
- streptolysins are cytotoxic
- diagnosis by indirect agglutination
167
Corynebacterium diphtheria
gram positive rod that causes diphtheria
168
diphtheria (2)
- diphtheria membrane of fibrin, dead tissue, and bacteria
- diphtheria toxin produced by lysogenized C. diphtheriae
169
cutaneous diphtheria
infected skin wound leads to slow healing ulcer
170
otitis media
middle ear infections via auditory canal
171
diseases of the lower respiratory tract: bacteria, viruses, and fungi cause... (3)
bronchitis, bronchiolitis, and pneumonia
172
Bordetella pertussis
| Describe the bacteria, and what does it cause?
gram negative coccobacillus, causes whooping cough
173
Pertussis - Whooping cough (2)
- capsule
- tracheal cytotoxin, a cell wall peptidoglycan fragment damages ciliated cells so mucus accumulates
174
Mycobacterium tuberculosis
acid-fast rod, transmitted from human to human
175
M. bovis
less than 1% of US cases of tuberculosis, not transmitted from human to human
176
M. avium-intracellulare
complex, infects people with late stage HIV infections
177
treatment of tuberculosis
prolonged treatment with multiple antibiotics
178
how to diagnose tuberculosis
tuberculin skin test screening
- positive reaction means current or previous infection
179
typical pneumonias pathology (3)
1. classic inflammatory response
2. fluid accumulation in alveoli
3. penetration-pleurisy and bacteremia
180
symptoms of typical pneumonias (5)
1. preceded by or secondary to influenza
2. acute disease with rapid onset
3. severe chest pain
4. productive cough
5. high fever, muscle pain, headache, nausea
181
what bacteria causes the primary typical pneumonia?
Streptococcus pneumoniae
182
streptococcus pneumoniae
gram-positive, encapsulated, diplococci
183
how do they diagnose pneumonia?
bacterial cultures
184
what is the drug of choice for pneumonia?
penicillin
185
Haemophilus influenzae
gram-negative coccobacillus, also causes pneumonia
186
atypical pneumonia symptoms (4)
1. insidious onset
2. nonproductive cough
3. fever develops with headaches, chills, chest pain, general muscle pain
4. recovery is usually within 14 days
187
atypical pneumonia pathology (3)
1. usually involves intracellular growth
2. often infected monocytes and macrophages
3. cell-mediated immunity-less inflammation
188
Mycoplasma pneumoniae
wall-less bacteria
189
what is the primary bacteria for atypical pneumonia?
Mycoplasma pneumoniae
190
how do they diagnose atypical pneumonia?
PCR or by IgM antibodies
191
what is mycoplasma atypical pneumonia treated with?
tetracycline
192
Legionella pneumophila
gram-negative rod
193
where is, and how is L. pneumophila transmitted?
water
194
what is L. pneumophila atypical pneumonia treated with?
| E
erythromycin
195
Chlamydia psittaci
gram-negative, obligate intracellular bacterium
196
what does C. psittaci cause? (3)
Parrot fever,, ornithosis, psittacosis
197
what is C. psittaci carried by?
birds
198
how do they diagnose C. psittaci atypical pneumonia?
culturing bacteria in eggs or cell cultures
199
how do they treat C. psittaci atypical pneumonia?
tetracycline
200
atypical pneumonia - chlamydia pneumoniae (3)
| transmitted by? diagnosed by? treated with?
- transmitted from human to human
- diagnoses by fluorescent Ab test
- treated with tetracycline
201
types of viruses for the common cold (3)
- rhinoviruses
- coronaviruses
- adenoviruses
202
where do common cold viruses infect?
nose and throat, upper respiratory tracts
203
RSV (3)
- an RNA virus
- causes cell fusion in cultures
- infant lower respiratory infections
204
type A influenza
causes most epidemics
H3N2
H1N1
H2N2
205
type B influenza
| cause what kind of outbreak?
moderate, local outbreaks
206
type C influenza
mild disease
207
influenza virus (3)
- eight separate, single strand, minus RNAs
- H spike: hemagglutinin
- N spike: neuraminidase
208
hemagglutinin (H) spikes
| What is it used for?
used for attachment to host cells
209
neuraminidase (N) spikes
used to release virus from the cell
210
antigenic drift (3)
- mutations in genes encoding H or N spikes
- may involve only 1 amino acid
- allows virus to avoid mucosal IgA antibodies
211
antigenic shift (2)
- changes in H and N spikes
- probably due to genetic recombination between different strains infecting the same cell
212
Amantadine
| what does this medication do?
interferes with viral protein M2 which is needed for the viral particle to become "uncoated"
213
Tamiflu
a neuraminidase inhibitor
214
Which organisms produces a tough, grayish membrane in the throat?
a. Streptococcus pneumoniae
b. Corynebacterium diphtheriae
c. Mycobacterium tuberculosis
d. Haemophilus influenzae
b. Corynebacterium diphtheriae
215
Mycoplasmal pneumonia can be distinguished from viral in that ..
a. viral pneumonia is treated with tetracycline
b. symptoms are distinctly different
c. doesn't have any known etiologic agent
d. is treatable with antibiotics
e. none of these
b. symptoms are distinctly different
216
The mycolic acids of the cell wall are an important factor in the pathogenicity of the organisms that cause...
a. influenza
b. diphtheria
c. pertussis
d. tuberculosis
d. tuberculosis
217
In the influenza virus, minor annual variations in the antigenic makeup are called
a. antigenic drift
b. antigenic shift
c. mutation
d. recombination
a. antigenic drift
218
microbial disease of the digestive system are second only to _____ diseases as causes of illness in the US
respiratory
219
the fecal-oral cycle of transmission can be broken by proper.... (3)
- disposal of sewage
- disinfection of drinking water
- proper food preparation and storage
220
the stomach and small intestine have ____ resident microorganisms
few
221
colonizers of the large intestine include (6)
| B.E.E.K.L.P.
- Bacteroides (!)
- E. coli
- Enterobacter
- Klebsiella
- Lactobacillus
- Proteus
222
what do bacteria in the large intestine assist with?
degrading food and synthesizing vitamins
223
dental caries (cavities) are caused by these bacteria (2)
- Streptococcus spp. (mutans)
- Actinomyces spp.
plaque-forming and acid producing
224
periodontal diseases (2)
- gingivitis
- periodontitis
225
what type of bacteria can cause food poisoning? (3)
- Staphylococcal type
- Clostridial type
- others
226
what is the most common cause of food poisoning in the US?
enterotoxigenic S. aureus
227
symptoms of S. aureus food poisoning (4)
1. short incubation (2-6 hrs)
2. severe cramping, pain nausea, vomiting, diarrhea
3. no fever
4. recovery within 24 hrs
228
how is S. aureus food poisoning transmitted? (2)
- by hands of food preparers
- uncooked food
- custards, cream-filled bakery product, meats, chicken salads, dairy products
229
S. aureus food poisoning is characterized by? (3)
- rapid course
- upper GI symptoms
- usually no fever
230
Clostridial food poisoning is characterized by? (3)
- slower course
- lower GI symptoms
- no systemic symptoms usually
231
what is Clostridial type food poisoning caused by?
contaminated meats and poultry stored without refrigeration
232
symptoms of Clostridial food poisoning (4)
- lower abdominal pain
- diarrhea
- nausea common
- vomiting, fever, and headache are rare
233
transmission of Clostridial type food poisoning
- meats or meat stews contaminated with contents of the animal during slaughter
- endospores are heat resistance, so bacteria grow rapidly during cooling of meat and poultry dishes
234
mechanism of S. aureus food poisoning
toxin stimulates brain's vomiting reflex center
235
mechanism of Clostridial type food poisoning
enterotoxin binds to microvilli in lower bowel, causes disruption of membrane and fluid loss
236
traveler's diarrhea (2)
- enterotoxigenic E.coli (ETEC)
- not invasive, enterotoxin causes a watery diarrhea that resembles a mild form of cholera
237
hamburger disease (3)
- enterohemorrhagic E. coli (EHEC)
- shiga toxin adhere to intestinal mucosa and cause destruction of microvilli
- causes hemorrhagic colitis and hemolytic uremic syndrome
238
shigellosis is spread by...
human to human contact, no animal reservoir
239
what exotoxins does Shigellosis have?
shiga toxin
- inhibits protein synthesis
240
infections of S. dysenteriae result in....
- ulceration of intestinal mucosa
- epithelial of large intestine damaged
- blood, mucus in stool, abdominal cramps, fever
241
how is Shigellosis diagnosed?
isolating and identifying the bacteria from rectal swabs
242
where do you get Salmonellosis from?
poultry and eggs
243
bacteria that causes Salmonellosis
S. enteritidis
244
bacteria that causes Typhoid fever
S. typhi
245
how is Typhoid fever spread?
in feces of humans
- more common before sewage treatment
246
Campylobacter (3)
gram-negative, spiral microaerophilic
247
what is the leading cause of foodborne illness and second most common cause of diarrhea in the US?
Campylobacter jejuni
248
Cholera
| describe it
gram-negative, slightly curved rod
249
what is one of the most serious gastrointestinal diseases?
Vibrio cholerae
250
what does cholera toxin do?
alters membrane permeability of the intestinal mucosa causing a loss of fluids
251
Rotavirus diarrhea (3)
- infects infants and children
- acute diarrhea, sometimes servere
- supportive treatment, but no vaccine
252
Norovirus - Norwalk agent (2)
- nonculturable
- infects all ages, not seasonal
253
how do you treat Rotavirus and Norovirus?
rehydration
254
Hep. A classificaiton
enterovirus in the Picornaviridae
255
Hep. A structure
picornavirus, naked, no envelope
256
Hep. B classification
Hepadnaviridae
257
Hep. B structure (3)
- enveloped, icosahedral
- circular, partially dsDNA genome
- four ORFs
258
how does Hep. B replicate?
reverse transcription
259
three major Hep. B antigens
1. HBsAg-surface antigen: protective Ab produced
2. HBcAg-core antigen: denotes acute or chronic infection
3. HBeAg-core related antigen
260
Hep. C classification
Hepacivirus
261
Hep. C structure
- envelope with E1 and E2 glycoproteins
- contains a plus strand of RNA`
262
Hep. D classification
unique satellite virus of HBV
263
Hep. D structure
- enveloped
- contains HBsAg (HBV surface antigen)
- RNA is single strand circular
264
The disease caused by Streptococcus mutans is
a. trachoma
b. dental decay or caries (cavities)
c. plague
d. atypical pneumonia
b. dental decay or caries (cavities)
265
Which of the following viruses has a DNA genome but its replication involves reverse transcription?
a. Hep. A
b. Hep. B
c. Hep. C
d. Hep. D
e. Hep. E
b. Hep. B
266
Which of these bacteria are usually responsible for digestive system disease due to intoxication rather than infection?
a. Salmonella enterica
b. Shigella species
c. Salmonella typhi
d. Staphylococcus aureus
e. E. coli
d. Staphylococcus aureus
267
All of the following are gram-negative rods that cause gastroenteritis except:
a. Shigella spp.
b. Yersinia enterocolitica
c. Clostridium perfringens
d. Salmonella typhi
e. E. coli
c. Clostridium perfringens
268
septicemia
bacteria in blood
269
sepsis
toxic reaction to septicemia; bacteria growing in blood
270
endotoxic shock is caused by what kind of bacteria?
gram negative
271
toxic shock is caused by what king of bacteria?
gram positive
(S. aureus)
272
what is shock caused by what in the body?
due to rapid release of cytokines aka cytokine storm
273
severe sepsis
decrease in blood pressure
274
septic shock
low blood pressure cannot be controlled
275
puerperal sepsis or childbirth fever (3)
1. a type of nosocomial infection
2. usually due to Strep. - S. pyogenes
3. progressive infections: uteritis -> peritonitis -> septicemia -> meningitis
276
Ignaz Semmelweis
saw Doctors' wards has three times the mortality of midwives' wards; the incidence of puerperal fever could be drastically reduced by hand washing
277
endocarditis
inflammation of the endocardium
278
infections of the heart
- congenital heart defects
- Rheumatic fever (S. pyogenes)
279
Rheumatic fever
- autoimmune disease
- inflammation of the heart
- caused by S. pyogenes
280
Plague is caused by...
Yersinia pestis
281
how is the plague transmitted?
from flea bite from rodents
282
types of plagues (3)
1. bubonic
2. septicemia
3. pneumonic
283
bubonic plague
bacterial growth in the blood and lymph
284
septicemia plague
septic shock
285
pneumonic plague
bacteria in the lungs
286
how to treat plagues?
tetracyclines
287
what is lyme disease caused by?
Borrelia burgdorferi
288
what is the most common tick-borne disease
lyme disease
289
reservoirs of lyme disease
deer
290
first symptom of lyme diease
bull's eye rash
291
second phase of lyme disease
irregular heartbeat, encephalitis
292
third phase of lyme disease
arthritis
293
Bacillus anthracis
low GC gram-positive, endospore forming, aerobic rod
294
what is anthrax treated with?
ciprofloxacin or doxycycline
295
cutaneous anthrax
endospores enter through a minor cut
- 20% mortality
296
gastrointestinal anthrax
ingestion of undercooked food, or contaminated food
- 50% mortality
297
inhalational anthrax
inhalation of endospores
- 100% mortality
298
bacterial zoonotic diseases
- Tularemia
- Brucellosis
299
Burkitt's lymphoma
caused by EBV
- high prevalence in eastern Africa
- major cause of childhood death
300
Cytomegalovirus (2)
- latent in white blood cells
- may be asymptomatic or mild
301
how is Cytomegalovirus transmitted? (4)
- across the placenta
- sexually
- by blood
- by transplanted tissue
302
yellow fever (3)
- a flavivirus
- hepatitis, jaundice, hemorrhage, black vomitus
- from mosquitoes
303
Dengue fever (4)
- a flavivirus
- few transmitted cases
- mosquito vectors
- break bone fever: myalgias, headache, high fever
304
ebola (3)
- filovirus
- pneumonitis, followed by high fever, chills, hemorrhage
- man to man transmission is poor
305
the urinary bladder and upper urinary tract are _____
sterile
306
_____ are predominant in the vagina
Lactobacilli
307
diseases of the urinary tract (4)
1. urethritis (Urethra)
2. cystitis (female bladder)
3. uteritis (uterine tubes)
4. pyelonephritis (kidney)
308
gonorrhea (3)
Neisseria gonorrhoeae (gram- cocci)
- attachment fimbriae
- binds mucosal cells of epithelium
309
male symptoms of gonorrhea
painful urethritis
310
female symptoms of gonorrhea
may be asymptomatic
- urethritis
- vaginitis
- other complications
311
how do you diagnose gonorrhea?
ELISA
312
Chlamydia trachomatis
- same symptoms but milder than gonorrhea
- coinfects with gonococcus
313
syphilis is caused by what bacteria?
Treponema pallidum - spirochete
314
bacterial vaginosis is caused by what bacteria?
Gardnerella vaginalis
315
treatment of bacterial vaginosis
metronidazole
316
Which of these bacteria would be capable of causing endotoxic septic shock?
a. Bacillus anthracis
b. Staphylococcus aureus
c. Streptococcus mutans
d. Streptococcus pyogenes
e. Escherichia coli
b. Staphylococcus aureus
317
Which of the following diseases is NOT caused by herpesviruses?
a. kissing disease
b. chickenpox
c. Kaposi's sarcoma
d. Burkitt's lymphoma
e. all of these are caused by herpesviruses
e. all of these are caused by herpesviruses
318
Effective vaccines are now available for preventing...
a. bacterial vaginosis
b. chlamydia
c. genital herpes
d. genital HPV
e. gonorrhea
d. genital HPV
319
Paul Ehrlich (2)
- developed concept of selective toxicity
- identified dyes that effectively treated African sleeping sickness
320
Sahachiro Hato
- working with Ehrlich, identified arsenic compounds (Salvarsan) that effectively treated syphilis
321
Gerhard Domagk, Jacques, and Therese Trefouel
discovered sulfonamides and sulfa drugs
322
who accidentally discovered penicillin?
Alexander Fleming
323
Selman Waksman
| what did he discover?
discovered strptomycin
324
streptomycin
antibiotic produced by Streptomyces griseus, and actinomycete bacterium found in soil
325
Emily Whitehead
girl with cancer that was cured by using HIV to re-write her immune system
326
microbial physiology that is not in humans (3)
- peptidoglycan
- differences in ribosome structure
- biochem pathways used by bacteria but not humans
327
Chloramphenicol
interferes with eukaryotic ribosomes
328
broad-spectrum antibiotics
effective against many species
329
narrow-spectrum antibiotics
effective against few or a single species
330
bactericidal antibiotics
kill the target organism
331
bacteriostatic antibiotics
prevent growth of the organism
332
minimal inhibitory concentration (3)
lowest concentration that prevents growth
- varies by species
- tested by diluting antibiotics
333
E-test determines
minimal inhibitory concentration
- gradient of antibiotic in paper strip
- drug must be above MIC in tissue in order to be effective
334
Kirby-Bauer disk susceptibility test
test strain sensitivity to multiple antibiotics
- multiple disks with different antibiotics
- size of cleared zone reflects relative sensitivity
335
antibiotics that target: cell wall synthesis (4)
- penicillins
- cephalosporins
- bacitracin
- vancomycin
336
antibiotics that target: protein synthesis (5)
| C.T.A.M.L
- chloramphenicol
- tetracyclines
- aminoglycosides
- macrolides
- lincosamides
337
antibiotics that target: cell membrane integrity (4)
| P.D.A.I
- polymyxin
- daptomycin
- amphotericin
- imidazoles
338
antibiotics that target: nucleic acid function (5)
| N.N.Q.R.
- nitroimidazoles
- nitrofurans
- quinolones
- rifampin
- some antivirals
339
antibiotics that target: intermediary metabolism (2)
| S.T.
- sulfonamides
- trimethoprim
340
peptidoglycan antibiotics
competitive inhibitor or crosslink transpeptidation
341
examples of peptidoglycan antibiotics (4)
| P.A.A.C
- penicillin
- amoxicillin
- ampicillin
- carbenicillin
342
vancomycin
| binds?
binds ends of peptides to prevent crosslink formation
343
cycloserine
| blocks what?
blocks formation of peptide crosslink
344
bacitracin
| blocks what?
blocks movement across membrane
345
characteristics of penicillin and its derivatives (3)
- penicilinase-resistance
- extended spectrum
- improved pharmacokinetics
346
quinolones
| blocks and prevents what?
blocks bacterial DNA gyrase and prevents DNA replication
347
sulfa drugs are an...
analogue of PABA, a vitamin precursor
348
rifampicin
| blocks what?
blocks bacterial RNA polymerase (TB teatment)
349
macrolides and chloramphenicols
| block what?
blocks large subunits and blocks the transfer of peptides
- erythromycin, azithromycin
350
aminoglycosides
| prevent?
prevents 30s and 50s subunits from binding to one another
- streptomycin
351
tetracyclines
| bind onto what?
bind small subunit, blocking binding of aminoacyl-tRNA
352
antibiotic inhibitors of membranes (4)
| G.P.P.D
- gramicidin
- polymyxin
- platensimycin
- daptomycin
353
Isoniazid
| is a?
mycobacterium inhibitor
354
gramicidin
| forms what?
forms a cation channel, H+ leaks, and the call cannot maintain PMF
355
Antibiotics are considered _____ _____
because they often have no apparent primary use in
the producing organism
secondary metabolites
356
selective pressure for
the establishment of drug-resistant strains (2)
| what bacteria?
- Streptococcus pneumoniae
- Acinetobacter baumanii
357
three basic strategies for antibiotic resistance
1. keep antibiotics out of the cell
2. prevent antibiotics from binding the target
3. dislodge an antibiotics already bound to its target
358
keep antibiotics out of the cell (3)
- destroy antibiotic before it enters the cell
- decrease membrane permeability across the outer membrane
- pump antibiotic out of the cell via specific transporters
359
prevent antibiotics from binding the target (2)
- modify the cellular target so it no longer binds the antibiotic
- add modifying groups that inactivate the antibiotic
360
dislodge an antibiotic already bound to its target
ribosome protection (or rescue)
361
ribosome protection/rescue
gram-positive organisms can produce proteins that bind to ribosomes and dislodge macrolide antibiotics bound near the peptidyltransferase site
- newest resistance mechanism discovered
362
_____ _____ antibiotic resistance develops through gene duplication and/or mutations
de novo (new)
363
antibiotic resistance also can be acquired via _____ _____ _____
horizontal gene transfer
- conjugation, transduction, transformation
364
integrons
highly-mobile gene expression elements
- attributed to multidrug resistance
365
ESKAPE pathogens
six highly resistant bacterial species that collectively cause about two-thirds of all US nosocomial infections
- Enterococcus faecium
- Staphylococcus aureus
- Klebsiella pneumoniae
- Acinetobacter baumannii
- Pseudomonas aeruginosa
- Enterobacter sp.
