Final Flashcards
(106 cards)
1
Q
Refers to the number of new cases in a location over a specified time, and reflects the risk a person has of acquiring that disease
A
Incidence
2
Q
describes the total number of active cases of a disease in a given location at a given time, regardless of when a case first developed (old plus new)
A
Prevalence
3
Q
larger than normal number of individuals in a population become infected over a short period of time
A
Epidemic
4
Q
disease always present at a low frequency in a population
A
endemic
5
Q
any bird, mammal, insect or other animal that harbors an infectious agent and is indigenous to a geographic area
A
reservoir
6
Q
epidemic that occurs over a wide geographic area, typically the world
A
pandemic
7
Q
first case of the disease
A
index case (patient zero)
8
Q
examines the distribution and determinants of disease in a human population
A
epidemiology
9
Q
infectious disease that recently appeared in a population
A
emerging disease
10
Q
vehicle transmission
A
food, water, or air
11
Q
vector transmission
A
any living organism that can carry a disease (typically insects that bite like mosquitos)
12
Q
direct contact transmission
A
direct contact with infected; typically through hands
13
Q
indirect contact transmission
A
touching something inanimate that the infected touched; like clothes, tissues, doorknobs
14
Q
droplet transmission
A
respiratory droplets within 3 feet of release
15
Q
the number of disease cases per 100,000 individuals
A
Morbidity rate
16
Q
the number of deaths from a disease for every 10,000 individuals
A
Mortality rate
17
Q
a disease found occasionally in a region with cases occurring mainly in isolation from each other
A
Sporadic
18
Q
complete fully developed infectious viral particle
A
virion
19
Q
Virion Taxonomy
A
order - virales
family - viridae
genus - virus
20
Q
Means of Classifying viruses
A
gnome composition
replication and mRNA expression strategies
morphology of capsid (protein coat)
host range
21
Q
viral envelope
A
membrane derive from the host
22
Q
which structure of a virus provides rigid protection from degradation and enables it to persist when it is transmitted outside the host?
A
protein capsid
23
Q
which of the following steps is NOT part of the life cycle (replication) of a lytic phage?
A
The phage DNA integrates into the bacterial chromosome becoming a prophage
24
Q
All of the following criteria are used to classify viruses according to the International Committee on Taxonomy of Viruses EXCEPT:
a. mechanisms of replication and mRNA expression
b. genome composition
c. mutation rate
d. capsid morphology
A
c. mutation rate
25
The gnome of ____ ssRNA viruses an serve directly as mRNA and be translated by the host cell's ribosomes to form viral proteins.
positive-sense (+)
26
T/F: Within a multicellular host, receptor molecules can determine viral tropism (tendency to infect a particular tissue type)
true
27
Some viral species obtain their _____ directly from membranes in the host cells they invade.
envelope
28
During a lysogenic viral cycle, the integrated phage genome is referred to as a _____.
prophage
29
T/F: Viroids are infections agents that contain only RNA.
True
30
T/F: The most current theory for how prions functions is that prions are a unique form of lytic viruses that make spongy holes in the brain causing a fatal form of encephalopathy
False
31
After an initial outbreak of cold sores, the herpes simplex virus (HSV-1) which caused the cold sores enters a ______________ which may allow it to cause future cold core outbreaks.
a latent state in nerve ganglia
32
Serological test
detect antibodies or virion antigens
33
Molecular tools for virus identification
PCR
DNA profile using electrophoresis (RFLPs)
34
Cultivation of Viruses
grown in living cells:
phages cultivated within bacterial cells
animal viruses grown in embryonic eggs
35
lytic cycle
phage causes lysis and death of host cell
attachment by tail fibers, penetration through cell wall, Biosynthesis: production of phage DNA and proteins, assembly of newly synthesized phage particles, phage lysozyme destroys cell well
36
lysogenic cycle
temperate phages incorporate DNA into host DNA (prophage)
3 results: immunity to reinfection, phage conversion, specialized transduction
37
viruses that remain dormant for long periods
latent viral infections
38
disease progresses slowly over a long period
persistent viral infection
39
infectious naked RNA
viroid
40
class of infectious agents thought to consist solely of proteins, mad cow disease
prions
41
T/F: microorganisms that reside on or within a host without causing infection/disease are referred to as the normal microbiota (microbiome).
True
42
Microorganisms using the _____ route of entry invades tissues via injections, bites, cuts, and/or surgical procedures
parenteral
43
Which of the following would be considered a bacterial virulence factor (e.g. contributes to the bacteria's pathogenicity)?
capsules
cell wall components
axial filaments/flagella
endospores
44
Virulence factors
contribute to the bacteria's pathogenicity
cell wall
fimbriae - attachment
flagella/axial filaments - motility
capsules
incomplete phagocytosis
exoenzymes
endospores
45
Generally speaking, which of the following is the most commonly used portal of entry for pathogens?
mucus membranes (e.g., gastrointestinal, respiratory, genitourinary)
46
An endotoxin is
a toxic lipid that is a component of the outer LPS membrane of gram negative bacteria
47
Organism that under NORMAL circumstances does not cause disease
opportunistic pathogen
48
one organism lives at the expense of the host
parasitism
49
aspects of a disease that are only apparent to the patient (e.g., headache, nausea, fatigue)
symptoms
50
disease caused by a pathogen which may or may not spread between hosts
infectious
51
a disease caused by a pathogen that will not spread between hosts
non-communicable
52
T/F: avoiding the host's defenses is the critical step in a pathogen being able to cause disease
False
53
An individual's susceptibility to disease can be influenced by which of the following factors
poor nutrition
lifestyle choices
antibiotic therapy
emotional disturbances
genetic background
54
T/F: the most acute signs and symptoms of a disease appear during the prodromal phase of an infectious disease
False
55
propagated epidemic
starts with one person and spreads to others (like the flu)
56
common source epidemic
everyone got sick all from the same source (like eating at the same restaurant)
57
the percent of individuals in a population immune to a disease; it is increased significantly through vaccination
Herd Immunity
58
Which of the following is not an example of direct transmission?
a. sharing food or drinks
b. kissing
c. shaking hands
d. sexual intercourse
a. sharing food or drinks
59
An island nation normally has low background level of cholera. After an earthquake, sanitation is disrupted and cholera cases spike to high levels on the island but not other areas of the world. The spike in cholera cases is an example of an
epidemic disease
60
Lily (who had lice) brings a comb to school for picture day. After Licey Lily combs her hair, Leticia asks to borrow the comb. Leticia later is diagnosed with lice. In this example, the comb is a
fomite
61
Vaccinating domesticated and wild (if possible) animals
lowers the number of reservoirs and reduces transmission of zoonotic diseases to humans
62
a patient in the hospital with a urinary catheter develops a bladder infection during their hospital stay. This is an example of a _______ infection.
nosocomial
63
T/F: one of the basic goals of vaccination is to increase herd immunity
true
64
The epidemiologic triad (triangle) of disease refers to:
pathogen, susceptible host, environment
65
Ebola epidemics occasionally occur. Where does the virus that causes Ebola "hide" in between epidemics? It is thought that bats naturally harbor the virus, and this would be considered
a reservoir
66
compounds in food that induce the growth or activity of beneficial microorganisms such as bacteria and fungi (food for microbiota)
Prebiotic
67
foods or supplements that contain live microorganisms intended to maintain or improve the "good" bacteria in the body
probiotics
68
Acid-producing microbes used to supplement commercial mining; many antibiotics come from actinomycetes
biomining
69
used to detect chemical pollutants
genetically engineered biosensors
70
the use of microbes to detoxify environmental containments
bioremediation
71
Replication of Animal Viruses
Attachment - attach to cell of membrane
penetration - by endocytosis or fusion
uncoating - by viral or host enzymes
biosynthesis - production of nucleic acid and proteins
maturation - nucleic acid and capsid assemble proteins
release - by budding or rupture
72
measure of oxygen required to fully metabolize organic matter in water; normally about 10mg/L of oxygen can be dissolved in water
Biochemical Oxygen Demand (BOD)
73
a sudden increase of a formerly limiting nutrient in an aquatic environment, leading to an overgrowth of algae and grazing bacteria and subsequent oxygen depletion
eutrophication
74
Koch's Postulates
demonstrates that specific microbes cause specific diseases
75
Predisposing factors for infectious disease
factors that affect disease virulence
genetics, age, climate, inadequate nutrition, habits and lifestyle, chemotherapy, being a punk ass bitch
76
steps of water treatment
1. coagulation: sedimentation and flocculation
2. filtration: sand or coal
3. disinfection: chlorine; ozone; UV light
77
Health care-associated infections (HAIs) and nosocomial infections
infections you get in the hospital, due in part to poor heath of patients and antibiotic-resistant nature of bacterial lurking in hospitals
78
Common Eradication/public heath Efforts
Improving Sanitation
Reservoir elimination
Vector control
Vaccination and Chemotherapy
79
microbiota relationships with host
protects from other disease-causing microbes
(competitive exclusion and chemical warfare)
80
Steps of infection
Gain entrance to host
adherence
avoid host defenses
colonization
cause host damage
leave host if possible
81
pathogenic portals of entry
mucus membranes (respiratory tract, gastrointestinal tract, genitourinary tract, placenta)
skin
parenteral route (bites, puncture, injection, wound)
82
exotoxins
produced mostly by Gram+ bacteria as part of their metabolism; secreted externally or released after cell lysis
83
lipid A portion of outer LPS membrane of gram- cell wall; released when cells die, and cell walls lyse; antibiotics may cause an immediate worsening of symptoms. Chills, fever, weakness, aches; disseminated intravascular coagulation (DIC); septic shock
endotoxins
84
Pathogenic portals of exit
Respiratory and gastrointestinal tract (most common)
genitourinary tract
skin/wounds
insects biting
needles and syringes
85
Carbon Cycle
autotrophs fix CO2 into organics
heterotrophs consume autotrophs
carbon reenters the environment (respiration, decomposition, fossil fuels)
86
nitrogen cycle
deamination - amino groups removed from proteins and converted to ammonia
ammonification - breakdown of organic nitrogen releasing ammonia
nitrification - oxidation of ammonium into nitrite; nitrite can be oxidized to nitrate
denitrification - nitrate reduction leads to loss of nitrogen back to the atmosphere as nitrogen gas
87
sulfur cycle
sulfates are incorporated into plants, animals and bacteria as disulfide bonds in proteins; proteins decompose and sulfur released as H2S; some lithotrophs oxidize H2S to form sulfates
88
phosphorus cycle
limiting factor for plant and animal growth (used in detergents and fertilizers, runoff may lead to eutrophication)
exists primarily as phosphate ion (PO4 3-)
89
Common Phases of infectious diease
Incubation period - no signs or symptoms
Prodromal period - vague/general symptoms
Illness
Decline
Convalescence - no signs or symptoms
90
Assimilation
process by which organism acquire elements to build cells
91
dissimilation
process of breaking down organic nutrients into inorganic minerals
92
Freshwater zones
littoral zone, limnetic zone and profundal zone, benthic zone
93
Marine zones
Neuston (about 10 micrometers) - air water interface
euphotic zone (100-200m) - light, phototrophs grow
aphotic zone - below light, heterotrophs & lithotrophs
benthos - ocean floor; benthic organisms
94
endomycorrhizal fungi
vesicular-arbuscular mycorrhizae (VAM)
95
Ectomycorrhizal fungi
colonize the rhizoplane
96
Benefits of Biofilms
cell-to-cell communication
share resources
protection
facilitates transfer of genetic information
97
Lichens consist of an intimate mutualistic symbiosis between a fungus, an alga, and/or cyanobacteria. What is one primary role of the cyanobacteria in the association?
nitrogen fixation
98
which region of marine habitat refers to the microscopic interface between water and air?
neuston
99
all of the following are likely to be found among the benthic microbes EXCEPT:
a. barophiles
b. methanogens
c. phototrophs
d. psychrophiles
e. thermophiles
phototrophs
100
eutrophic lakes typically support ten times the microbial concentrations of an oligotrophic lake. which of the following statements is NOT true of eutrophic lakes?
population of aquatic animals like fish increases due to an abundance of oxygen
101
bacteria found growing in between crystals of solid bedrock as deep as 3km below Earth's surface are called
endoliths
102
fungi play a much larger and more significant role in the decomposition of terrestrial biomass than they do in marine ecosystems. This is because fungi
can degrade the abundant lignin in terrestrial habitats
103
Vascular abuscular mycorrhizae (VAM) are an example of which of the following?
endomycorrhizae
104
Microbes participate in which step of wastewater treatment by decomposing organic material?
secondary
105
wastewater treatment generates which of the following gases during anaerobic sludge digestion in quantities sufficient for recovery as a fuel source?
methane
106
What types of bacteria will carry out nitrification (oxidation of nitrates & nitrites)?
chemolithotrophs
