Overview Of Infectious Disease & Microbiology Flashcards
1
Q
Disease
A
pathological condition of body parts or tissues characterized by an identifiable groups of signs and symptoms
2
Q
infectious disease
A
Caused by pathogenic microorganisms
-such as bacteria, viruses, parasites or fungi
3
Q
infectious diseases can be spread
A
directly or indirectly from one person to another
4
Q
zoonotic diseases
A
infectious diseases of animals that can cause disease when transmitted to humans
5
Q
infection
A
occurs when an infectious agent enters the body and begins to reproduce
-may or may not lead to disease
6
Q
pathogen
A
infectious agent that causes disease
7
Q
Infectious agents that cause disease are
A
microscopic in size (microbes or microorganisms)
8
Q
different groups of agents that cause disease are
A
bacteria, viruses, protozoa, fungi, helminths
9
Q
protist
A
eukaryotic organism that is not an animal, a plant, or a fungus
-include algae and protozoa
10
Q
True or False: Infectious agents have probably always caused disease in humans
A
True
11
Q
smallpox
A
described in ancient Egyptian and Chinese writings and may have been responsible for more deaths than all other infectious diseases combined
12
Q
evidence that_______ and _____ have existed since ancient times
A
malaria, poliomyelitis
13
Q
What disease killed about 20 million people in Europe alone in the 14th century?
A
bubonic plague or black death
14
Q
How many people have AIDS to date?
A
36.5 million
15
Q
How do infectious agents cause disease?
A
- produce toxins and enzymes that destroy cells and tissues
- direct invasion and destruction of host cells
- trigger response from host’s immune system leading to disease signs and symptoms (cytokine storm)
16
Q
phases of infectious disease
A
incubation, prodrome, clinical, decline, recovery/convalescence
17
Q
incubation period
A
time between infection and appearance of signs and symptoms
18
Q
prodromal period
A
mild, vague,nonspecific symptoms that signal onset of some disease
19
Q
clinical phase (illness)
A
person experiences typical signs and symptoms of disease
20
Q
decline phase
A
subsidence of symptoms
21
Q
recovery phase (convalescence)
A
symptoms have disappeared, tissues heal, and the body regains strength
22
Q
classification of infectious disease
A
- by duration (acute, chronic, latent)
- by location (local, systemic)
- by timing (primary, secondary)
23
Q
acute disease
A
develops and runs its course quickly
24
Q
chronic
A
develops more slowly and is usually less severe
-may persist for a long, indefinite period of time
25
latent
characterized by periods of no symptoms between outbreaks of illness
26
local
confined to a specific area of the body
27
systemic
generalized illness that infects most of the body with pathogens distributed widely in tissues
28
primary
initial infection in a previously healthy person
29
secondary
infection that occurs in a person weakened by a primary infection
30
transmission of infectious diseases
through air, contaminated food/water, body fluids, direct contact with contaminated objects, animal vectors, spillover
31
Ways spread of infectious disease can be reduced
vaccine, antimicrobial drugs, good personal hygiene/sanitation, quarantine, protections against mosquitoes, face mask, social distancing
32
infectious diseases are responsible for:
quarter to third of all deaths worldwide
33
infectious diseases account for more than
half of all deaths in children under 5
34
The top single agent killers
HIV/AIDS, malaria, tuberculosis
35
emerging infectious diseases
those that have recently appeared or suddenly became prevalent within population
36
Diseases can emerge or re-emerge due to:
- appearance of previously unknown agent
- evolution of new infectious agent
- spread of infectious agent to new host or locations
- aquisition of resistance to antimicrobial drugs
- deliberate introduction into population
- no vaccination
37
evolution
process of change over time the results in new varieties and species of organisms
38
phlogeny
evolutionary relationships between organisms
39
Ribosomal RNA (rRNA)
excellent for determining phylogeny
40
Comparative rRNA sequencing has defined three distinct lineages of cells called:
domains
- prokaryotic (bacteria and archaea)
- eukaryotic (eukarya)
41
LUCA
last universal common ancestor
| -domains are thought to have diverged from common ancestral organisms
42
eukaryotes
organisms whose cells contain a nucleus and other structures enclosed within membranes
43
prokaryotes
cells lack membrane-bound nucleus
44
True or False: Archaea & Bacteria are closely related
False
45
True or False: Archaea are more closely related to eukarya than bacteria
True
46
eukaryotic microorganisms were
ancestors of multicellular organisms
47
mitochondria and chloroplasts
contain their one genomes and ribosomes
- organelles related to specific lineages of bacteria
- descendants of free-living bacterial cells that developed and association with cells of eukaryotic domain
48
endosymbiosis
condition in which one cell lives inside another cell for benefit of both
49
domain bacteria contains
enormous variety of prokaryotes
50
all known pathogenic (disease causing) prokaryotes are
bacteria
51
binary fission
reproduce by asexual division
52
make up the largest and most diverse phylum of bacteria
proteobacteria
53
Gram-negative bacteria
thin peptidoglycan layer, outer membrane
- stain red
- proteobacteria
54
Gram-positive bacteria
phylum united by phylogeny and cell wall structure
- thick peptidoglycan layer
- stain purple/violet
55
cyanobacteria are relatives of
gram positive bacteria
56
Chemoorganotrophs
organisms that depends on organic chemicals for its energy and carbon
57
green sulfur bacteria and green nonsulfur bacteria are
photosynthetic
58
Deinococcus
extremely resistant to radioactivity
| -divide in two planes to yield clusters of cells
59
chlamydia
obligate intracellular parasites
60
peptidoglycan
cell wall of bacteria
61
some bacteria lack
cell wall structure
| -survive only inside host cells or in hypertonic environment
62
mycoplasmas
group of pathogenic bacteria that causes several infectious diseases in humans and animals
63
thermoplasma
species of archaea that naturally lack cell wall
64
bacteria able to survive without cells walls because
they contain unusually tough cytoplasmic membranes or because they live in osmotically protected habitats such as the animal body
65
eukaryotic microorganisms are related by
cell structure and phylogenetic history
66
algae
phototrophic, contain chloroplasts, mineral requirements are low
67
What disease killed 50 million people worldwide in 20th century?
1918 influenza
68
protist
include algae and protozoa
69
True or False: Protozoa are phototrophic
False
70
True or False: Protozoa are decomposers
True
71
Which have cell walls:
| Algae and fungi or protozoa and slime molds
Algae and fungi
72
phylogeny of eukarya was originally inferred from
sequences of the 18S rRNA gene
73
18S rRNA gene encodes
small subunit (SSU) RNA of the cytoplasmic ribosomes of eukaryotes
74
True or False: 18S rRNA genes are much weaker for eukaryotes than 16S rRNA genes are for eukaryotes
True
75
Dark green and red arrows indicate
primary endosymbiotic events for the acquisition of the mitochondrion and chloroplasts
76
light green arrows indicate
secondary endosymbiotic acquisition of chloroplasts from red and green algae by various protists
77
endosymbiotic theory states
that several key organelles of eukaryotes originated as symbioses between separate single-celled organisms
78
molecular and biochemical evidence suggest that the mitochondrion developed from
proteobacteria and chloroplasts from cyanobacteria
79
fungi can exist in
unicellular form (yeast) or filamentous form (mold)
80
yeast can replicate
sexually
81
mold can replicate
asexually and sexually
82
most fungi exist as either
yeast or mold
83
dimorphic fungi
fungi that can assume yeast or mold morpholgies
84
coccus
spherical or ovoid
85
rod/bacillus
cylindrical shape
86
spirillum
spiral shape
87
staining cells for microscopic observation
1. prepare a smear
- thinly spread culture
- dry in air
2. heat fix and stain
3. microscopy
88
differential stains (gram stain)
separate bacteria into groups
89
gram stain steps
1. crystal violet for 1 min
2. iodine solution for 1 min
3. decolorize with alcohol about 20 sec
4. counterstain with safranin for 1-2 min
90
gram positive cell walls can contain up to____ peptidoglycan
90%
91
lipoteichoic acids
teichoic acids covalently bound to membrane lipids
92
gram-negative bacteria only ____ of total cell wall consist of peptidoglycan
10%
93
LPS
- consist of core polysaccharide and O-polysaccharide
| - replaces most of phospholipids in outer half of outer membrane
94
endotoxin
toxic component of LPS in particular Lipid A
95
What's responsible for differences in the gram stain reaction?
structural differences between cell walls of gram positive and negative bacteria
96
gram stain is
an insoluble crystal violet-iodine complex forms inside the cell
97
R-OH penetrates the
lipid rich outer membrane and extracts the crystal violet-iodine complex from the cell
98
capsule and slime layers
- assist in attachment to surfaces
- protect against phagocytosis
- resist desiccation
99
fimbria and pili
filamentous structures composed of proteins that extend from surface of a cell and can have many functions
100
fimbriae
- filamentous protein structures
| - enable organisms to stick to surfaces
101
pili
- filamentous protein structures
- typically longer than fimbriae and only one or a few pili are present on the surface of a cell
- conjugation
102
endospores
- highly differentiated cells resistant to heat, harsh chemicals and radiation
- function as survival structures, enable organism to endure unfavorable growth conditions
- dormant stage of bacterial life cycle
- ideal for dispersal
- only present in some gram-positive bacteria
103
cells don't sporulate when
they're growing
104
endospore can remain dormant for
years
105
endospore structure is
- impermeable to most dyes
- structurally complex
- contains dipicolinic acid
- enriched in Ca2+
106
BSL
biosafety level
107
BSL-1 labs
lowest level of containment
- work can be done on open bench
- non pathogenic organisms
- workers should be protected by lab coats and gloves
108
BSL-2 labs
organisms that present a moderate risk of infection due to accidental ingestion, percutaneous injection or exposure to mucous membranes via aerosols
-protection such as face and eye, gloves, lab coats/gowns
109
BSL-3 labs
emerging /high risk pathogens
- negative pressurized rooms and air filters to prevent accidental release of pathogen
- safety cabinets required for manipulation
110
BSL-4 labs
design for maximum containment of life threatening pathogens
- high transmission by aerosol, no vaccine, treatment or cure
- full body, positive-pressure suit with air supply
111
you can't be in a BSL-4 lab for more than
5 hours
112
you have to shower every time you leave a
BSL-4 lab
113
What biosafety level must be used for HIV?
BSL-2
114
sterilization
killing or removal of all viable organisms from a growth medium or surface, the destruction of all microbial life (includes bacterial endospores and viruses)
115
inhibition
effectively limiting microbial growth
116
cidal
bacterial killing
117
static
bacterial-inhibiting
118
Used to destroy or remove microorganisms
heat, radiation and filtration
119
What is the most widely used method of controlling microbial growth?
heat sterilization (HE)
120
What has better penetrating power?
moist heat
121
high temperatures
denature macromolecules
122
decimal reduction time (D)
time required at a certain temperature to kill 90% of organisms being studied
123
thermal death time
time it takes to kill all cells at given temperature
124
Endospores require autoclave temp/time for a D
121 degrees C for 4-5 minutes
125
Vegetative cells require temp/time for a D
0.1-0.5 min at 65 degrees C
126
microbial death is
more rapid at acidic pH
127
autoclave
a sealed device that uses steam under pressure to kill microorganisms
128
killing of heat resistance requires heating at temperatures above
100 degrees C
129
ionizing radiation
gamma radiation of sufficent energy to produce ions and other reactive molecular species from molecules with which the radiation particles collide
130
ionizing radiation generates
e- hydroxyl radicals OH and hydride radicals H
131
What is the standard killing dose for radiation sterilization?
12D
132
gas sterilization is done by using
```
ethylene oxide (EtO)
-comman gas used for low temperature sterilization
```
133
EtO sterilization cycle
preconditioning
sterilization
aeration (degassing)
134
robert hooke
- 1635-1708
| - first to describe microbes in book
135
antoni van leeuwenhoek
- 1632-1723
| - first to describe bacteria in 1676
136
Ferdinan Cohn
- 1828-1898
| - founded field of bacteria classification and discovered bacterial endospores
137
louis pasteur
-1822-1895
discovered that living organisms discriminate between optical isomers
-disproved theory of spontaneous generation
-developed vaccines for anthrax, fowl cholera and rabies
138
enantiomers
two stereoisomers that are mirror images of each other that aren't superimposable (not identical)
139
robert koch
- 1843-1910
- german physician and microbiologist
- demonstrated link between microbes and infectious diseases
- discovered using solid media provided simple way of obtaining pure culture
- observed diff shapes, colors and sizes
140
microbial diversity
field that focuses on nonmedical aspects of microbiology such as microbial diversity of soil and water & metabolic processes that microorganisms in these habitats
141
martinus beijerinck
- 1851-1931
| - developed enrichment culture technique
142
sergei winogradsky
- 1856-1953
- concept of chemolithotrophy
- performed first isolation of a nitrogen-fixing bacterium
143
operon
functional unit of genomic DNA containing cluster of genes under control of a single regulatory signal o promoter
144
have roots in Koch's work
medical microbiology and immunology
145
developed from concepts developed by Beijerinck and winogradsky
agricultural and industrial microbiology
146
developed from advances in soil microbiology
aquatic and marine microbiology
147
emerged in 1960-70s
microbial ecology
148
biotechnology
products of genetically engineered microorganisms
149
microbial systematics
science of grouping and classifying microorganisms
150
microbial physiology
study of nutrients that microbes require for metabolism and growth and products they generate
151
microbial ecology
study of microbial diversity and activity in natural habitats
152
cytology
study of cellular structure
153
microbial biochemistry
study of microbial enzymes and chemical reactions
154
bacterial genetics
study of heredity and variation in bacteria
155
virology
study of viruses
156
biotechnology
- manipulation of cellular genomes
- DNA sequencing
- PCR
- identification of iRNA
- CRISP: clustered regulatory interspaced short palindromic repeats
157
genomics
study of all of the genetic material (DNA) in living cells
158
transcriptomics
study of RNA patterns
159
proteomics
study of all the proteins produced by cells
160
metabolomics
study of metabolic expression in cells
