Microbe Human Interaction Flashcards
(160 cards)
1
Q
how much more microbial cells in/on bodies than in human cells in body?
A
3x
2
Q
human body conditions favorable for microbes
A
source of nutrients, environment, moisture, stable pH, temperature, different surfaces
3
Q
how can microflora change?
A
vary with age, diet, health, hygiene practices, hormones, drug therapy
4
Q
resident microflora
A
microbes which are present and permanent in some areas of the body (eg. skin and large intestine)
5
Q
transient microbes
A
microflora that can only remain for a short period of time
6
Q
transient v resident microflora
A
transient must compete in order to stay on/in but resident microflora are better adapted
7
Q
how do resident microflora compete?
A
they compete with space nutrients and release toxins to kill transient microbes
8
Q
infection
A
microorganism invades the host and bypasses the host defense mechanisms
9
Q
how does an infection occur?
A
first initial contact and then microorganisms invade our tissues and grow in it
10
Q
disease
A
overall organismal health is suffering a cost
11
Q
amniotic sac
A
fetal membranes
12
Q
microbe introduction during natural birth
A
lactobacilli streptococci and staphylococci when passing through birth canal
13
Q
what does breast milk contain
A
oligosaccharides
14
Q
what digests oligosaccharides?
A
bifidobacterium invantis
15
Q
what does bifidobacterium invantis ensure?
A
baby’s digestive tract is seeded by healthy microbes and does not acquire pathogenic microbes
16
Q
why does microflora change in mouth when getting teeth?
A
there is additional surface area in the mouth for different microbial growth and new consumption of foods
17
Q
microbe introduction through c section
A
breast milk and human-skin interactions
18
Q
what organ bacteria is the most unique?
A
skin bacteria
19
Q
microbes on skin
A
staphylococcus corny bacterium. propionibacterium, yeast
20
Q
where does normal flora reside on skin?
A
dead cell layers on surafce to dermal layer in follicles/glands
21
Q
microbes common in sebaceous glands
A
mycobacterium, staphyococcus
22
Q
digestive tract is considered
A
a tube within a tube which separate it from the the body cavity; Microbes residing within the digestive tract are therefore technically outside the body’s internal environment
23
Q
Peristalsis
A
wave-like muscle contractions which pushes microbes downward, preventing colonization in the esophagus
24
Q
Exceptions of microbial growth in the stomach
A
Lactobacilli and Helicobacter pylori
25
lactobacilli
ferments lactose, producing lactic acid
26
Helicobacter pylori
can cause ulcers under stress
27
The acidity of the stomach
is analogous to a highly concentrated cleaning solution that kills most bacteria.
28
what limits microbial growth in the small intestine?
Enzymes and digestive molecules, along with peristalsis
29
most common genus in oral cavity/mouth
streptococcus
30
What kind of microbes contribute to cavities?
Anaerobic microbes through acid production from fermentation
31
are mouthwashes generally ineffective against the diverse microbial population of the mouth?
yes
32
what does dry mouth cause?
increases microbial growth and halitosis
33
highest concentration of microbes in the body
anaerobic bacteria
34
what bacterias aid in aid digestion, produce vitamins and contribute to intestinal odor
Bacteroides, Bifidobacterium, Fusobacterium, Clostridium
35
vitamins produced by microbes Bacteroides, Bifidobacterium, Fusobacterium, Clostridium
B12, K, riboflavin, thiamine
36
intestinal odor
flatulence
37
The large intestine's microbial community is essential for
nutrient absorption and overall gut health
38
Upper Respiratory Tract
Colonized by resident microflora: oral streptococci, Staphylococcus aureus (nose), and Neisseria species (mucous membranes)
39
Lower Respiratory Tract (Lungs)
Mucus and cilia trap and remove inhaled microbes; microbe free in healthy individuals
40
why is lower respiratory tract's environment is unfavorable for microbial growth?
efficient clearance mechanisms
41
internal Reproductive Organs include
uterus, fallopian tubes, ovaries
42
Internal Reproductive Organs are
Generally sterile. The closed cervix prevents microbial ascent from the vagina.
43
Vagina microbe environment
Low diversity, low microbial count, but resident microbes
44
what do resident microbes do in vagina
maintain an acidic pH, inhibiting pathogenic growth
45
microbes in vagina
lactobacilli
46
Estrogen stimulates
glycogen production: fueling Lactobacilli growth and acid production.
47
menopausal
and prepubescent vaginal infections
lower estrogen levels, have a more neutral vaginal pH, increasing susceptibility to infections
48
External Genitourinary Organs microbes
Colonized by streptococci, staphylococci, corynebacteria, and some coliforms
49
Virulence
A measure of how severe a disease it causes
50
True Pathogens
Cause disease in healthy individuals with normal immune systems
51
Eg of true pathogens
influenza, malaria, bubonic plague
52
Opportunistic Pathogens
Cause disease when the host's immune system is compromised
53
Eg of opportunistic pathogens
Pseudomonas, Candida albicans
54
stages of infection
1. entry 2. adhesion 3. invasion 4. multiplication 5. exit/egress
55
entry
microbe enters the body
56
adhesion
microbe attaches to host tissues
57
invasion
The microbe spreads to other tissues
58
Multiplication
The microbe grows and reproduces
59
Egress (Exit)
The microbe leaves the host, enabling transmission to new hosts.
60
Portals of entry
endogenous, exogenous
61
Types of portals of entry
skin, GI tract, respiratory tract, urogenital tract, placenta
62
BSL
biosafety level
63
BSL-1
Low risk; microbes not known to cause disease in humans
64
BSL-2
Moderate risk; not easily contagious (HIV)
65
BSL-3
High risk; contagious, often via respiratory transmission, and potentially fatal (yellow fever)
66
BSL-4
Highest risk; highly contagious, highly virulent, and extremely dangerous (ebola)
67
what does BSL determine?
safety measures required when handling microbes in a laboratory setting
68
what portals of entry can Staphylococcus aureus enter through?
skin, respiratory tract, or GI tract
69
Infectious Dose
The minimum number of microbes required to cause an infection. A smaller ID indicates higher virulence.
70
adhesion of microbes
pili, flagella, fimbriae, glycocalyx, viral spikes
71
Virulence factors
molecules produced by microbes that enhance their ability to cause disease
72
Virulence factors include
Exoenzymes, Toxins, Anti-phagocytic Factors
73
Exoenzymes
Extracellular enzymes that break down host tissues
74
Eg exoenzymes
muconase, keratinase
75
Toxins
Poisons that damage host cells
76
Types of toxins
Exotoxins, endotoxins
77
Exotoxins
Secreted by microbes; often A-B toxins
78
eg. exotoxin
botulinum toxin
79
Endotoxins
Part of the microbial cell; released upon cell lysis
80
eg. endotoxins
lipopolysaccharide in Gram-negative bacteria
81
Anti-phagocytic Factors
Prevent destruction by white blood cells
82
Direct killing of phagocytes
Some pathogens produce toxins, like leukocidins, that directly kill white blood cells.
83
Capsule formation
A polysaccharide capsule surrounding the bacterial cell hinders phagocyte binding and engulfment.
84
what does the capsule formation act as?
physical barrier, preventing the phagocyte from making contact with the bacterial cell surface.
85
Intracellular survival and multiplication
Certain pathogens can survive and even replicate within phagocytes, effect
86
stages of infections/diseases
1. incubation period 2. prodromal stage 3. invasion period 4. convalescent period
87
incubation period
time between initial exposure to the pathogen and the appearance of the first symptoms; symptom free
88
Eg. of incubation periods
common cold: 24-72 hours; plague: a few hours; leprosy: years
89
prodromal stage
The onset of initial, often non-specific symptoms
90
Eg. prodromal stage
Feeling tired, experiencing headaches or muscle aches are common prodromal symptoms for many infections.
91
invasion period
This is the period when symptoms are most severe and specific to the infection; pathogen multiplies rapidly, becoming well-established in the body
92
invasion period effected by
host health and pathogen virulence
93
convalescent period
The recovery phase, where the body returns to normal health.
94
Transmission of the pathogen is most likely during what period
invasion period due to high pathogen loads
95
type of infections
localized, systemic, focal, mixed, primary, secondary, acute, chronic
96
localized infection
pathogen remains confined to a specific area of the body
97
eg. localized infection
Boils, athlete's foot, and warts
98
systemic infection
pathogen spreads throughout the body, affecting multiple tissues and organs.
99
eg. systemic infection
Influenza
100
focal infection
infection begins in a localized area but then spreads to other parts of the body, either through dissemination of the pathogen or release of toxins.
101
mixed infection
two or more microbes to cause infection
102
eg. mixed infection
dental carriers (anaerobic and aerobic) microbes)
103
primary infection
weakens the host defenses
104
primary/secondary infection
two infections occur one after the other
105
eg. primary/secondary infection
UTI to vaginal yeast infection
106
acute infection
rapid short lived infection
107
chronic infection
long lasting and (more commonly) less severe
108
signs
objective evidence
109
eg. signs
fever, redness, swelling
110
symptoms
Subjective evidence of disease reported by the patient
111
eg. symptoms
headaches, fatigue
112
signs of blood infection
Leukocytosis, Leukopenia, Septicemia, Bacteremia/Viremia
113
Leukocytosis
increased white cell count
114
Leukopenia
decreased white cell count
115
Septicemia
high numbers of microbes in the blood
116
Bacteremia/Viremia
low number of bacteria/viruses in the blood
117
portals of exit
Respiratory Tract, skin, digestive tract, urinary tract, blood feeding insects, persistence in the host
118
eg. bloodfeeding insects
malaria from mosquitos
119
portal of exit vs method of transmission
portal of exit: location
method of transmission: how it gets to host
120
reservoirs
where pathogens persist
121
living reservoirs
human carriers
122
human carriers
people who are carrying the microbe
123
active
infected with microbe and the microbe is growing inside them
124
passive
not infected with the microbe but have on the surface
125
Asymptomatic
infected with the microbe and transmitting, but not showing
126
incubation carriers
HIV
127
convalescent carriers
diphtheria
128
chronic carriers
typhoid
129
Vectors
animals that transmit microbes from person to person
130
Biological vector
involved in the life cycle
131
eg. biological vector
Fleas, tics, kissing bugs
132
mechanical vector
on the surface on their body
133
eg. mechanical vector
flies, cockroaches
134
zoonotic infections
Diseases transmitted from animals to humans (rabies)
135
Non-living Reservoirs
Environmental sources like soil and water
136
Communicable
Transmitted from one host to another.
137
Contagious
Highly communicable.
138
modes of transmission
direct and indirect
139
direct tranmission
person to person
140
indirect transmission (vechiles)
Requires an intermediate source; surfaces, animal to people, surface droplets
141
Nosocomical infections/HAIs (hospital acquired infections)
Infections acquired in a healthcare setting
142
causes of HAI
surgery/lowered defences, infection from surfaces, passive carriers/hospital workers
143
Epidemiology
study of tracing the patterns of disease
144
CDC
Centers for Disease Control and Prevention
145
where is the CDC located?
atlanta, georgia
146
WHO
World Health Orginization
147
where is WHO located
Geneva, Switzerland
148
reportable
required by law
149
notifiable
recommended to report
150
epidiemology statistics
prevalence, incidence, mortality, case fatality rate
151
prevalence
total number of existing cases in respect to population
152
incidence
number of new cases (time frame)
153
mortality
chance to die from a given disease
154
Case fatality rate
chances of dying from disease once infected
155
endemic
disease that has known predictable infection in population (seasonal flu)
156
epidemic
above expected levels in localized area
157
sporadic
random occurrence (rabies, bubonic plague)
158
pandemic
epidemic that has gotten to 2+ continents
159
Koch's postulates for determining disease
1. find the microbe 2. isolate and cultivate 3. inoculate and observe 4. re-isolate
160
problems with koch's posulates
detect microbe that only infects humans, viable but nonculturable, mixed infections
