Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Micro B2 > Host-Microbe Relationships > Flashcards

Host-Microbe Relationships Flashcards

(84 cards)

Start Studying
1
Q

Close association and interaction of two dissimilar organisms living together.

A

Symbiosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Microorganisms which are normally and consistently found in or on the body in the absence of disease.

A

Normal flora

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

association between organisms in which one is benefitted and the other is neither benefitted nor harmed.

A

Commensalism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

both the microbe and host derive benefits from the relationship

A

Mutualism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

disease traits of the resident flora are demonstrated only when normal host-microbe relationship is altered

A

opportunism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Alterations to the host-microbe relationship are common results from these circumstances:

A

Prolonged antibiotic therapy alters flora

Traumatic injury, surgery

Immunological compromise

Hormonal or chemical changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Resident microbe

A

always present

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

transient microbe

A

can be normal, if present, but not always present (environmental, aging/birthing circumstances)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Nature/variety of microbes are often distinctive for different regions of the ____

A

body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Normal flora of one area may cause ____ of another

A

infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

symbiotic relationship in which a microorganism lives in or on a host at the expense of the host

A

parasitism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

a carrier of microbes from one host to another

A

Vector (usually refers to a living entity, but could be non-living)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Vector could be insects/animals or an inanimate object, called a ____

A

fomite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

the growth and spread of a pathogen in or on a host resulting in injury to the host tissue

A

Infectious dz

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

a microbe capable of causing disease by invading tissues, producing toxins, or both

A

pathogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

the degree of pathogenicity

A

virulence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

how easily the microbe survives the normal host defenses and establishes infection

A

infectivity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Two virulence components

A

Infectivity

Severity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Modes of transmission

A

Direct contact
Inhalation
Ingestion
Parenteral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

direct contamination of blood, body fluids, or tissues by arthropod and other animal vectors and by nonsterile syringes and needles

A

Parenteral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Virulence factors

A

Attachment/Establishment Factors

Antiphagocyctic Factors

“Invasive” Enzymes

Exotoxins

Endotoxins

Genetic Alterations

Special Antimicrobic Resistance Situations

Global & US Antimicrobial Health Threat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

enable the establishment of infection

A

Attachment & Establishment Factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

The organism must enter the correct portion of the body (e.g. ingestion vs. inhalation vs wound), which requires:

(Attachment & Establishment Factors)

A

overcoming local defenses

Finding the best environment for growth/survival

(portal of entry)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

The attachment of the microbe to tissue is required in order to establish a site of infection.

Attachment mechanisms:

(Attachment & Establishment Factors)

A

fimbrae

surface chemicals

Adhesive Matrix Molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
attach to specific receptor sites on specific tissue | Attachment & Establishment Factors
fimbrae
26
Dissolve covering of cells and aid chemical attachment | Attachment & Establishment Factors
surface chemicals
27
produce biofilm thus providing "protection" for bacteria within harsh human environment (Attachment & Establishment Factors)
adhesive matrix molecules
28
a certain minimum number of organisms are required to establish infection -- presumably needed to overcome host defenses (Attachment & Establishment Factors)
Quantity (also a component of a pathogen's virulence)
29
various chemicals that (1) restrain the disease-causing actions of the microbe until sufficient quantity of microbes are present, then (2) switch on the disease-causing actions all at once. (Attachment & Establishment Factors)
Quorum-sensing Regulators | an OPERON
30
In this attachment/establishment feature, symptoms maybe unnoticed or mild until the bacteria reach a certain number
Quorum-sensing Regulators | an OPERON
31
prevent microbe from being engulfed and/or destroyed by white blood cell (physical protection or chemical poison)
Antiphagocytic factors
32
Antiphagocytic factors examples:
Capsule Coagulase Leukocidin Survival of phagocytosis
33
slippery & slimy nature assists bacteria from being engulfed by phagocyte (Antiphagocytic factors)
capsule
34
causes destruction of white blood cells | Antiphagocytic factors
Leukocidin (staphylococci, streptococci, & certain bacilli)
35
causes fibrin clot to form around the microbes | Antiphagocytic factors
Coagulase (Staphylococcus aureus)
36
resistance to killing within a phagocyte (e.g. mycobacteria, gonococcus, Listeria) (Antiphagocytic factors)
survival of phagocytosis
37
factors that promote the invasion and spread of a pathogen in/on the tissue enable the pathogen to invade the tissue or the site of infection to spread
"Invasive" Enzymes
38
"Invasive" Enzymes examples
``` Collagenase Fibrinolysin/Streptokinase Hyaluronidase Hemolysins Lecithinase Lipase Proteases Super Antigens ```
39
breaks down collagen fibers thus destroying tissue integrity | "Invasive" Enzymes
Collagenase
40
destructive to cell membranes of red blood cells and other tissue cells ("Invasive" Enzymes)
Lecithinase
41
breaks down hyaluronic acid in cell membranes | "Invasive" Enzymes
Hyaluronidase | Staphylococcus, Streptococcus, Clostridium perfringens
42
lyses fibrin in blood clots thus preventing isolation of the infection ("Invasive" Enzymes)
Fibrinolysin & Streptokinase
43
dissolve red blood cell membranes | "Invasive" Enzymes
Hemolysins | Staphylococcus, Streptococcus, C. perfringens
44
digest lipids allowing bacteria to enter | "Invasive" Enzymes
Lipase
45
digest proteins (e.g. IgA, certain other protective chemicals) thus permitting bacteria to evade entrapment, digestion, etc. ("Invasive" Enzymes)
proteases
46
cause exacerbated immune or inflammatory response | "Invasive" Enzymes
Super Antigens
47
Proteins excreted from the cell that can cause specific and widespread biological effects on the body
Exotoxin
48
(1) Cytolytic and Receptor-binding proteins (usually) (2) Many are dimeric: A & B subunits; facilitates entry into tissue cells (3) Tissues affected are very defined and limited (4) Superantigens are special group of toxins (5) Often coded on plasmid or lysogenic phage
exotoxin
49
Examples of exotoxins
Tetanus neurotoxin (attacks motor nerves) Staphylococcal enterotoxin (diarrhea, vomiting) Cholera toxin (diarrhea) Diptheria toxin (causes overprodcution of mucous blockage of respiratory tract and causes protein production issues in the heart) Streptococcal erythrogenic toxin (Scarlet fever)
50
Elicit good, protective antibodies
Exotoxins (due to its protein nature)
51
the lipopolysaccharide (LPS) component of gram-negative cell walls which is released upon disintegration of the cell (endotoxin)
Lipid A
52
Binds to CD14 and TLR4 (Toll-Like Receptor 4) on macrophages, B-cells, other cells.
"Lipid A"
53
Stimulates production and release of Acute-phase Cytokines, e.g. IL-1, TNF, IL-6 (i.e. it triggers white blood cells to discharge chemicals which induce fever, pain, hemorrhage, blood pressure drop, etc.
"Lipid A"
54
Not very potent per unit weight; however, very high levels in bloodstream can trigger very large effects including shock and death
"Lipid A"
55
Because it's an LPS, lipid "A" doesn't elict a good...
immune response
56
Genetic Alterations include:
plasmid lysogeny gene recombination
57
(1) Code for some exotoxins, antibiotic resistance, invasive enzymes, etc. (2) Transmitted to daughter cells during cell division (3) Passed to another bacterium during conjugation
plasmid | genetic alteration
58
Viral DNA incorporated into bacterial DNA (1) Code for some exotoxins and invasive enzymes (2) Introduced by viral infection of the bacteria and transmitted to daughter bacterial cells during cell division
lysogeny
59
Gene recombination -- pieces of genetic material from one organism are incorporated into the genetic material of another organism. Results in:
(1) Different (new types) antigens are produced -- current immunity not effective (e.g. Influenza virus) (2) Causes increased resistance to antibiotics
60
Many bacteria gain antibiotic resistance by:
(a) Mutated genes (“successful” about 1 in 10 billion cell reproductions ?) (b) Plasmid encoded genes (c) Lysogenic virus
61
Presence of an antibiotic-resistant bacterium in the community / hospital leads to:
(a) Survival of the mutant (b) Increasing numbers of the mutant in the population (c) Disease problems increase and spread to new geographic locations
62
Abx-resistant examples
Beta lactamase MRSA Carbapenem-resistant enterobacteriaceae-Carbapenemase-producing Enterobacteriaceae (CPE)
63
Bacterial enzyme which inactivates many beta-lactam antimicrobics (e.g. penicillin, cephalosporin, carbapenem, monobactam classes).
Beta lactamase
64
Plasmid encoded gene – Frequently carried by Enterobacteriaceae (family of gram-negative bacilli) Staphylococcus, Neisseria gonorrhoeae, Haemophilus influenzae) that frequently produce the enzyme
Beta lactamase
65
version that affects a larger group of antimicrobics that are typically not affected by typical beta-lactamase
Extended spectrum Beta lactamase | ESBL
66
Mutated mecA gene – encodes a low-affinity penicillin binding protein (PBP2a)
Methicillin-Resistant Staphylococcus aureus (MRSA)
67
Consider ____ to be resistant to all beta-lactam antibiotics (e.g. penicillins and cephalosporins regardless of the in vitro lab results.)
MRSA
68
Mutated genes for outer membrane porins (pore proteins) and PBP transpeptides A form of beta-lactamase Carried by plasmids
Carbapenem-Resistant Enterobacteriaceae (CRE) – Carbapenemase-producing Enterobacteriaceae (CPE)
69
CRE-CPE results in:
Loss of drug diffusion into periplasm loss of cross-linking activity of PBP
70
Non-specific Factors | Host Resistance Factors
Innate species immunity/resistance Physical/mechanical barriers chemical barriers phagocytosis inflammation
71
(1) Intact skin prevents entry of organism (2) Mucous membranes -- sticky linings trap invading organisms (3) Cilia of respiratory tract -- move particles to the throat where they are swallowed (4) Peristaltic action of gut -- moves gut contents at a slow, steady pace thus preventing overgrowth (5) Normal flora -- occupy attachment sites & compete for nutrients
Physical/Mechanical Barriers
72
(1) Acid pH (stomach, skin, vagina, urine) -- denatures most organisms Exceptions: typhoid & tubercule bacilli, protozoan cysts, polio & hepatitis A viruses (2) Bile salts (intestine) -- inhibitory to many microbes (3) Lysozyme (tears, saliva) – digests gram-positive cell walls (4) Antimicrobial chemicals from normal flora (5) Interferon (a type of lymphokine) -- human host cell protein(s) produced in response to invasion by certain viruses. It acts as a local defense against certain viruses by producing inhibiting substances that "interfere" with viral reproduction.
Chemical barriers
73
denatures most organisms (chemical barriers)
Acid pH (stomach, skin, vagina, urine)
74
Exceptions to acid pH efficacy
typhoid & tubercle bacilli, protozoan cysts, polio & hepatitis A viruses
75
Digests gram positive bacteria | chemical barriers
lysozyme
76
human host cell protein(s) produced in response to invasion by certain viruses. It acts as a local defense against certain viruses by producing inhibiting substances that "interfere" with viral reproduction. (chemical barrier)
interferon (a type of lymphokine) Paul Revere
77
moves gut contents at a slow, steady pace thus preventing overgrowth (physical/mechanical barrier)
peristaltic action of gut
78
occupy attachment sites & compete for nutrients (physical/mechanical barriers)
normal flora
79
inhibitory to many microbes | chemical barrier
bile salt
80
Antimicrobial chemicals from ____ | chemical barrier
normal flora
81
(1) "Foreign" particles are ingested & digested by polymorphonuclear leukocytes, monocytes, and macrophages (2) Numerous enzymes act to degrade and digest the ingested particles (3) Local tissue damage may occur due to egestion of waste materials
phagocytosis
82
(1) Develops after mechanical injury or exposure to certain chemicals (2) Inflammatory process limits the extent of injury
Inflammation
83
_____ is formed to enclose the pus (phagocytes, dead microbes, dead tissue cells, plasma) (inflammation)
Fibrin clot/wall
84
Increased capillary ____ causes fluid accumulation and influx of phagocytic leukocytes (inflammation)
permeability

Micro B2 (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions