Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Microbiology > Ch. 13 > Flashcards

Ch. 13 Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

What is disease?

A
  • a disorder of structure or function leading to signs and symptoms
  • a deviation from a normal state of health
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What causes disease?

A

Genetics, environment, and microbes (Koch’s Postulates - microbes cause disease)

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

Pedigrees

A

Used to understand what type of Mendelian inheritance pattern diseases or traits follow - human traits.disease follow the principle of inheritance

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

Cystic Fibrosis (1979-1989)

A
  • CF developed in a person who inherits a mutant form of the gene from both parents
  • Clear Mendelian inheritance pattern
  • caused by mutated gene, CFTR
  • 3 letters out of 3 billion
  • took 5 years to narrow it down to 2 million base-pair region
  • 10 years and $50 million to find the responsible gene
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Discovery of the structure of DNA (1953)

A
  • in 1953, Watson and Crick build a DNA model that fit all the clues that they had gathered from other sources
  • 50 years later in 2003 the human genome was sequenced
  • Human Genome Project (2003)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Human Microbiome Project

A

Lack of clarity on human genome and recognition of role of microbes in diseases other than infectious diseases led to this project - referred to as our “second genome”

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

Barriers

A

Epithelial surfaces interact with external environments

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

Normal Micorbes - where they are

A
  • skin and it’s contiguous mucous membranes
  • upper respiratory tract (oral cavity, pharynx, nasal mucosa)
  • gastrointestinal tract (mouth, colon, rectum, anus)
    -outer opening of urethra
  • Vagina
  • external ear and canal
  • external eye (lids, lash follicles)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Normal Microbes - where they should not be

A

All internal tissues and organs
- heart and circulatory system, liver, kidneys and bladder, lungs, brain and spinal cord, muscles, bones, ovaries/testes, glands (pancreas, salivary), sinuses, middle and inner ear, internal eye
Fluids within an organ or tissue
- blood (can contain transient bacteria through brushing your teeth etc), urine in kidneys, ureters, bladder (not completely sterile/ free from micorbes), cerebrospinal fluid, saliva prior to entering the oral cavity, semen prior to entering the urethra

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

VMS

A
  • Vaginal Microbial Seeding
  • take 4x4 gauze inside vagina before c section and taken out after c section and rubbed on baby’s face
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How do you know is a baby is breast fed or formula fed?

A

Bifold-bacteria
- found in breastfed babies
- can synthesize all amino acids and growth factors from simple carbohydrates
- have surface proteins that can bind sugars - fermentation of these sugars provides the infant with calories and lowers gut pH, limiting growth of certain pathogens

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

HMO

A
  • human milk oligosaccharide
  • sugars that are delivered by mother in breast milk - produced to feed bifidobacteria - sugars also go to infant
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Normal healthy stool

A

Bacteroidetes and firmicutes
- balance of micorbes in healthy individual stool varies
- Lee diverse means you have more of a collection of all functions that bacteria play out

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

Skin

A
  • microbes live only in upper dead layers of epidermis, glands, and follicles ; dermis and layers below are sterile
  • dependent on skin lipids for growth
  • present in sebaceous glands and hair follicles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Oral cavity - GI Tract

A
  • colonize epidermal layer of cheeks, gingiva, pharynx; surface of teeth; found in saliva in huge numbers; some members involved in dental caries and periodontal diseases
  • c. Albicans can cause thrush
  • inhabit the gingiva of persons with poor oral hygiene
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Large Intestine and Rectum - GI Tract

A
  • areas of lower gastrointestinal tract other than large intestine and rectum have sparse or nonexistent residents
  • microbiota consist predominantly of of strict anaerobes; other microbes are aerotolerant or facultative
  • yeast can survive this habitat - but not molds
  • feed on waste materials in large intestine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Upper Respiratory Tract

A

Trachea may harbor a sparse population; bronchi, bronchioles, and alveoli are essentially sterile due to local host defenses

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

Genital Tract

A
  • In females, microbes occupy the external genitalia and vaginal and cervical surfaces; internal reproductive structures normally remain sterile - vaginal colonists respond to hormonal changes during life
  • cause of yeast infections
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Urinary Tract

A
  • in females, microbiota exist only in the first portion of the urethral mucosa; the remainder of the tract is sterile. In males, the entire reproductive and urinary tract is sterile except for the portion of the anterior urethra
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Eyes

A

The lid am follicles harbor similar microbes as skin; the conjunctiva has a transient population; deep tissues are sterile

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

Ear

A

The external ear is similar to the skin in content: areas internal to the tympanum are generally sterile

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

Skin: common genres

A

Corynebacterium, propionibacterium, staphylococcus

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

Oral Cavity: common genres

A

Streptococcus and Neisseria

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

Large Intestine and Rectum: common genres

A

Bacteroides (most abundant in adults), bifidobacterium (most abundant in infants), clostridium, coliforms (escherichia and enterobacter)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Genital Tract: common genres

A

Lactobacillus and Escherichia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Urinary Tract: common genres

A

Lactobacillus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Factors that alter normal microbiota

A

Food, antibiotics, environment, interactions, age, immune status

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Dysbiosis

A

Disruption of microbial population in and on us
- can cause: rheumatoid arthritis, diabetes, Inflammatory bowl disease, obesity, non-alcoholic fatty liver disease, pulmonary disease, asthma, atherosclerosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Probiotics

A

Intentional consumption of microorganisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

FMT

A
  • basically an organ transport
  • fetal microbiomeal transplantation for people with sever dysbiosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Resident Microbiota

A

Normally found in/on our body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Transient Microbiota

A

Temporary organism (time - some are more like squatters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Pathogen

A

An organism that is capable of causing disease
- true pathogen
- opportunistic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Virulence

A

Severity of disease associated with a particular pathogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Virulence Factor

A
  • component of an organism that supports or enhances its ability to cause disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Contamination

A

Contact
- we interact with microorganism
- sometimes contamination can lead to infection if our environment is suitable

37
Q

Infection

A

Break barriers, attach, grow, avoid most defenses
- can make it to disease

38
Q

Disease

A

Few result in disease
- disrupt normal processes

39
Q

Direct Expsoure

A

Physical contact, respiratory contact, vertical (mother to child), biological vectors

40
Q

Indirect Exposure

A

Fomites are contaminated through inanimate contact, food, water, droplet nuclei, airborne microbes, aerosols

41
Q

Respiratory Transmission vs Droplet Nuclei

A

Difference between distance
- respiratory transmission takes place during normal convo - include coughing and sneezing
- droplet nuclei remain suspended in air and can travel more quickly

42
Q

Vectors

A

Mechanical: pathogen outside
- ie housefly, cockroach
Biological: pathogen inside
- ie: mosquito

43
Q

Parenteral

A

Bypassing barriers (cuts/needles/fluid-feeding insects)

44
Q

Placental

A

Crossing the placental barrier (STORCH OR TORCHES, or SALTORCHES
- syphilis
- toxoplasmosis
- others (Hep B, AIDS, Chlamydia, Listeria, Salmonella)
- Rubella
- cytomegalovirus
- herpes simplex virus

45
Q

Factors that support infection

A
  1. Infectious dose: 50(ID50)
    - number of pathogens that will infect 50% of inoculated hosts
    - varies with pathogens
  2. Hand washing reduces number of pathogens
  3. Lethal dose 50(ID50)
    - dose that kills 50% of experimental animals within a specified period
46
Q

Strategies that support attachment of bacteria to cells

A

Fimbriae, capsule, spikes

47
Q

Invasion (dissemination) and immune avoidance strategies

A

Exoenzymes, toxins, blocked phagocytic responses, invasion factors

48
Q

Exoenzymes

A

Bacteria produce Extracellular enzymes that dissolve barriers and penetrate through and between cells to invade underlying tissues

49
Q

Toxins

A

Toxins (primarily exotoxins) secreted by bacteria cells which die and begin to slough off

50
Q

Blocked phagocytic response

A

Bacteria have a property that enables them to escape phagocytosis and continue to grow and cause further infections - ie: capsule

51
Q

Invasion Factors

A

Salmonella has a unique system to invade an intestinal cell. After adhering to the cell’s microvilli with its fimbriae, it injects proteins into the cell with a probe-like structure. These proteins disrupt the actin filaments and cause the cell membrane to form a series of ruffles that surround the bacterium and pull it inside. It becomes shielded within a vacuole and begins to grow. From here, it can gain entrance to nearby tissues

52
Q

Toxins

A

Endotoxin: lipopolysaccharide (lipid A portion) - gram negative organisms
Exotoxin: any secreted toxin - diverse

53
Q

Exotoxins

A
  • toxic in small amounts
  • impacts the body in a way that is specific to a cell type (blood, liver nerve)
  • composed of small proteins
  • unstable heat denaturatiom at 60 degrees Celsius
  • stimulate the immune system response of antitoxins (an antibody that reacts specifically with a toxin)
  • can be converted to a toxoid (an inactivated toxin used in vaccines)
  • does not stimulate fever
  • secreted from live cell
  • a few gram positive and gram negative bacteria
  • can cause tetanus, diphtheria, cholera, anthrax
54
Q

Endotoxin

A
  • toxic in higher quantities
  • effects the body systematically and less specific - induces fever, inflammation, weakness, shock
  • composed of LPS on cell wall
  • stable heat denaturation at 60 degrees Celsius
  • can not be converted to a toxoid
  • does not stimulate antitoxins
  • it is released from cell wall during lysis
  • all gram negative bacteria
  • can cause meningitis, endoscopic shock, salmonellosis
55
Q

Exotoxins: A/B toxins

A

Consist of two portions: A and B
B - binds to target cell and promotes uptake
A - gets translocated into the cytoplasm where it can disrupt cell function/cell signaling

56
Q

Strategies to avoid immune system

A
  • camouflage - putting things on surface that mimic host cell (putting fake antibodies on surface that look like our own but don’t actually release antibodies)
  • Superantigens
  • avoidance - getting into an area with poor surveillance
  • destroy: A/B toxins destroy immune cells
  • confuse
  • miscommunication by destroying chmotacix factors that would induce phagocytes
57
Q

Chain of infection

A

Agent, virulence, exposure, dose, susceptibility

58
Q

Stages of Disease

A

Incubation period, prodromal stage, period of invasion, convalescent period

59
Q

Incubation Period

A

Time from initial contact with the infectious agent to the appearance of her symptoms; agent is multiplying. The damage is insufficient to cause symptoms; several hours to several years.

60
Q

Prodromal stage

A

Vague feelings of discomfort; nonspecific complaints
- person feels like something is coming on

61
Q

Period of invasion

A

Multiplies at high levels, becomes well-established; more specific signs and symptoms

62
Q

Convalescent Period

A

As person begins to respond to the infection symptoms decline

63
Q

Patterns of infection.

A
  • localized (boil)
  • systemic (influenza)
  • focal infection (infection starts at one location and either pathogen or toxin disseminates throughout the body) - original site remains as home base
  • mixed/polymicrobial infection (caused by multiple infectious agents)
  • secondary infection (super infections) primary infection results in alteration in environment that leads to the growth of another organisms causing a secondary infection
64
Q

Sign

A

Objective evidence of disease as noted by an observer
- Fever, microbes in tissue fluids that should be sterile, abnormal chest, sounds, skin eruptions, leukocytosis, leukopenia, swollen lymph nodes, abscesses, tachycardia, antibodies in serum, septicemia

65
Q

Symptoms

A

Chills, pain, irritation, nausea, malaise, fatigue, chest tightness, itching, headache, weakness, abdominal cramps, anorexia, sore throat

66
Q

Syndrome

A

Sign + symptom 

67
Q

Epidemiology

A

Evidence based science
- science that evaluates occurrence, determinants, distribution, and control of health and sieges in a defined human population
- epidemiologist: one who practice’s epidemiology
- John Snow: was the first epidemiologist- studied cholera in London
- monitor public health: survival and death rates
- respond to disease outbreaks: determine cause and institute control measures
- investigate emerging and re-emerging diseases: determine risk factors and recommend control measures

68
Q

CDC

A
  • located in Atlanta
  • functions as National function for: developing and applying disease, prevention and control, environmental health, and health promotion and education activities
  • International counter part is the world health organization located in Geneva, Switzerland
69
Q

Sporadic disease

A

Occurs occasionally and at irregular intervals

70
Q

Endemic disease

A

Maintains a relatively steady low-level frequency at a moderately regular interval

71
Q

Hyper-endemic diseases

A

Gradually increases in frequency above endemic level, but not to epidemic level

72
Q

Outbreak

A
  • Sudden, unexpected occurrence of disease
  • usually focal or in a limited segment of population
73
Q

Epidemic

A
  • Outbreak affecting many people at once
  • sudden increase in occurrence above expected number
  • Index case-first case in an epidemic
74
Q

Pandemic

A

Increase in disease occurrence within a large population over at least two countries around the world

75
Q

Morbidity

A
  • an incidence rate
  • number of new cases in a specific in a specific time period per unit of population
    (number of new cases during a specific period/number of individuals in a population)
76
Q

Mortality

A

Number of deaths from a disease per number of cases of the disease
(Number of deaths due to given disease/total number of cases of the disease)

77
Q

Incidence

A

Number of new infections over a period of time (typically a year)

78
Q

Prevalence

A

number of infected people in a population at a given time

79
Q

Infectious disease

A

Disease resulting from an infection by microbial agents

80
Q

Communicable disease

A

Can be transmitted from one host to another

81
Q

Two types of epidemics

A
  1. Common source epidemic: single common contaminated source (food)
  2. Propagated epidemic: one infected individual into a susceptible group, infection propagated to others
82
Q

Herd immunity

A

Resistance of a population to infection, and pathogens spread because of immunity of large percentage of the population
- Level can be altered by introduction of new susceptible individuals in a population
- level can be altered by changes in pathogen
A. Antigenic shift: major changes in antigenic character of pathogen.
B. Antigenic drift: accumulation of small, genetic changes over time 

83
Q

Reproductive number: R0

A

1/R0 = % of population that is required for R0 to equal 1
Ex: R0 of Covid is 6 - 1/6 = 16% of population needs to be susceptible in order to keep the new cases increasing

84
Q

Reducing susceptible population

A

Three types of control
1. Reduce or eliminate source of Reservoir or infection.
2. Break a connection between source and susceptible individual
3. Reduce number of susceptible individuals
- raises herd immunity
- passive immunity following exposure
- active immunity for protection

85
Q

Systematic Epidemiology

A

Focuses on ecological and social factors that influence development and spread of emerging and re-emerging diseases
- numerous factors have been identified

86
Q

Reasons for increase in emerging and re-emerging infectious diseases

A

World population growth, urbanization, inadequate public infrastructures, increased, international travel, mass, migration, climate, change, habitat disruption, and microbial evolution and development of resistance 

87
Q

Nosocomial infections

A

Healthcare acquired infections
- From pathogens within a hospital or other clinical care facility acquired by patience in the facility
- 5 to 10% of all hospital patients acquire a nonsocomial infection
- often caused by bacteria that are members of normal microbiota
- Many hospital strains are antibiotic resistant
- Prolong hospital stays by 4 to 14 days
- result in additional 28 to 33 billion per year to direct healthcare costs
- Result in approximately 99,000 deaths annually
- Proper training of personnel in basic infection control measures - for example, handling of surgical, wounds and handwashing
- monitoring of patient for signs and symptoms of nonscomial infection 

88
Q

Sources of healthcare associated infections

A
  1. Endogenous pathogen
    - brought into a hospital by a patient
    - Patient is colonized after admission
  2. Exogenous pathogen
    - microbiota other than the patients’
    - May come from hospital staff, other patients, visitors, food, plants, flowers, keyboards, intravenous and respiratory therapy equipment, water systems like dialysis

Microbiology (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions