1
Q
Identify who among the following prominent individuals in the field of microbiology developed the process of heating liquids to kill harmful microorganisms.
A
Louis Pasteur
2
Q
Robert Koch’s postulates
(Used to establish criteria for determining causative agent of an infectious disease)
A
- The same organism must be present in every case of the disease
- The organism must be isolated from the diseased host and grown in pure culture
- The isolated organism *should cause the disease in question when it is introduced into a susceptible host.
- The organism must then be reisolated from the inoculated diseased animal.
3
Q
Microbe
A
Cellular living organisms such as bacteria, archaea, fungi, protists, and helminths
And non living/ non cellular entities viruses and prions (infectious proteins)
4
Q
prokaryotic cells
A
Earth’s earliest lifeforms. They include unicellular bacteria and archaea (are-KEY-uh), which are structurally and functionally simpler than eukaryotic cells.
No membrane, no organelle
5
Q
eukaryotic cells
A
Eukaryotic cells make up all multicellular organisms and a number of unicellular microorganisms such as amoebae and yeast. The endosymbiotic theory states that eukaryotic cells evolved from prokaryotic cells.
Protists
Fungi
Helminths
NONliving : viruses and prions
6
Q
pathogens
A
microbes that cause disease. However, most microbes are not pathogens.
7
Q
opportunistic pathogens
A
Among pathogens, we find so-called true pathogens, which in theory can cause disease in any otherwise healthy host, and we find opportunistic pathogens, which tend to cause disease only in a weakened host.
8
Q
Archaea
A
Prokaryotic
Unicellular; nonpathogenic; most live in extreme environments
9
Q
Protists
A
Eukaryotic
Unicellular (amoebae) and multicellular (algae) pathogenic and nonpathogenic
10
Q
Fungi
A
Eukaryotic
Unicellular (yeast) and multicellular (mushroom) pathogenic and nonpathogenic
11
Q
Robert Hooke
A
The first to observe eukaryotic cells publishes micrographia
12
Q
Antonie van Leeuwenhoek
A
Observes bacteria
Contemporary of Hooke, refined earlier versions of the microscope and became the first to see bacteria*
13
Q
Carl Linnaeus
A
Develops taxonomic naming system for organisms
14
Q
Edward Jenner
A
Successfully vaccinates against smallpox
15
Q
Ignaz Semmelweis
A
Implements handwashing to prevent childbed fever
16
Q
Florence nightingale
A
Establishes formal aseptic practices in nursing.
17
Q
Louis Pasteur
A
Presents his findings against spontaneous generation.
18
Q
Joseph Lister
A
Publishes his aseptic surgery techniques
19
Q
Robert Koch
A
The first person to prove microbe cause disease (work on anthrax)
Published postulates of disease.
Developed staining techniques and ways to grow and isolate bacteria.
20
Q
Alexander Fleming
A
Discovered penicillin
21
Q
Golden age of microbiology
A
1850-1920
Invention of microscope and new techniques.
22
Q
Spontaneous generation
A
The idea that life comes from nonliving items
23
Q
A
24
Q
Biogenesis
A
The idea that life emerges from life
25
One piece of evidence often cited as proof of spontaneous generation *
Was that rotting meat gave rise to maggots (Francesco Redi)
26
Pasteur proved
That yeast performed fermentation (they were not spontaneously generated by it) disproved spontaneous generation
The heating process to kill off yeast is known as pasteurization
Also proved that microbes contaminate through the air by using the S flask.
Developed the first vaccine to protect against anthrax and rabies
Played role in solidifying the germ theory disease.
27
The germ theory disease
States that microbes cause infectious disease.
28
Koch confirmed that
Not all infections cause evident disease
This is why the third postulate states that disease “should” result, but avoids the term “must”
29
Aseptic technique
Entails preventing the introduction of potentially dangerous microbes to a patient
(It does not mean that everything in the environment needs to be sterile (absent of microbes))
Techniques include:
Washing hands, wearing gloves, sterilizing instruments, and decontaminating surfaces.
Ignaz Semmelweis first developed aseptic techniques in 1840s
30
Scientific method
Starts with a question that can be investigated.
Next a hypothesis (a prediction based on prior experience or observation) is proposed as a potential answer to the question.
The researcher collects and analyses observations (data) and uses them to formulate a conclusion that states whether the data supported or contradicted the hypothesis.
31
An observation vs conclusion
Is any data collected using our senses or instrumentation
Whereas a conclusion interprets the observation
32
Law vs theory
Laws only hold true under carefully defined and limited circumstances.
By contrast a theory is a hypothesis that has been proven through many studies with consistent, supporting conclusions.
Laws predict what happens
While theories explain how and why something occurs.
Furthermore theories encompass laws.
33
Taxonomy groups and organisms
Carl Linnaeus established criteria for classifying and naming organisms
34
Taxonomic Hierarchy
Eight rankings
Domain, kingdom, phylum, class, order, family, genus, species
(Delightful King Phillip came over for great spaghetti)
35
Domain archaea
Living in extreme environments : high temperature deep sea vents.
Have not been shown to be pathogens.
36
Three domains
Bacteria: kingdom bacteria ex: S. Aureus
Archaea: kingdom archaea ex:Sulfolobus
Eukarya: kingdom (fungi, plantae, animalia, protists (not true kingdom)
37
Species is defined as
A group of similar organisms that sexually reproduce together or breed.
Such definition doesn’t work for prokaryotic cells like bacteria because they reproduce asexually.
Instead prokaryotic species are defined as cells that share physical characteristics but also have at least 70% DNA similarity * also at least 97% identical when genetic material in ribosomes (organelles that build proteins) is compared.
38
Strains
Prokaryotic species transfer genes and can take u genetic material from the environment.
Therefore recognizing genetic variants is helpful to microbiologists
Mutations and gene transfer often lead to new strains.
39
Scientific names
Binomial nomenclature system
Organisms first name is capitalized and reflects the genus,
Whereas the second name is lowercase and designates the species.
Scientific names are also italicized (or underlined if handwritten)
40
Symbiotic relationship
Exist when two or more organisms are closely connected
Parasitism: hurt host
*Mutualism: help the host
Commensalism: no benefit or cost to the host
41
People who carry the gene for sickle cell anemia
Are less likely to develop serious disease if infected by the *protozoan pathogens that cause malaria
42
Our normal microbiota includes
Bacteria, archaea, and eukaryotic microbes.
They train our immune system, produce vitamins for us, and help us digest food. They may even impact our moods and brain function. *
43
What makes microbiota “normal”
Location of the microbes rather than the species itself.
For example normal microbiota includes pathogens — 27% of adults asymptomatically carry Staphylococcus aureus on their skin.
44
Biofilms
Sticky communities made up of single or diverse microbial species.
Planktonic (free-floating) bacteria
Adhesion factors (fimbriae)
*Dental plaque is an example of biofilm
*60-80% of infectious diseases in humans are due to biofilm creating microbes.
*cystic fibrosis patients, kidney stones, inner ear infections, atherosclerosis, endocarditis and urinary tract infections involve biofilms.
45
Bioremediation
Typically involves introducing nitrogen, sulfur, phosphate, and sometimes iron supplements to a spill environment along with dispersants which break oil into smaller droplets to encourage microbes to more effectively breakdown the oil slick.
46
Growth media
Most culture media are poured as plates (Petri dish filled with solidified medium) deeps, slants, or broths.
47
Aseptic culture technique
Where conditions are maintained to limit contaminants so that only the desired microbes in a given sample are grown ( any not just pure )
48
Pure culture
In nature, microbes do not tend to grown in pure culture— that is they rarely exist as single species groups.
49
Streak plate technique
Helps to isolate a specific species of microbe for study, the general goal is to spread the sample thin enough on an agar plate so that the various cells in the sample are sufficiently separated and can give rise to individual colonies.
50
When grown on a plate
A pure culture has colonies that appear somewhat uniform in shape and color, even when the colonies vary in size.
By contrast a plate with mixed cultures will have at least two characteristically different colonies.
51
Stains
Increase contrast so the sample was easier to see.
52
Smear
Involves placing small amount sample on a glass slide.
53
Basic dyes (alkaline)
Positively charged ( attracted to negatively charged cell surface of microbes, easily enters cell)
Ex: methylene blue, crystal violet, safranin, malachite green.
54
Acidic dyes
Negatively charged (do not easily enter cells) stain background
Does not require heat or chemical fixation
Ex: nigrosin or India ink.
55
Mordants
Are chemicals that may be required in certain staining procedures to interact with a dye and fix or trap it on or inside a treated specimens .
Ex: iodine, alum,tannic acid
56
Simple staining
Technique use one dye, typically only size, shape, and cellular arrangement can be determined using simple stain.
57
Flagella
Eukaryotic microbes tend to have only one flagellum.
Prokaryotic have single or multiple flagella with diverse arrangements.
Staining techniques: coat sample with chemicals that act as mordants.
58
Capsule staining
Capsules are sticky carbohydrate based structures that some bacteria produce as a form of protection, also help them adhere to surfaces.
Capsules easily dissolve in water and cause infection.
Negative staining using acidic dye and usually used in coordination with basic dye.
59
Endospore staining
Heating to drive dye into spore, malachite green, counter stain with safranin.
Endospores dormant structure respond to stressful or harsh environmental conditions.
Spores green
60
Differential stains
Gram stain and acid fast stain.
61
Structural stains
Flagella staining
Capsule staining
Bacterial endospore staining
62
Gram stain
Gram positive: purple.
Thick peptidoglycan (protein carbohydrate substance)
No outer membrane
Gram negative: pink
Thin peptidoglycan
Outer membrane lipopolysaccharide (LPS) - toxic to animals and can trigger septic shock
63
Mycobacterium
Include pathogens that cause tuberculosis and leprosy.
These gram positive bacteria have a waxy cell wall that resists staining with crystal violet making them appear gram negative.
64
Acid fast staining
Waxy or no waxy cell wall
Mycolic acid
Positive: pink/red (primary stain)
Negative: blue (counter stain)
Important for detecting mycobacterium species: tuberculosis and leprosy.
65
Iris diaphragm
Allows viewers to modulate how much light is aimed at the specimen in order to improve contrast.
The light that interacts with the specimen is channeled through the objective lens, which magnifies the image and also enhances the resolution.
It continues up to the ocular lens where the image is further magnified before reaching the viewers eyes.
66
Immersion oil
Improves resolution
67
Dark field microscopy
Based on how light is scattered as opposed to how light is absorbed, so no staining is necessary*
(Not negative staining)
68
Electron microscopy
Resolution improves
With smaller wavelengths
TEM and SEM
69
TEM transmission electron microscopy
Most common for of electron microscopy
Provides 1 million times magnification and resolution, about 1,000 times better than that of light microscopy
TEM samples must be extensively pretreated.
Has been central to understanding viruses and how they interact with host cells.
70
SEM scanning electron microscopy
Overall resolution and magnification potential of SEM is lower than TEM
SEM helps see surface structure
TEM internal structures
71
UV light microscopy and probe microscopy techniques
Probe techniques:
Scanning tunneling- 3D image- atoms can be visualized sample must conduct electricity which limits what can be visualized.
Atomic force- 3D image- atoms cab be visualized *live samples under physiological conditions or fixed samples.
Microbiology Nursing
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