Chapter 1: The Microbial World And You

Question 1

Microbe

Answer 1

“Microorganism”

Very small organism- microscope needed

Autotroph(self-feeders)

Question 2

(Human) microbiome

Answer 2

“Microbata”

Group of microbes
-in and out if our bodies
-keeps us healthy

Question 3

Staphylococcus aureus

Answer 3

Bacteria

Location: nasal epithelial cells

Generally live harmlessly on or inside nose

Exception: misuse of antibiotics
➡️ survival of bacteria w/ antibiotic resistance genes
-ex. Methicillin-resistant S. Aureus (MRSA)

Cocci(spherical)

Question 4

Signs

Answer 4

Objective changes observed and measured by healthcare practitioners

Ex. Ring-like rash- sign of infection

Question 5

Symptoms

Answer 5

Changes felt by pt

Subjective

Not measurable by an observer

Ex. Itchy, burning skin

Question 6

Bacteria

Answer 6

Simple-celled

Prokaryotic (no nucleus or organelles) organisms

Contain peptidoglycan (carb and protein complex) in cell walls

3micrometers

Reproduce asexually via binary fission

Shape: coccus, bacillus, or spiral-shape
-important in dx

Genetic info: DNA

Lipid bilayer: present

Ribosome: small, unique

RNA polymerase: simple, 5 subunits

Grow w/o outside help: yes

Max # of cells: 1

First cells on earth

Contain over 50 different phyla (major groups)

Most abundant form of life- no matter bacteria growing in/on humans than they have human cells

Antibiotic sensitivity: Yes

Nutrition source: organic chemical (derived from dead or living organisms); photosynthesis; inorganic substances

Motile: flagella

Question 7

Binary fission

Answer 7

type of asexual reproduction where a cell splits into two identical daughter cells

Used by bacteria

Question 8

Cocci

Answer 8

Spherical

Of arranged in clusters or chains

Question 9

Fungi

Answer 9

-eukaryotes
-reproduce sexually and asexually
-true fungi contain chitin (carb) in cell walls
-nutrition source: absorption of organic material from their environment

-yeast- unicellular fungi
-larger than bacteria
-oval-shaped

-mold- multicellular fungi
-composed of long filaments of cells (hyphae) that branch and intertwine to form visible masses (mycelia)

Question 10

Branch-intertwined nucleated hyphae may indicate

Answer 10

A fungal infection like Tinae corporis (ring worm)

-cause by fungus: Trichophyton rubrum

-anti fungal cream

Question 11

Nomenclature: Genus; species naming

Answer 11

Genus: capitalized and italicized or underline

Species: noncapitalized and italicized or underlined

Trichophyton (genus) rubrum (species)

Abbreviation: T. rubrum

Established by Carolus Linnaeus in 1735

Question 12

Protozoa

Answer 12

-unicellular eukaryotes
-5 micrometers
-most live on their own
-exception: some- parasitic, requires host for nutrients
-motile- via flagella,cilia, pseudopods
-some are photosynthetic (ex. Euglena)
-reproduce sexually or asexually

Question 13

Bacilli

Answer 13

Rod-shaped

Question 14

Helminths

Answer 14

-parasitic worms
-eukaryotic
-0.7mm
-adult: macroscopic
-child: microscopic
-dx of tapeworm infection requires microscopic observation of eggs in feces

Question 15

Spirilli

Answer 15

Spiral-shaped

Question 16

Viruses

Answer 16

-acellular
-ultra small particles
-contain a core made up of DNA and RNA surrounded by a protein coat
-require host to reproduce
-strict parasites of other forms of life
-many feel viruses are not alive as they are obligate parasites and cannot replicate w/o other cells
-reproduce by using cellular machinery of other organisms- considered living only when they multiply in host cell they infect

Question 17

Microbiology

Answer 17

Study of living things too small to be seen w/ naked eye
1) bacteria
2) archea
3) eukaryota
4) viruses

Question 18

Antibiotics

Answer 18

Chemicals naturally produced by bacteria or fungi to act against bacteria

Question 19

Pleomorphic

Answer 19

Multiple shapes are possible

Question 20

Pathogen

Answer 20

Microorganism or other substance that can cause disease in a host organism

Question 21

Infectious disease

Answer 21

Condition caused by invasion and multiplication of microorganisms in a living host

Question 22

List several ways in which microbes affect our lives

Answer 22

1) Important in maintaining Earths ecological balance.
-marine/freshwater: form basis of food chain in oceans, lakes, and rivers
-soil: breakdown wastes and incorporate nitrogen (g) from air into organic compounds➡️ recycle elements among soil, H2O, living organisms, and air
2) Live in humans and other animals and are needed to maintain good health.
3) Are used to produce foods and chemicals
-vitamins, organic acids, enzymes, alcohols, and many drugs
-acetone, butanol,vitB2 (riboflavin) and B12 (cobalamin)
4) Can cause disease.
5) photosynthesis
6) enzymes in microbes can be manipulated to cause microbes to produce substances they normally don’t synthesize
-cellulose, insulin, and proteins (for vaccines)

Question 23

Explain the importance of observations made by Hooke and van Leeuwenhoek

Answer 23

1. Robert Hooke observed that cork was composed of “little boxes”; he introduced the term cell (1665).
2. Hooke’s observations laid the groundwork for development of the cell theory, the concept that all living things are composed of cells.
3. Anton van Leeuwenhoek, using a simple microscope, was the first to observe microorganisms (1673).
   -microorganisms, living beings he characterized as “animalcules” (little animals)

Question 24

Spontaneous generation

Answer 24

1) Until the mid-1880s, many people believed in spontaneous generation, the idea that living organisms could arise from nonliving matter.

2) Francesco Redi demonstrated that maggots appear on decaying meat only when flies are able to lay eggs on the meat (1668).

3) John Needham claimed that microorganisms could arise spontaneously from heated nutrient broth (1745).

4) Lazzaro Spallanzani repeated Needham’s experiments and suggested that Needham’s results were due to microorganisms in the air entering his broth (1765).

5) Rudolf Virchow introduced the concept of biogenesis: living cells can arise only from preexisting cells (1858).

6) Louis Pasteur demonstrated that microorganisms are in the air everywhere and offered proof of biogenesis (1861). S-shaped flask

7) Pasteur’s discoveries led to the development of aseptic techniques used in laboratory and medical procedures to prevent contamination by microorganisms.

Question 25

Identify the importance of Koch’s Postulates

Answer 25

discovers bacillus anthrasis prove that specific mocrobes casue specific disease Criteria used to determine the causative agent of infectious disease 1. The causative agent must be isolated in every case of the disease, but absent from those who are healthy. 2. The causative agent must be cultured outside the host. 3. When injected into a healthy, susceptible host, the host must get the disease. 4. The pathogen must be isolated from the once healthy host when it becomes sick, and must be shown to be the original organism.

Question 26

Identify the importance of Jenner’s work

Answer 26

1) In a vaccination, immunity (resistance to a particular disease) is conferred by inoculation with a vaccine. 2) In 1798, Edward Jenner demonstrated that inoculation with cowpox material provides humans with immunity to smallpox. 3) About 1880, Pasteur discovered that avirulent bacteria could be used as a vaccine for fowl cholera; he coined the word vaccine. 4) Modern vaccines are prepared from living avirulent microorganisms or killed pathogens, from isolated components of pathogens, and by recombinant DNA techniques.

Question 27

Identify the importance of Fleming’s work

Answer 27

Alexander Fleming observed that the Penicillium fungus (mold) inhibited the growth of a bacterial culture. He named the active ingredient penicillin (1928). Penicillin has been used clinically as an antibiotic since the 1940s (when 2nd Golden Age of Microbiology began)

Question 28

Identify the importance of pasteur’s work

Answer 28

Pasteur became a pioneer in the development of vaccinations- the introduction into the body of a mild (attenuated) form of a pathogen to produce immunity from the more harmful strain of the disease. He developed vaccinations for anthrax and fowl cholera, but his rabies vaccine was the most famous.

Question 29

Identify the importance of Redi’s work

Answer 29

Francesco Redi is recognized for his significant contribution to biology by conducting one of the first controlled experiments that effectively disproved the theory of spontaneous generation, demonstrating that maggots on decaying meat arise from flies laying eggs on it, not from the meat itself this established the concept that life only comes from pre-existing life, marking him as a pioneer in experimental biology and parasitology

Question 30

Identify the importance of Semmelweis’ work

Answer 30

Ignaz Semmelweis is credited with significantly contributing to the field of medicine by discovering the importance of handwashing in preventing the spread of infection, particularly in the context of childbed fever (puerperal fever), which he identified as being transmitted by doctors who did not properly sanitize their hands after performing autopsies, leading to a dramatic reduction in maternal mortality rates when he implemented mandatory handwashing with a chlorinated lime solution among medical staff.

Question 31

Identify the importances of Lister’s work

Answer 31

Joseph Lister helped introduce germ theory and laid the foundation for the use of antiseptics in the practice of medicine and surgery. Today, asepsis and sterile techniques have replaced antisepsis as the principal method in combating wound infection

Question 32

Identify the importance of Koch’s work

Answer 32

-Koch established the principle that specific pathogens cause specific diseases, which was a major advancement in medical microbiology. -He developed agar plates for culturing bacteria, allowing for the isolation and identification of pathogens. -Koch's postulates outline a four-step process to establish a causal relationship between a microbe and a disease, which includes: 1) The same pathogen must be present in every case of the disease. 2) The pathogen must be isolated and grown in pure culture. 3) The cultured pathogen must cause the disease when introduced to a healthy organism. 4) The pathogen must be re-isolated from the inoculated, diseased host.

Question 33

Identify the importance of Needham’s work

Answer 33

John Needham's main contribution to science was his experiment attempting to prove the theory of spontaneous generation by boiling broth, which he believed would kill existing microbes, then sealing the flask and observing the later growth of microorganisms, leading him to conclude that life arose spontaneously from non-living matter However, his experiment was later disproven by other scientists who showed that he did not adequately sterilize the broth, highlighting a flaw in his methodology.

Question 34

List the 3 domains to classify organisms

Answer 34

1) bacteria 2) archae 3) eukarya

Question 35

Biofilm

Answer 35

Cultures (usually mixed) that are stuck to a surface Often more resistant than single colonies and have health and environmental issues

Question 36

Prions

Answer 36

Abnormal forms of naturally occurring proteins in the brain that cause various neurodegenerative diseases (transmissible spongiform encephalopathies (TSEs))

Question 37

Archaea

Answer 37

Most common in extreme environments -combine feature of prokaryotes and eukaryotes -extremophiles; some will grow when other organisms cannot -halophiles: salt loving -sulfophiles: sulfur loving -thermotropes: heat loving -lithotrophs: rock loving -methanophiles: methane loving Antibiotic sensitivity: No Does not cause disease in humans

Question 38

Eukarya

Answer 38

Single celled (yeast, algae, and amoebas) or multicellular (fungi, plants, and animals Contain membrane-bound sub compartments that separate specific functions, particularly the nucleus Division includes microscopic organisms previously belonging to the Monera kingdom Antibiotic sensitivity: No No cell wall

Question 39

Pathogen

Answer 39

Disease-causing

Question 40

Bactericides

Answer 40

Bacterium commonly found in large intestine

Question 41

Horizontal gene transfer

Answer 41

movement of genetic material between organisms that are not related by parent and offspring Bacteria’s ability to swap genes w/ other genes

Question 42

Normal microbiota

Answer 42

“Normal microbiota” Microorganism that colonize a host w/o causing disease

Question 43

Transient microbiota

Answer 43

Microorganisms that are present in an animal for a short time w/o causing a disease

Question 44

coli-

Answer 44

Of the large intestine

Question 45

entero-

Answer 45

Found in intestines

Question 46

pyo-

Answer 46

Forms pus

Question 47

cerevisia

Answer 47

Make beer

Question 48

chryso

Answer 48

Produce yellow pigment

Question 49

Antibiotics

Answer 49

Can treat bacterial infections No effect on viruses

Question 50

Algae description

Answer 50

-photosynthetic eukaryotes -wide variety of shapes -reproduce sexually and asexually -unicellular (ex. Diatoms) or multicellular (ex green algae) -cell walls composed of cellulose (carb) -photosynthetic -do not require organic compounds from environment

Question 51

Multicellular animal parasites

Answer 51

-not strictly microorganisms -eukaryotes 1)parasitic worms= flatworms 2)helminths= roundworms -early life: microscopic

Question 52

Cellular organization of organisms

Answer 52

By Carl Woese in 1978 1) bacteria (cell walls contain a protein-carb complex- peptidoglycan) 2) archaea (cell walls, if present, lack peptidoglycan) 3)eukarya -protists (slime molds, protozoa, and algae) -fungi (unicellular yeasts, multicellular molds, and mushrooms) -plants (mosses, ferns, conifers, and flowering plants) -animals (sponges, worms, insects, and vertebrates)

Question 53

Robert Hooke importance

Answer 53

1665- observed thin slice of cork through crude microscope Conclusion: life’s smallest unit: cells Hooke used improved microscope and saw individual cells➡️ marked beginning of cell theory -“all living things are composed of cells”

Question 54

Anton van Leeuwenhoek importance

Answer 54

First to observe microbes (1673-1723)- wrote about “little animalcules”- bacteria and Protozoa

Question 55

Fermentation

Answer 55

Process discovered by Pasteur in which microbes called yeast convert the sugar to alcohol in the absence of air -souring and spoilage of wine and beer caused by bacteria -in the presences of air, bacteria changes alcohol into vinegar (acetic acid)

Question 56

Algae

Answer 56

Not plants- no stems, leaves, or vascular system to transport water and nutrients throughout their body Unicellular or multicellular Motile Do not make flowers or seeds Green algae contain chloroplasts and cellulose in cell walls composed

Question 57

Chemotherapy

Answer 57

Treatment of disease using chemical substances For noninfectious diseases (ex. Cancer)

Question 58

Synthetic drugs

Answer 58

Chemotherapeutic agents prepared chemicals in lab The success of chemotherapy is based on the fact that some chemicals are more poisonous to microorganisms than to hosts infected by the microbes By 1930s several synthetic drugs- most derive red from dyes along w/sulfa drugs

Question 59

Paul Ehrlich importance

Answer 59

-(1910) -found salvarsan (chemotherapeutic agent; arsenic derivative effective against syphilis) -not “magic bullet”

Question 60

Alexander Fleming importance

Answer 60

-1928, penicillin, an antibiotic (substance that is made by organism (ex. Mold))- ➖growth of another organism, was discovered

Question 61

Negative effects of antibiotics

Answer 61

-many anti microbial chemicals kill infected host as well pathogenic microbes

Question 62

Viral growth

Answer 62

Process by which a virus replicates itself w/in host cell

Question 63

Why is there very few successful antiviral drugs?

Answer 63

B/c a drug that would interfere w/ viral reproduction would also likely affect uninfected cells of the body

Question 64

Bacteriology

Answer 64

-study of bacteria -began w/ van Leeuwenhoeks first exam of tooth scrapings

Question 65

Heide Schultz importance

Answer 65

1997- discovered bacterium (Thiomargarita namibiensis)large enough to be seen w/ unaided eye (0.2mm wide) -lives in mud on African coast -consumes hydrogen sulfide- toxic to mud-dwelling animals

Question 66

Mycology

Answer 66

Study of fungi

Question 67

Parasitology

Answer 67

Study of Protozoa and parasitic worms Parasitic diseases have recently been found in pts whose immune systems have been suppressed by organ transplants, cancer therapy, or AIDS

Question 68

Immunology

Answer 68

Study of immunity Smallpox vaccine was so effective that the disease has been eliminated

Question 69

Rebecca Lancefield importance

Answer 69

1933- proposed that streptococci be classified according to serotypes (variants w/in a species) based on certain components in the cell walls of bacteria Allowed for prevention of the variety of diseases caused by Streptococcus pyogenes -strep throat -scarlet fever -septicemia (blood poisoning)

Question 70

Interferons

Answer 70

Substances generated by the body’s own immune system Discovered in 1960s ➖replication of viruses and have triggered considerable research related to the treatment of viral diseases and cancer

Question 71

Virology

Answer 71

Study of viruses Originated during First Golden Age of Microbiology

Question 72

Dimitri Iwanowaski importance

Answer 72

1892- reported that the organism that caused mosaic disease was so small that it passed through filters fine enough to stop all known bacteria At the time he was not aware that organism in question was a virus

Question 73

Mosaic disease

Answer 73

plant disease caused by viruses that cause leaves to develop a mottled, discolored appearance

Question 74

Wendell Stanley importance’s

Answer 74

1935- demonstrated that the organism (tobacco mosaic virus (TMV)) was fundamentally different from other microbes and so simple and homogeneous that it could be crystallized like a chemical compound Facilitated the study of viral structure and chemistry

Question 75

e-microscope

Answer 75

1930s Observation of the structure of viruses in detail

Question 76

Microbial genetics

Answer 76

Studies the mechanisms by which microorganisms inherit traits

Question 77

Molecular biology

Answer 77

Looks at how genetic info is carried out in molecules of DNA

Question 78

Who demonstrated relationship between genes and enzymes?

Answer 78

George W. Beadle and Edward L. Tatum

Question 79

Conjugation

Answer 79

When genetic material is transferred from one bacterium to another Discovered by Joshua Lederberg and Edward L. Tatum

Question 80

Genomics

Answer 80

Study of all of an organism’s genes Allows scientists to classify bacteria and fungi according to their relationships with other bacteria, fungi, and Protozoa

Question 81

Joseph Lister importance

Answer 81

Applied disinfectant phenol to surgical dressings

Question 82

Joseph Lister importance

Answer 82

Applied disinfectant phenol to surgical dressings

Question 83

Joseph Lister importance

Answer 83

Applied disinfectant phenol to surgical dressings

Question 84

Ignaz Semmelweis

Answer 84

Showed the importance of handwashing to reduce puerperal (child fever) infections

Question 85

Smallpox cause by…

Answer 85

Virus

Question 86

Smallpox cause by…

Answer 86

Virus

Question 87

R

Question 88

Who proved germ theory?

Answer 88

Robert Koch

Question 89

members of which genus of bacteria are best stained using acid fast method

Answer 89

Mycobacterium

Question 90

While _ bacteria retain carbol fuchsin after acid-alcohol treatment, _ bacteria’s decolonized by acid-alcohol

Answer 90

Acid-fast; non-acid-fast

Question 91

thick waxy layer of what substance in the cell wall constitutes the major portion of the mycobacterial cell wall, separating it from other microorganisms?

Answer 91

Mycolic acids (lipoidal)

Question 92

What color do you expect Escherichia coli to be after performing the acid-fast stain?

Answer 92

Blue

Question 93

What color would you expect Mycobacterium smegmatis to be after performing the acid-fast stain?

Answer 93

Red

Question 94

What is the purpose of heating a slide during the staining process?

Answer 94

Allows for further penetration of the stain through the lipoidal wall and into the cytoplasm

Question 95

Loss of bent, or refracted, light results in a reduced numerical aperture, which diminishes the resolving power of the objective lens. Adding which of the following substances between the slide and the lens acts to decrease the refraction of light?

Answer 95

Oil

Question 96

Microbes and human welfare

Answer 96

A.​Recycling Vital elements (nitrogen, hydrogen, carbon, sulfur) 1.​Nitrogen, carbon, and oxygen cycle 2.​Sewage Treatment B.​Bioremediation 1.​Definition: Bacteria (bacillus or pseudomonas) degrade or detoxify pollutants such as oil and mercury C.​Biological Insecticides D.​Modern Biotechnology and Genetic Engineering

Question 97

Microbes and human diseases

Answer 97

A.​Normal Microbiota or Normal Flora (Human Microbiome) are bacteria and yeast present in and on the human body, causing no harm. 1. Benefits: digestion, synthesis of vitamins, growth factors; nonspecific defenses (innate); microbial antagonism B.​Biofilms Definition: complex aggregation of microbes; attach to each other and surfaces in contact w/ water C. ​Pathogens (disease-causing organisms) D.​Susceptible Host- an organism in which the pathogen causes disease E. ​Opportunistic Pathogens (potentially pathogenic organisms)- immunocompromised persons more susceptible ​ 1. Examples: E. coli (bacteria) and yeast > U.T.I. F.​Resistance is the ability of the body to ward off disease. Resistance factors include skin, stomach acid, and antimicrobial chemicals

Question 98

How are biofilms beneficial and harmful?

Answer 98

​Biofilms may be beneficial: 1. Protect mucous membranes from harmful microbes 2. In lakes are an important food source for aquatic animals Biofilms may be harmful: 1. Biofilms can form on teeth (dental plaque), contact lenses, and catheters 2. Microbes in biofilms are more resistant to antibiotics and disinfectants 3. Microbes in biofilms are protected from host’s defenses