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Microbiology - Exam 2


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example of aerobe
Humans, Mycobacterium

(requires oxygen gas for metabolism)
example of anaerobe
- anaerobic metabolism in animal tissue(fermentation)
- bacteriods in large intestine

(doesn't require oxygen gas for metabolism)
example of obligate anaerobe

(doesn't require oxygen gas for metabolism, it is detrimental)
example of facultative anaerobe
E. coli

(can exist without oxygen gas but uses it when present)
example of microaerophile
Helicobacter pylori

(uses oxygen but grows best at lower than atmosheric levels of oxygen gas)
organic carbon source
Auto (concerning energy gathering by microbes)
inorganic carbon source
most common microbe

examples of:

- humans
- E. coli
List some inorganics used for energy
- sulfur
- iron
- ammonia
example of a chemoautotroph
example of photoautotrophs
-cyanobacteria (bluegreen algae)
example of photoheterotrophs
- green nonsulfur bacteria
- purple nonsulfur bacteria
Five classifications of Prokaryotes:
1. Cell shape and Arrangement
2. Colony Morphology
3. Differential Staining Response
4. Energy and C source
5. Serology (study of blood serum, examines antibodies)
basic cell shapes:
- bacillus
- coccus
- spiral
intermediate shapes:
- coccobacillus
- vibriod
variability in shape
example of a pleomorphic bacteria:
Corynebacterium diptheriae
population of microbes assumed to have grown from cfu on solid nutrient medium
1 cfu =
single microbial cell unless characteristically found in clusters or chains
Four colony characteristics:
1. Color
2. Margin
3. Elevation
4. Smooth or Rough
Hemolytic bacteria causing partial breakdown.
Alpha hemolytic

ex) Alpha hemolytic Strep (tooth abscess)
Hemolytic bacteria causing complete breakdown.
Beta hemolytic

ex) beta hemolytic Strep
Three enzymes involved in bacterial energy
1. Hemolysin
2. Lipase
3. Amylase
In a plate with triglyceride, a microbe with lipase:
dissolves the triglyceride out of the agar to use for energy
example of microbes pos. and neg. for lipase
neg. - Salmonella

pos. - Pseudomonas
In test for amylase (starch digestion):
iodine reacts and turns blue.
examples of microbes that can't use starch:
- Streptococcus
- Staphylococcus
examples of microbes that can use starch:
- Bacillus
Indicator color concerning acid production by microbes:
- acid production - red indicator
- no acid production - yellow indicator
test to tell apart many of the facultative anaerobic bacteria of family Enterobacteriaceae
examples of microbes from family Enterobacteriaceae
- Escherichia
- Salmonella
- Shigella
- Klebsiella
- Enterobacter
study of blood serum
locations of antigens
- can be part of cell wall
- can be glycocalyx
- can be flagella
- can be toxins secreted by microbes
O antigen

H antigen

K antigen
lipopolysaccharide antigen

flagellin antigen antigen

capsular antigen antigen
another name for strains
serovars or biovars
Use presence of unique flagellin protein on ______ flagella to identify _______
- E. coli
- 0157:H7
When first identified, thought to be poison
- could pass through a filter that trapped known microbes
- one of the first isolated was crystallized
example of virus
Tobacco Mosaic Virus
Noncellular infectious agent. Too small to be seen with Light Microscopy
capable of causing disease
Infectious agent
Each infectious agent =
Virion or Viral Particle
E. coli is ____x (or more) bigger than the avg. virus
use what unit of measurement to describe size of viruses?
What two groups of viruses look identical?
- Picornaviruses (18-30nm)

- Reoviruses (70nm)
Example of viruses within Picornaviruses (3)
1. common cold virus (Rhinovirus)
2. polio virus (Enterovirus)
3. Hepatitis A (Hepatovirus)
Example of Reovirus
Rotavirus - cause of GI upset
Viral Characteristics (2)
- Noncellular
- Obligate Intracellular Parasites
Viral Components (2)
- Nucleic Acid
- Capsid
Viruses have _____ nucleic acid(s)
Only one
Variations of viral nucleic acid
- dsDNA
- ssDNA
- dsRNA
- ssRNA
Variations of viral nucleic acid shape
- linear
- circular
- segmented
Protein covering that surrounds the nucleic acid
_______ are why viruses can be crystallized like facets on a gem crystal
What are the 3 varieties in capsid shape?
1. Helical
2. Polyhedral
3. Complex
Elongate, slender, thread-like virus
Helical virus
Examples of Helical virus (2)
- Tobacco Mosaic Virus
- Ebola Virus
20 sided polyhedral virus
example of icosahedral virus
Human Papillomavirus (HPV)
Cause of condyloma acuminata, One associated with cervical cancer HPV16, also genital warts
Human Papillomavirus (HPV)
This is a variation of polyhedral and helical and other shapes as well.
Complex virus
Is a virus that attacks bacteria = bacteriophage or phage
Complex virus
refers to the nucleic acid of a virus and it's capsid
Two extra components found in some virus
- envelopes
- enzymes not found in host cells
Simple viral envelope composition
1. lipids
2. or lipids & proteins
a. may find some CHO's
More complex viral envelopes
1. find spikes of protein or glycoprotein
example of virus with complex viral envelope
influenza virus
Examples of viral enzymes
- Reverse transcriptase
- HIV (retrovirus)
Early classification of viruses included _______ ________
target tissues
Viruses that target the skin
Viruses that target the nervous tissue
Viruses that target WBCs and Lymphatics
Newer classification of viruses includes: (4 common, 2 less common)
- nucleic acid
- capsid
- whether enveloped
- size

less common
- geographic location
- shape
use limited nomenclature with viruses because?
they're not alive
Classification of viruses occurs mostly at the _______ level

- ending w/ idae
Genus name ending of _______
- virus (italisize or underline)
example of common virus name
Cold sore virus
Cold sore virus
Final name
- Herpes viridae
- Simplexvirus
- Human Herpes Virus 1 (HHV1)
Breakdown of family name Picornaviridae
Pico - small
rna - RNA is nucleic acid
vir - virus
idae - is family ending
5 phases of the viral replication life cycle
1. Adsorption/attachment
2. Penetration
3. Synthesis/biosynthesis
4. Maturation/assembly
5. Release
Viruses specific to host tissues, attaches to host protein receptor like lock & key
In this phase, the genetics of the virus enter the cell and are released.
Two means of viral Penetration
1. Fusion (aka Envelope Fusion)
2. Endocytosis
In the envelope is the viral antigen, when antigen contacts the receptor lipids merge (envelope and cell membrane)
Fusion/ Envelope Fusion
Host cell brings viral particle in and digests away its capsid
- host cell pinches in its membrane to bring particle into cell
- virus ends in vessel or vacuole, and capsid digestion occurs
- capsid breaks down (uncoating) releasing the nu
Endocytosis (occurs with naked virus)
In this phase the viral nucleic acid takes over the cell and tells the cell to make more viruses.
- The virions are formed inside the host cell.
- The capsomeres forming a capsid around the viral nucleic acid
Maturation (Assembly)
The virions are released from the host cell usually by one of two means
Two means of Release
1. Rapid lysis
2. Budding
Host cell deteriorates and all virions are loose
Rapid lysis

(associated with cell death)
Virions approach cell membrane and push through it.

(doesn't necessarily cause cell death, depends on number released at one time)
- Virus penetrates and goes into an equilibrium with host
- May not cause host cell damage
- May be years before cycle completes if ever
Latent Viral Infection
Example of Latent Viral Infection
- persistent viral infection
- occurs gradually over long time, perhaps building up over decades
- can see changes in numbers of infectious viral particles
Slow Virus Infection
Example of Slow Virus Infection
Measles virus
Virus were first associated with cancer in what case?
Chickens with leukemia, and sarcoma
What was the viral cause in mice?
Adrenocarcinoma of mammary tissue
Cancer of the connective tissue
Cancer of the epithelial tissue
cancer of glandular epithelium
________ are part of normal host cell genetics.
Factors which can triggered abnormalities in oncogenes
- Radiation
- Mutagenic (carcinogenic) chemicals
- viruses (Oncovirus)
Causes of _______ ?

- Cancer cell transformation
- Cell shape changes, nucleus appears different with strange chromosomes
- See new proteins added to cell membranes
- (Tumor Specific Transplantation Antigen) or nucleus (T antige
triggered Oncogene
Viruses associated with cancer in humans (2)
- Epstein Barr Virus (Type of Herpesvirus) associated w/ nasopharyngeal carcinoma
- Papillomavirus associated w/ cervical cancer
Viral cultivation methods (3)
- Living animal hosts
- Embryonated eggs
- Cell culture
Living animal hosts method
adv. and disadv.
- Study the immune system responses to the virus
- Not all animals can contract human viruses, cannot be grown this way (also labor intensive and expensive)
- Use of fertile eggs w/ fetal chick or duck
- Drill hole inject virus on membranes around the chick/duck
- After virus grows, will see lesions called plaques on membrane - harvest these
Embryonated culture
Advantages of embryonated eggs method
- less expensive, more convenient than animals

- Can grow relatively large amounts of viruses
Disadvantages of embryonated eggs
- Must keep entire area sterile, to prevent other microbes from incubating
- When harvesting may contaminate with egg protein, problem if people have allergies to eggs (or feathers)
- Grows cells of tissue in a nutrient medium in a shallow dish like a Petri dish
- Normal cells divide until a layer of single cells is formed across the bottom of dish (called a monolayer)
- Inoculate the monolayer with the viruses
- May
Cell culture
Advantages of cell culture
- easiest means of cultivating viruses, requiring the least amount of space, no egg incubators/ animal eggs
- Less chance of allergic reaction since using human tissue
Disadvantages of cell culture
- Not all human tissues can be grown in cell culture
- Must still keep area sterile and use aseptic
- Not all tissues can be grown indefinitely from one harvest of tissue
Won't last well in labs (last ~ 2 weeks)
Primary lines
Grow well in labs (must be of living fetus, last 2 weeks)
Fetal lines
Potential unlimited line (line from woman 1951 still used today)
Cancer cell line
Defense that works the same against any kind of invading pathogen
Nonspecific defense
- Defined as body resistance associated with our portals of entry
- Portals of entry are places microbes use to gain access to our body
First Line of Defense (FLOD)
3 subcategories of FLOD
- Mechanical Defense
- Chemical Defense
- Biological Defense
Defense that physically blocks or entraps particles
Mechanical defenses
Parts of _______

- Intact dry skin
- Ciliated Mucous Membrane in Respiratory area
- Tears
- Earwax (cerumen)
- vomiting/diarrhea
Mechanical defense
Use general chemical to kill microbes
Chemical defenses
Examples of _______

- Stomach Acid
- Acidic Vaginal Secretions
Chemical defenses
- resident microbes in and on certain places of the body.
Biological defenses
Biological microbes commonly found in (3 places of body)
- skin
- nasal passages
- large bowels
microbes adapted to exist in various parts of the body
Resident Flora
example of Biological defense resident flora
- E. coli
Two parts of SLOD
- Inflammation
- Phagocytosis
4 cardinal signs and symptoms of tissue damage
Itch sometimes
Causes of inflammation
- increased permeability of blood vessels (capillaries)
- increased blood flow by vasodilation
- pain(itch) from trigger of local neurons
Method of body's response to damage
- Damaged cells and local WBC's release chemical messengers that alert local blood vessels and neurons
Examples of chemical messengers (2)
- histamines (from WBC)
- prostaglandins (from damaged cells)
Advantages of inflammation
- swelling allows defensive chemicals and cells to escape the bloodstream (antibodies, clotting agents, WBC's)

- heat and redness - increased blood brings more oxygen, nutrients to damaged cell

- pain alerts you that you have hurt yourself so stop doing it
All WBCs except _______ do phagocytosis
________ is usually first on scene of infection. _________ usually arrive second on the scene.
neutrophil, monocytes
If infection persists more chemical signals are released that trigger the Red Bone Marrow to start producing even more WBC's. This is called _________
Transfer of genes by a virus
Transfer of genes as "naked" DNA in solution
example of bacteria that underwent transformation
Streptococcus pneumoniae
Transfer of genetic material via cell-to-cell contact
Examples of bacteria which use Sporolation
- Bacillus
- Clostridium
Three methods of measuring numbers of bacteria
1. Waterblank
2. Petroff-Heusser Counting cell
3. Turbidometer
Problems with Waterblank
takes day to get results
range of colonies for waterblank
problem with Petroff-Heusser counting cell
can't tell dead bacteria from living. Eye strain
Problem with turbidometer
counts dead bacteria (they also block light
Viral diseases of the Lower Respiratory system
- Viral Pneumonia
- RSV (Respiratory Syncytial Virus)
- Influenza
Causative agent of ________

- mycoplasmal pneumonia
- Can be complication of influenza, measles, or pneumonia
Viral Pneumonia
Cause of _______

- Respiratory Syncytial Virus
RSV, respiratory disease in INFANTS
Symptoms of ________

- coughing
- wheezing for more than a week
Prevention of RSV
- Naturally aquired immunity is poor
- Protective vaccines being developed
Treatment for RSV
- Antiviral ribavirin reduces symptoms for sever patients
Causative agent of _______

- Influenzavirus
Symptoms of Influenza
- chills
- fever
- headache
- muscular aches
Prevention of Influenza
- No vaccine
Causative agent of Mumps
Mumps virus
Symptoms of Mumps
- swelling of one or both parotid glands 16-18 days after exposure
- fever
- pain during swallowing
Prevention of Mumps
- vaccine available
Causative agent of Hep. A
- HAV, ssRNA (no envelope)
Symptoms of Hep. A
- usually none, fever, headache, malaise, jaundice
Prevention of Hep. A
- no vaccines, immune globulin provides temp. protection
Causative agent of Hep. B
- HBV, dsDNA (envelope)
Symptoms of Hep. B
- usually none, fever, likely to cause severe liver damage
Prevention of Hep. B
- Genetically engineered vaccine
Causative agent of Hep. C
- HCV, ssRNA (envelope)
Symptoms of Hep. C
- like HBV, but likely to become chronic
Prevention of Hep. C
- None
Causative agent of Hep. D
- HDV, ssRNA (envelope)
Symptoms of Hep. D
- Severe liver damage. Increased mortality rate
Prevention of Hep. D
- HBV vaccine protective
Causative of Hep. E
- HEV ssRNA (no envelope)
Symptoms of Hep. E
- like HAV/ but pregnant women have increased mortality
Prevention of Hep. E
- none (under development)
Epidemiology of Genital Herpes
~ 44 million in U.S. have HSV-2
~ 4 million in U.S. have HSV-1
Epidemiology of Genital Warts
~ 1 million new cases / year

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