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SCCC Micro Lab Final
SCCC Micro Lab Final
107
Microbiology
Undergraduate 2
05/08/2012

Additional Microbiology Flashcards

 


 

Cards

Term
(2-9) Bacteria can survive at temperatures as low as ____ and as high as _____.
Definition
-10°C, 110°C
Term
(2-9) Define the 3 cardinal temperatures:
Definition

-minimum - organism will not survive below this temp

-maximum - organism will not survive above this temp

-optimum - temperature at which an organism shows its highest growth rate

Term
(2-9) Define the optimum temperature range for - Psychrophile
Definition
below 20°C
Term
(2-9) Define the optimum temperature range for - Psychrotroph
Definition
between 0°C - 30°C
Term
(2-9) Define the optimum temperature range for - Mesotroph
Definition
between 15°C - 45°C
Term
(2-9) Define the optimum temperature range for - Thermophile
Definition
above 40°C
Term
(2-9) Define the optimum temperature range for - Obligate Thermophile
Definition
will not grow below 40°C
Term
(2-9) Define the optimum temperature range for - Faculative Thermophile
Definition
will grow below 40°C
Term
(2-9) Define the optimum temperature range for - Extreme Thermophile
Definition
grow best betwen 65°C - 110°C
Term
(2-9) Thermal Classifications of Bacteria
Definition
[image]
Term
(2-9) Why do different temperatures produce different growth rates?
Definition
Because different bacteria are adapted to different habitats. Different enzymes dictate what temperature organisms can thrive.
Term
(2-14) Define - Germicide
Definition
substances designed to reduce the number of pathogens
Term
(2-14) Define - Disinfectant
Definition
germicides used on surfaces & liquids
Term
(2-14) Define - Antiseptic
Definition
germicides used on or in living tissue
Term
(2-14) Name the test used to determine the effectiveness of a germicide
Definition
Use-Dilution Test
Term
(2-14) Write the genus of each of the 3 organisms usually tested
Definition
Staphylococcus, Salmonella, Pseudomonas
Term
(2-14) Glass ______ are coated with _________.
Definition
beads, living bacteria
Term
(2-14) The coated beads are then dipped in varying ____________ of a test germicide
Definition
dilutions
Term
(2-14) They are then _______________.
Definition
transferred to a growth medium
Term
(2-14) After incubation, we look for _______________
Definition
microbial growth
Term
(2-14) To meet the standards, the solution must be able to inhibit growth ________% of the time
Definition
95
Term
(2-14) Which germcide was the most effective and at what concentration? Which was the least effective?
Definition

Lysol was the most efffective, worked at all concrentrations on S. aureus and E. coli.

Hydrogen peroxide was the least effective, did not work on E. coli at any concentration, only worked at 3% concentration to kill S. aureus. Hydrogen peroxide will not work on organisms that produce catalase.

Term
(2-14) Which organism seemed to be most resistant to the most germicides?
Definition
E. coli
Term
(2-14) Explain the purpose of the control tubes.
Definition

-control tube #1 was to make sure the bacteria are alive

-control tube #2 was to make sure the broth is sterile

-control tube #3 was to make sure the bacteria was not washed of the glass beads

-control tube #4 was to make sure the beads and the sterile water were sterile

Term
(7-3) Define antibiotic
Definition
natural antimicrobial agents produced by microorganisms
Term
(7-3) What is the current term for an agent that is used to treat a bacterial infection?
Definition
anti-microbials
Term
(7-3) The disc diffusion test is also called the:
Definition
Kirby-Bauer test
Term
(7-3) Paper discs are impregnated with
Definition
antimicrobics
Term
(7-3) They are then placed on a large plate that has been covered with a _____ of bacteria
Definition
lawn
Term
(7-3) Explain the 2 things that occur during incubation
Definition

-growth of the bacteria

-diffusion of antimicrobial into the agar

Term
(7-3) The concentration of the antimicrobial substance is ____________ close to the disc
Definition
higher
Term
(7-3) The size of the "zone of inhibition" is dependant on:
Definition

-sensitivity of the bacteria to the specific antimicrobial agent

-the point at which the chemical's minimum inhibitory concentratio (MIC) is reached

Term
(7-3) Define bactericidal
Definition
a drug that kills the organism
Term
(7-3) Define bacteriostatic
Definition
a drug that stops the organism's growth but does not kill it
Term
(7-3) The name of the type of agar used is
Definition
Mueller-Hinton
Term
(7-3) The pH of the media is
Definition
7.2 - 7.4
Term
(7-3) The media is ______ deep in the plate
Definition
4 mm
Term
(7-3) What effect will thick agar have on zone size?
Definition
slows lateral diffusion and produces smaller zones
Term
(7-3) The bacterial broth must have a _____________ turbidity standard
Definition
0.5 McFarland turbidity standard
Term
(7-3) The chemical used to prepare McFarland standards is called
Definition
barium sulfate
Term
(7-3) Chloramphenicol - Cellular target
Definition
prevents peptide bond formation during translation
Term
(7-3) Ciprofloxacin - cellular target
Definition
interferes with DNA replication
Term
(7-3) Trimethoprim - cellular target
Definition
inhibits purine and pyrimidine synthesis
Term
(7-3) Penicillin - cellular target
Definition
inhibits cross-linking of the cell wall's peptidoglycan
Term
(7-3) What might be the consequence of pouring the plates 2 mm deep instead of 4 mm deep?
Definition
The antimicrobial will diffuse faster and produce larger zones than the standard
Term
(7-3) The Mueller-Hinton plates are supposed to be used within a specific time after their preparation and should be free of visible moisture. Why do you think this is so?
Definition

-Dry plates will slow lateral diffusion producing smaller zones

-Moisture will dilute the bug

Term
(7-3) In clinical applications of the Kirby-Bauer test, diluted cultures (for the McFarland standard comparison) must be used within 30 minutes. Why is this important?
Definition
Bugs may keep growing in the broth causing too much turbidity
Term
(7-3) E. coli and S. aureus were chosen to represent Gram-negative and Gram-positive bacteria. For penicillin, is there a difference in susceptibility between the Gram-positive and Gram-negative bacteria? If so, why?
Definition
Penicillin is a cell wall inhibitor. Penicillin breaks down the peptidoglycan in the bacterial cell wall. Gram positive bacteria have cell walls made up of peptidoglycan, but gram negative bacteria have a cell wall made of a phospholipid bilayer and not much peptidoglycan. Also, gram negative cell walls have pumps to remove antibiotics.
Term
(7-3) You record zone diameters of 25 mm for chloramphenicol and penicillin disks. Which antibiotic would be more effective against this organism? What does this tell you about comparing zone diameters to each other and the importance of the zone diameter chart?
Definition
The chloramphenicol would be more effective against this organism because the susceptible standard is ≥ 18. The resistant standard for penicillin is ≤ 28. You cannot go by the diameter of the clearing without using the interpretive chart.
Term
(7-3) How does the antibiotic get from the disk into the agar?
Definition
The antibiotic diffuses into the agar
Term
(7-3) Does the agar have an antibiotic beyond the zone of inhibition?
Definition
Yes, but it is not at a concentration that will inhibit visible growth of the bacteria
Term
(7-3) What was the purpose of inoculating NA plates with samples taken from the zones of inhibition?
Definition
to see if the antibiotic killed the bacteria (bactericidal) or if it stopped the growth but did not kill the microbe (bacteriostatic)
Term
(7-6) Define epidemiology
Definition
the study of the causes, occurrence, transmission, distribution, and prevention of diseases in a population
Term
(7-6) Define fomite
Definition
contaminated object
Term
(7-6) Define vector
Definition
biting insect
Term
(7-6) Define common source epidemic
Definition
when a disease is transmitted from an area or from water that infects many people at once
Term
(7-6) Define propagated transmission
Definition
a disease transmitted from person to person
Term
(7-6) Define index case
Definition
first case of the disease
Term
(7-6) Twelve ways infectious diseases are transmitted
Definition
ingestion, inhalation, direct skin contact, open wounds or lesions in skin, animal bites, direct blood to blood contact, sexual contact, people & animal, biting insects, aerosols, contaminated objects, water contaminated with feces
Term
(7-6) Equation for incidence rate
Definition

number of new cases in a  time period

------------------------------------------- x K

size of at-risk population at midpoint of time period

Term
(7-6) Equation for point prevalence
Definition

number of existing cases at a point in time

------------------------------------------- x K

size of at-risk population

Term
(7-6) What is "K" in the two equations and why do we use it?
Definition
K is some power of 10 to get its value up to a number bigger than one
Term
(7-6) Descriptive epidemiology
Definition
Looks at the cause and source of the disease
Term
(7-6) Analytical epidemiology
Definition
Compares two groups of pepole, one that had contact with the injurious agent and one that did not. Looks for factors that may have preceded the disease
Term
(7-6) Experimental epidemiology
Definition
begins with a hypothesis and uses experimentation
Term
(7-6) Case reporting
Definition

-used to determine the chain of transmission of a particular disease

-once the chain of transmission is discovered, measures can be taken to stop the spread of the disease

-case reporting use used to approximate the incidence and prevalence of a disease

-these are also called "Morbidity Measures"

Term
(7-6) Incidence & Prevalence Calculations
Definition

week - # of new cases

1 - 2

2 - 5

3 - 4

4 - 3

5 - 5

6 - 2

 

Assume population 1,200 & illness lasts 3 weeks, K=1000

 

week 1 incidence

2/1,200 = 0.0001666 x 1000 = 1.7 cases per 1000 people

week 1 prevalence

2/1,200 = 0.0001666 x 1000 = 1.7 cases per 1000 people

 

week 2 incidence

5/1,200 = 0.00416 x 1000 = 4.2 cases per 1000 people

week 2 prevalence

2+5/1,200 = 0.00583 x 1000 = 5.8 cases per 1000 people

 

week 3 incidence

4/1200 = 0.0033 x 1000 = 3.3 cases per 1000 people

week 3 prevalence

2+5+4/1200 = 0.0091 x 1000 = 9.1 cases per 1000 people

 

week 4 incidence

3/1200 = 0.0025 x 1000 = 2.5 cases per 1000 people

week 4 prevalence

5+4+3/1200 = 0.01 x 1000 = 10 cases per 1000 people

 

week 5 incidence

5/1,200 = 0.00416 x 1000 = 4.2 cases per 1000 people

week 5 prevalence

4+3+5/1200 = 0.01 x 1000 = 10 cases per 1000 people

 

week 6 incidence

2/1,200 = 0.0001666 x 1000 = 1.7 cases per 1000 people

week 6 prevalence

3+5+2/1200 = 0.0083 x 1000 = 8.3 cases per 1000 people

Term
(7-6) Explain how you determined the index case
Definition
this was the first time growth appeared
Term
(7-6) Suggest possible reasons for cases showing no growth between cases that exhibited growth
Definition
They had a subclinical infection so they did not have enough bug to cause disease or only a mild case of the disease, but they may have been carriers to spread the disease
Term
(12-1) Candida albicans - what is it called when it infects the oral cavity
Definition
thrush
Term
(12-1) Candida albicans - what is it called when it infects female genitals
Definition
vulvovaginitis
Term
(12-1) Candida albicans - what is it called when it infects the skin
Definition
cutaneous candidiasis
Term
(12-1) Candida albicans - name three other organs it can infect
Definition
lungs, bronchi, kidneys
Term
(12-1) Candida albicans - who is most susceptible
Definition
diabetics, immunocompromised (AIDS), catheterized patients, antibiotic therapy
Term
(12-1) Candida albicans  is unique in that cells form ___________ when grown at 37°C
Definition
pseudohyphae
Term
(12-1) Candida albicans - pseudohyphae help them to ______ to tissue
Definition
adhere
Term
(12-1) Aspergillis - what is the general term for infection with this organism
Definition
aspergillosis
Term
(12-1) Aspergillis - what is caused by invasive aspergillosis
Definition
necrotizing pneumonia
Term

(12-1) septate or nonseptate hyphae?

[image]

Definition
septate hyphae
Term

(12-1) septate or nonseptate hyphae?

[image]

Definition
nonseptate hyphae
Term
(12-1) [image]
Definition
Rhizopus sporangiophoes
Term
(12-1) [image]
Definition
Aspergillus condiophore
Term
(12-1) [image]
Definition
Penicillum condiophore
Term
(8-12) Fecal contamination is evidenced by the presence of a group of bacteria called:
Definition
Enterobacteriaceae
Term
(8-12) Most Enterobacteriacea can ferment ______ and produce ________ & ________.
Definition
lactose, acid, gas
Term
(8-12) These organisms are called ________
Definition
coliforms
Term
(8-12) The pores in the membrane filter are ____ wide.
Definition
0.45 μm wide
Term
(8-12) The agar that is used is called
Definition
Endo agar
Term
(8-12) Endo agar selects against Gram _____ bacteria
Definition
positive
Term
(8-12) It contains the sugar ___________
Definition
lactose
Term
(8-12) A dye in the media changes in response to changes in ____
Definition
pH
Term
(8-12) Coliform colonies appear:
Definition
red and/or mucoid with a gold or green metallic sheen
Term
(8-12) Does Endo agar only support the growth of coliforms
Definition
No
Term
(8-12) What is the color of the colonies we should count?
Definition
red or metallic
Term
(8-12) a countable plate has between ___ & ___ coliform colonies
Definition
20 & 80
Term
(8-12) In order to be safe to drink (________), a sample must contain less than __________
Definition
potable, one coliform per 100 ml
Term
(8-12) Formula to find total coliforms/100 ml
Definition

total coliforms/100 ml =

coliform colonies counted x 100 ml/volume of original sample in ml

 

ex. 2 colonies counted in 10 ml sample =

2 x 100ml/10 ml =

2 x 10ml =

20 colonies per 100 ml (not potable)

Term
(11-7) ELISA - a positive result is:
Definition
color change
Term
(11-4) Define antigen
Definition
any substance that causes antibody formation
Term
(11-4) define antibody
Definition
a protein produced by the body in response to a specific antigen
Term
(11-4) when large antigens and antibodies combine it is called:
Definition
agglutination
Term
(11-4) A direct agglutination test involves combining antibodies and naturally particulate antigens. What does "particulate" mean?
Definition
can be seen with the naked eye
Term
(11-4) Why did they have to combine the antigens with the red beads before adding the antibody?
Definition
The antigens are too small to be seen even when bound to antibodies
Term
(11-4) Application
Definition
agglutination reactions may be used to detect the presence of either antigen or antibody in a sample. Direct agglutination reactions are used to diagnose some diseases, determine if a patient has been exposed to a certain pathogen, and are involved in blood typing. Indirect agglutination is used in some pregnancy tests as well as in diagnosing disease.
Term
(11-4) [image]
Definition
Direct agglutination
Term
(11-4) Indirect agglutination
Definition
[image]
Term
(11-6) Mononucleosis Hemagglutination Test
Definition

-Some IgM antibodies are not specific

-They react with more than one antigen

-They are called heterophile antibodies

-To test for mono, we look for antibodies (IgM) against the Epstein-Barr Virus (EBV)

-Patient serum is 1st mixed iwith guinea pig kidney. It binds all the IgM except IgM directed against EBV

-Next mix the above mixture with horse RBCs

-If IgM against EBV is in the serum, the horse RBCs will agglutinate

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