question
The concentration of antibiotic will ____ as you move further away from the disk.
answer
Decrease
question
Antimicrobials are effective for a fixed period of time, and as such, will appear in the zone of inhibition as the inhibition is no longer in effect.
answer
Satellite colonies
question
_________ are used on non-living surfaces and ___________ are used on living tissue.
answer
Disinfectants; antiseptics
question
Chemicals which inhibit the growth of bacteria are called ______; chemicals which kill them are called ______.
answer
Bacteriostatic;bacteriocidal
question
The production of urine is a "_____________" process
answer
Sterile
question
Infection that can spread to the kidneys results in
answer
Pyelonephritis
question
Agar that is selective for gram-NEGATIVE bacteria, and differential for lactose fermenters.
answer
eosin methylene blue agar
question
Are shigella species true pathogens or opportunistic pathogens?
answer
True Pathogens
question
Characteristics: Gram negative bacilli, Catalase positive, Oxidase negative, Produce acid by glucose fermentation, nitrate positive (to nitrite), facultative anaerobes, peritrichous flagella (if motile)
answer
Enterobacteriaceae
question
Name the 3 TRUE pathogens of enterobacteriaceae
answer
Salmonella, Shigella, Yersinia
question
________ -pathogens are not part of the normal microbiota
answer
True pathogens
question
Name the 5 opportunistic pathogens of Enterobacteriaceae
answer
E. Coli, S. Marcescens, P. Vulgaris, E. Aerogenes, K. Pneumoniae
question
Common infections associated with enterobacteriaceae (x4)
answer
UTI, Wound infections, Pneumonia, Septicemia
question
Used in place of individually inoculated tubes/broths. 12 test at once; identify 15 biochemical characteristics total.
answer
Enterotube
question
a positive result for Lactose fermentation on EMB (eosin methylene blue) agar will be _________________ in color and sometimes __________ in E.coli
answer
Dark pink/purple; metallic green
question
MacConkey Agar is selective for gram ______________ bacteria and differentiates for ______________________. The indicator is _________________.
answer
Negative; lactose fermenters; neutral red (starts yellow)
question
UTI's are commonly caused by which pathogen
answer
Enterobacteriaceae (moves up the urethra)
question
Pain/burning and frequent urination
answer
Dysuria
question
WBC, pus and blood in urine.
answer
Pyuria
question
The method in which allows us to quantify the amount of bacteria in the urine.
answer
Semiquantitative streak method
question
CFU's Stands for
answer
Colony forming units
question
The typical agars that are used in the semiquantitative streak method are:
answer
Columbia CNA and MAC or EMB
question
Columbia CNA agar is selective for _________ and detects___________
answer
Gram + ; Hemolysis
question
MAC Agar (MacConkey Agar) and EMB is selective for __________ and differential for _____________ or other results
answer
Gram - ; Fermentation
question
When quantifying CFU's what are the 3 steps?
answer
1. Count the number of CFU on the plate
2. Calculate CFU/mL per plate (assume 10microliter loop) convert by multiplying by 100.
3. Combine plate counts to calculate total CFU/mL
2. Calculate CFU/mL per plate (assume 10microliter loop) convert by multiplying by 100.
3. Combine plate counts to calculate total CFU/mL
question
If you were to perform a gram stain from a urine sample that produced positive results for both what type of antibiotic would you prescribe and why?
answer
Broad spectrum; because it will tackle both gram + and Gram - bacteria
question
Name some examples of Disinfectants (5)
answer
1. Bleach
2. Quaternary Ammonium Compounds
3. Lysol
4. Formaldehyde
5. Barbacide
2. Quaternary Ammonium Compounds
3. Lysol
4. Formaldehyde
5. Barbacide
question
Name some examples of Antiseptics (5)
answer
1. Mouthwash
2. Hand sanitizer
3. Iodine
4. bactine
5. Detergent
2. Hand sanitizer
3. Iodine
4. bactine
5. Detergent
question
a substance that is both antiseptic and disinfectant
answer
Alcohols such as phenol.
question
method that is used to test the effectiveness of antiseptics or disinfectants.
answer
Disk diffusion method
question
a way to standardize the necessary meaningful comparison of substances
answer
McFarland dilution scale
question
The area of the plate that has no bacterial growth surrounding the saturated disk is referred to as the
answer
Zone of inhibition
question
Zone of inhibition is measured in _______.
answer
millimeters (mm) centimeter side of the ruler
question
Identifying the best treatment option and dose is done by testing antibiotic resistance to infectious diseases is known as
answer
Clinical relevance
question
The agar used for antibiotic susceptibility testing is called:
answer
Mueller Hinton Agar
question
Mueller-Hinton agar is ___________ and ____________. It has low ingredients that ___________ antibiotics. Contains starch to absorb bacterial toxins, and has porous agar which enables diffusion of antibiotics.
answer
Non selective; Non-differential; Inhibit/inactivate
question
When referring to the interpretation of ZOI: (sensitive) high likelihood of therapeutic success.
answer
Susceptible
question
When referring to interpretation of ZOI: high likelihood of therapeutic failure; may negatively impact patients resident microbes without benefit of treating the infection.
answer
Resistant
question
When referring to interpretation of ZOI: uncertain therapeutic effect
answer
Intermediate (in between susceptible and resistant)
question
Factors that effect the results of antibiotic susceptibility (3)
answer
1. Cell wall composition
2. Genus
3. Presence of resistance genes (strain variability)
2. Genus
3. Presence of resistance genes (strain variability)
question
Antibiotics that affect both gram positive and gram negative bacteria
answer
Broad spectrum
question
Antibiotics that affect only a certain structure or type of bacterium
answer
Narrow Spectrum
question
Why is important to complete the full course of antibiotics?
answer
Because the growth is inhibited quickly with antibiotics, although it may seem like you are feeling better the bacteria is still alive and they could start to grow again if the course is not completed.
question
Some, like Escherichia coli, are found as part of the normal biota or __________________ of mammalian intestinal systems.
answer
Commensals
question
Detects the ability of a certain bacteria to produce enzyme tryptophanase that breaks down amino acid tryptophan present in the medium.
answer
Indole test
question
Detects the ability of a few bacteria to utilize citrate as the sole source of carbon for its growth with the production of alkaline metabolic products.
answer
Citrate test
question
Detects the ability of an organism to produce and maintain stable acid end products from glucose fermentation
answer
MR (Methyl red test)
question
Detects the ability of an organism to produce the enzyme that attacks the nitrogen and carbon bond in amide compounds and forms the alkaline end product ammonia.
answer
Urease test
question
Test used to differentiate species of the family enterobacteriacae. The ability to reduce sulfur into ______________. Stab method is used to inoculate media.
answer
H2S test
question
Used to determine whether or not a bacterium can utilize a certain carbohydrate to produce acid and gas.
answer
Glucose/lactose/mannitol (carbohydrate) fermentation test
question
Inflammation of the urinary bladder
answer
Cystitis
question
The growth of any microorganism is known as
answer
Sepsis