This one test chapter 6 & 7
chemoheterotroph?
(NH4)2SO4
in which tube is the obligate aerobes the growing?
1
Which of the following is NOT a factor contributing to hospital-acquired infections?
1)Some bacteria can metabolized disinfectants 2)Gram-negative bacteria are often resistant to disinfectants, 3) Invasive procedures can provide a portal of entry for bacteria, 4)Bacteria may be present in commercial products such as mouthwash.
WHich line best depicts Neisseria gonorrhoeae when growing inside the human body?@
A@
Which concentration of ethanol is the most effective bactericide?
70%
Which line best illustrates the growth of a facultative anaerobe incubated aerobically?**
A **
When the experiement is first set up, the initial movement of water will be
A to B; C to B; C to A
2H2O2->2H2O+O2
Catalase
Which of the following substances is used for surgical hand scrubs?
Chlorhexidine
A culture medium consisting of agar, human blood, and beef heart is a?
Complex defined medium
A disk-diffusion test using Staphylococcus gave the following results: disinfectant/ zoneofinhibition(mm) A 0 B 2.5 C 10 D 5 which compound was the most effective against E. coli?
E) Can't tell
table 7.1 A disk-diffusion test using Staphylococcus gave the following results: Disinfectant Zone of inhibition (mm): A 0 B 2.5 C 10 D 5 In Table 7.1, which compound was bactericidal?
E) Can't tell
Assume that one culture is a freshly opened package of dried yeast with 0.1% moisture, another culture is the same yeast with 7.5% moisture, and the third culture is a package of yeast mixed with water. Each culture was exposed to 130°C in a hot-air oven. Which graph in Figure 7.1 most likely shows the yeast with 0.1% moisture?
C
Which line depicts the growth of an anaerobe in the presence of O2?
C
Which section shows a growth phase where the number of cells dying equals the number of cells dividing?
C
Which line best depicts a psychrophile incubated at room temperature? %
C %
WHich line shows the growth of an obligate aerobe incubated anaerobicaly? *
C *
WHich line best depicts a catalase-negative cell incubated aerobically?^^
C ^^
Table 7.3 The following data were obtained by incubating gram-positive bacteria in nutrient medium + disinfectant for 24 hr, then transferring one loopful to nutrient medium (subculturing). (+ = growth; - = no growth) Doom K.O. Dilution Initial Subculture Initial Subculture 1:16 - + + + 1:32 - + + + 1:64 - + + + 1:128 + + + + Mortum Sterl Dilution Initial Subculture Initia Subculture 1:16 - - - + 1:32 - + + + 1:64 + + + + 1:128 + + + + In Table 7.3, which disinfectant was bactericidal?
Mortum
Which one of the following is most resistant to chemical biocides?
Mycobacteria
Which of the following is an organic growth factor?
NAD+
If you were preparing nutrient agar at home and didn't have an autoclave, what could you use to sterilize the nutrient agar?
Pressure cooker at 121°C for 15 minutes
Which of the following pairs is mismatched?
Thermophile-growth at 37*C
Which of the following is an advantage of the direct microscopic count?
requires no incubation time
A culture medium on which only gram-positive organisms grow and a yellow halo surrounds Staphylococcus aureus is called a(n)
selective and differential medium
table 7.1 A disk-diffusion test using Staphylococcus gave the following results: Disinfectant Zone of inhibition (mm): A 0 B 2.5 C 10 D 5 In Table 7.1, which compound was the most effective against Staphylococcus?
table 7.1= C
foods are preserved with all of the following substances except?
biguanides
In one hospital, Pseudomonas aeruginosa serotype 10 infected the biliary tract of 10% of 1300 patients who underwent gastrointestinal endoscopic procedures. After each use, endoscopes were washed with an automatic reprocessor that flushed detergent and glutaraldehyde through the endoscopes, followed by a tap water rinse. P. aeruginosa 10 was not isolated from the detergent, glutaraldehyde, or tap water. What was the source of the infections?
biofil in the reprocessor
Which of the following does NOT directly result from application of heat?
cell lysis
A disk-diffusion test using Staphylococcus gave the following results disinfectant/ zoneofinhibition(mm) A 0 B 2.5 C 10 D 5 which compound was the most effective against?
desinfectant=C, zone of inhibition= 10 D
Place the following surfactants in order from the most effective to the least effective antimicrobial activity: 1-Soap; 2-Acid detergent; 3. cationic detergent
3, 2,1
Most bacteria grow best at pH
7
at what temperature a psychrophile grow best?
10*C
In figure 7.2, the decimal reduction time (D value) for the culture is approximately
15 min.
in which tube is the facultative anaerobes growing?
2
a microbiologist inaculates a growth medium whit 1,000 bacterial cell/ml. if the generation time of the species is 30 minutes how long will be before the culture contains more than 10,00 cell/ml?
2 hours
in which tube is the obligate anaerobes growing?
3
Three cells with generation times of 30 minutes are inoculated into a culture medium. How many cells are there after 5 hours?
3 x 2^10
36 colonies grew in nutrient agar from 1.0 ml of undiluted sample in a standard plate count. How many cells were in the original sample?
36
in which tube is the aerotolerant anaerobes growing?
4
An experiment began with 4 cells and ended with 128 cells. How many generations did the cells go through?
5
in which tube is the microaerophiles growing
5
In Figure 7.2, the thermal death time for this culture is
60 min.
what is the thermal death time for culture (a)
60 min.
Which one of the following does NOT belong with the others?
Acid-anionic detergents
This organism produces catalase and superoxide dimutase
Aerobe
Which of the following substances is NOT effective against nonenveloped viruses?
Alcohol
Figure 7.3 Assume 109 E. coli cells/ml are in a flask. Which graph in Figure 7.3 best depicts the effect of placing the culture in an autoclave for 15 min. at time x?
B
Which line best depicts a facultative anaerobe in the absence of O2?
B
Which line best illustates a mesophile at 5*C its optimum temperature?
B
Micrococci are facultative halophiles. Which line best depicts the growth of M. luteus in a nutriend medium containing 7.5% NaCl %
B %
Which line depicts the growth of mesophile with an optimum temperature of 35*C INCUBATED AT 40*c? ***
B ***
Which sections of the graph illustrate a logarithmic change in cell numbers?
B and D
Which line best depicts a psychrotroph incubated at 0*C?#
B#
Table 7.2 The fate of E. coli O157:H7 in apple cider held at 8°C for 2 weeks, with and without preservatives, is shown below: Bacteria/ml Cider only 2.2 Cider with potassium sorbate 2.0 Sodium benzoate 0 Sorbate + benzoate 0 In Table 7.2, which preservative is most effective?
Benzoate
Which of these disinfectants acts by denaturing proteins?
Bisphenol
Which of the following will NOT destroy prions?
Boiling
The addition of which of the following to a culture medium will neutralize acids?
Buffers
A suspension of 106 Bacillus cereus endospores was put in a hot-air oven at 170°C. Plate counts were used to determine the number of endospores surviving at the time intervals shown. In Figure 7.2, the thermal death point for this culture is
Can't tell from the data provided.
Which of the following is a limitation of the autoclave?
D) Cannot be used with heat-labile materials
Which of the following is an advantage of the standard plate count?
Determines the number of viable cells
7) Iodophors differ from iodine (I2) in that iodophors
Don't stain, Are less irritating, Are longer lasting. Are combined with a nonionic detergent.
Table 7.3 The following data were obtained by incubating gram-positive bacteria in nutrient medium + disinfectant for 24 hr, then transferring one loopful to nutrient medium (subculturing). (+ = growth; - = no growth) Doom K.O. Dilution Initial Subculture Initial Subculture 1:16 - + + + 1:32 - + + + 1:64 - + + + 1:128 + + + + Mortum Sterl Dilution Initial Subculture Initia Subculture 1:16 - - - + 1:32 - + + + 1:64 + + + + 1:128 + + + + In Table 7.3, which disinfectant is the most effective at stopping bacterial growth?
Doom
Which of the following substances can sterilize?
Ethylene oxide
The following data show growth of two bacteria on different media
Facultative halophile
Which of the following will NOT inactivate endospores?
High pressure
WHich of the following is an example of metabolic activity that could be used to measure microbial growth?
Glucose consumption
which of the following substances is NOT an oxidizing agent?
Glutaraldehyde
Which group of microorganisims is most likley to spoil a freshwater trout preserved with salt?
Halophiles
Which of the following is NOT used to disinfect water?
Heat
Which one of the following does NOT belong with the others?
Hydrogen peroxide
Salts and sugars work to preserve foods by creating a?
Hypertonic Environment
During which growth phase will gram-positive bacteria be most susceptible to penicillin?
LOG phase
On which medium would an autotroph grow?
Medium A
Which medium (media) is chemically defined?
Medium A
Which of the following is the best method to sterilize heat-labile solutions?
Membrane filtration
All of the following are direct methods to measure microbial growth except...
Metabolic activity
Which of the following affects the elimination of bacteria from an object?
Number of bacteria present, Temperature, pH, Presence of organic matter
THis organism is killed by atmospheric O2
Obligate anaerobe
Which of the following does NOT achieve sterilization?
Pasteurization
The source of nutrients in nutrient agar is
Peptone and beef extract
H2O2 + 2H= -> 2H2O
Peroxidase
Glutaraldehyde is considered one of the most effective disinfectants for hospital use. Which of the following statements about glutaraldehyde is false?
Stains and corrodes
Producers in the hydrothermal vents on the ocean floor use CO2 for their carbon souce and what for energy?
Sulfide
Bone and tendons for transplant are decontaminated by
Supercritical fluids.
Catalyzes the reaction: O2- + O-2 + 2H+ -> H2O2+O2
Superoxide dismutase
Which of the following best describes the pattern of microbial death?
The cells in a population die at a constant rate
The antimicrobial activity of chlorine is due to which of the following?
The formation of hypochlorous acid
Which of the following is the best definition of generation time?
The length of time it takes for a cell to divide
Assume you inoculated 100 cells into 100 ml nutrient broth. You then inoculated 100 cells of the same species into 200 ml nutrient broth. After incubation fo 24 hr, you should have
The same number of cells in both
Which of the following is not used to determine metabolic activity?
Turbidity
The term facultative anaerobe refers to an organism that?
Uses oxygen or grows without oxygen
all of the fallowing statements concerning radiation as a method of microbial control are true EXEPT?
X rays are the most practical form of ionizing radiation for microbial control
Which graph in Figure 7.3 best depicts the effect of placing the culture at 7°C at time x?
d
Table 7.3 The following data were obtained by incubating gram-positive bacteria in nutrient medium + disinfectant for 24 hr, then transferring one loopful to nutrient medium (subculturing). (+ = growth; - = no growth) Doom K.O. Dilution Initial Subculture Initial Subculture 1:16 - + + + 1:32 - + + + 1:64 - + + + 1:128 + + + + Mortum Sterl Dilution Initial Subculture Initia Subculture 1:16 - - - + 1:32 - + + + 1:64 + + + + 1:128 + + + + In Table 7.3, which disinfectant was most effective against Salmonella?
e) Can't tell
Which one of the following pairs is mismatched?
e)Ultraviolet radiation - desiccation
tap water is used sometimes to prepare growth media in the laboratory because
it provides microbes with the necessaries trace elements
Which of the following pairs is not correctly match?
merthiolate- open wounds
Which of the following will is NOT preserve foods?
microwaves