Lab II

T/F: in negative staining you can see flagella

False

T/F: restriction enzymes mend DNA and protect the cell

False

Working distance of microscope during oil immersion:

.16mm

how do you find something in a blood agar plate.

0.5-1mm opaque

If a recently isolated TS of E coli isolated from food is the same as a known food outbreak bacterial isolate train OS that occurred in 3 other states as a result of RFLP analysis using a gel: a) It can be concluded that the test strain is the same strain that is a part of the outbreak that has also occurred in 3 other states b) It can be concluded that the test strain came from the same individual that traveled to 3 other states.

A

Lancefield's classification is based on which of the following: a) A type of carbohydrate antigen found in the bacterial cell wall b) A type of antibody found in the bacterial cell wall c) The type of hemolysis d) A type of protein found in the bacterial cell wall e) A type of mycolic acid found in the bacterial cell wall

A

Mycobacterium is: a) Capsule producing b) Endospore forming c) Acid-fast negative d) Gram positive e) Gram negative

A

Oxidative tests include glucose fermentation and butanediol fermentation (Voges-Proskauer [VP] test): (Ex: 65) a) True b) False

A

Pseudomonas aeruginosa is not considered a member of the family Enterobacteriaceae a) True b) False

A

Some Pseudomonas species are capable of producing fluorescent pigmented siderophores called pyoverdin: a) True b) False

A

VP test: what does a methyl red color mean a) positive b) negative

A

When Mycobacterium's cell is in dormancy state it is different from its vegetative cell form: a) True b) False

A

Which of the following processes is associated with nitrate reduction a) Anaerobic respiration b) Aerobic respiration c) Substrate level phosphorylation d) Fermentation e) None of the above

A

Which of the following streptococcus Lancefield is most pathogenic to humans? (Ex: 68) a) A b) B c) C d) D e) F

A

Staph aureus produces alpha toxin that is released by

Beta hydrolysis

*The PulseNet database was used in the lab to do bacterial classification via API number: (Ex: 6) a) True b) False

B

Acid-fast rapid growing bacteria grow faster than E coli: (Ex: 11) a) True b) False

B

Alpha-hemolysis on the sheep blood agar shows a complete clearing zone surrounding the colony on the plate a) True b) False

B

Gelatin is chemically classified as a protein. The nutrient gelatin tube cultures were placed in the refrigerator to test for the presence of these enzymes that hydrolyze gelatin because: (Ex: 79) a) The test no longer is valid if the tubes are incubated too long and by lowering the temperature of the cultures they stop growing b) Gelatin normally becomes solid at low temperatures, and upon hydrolysis, it will be liquid even at these low temperatures c) The enzymes are activated by the lower temperatures d) The enzymes involved with the reaction are readily denatured at higher temperatures and the lower temperatures preserve them e) Bacteria that possess these enzymes grow only in the lower temperatures in this medium

B

Glucose can be broken down to acetoin by the Entner-Doudoroff pathway (ex:5) a) True b) False

B

The ONPG test (ex 76) determines: a) If the organisms possess beta-galactosidase permease but lack the enzyme beta-galactosidase b) If the organisms possess beta-galactosidase but lack the enzyme beta-galactosidase permease pg. 487 c) If glucose fermentation occurred d) All of the above e) None of the above

B

When serological testing is done to identify an unknown organism, it is not necessary to know the antibodies being used. (ex: 5) a) True b) False

B

Which of the following statements regarding citrate test is correct a) a negative reaction results in an alkaline reaction due to ammonium production b) citrate is the only source of carbon in the medium c) glucose is one of the carbohydrates in the medium d) none of the above

B

A positive indole test indicates cleavage resulting in indole from what substrate? (ex: 43) a) Ornithine b) Phenylalanine c) Tryptophan pg. 258 d) Lysine e) citrate

C

Enterobacteriaceae are usually positive for hydrogen sulfide production a) the enzyme thiosulfate reductase b) the enzyme catalase c) the enzyme crysteine desulfurase d) the enzyme arginine dihyldrolase e) none of the above

C

If no red color is present after adding reagents A and B to nitrate broth, zinc powder is commonly used as the fast step in testing for nitrate reduction because a) oxygen and water may be interfering with a positive result and zinc pulls these substances out of the reaction so that the true test results can be observed b) Zinc will react within the terminal product of the electron transport chain to enhance the test result c) Two possibilities still exist: either it is a true negative in that nitrate was not reduced at all and is still present in the media or it is a false negative in that nitrate was reduced to an end product beyond nitrite (pg. 334) d) Reagents A and B may have deteriorated and are no longer active e) None of the above

C

Ornithine is decarboxylated in the presence of the proper enzyme to the end product: Ex: 72 a) Cadaverine b) Heme c) Putrescine pg. 345 d) Indole e) esculetin

C

The 2nd edition Bergey's manual of systematic bacteriology, Volume 2 Part B was used by all teams in your lab section for identification. This is because all of the unknowns are Gram negative bacilli in the Phylum: a) Archaea b) Actinobacteria c) Firmicutes d) Proteobacteria e) Spirochaetes

D

The capsule- producing bacteria studied in this lab: (ex: 14) a) Are capable of producing capsules only in certain laboratory media b) Are capable of producing capsules only on the foot pads of the nine-banded armadillo c) Are capable of producing capsules only in vivo (in living organisms) pg. 162 d) Are capable of producing capsules only in vitro (in non living lab media) e) None of the above

C

The enzyme, galactosidase tests for the breakdown of: a) Sucrose b) Glucose c) Lactose d) Rhamnose e) None of the above

C

The present system classification in Bergey's Manual consists of: a) The test results of david hendricks Bergey who ran a broad spectrum of tests on the bacteria and published his results b) A scheme in which prokaryotes are ordered into groups that share a common set of genetic characteristics not shared by the other groups c) A scheme in which prokaryotes are ordered into groups that share a common set of phenotypic and genetic characteristics not shared by the other groups. d) A scheme in which prokaryotes and microbial eukaryotes are ordered into groups that share a common set of phenotypic and genetic characteristics not shared by the other groups. e) None of the above

C

Which of the following bacteria is/are capable of capsule formation? (ex: 14) a) Staphylococcus aureus b) Streptococcus pyogenes c) Klebsiella pneumoniae pg. 162 d) Both B and C e) All of the above

C

Which of the following is a hemolysin that is inactivated by oxygen: a) Catalase b) Optochin c) Streptolysin O d) Streptolysin S e) Bacitracin

C

Why are certain organisms' cell structures "acid-fast" a) it is bc the cells structures that the organisms possess render the to be acidophiles that grow in acid environments b) It is because of the type of lipid found in their cell walls c) It is because of the type of lipid found in their cell walls d) all of the above e) none of the above

C

In the following scenario, where could laboratory transmission of a bacterium occur? A microbiology student was performing a lab exercise. While performing this exercise the student was wearing a lab coat, eye goggles, and gloves. As the exercise was progressing the student diligently recorded the data with a pen, still wearing gloves. At the end of the lab, the student removed her lab coat, goggles and gloves. She proceeded to wash her hands and place her pen into her backpack. a) Students backpack b) Students pen c) Students clothes under the lab coat d) A and B only e) non of the above

D

RFLP testing is commonly used to: a) Verify the Genus and species of a bacterium b) Purify and amplify bacterial DNA c) Isolate DNA d) Compare and determine relatedness of a bacterial strain to a known pathogenic strain e) All of the above

D

The ______ test is primarily used to differentiate opportunistically pathogenic and nonpathogenic species in the genus _____ a) Catalase; Streptococcus b) Catalase; Staphylococcus c) Coagulase; Streptococcus d) Coagulase; Staphylococcus e) Indole; Escheria

D

What is the shape of what you find in the teeth?

Clusters

What bacteria do you find in between teeth? (I think it was cocci bc all I remember is streptococcus mutants from the dentist LOL)

Cocci

A work culture is needed for running tests over an extended period of time. When not in use, it should be placed: a) in the incubator at its optimum temperature b) at room temperature c) in the freezer d) in the refrigerator e) none of the above

D

At a glance at the gel below, which, if any, of the test strains (TS) seem to be the same as the outbreak strain (OS)? a) TS 1 b) TS 2 c) TS 3 d) TS 4 e) None of the TS match the same as the outbreak

D

The urease test turns pinkish during a positive reaction because: a) The organism ferments urea to acidic end-products which then lower the pH of the medium b) The organism can utilize citrate as a carbon source and release carbon dioxide which then combines with water and sodium to produce sodium carbonate and raises the pH of the medium c) The organism produces urease which accumulates and lowers the pH of the medium d) The organism produces urease that cleaves urea to produce carbon dioxide and ammonia which then raises the pH of the medium. e) Both B and C

D

What test would best differentiate and be the simplest and fastest way to differentiate btw these two bacteria, Mycobacterium kansasii and Bacillus anthracis? a) Lysine decarboxylase test b) Gram stain c) Lactose fermentation durham tube d) Acid-fast stain e) IMviC tests

D

Bacterial unknowns grew in the large nutrient gelatin tubes (ex 79) and were tested for gelatinase. It is usually a good idea to run the test ideally for 2 weeks under these circumstances when using nutrient gelatin media due to the possibility of (Ex: 79) a) No growth b) Microaerophilic growth c) Long lag phase d) Stationary phase e) Catabolite repression

E

What drives the stain the most into the cell when doing an acid-fast stain? Ex: 11 a) Carbol fuchsin b) Acid c) Water d) Diffusion e) Heat

E

Which of the following organisms is a non-spore forming bacillus that is an obligate aerobe: a) staphylococcus epidermidis b) clostridium perfringens c) entercoccus faecalis d) bacillus anthracis e) mycobacterium smegmatis

E

Nitrate test: what does a red color indicate

Nitrate is present by partial reduction of nitrate to nitrite and the presence of nitrate reductase

T/F: hydrolysis of amino acids produces urea as a byproduct

True

T/F: negative staining produces positive chromatophores that repel against positively charged bacteria → negative stains are acidic and thus have negatively charged chromatophores that do not penetrate the cell but rather are repelled by the similarly charged bacterial cell.

false

What enzyme is used to break down Amino Acids into cadaverine and carbon dioxide Lysine decarboxylase → if putrescine and CO2:

ornithine decarboxylase

Before doing the API 20 test, what test do you need to perform to ensure your microbe is not from enterobacteria family

oxidase test

question was like "protein" and the answer was "protein degradase" or something. I don't remember the exact molecule that was in the question but I think the answer was the one that had the same molecule in it as the question

protein degradase