Question 1

This test is useful in the initial differentiation of Proteus,Morganella,and Providencia species from the rest of the Enterobacteriaceae.

Accepted Answer

A)  Oxidation-fermentation 
B)  Methyl red 
C)  Amino acid decarboxylase 
D)  Phenylalanine deaminase 
A)  Oxidation-fermentation 
B)  Methyl red 
C)  Amino acid decarboxylase 
D)  Phenylalanine deaminase

Question 2

A bacterial DNAase is:

Accepted Answer

A)  An oligonucleotide formed from a native DNA 
B)  An oligonucleotide formed from a native RNA 
C)  A proteolytic enzyme that forms extracellular DNA in the bacterial cell 
D)  An endonuclease that cleaves internal phosphodiester bonds, resulting in smaller subunits of DNA 
A)  An oligonucleotide formed from a native DNA 
B)  An oligonucleotide formed from a native RNA 
C)  A proteolytic enzyme that forms extracellular DNA in the bacterial cell 
D)  An endonuclease that cleaves internal phosphodiester bonds, resulting in smaller subunits of DNA

Question 3

Name the two reagents that are needed to visualize nitrite in the nitrate reduction test.

Accepted Answer

A)  Sulfanilic acid and 40% sodium hydroxide 
B)  Sulfuric acid and a-naphthol 
C)  N,N-dimethyl-a-naphthylamine and sulfanilic acid 
D)  N,N-dimethyl-a-naphthylamine and sulfuric acid 
A)  Sulfanilic acid and 40% sodium hydroxide 
B)  Sulfuric acid and a-naphthol 
C)  N,N-dimethyl-a-naphthylamine and sulfanilic acid 
D)  N,N-dimethyl-a-naphthylamine and sulfuric acid

Question 4

Biochemical tests are based on the _____ of microorganisms.

Accepted Answer

A)  Phenotype 
B)  Genotype 
C)  Plasmid 
D)  Lysogeny 
A)  Phenotype 
B)  Genotype 
C)  Plasmid 
D)  Lysogeny

Question 5

When performing the oxidative/fermentative (O/F)test,one tube is covered with mineral oil and one tube is left uncovered.Why is one tube covered with mineral oil?

Accepted Answer

A)  To create an anaerobic (fermentative) environment 
B)  To create an aerobic (oxidative) environment 
C)  To create a reductive environment 
D)  To create an asaccharolytic environment 
A)  To create an anaerobic (fermentative) environment 
B)  To create an aerobic (oxidative) environment 
C)  To create a reductive environment 
D)  To create an asaccharolytic environment

Question 6

Some bacteria are asaccharolytic.This means that these bacteria:

Accepted Answer

A)  Ferment glucose and use the Embden-Meyerhof pathway 
B)  Do not utilize any carbohydrate; instead they use other organic molecules for energy 
C)  Reduce glucose-that is, send it through the Entner-Doudoroff pathway 
D)  Induce glucose into glycolysis so that it can be oxidized 
A)  Ferment glucose and use the Embden-Meyerhof pathway 
B)  Do not utilize any carbohydrate; instead they use other organic molecules for energy 
C)  Reduce glucose-that is, send it through the Entner-Doudoroff pathway 
D)  Induce glucose into glycolysis so that it can be oxidized

Question 7

The medium used in the decarboxylase test is called:

Accepted Answer

A)  Clark's decarboxylase base medium 
B)  Voges decarboxylase base medium 
C)  Möeller decarboxylase base medium 
D)  OF decarboxylase base medium 
A)  Clark's decarboxylase base medium 
B)  Voges decarboxylase base medium 
C)  Möeller decarboxylase base medium 
D)  OF decarboxylase base medium

Question 8

This system provides rapid identification of gram-negative bacteria through the use of cards.

Accepted Answer

A)  MicroScan 
B)  BD Phoenix 100 
C)  Vitek AutoMicrobic system 
D)  Sherlock Microbial Identification system 
A)  MicroScan 
B)  BD Phoenix 100 
C)  Vitek AutoMicrobic system 
D)  Sherlock Microbial Identification system

Question 9

If a bacterium utilizes lactose or sucrose and produces H₂S,what will the triple sugar iron (TSI)reaction look like?

Accepted Answer

A)  Acid/acid, black butt 
B)  Acid/alkaline, black butt 
C)  Alkaline/alkaline, black slant 
D)  Alkaline/acid, black slant 
A)  Acid/acid, black butt 
B)  Acid/alkaline, black butt 
C)  Alkaline/alkaline, black slant 
D)  Alkaline/acid, black slant

Question 10

The biochemical pathway that the methyl red test confirms is:

Accepted Answer

A)  Glucose ® pyruvic acid ® mixed acid fermentation 
B)  Pyruvic acid ® glucose ® mixed acid fermentation 
C)  Glucose ® pyruvic acid ® acetoin ® diacetyl KOH 
D)  Butylene ® pyruvic acid ® diacetyl KOH 
A)  Glucose ® pyruvic acid ® mixed acid fermentation 
B)  Pyruvic acid ® glucose ® mixed acid fermentation 
C)  Glucose ® pyruvic acid ® acetoin ® diacetyl KOH 
D)  Butylene ® pyruvic acid ® diacetyl KOH

Question 11

The decarboxylase tests determine:

Accepted Answer

A)  Whether the bacteria possess enzymes capable of removing the carboxyl group of specific amino acids in the test medium 
B)  Whether the bacteria can further metabolize the acids formed during fermentation to 2,3 butanediol 
C)  If bacteria can maintain an acid pH if only sucrose is present in the media 
D)  To see if a-naphthol can be broken down into its constituent parts: acetoin and diacetyl KOH 
A)  Whether the bacteria possess enzymes capable of removing the carboxyl group of specific amino acids in the test medium 
B)  Whether the bacteria can further metabolize the acids formed during fermentation to 2,3 butanediol 
C)  If bacteria can maintain an acid pH if only sucrose is present in the media 
D)  To see if a-naphthol can be broken down into its constituent parts: acetoin and diacetyl KOH

Question 12

Extracellular DNAase can be produced by:

Accepted Answer

A)  Staphylococcus aureus 
B)  Streptococcus agalactiae 
C)  Micrococcus luteus 
D)  Haemophilus influenzae 
A)  Staphylococcus aureus 
B)  Streptococcus agalactiae 
C)  Micrococcus luteus 
D)  Haemophilus influenzae

Question 13

What advantage do the methods based on enzyme substrates have over conventional methods?

Accepted Answer

A)  They use filter paper as the structure to hold the bacteria. 
B)  They reduce the amount of substrate needed for the reactions. 
C)  They use fluorogenic substrates. 
D)  They do not require growth of the organism in the system. 
A)  They use filter paper as the structure to hold the bacteria. 
B)  They reduce the amount of substrate needed for the reactions. 
C)  They use fluorogenic substrates. 
D)  They do not require growth of the organism in the system.

Question 14

Amino acids can be metabolized by these substances that remove an amine group.What is this substance?

Accepted Answer

A)  Amino acidase 
B)  Amylase 
C)  Deaminase 
D)  Decarboxylase 
A)  Amino acidase 
B)  Amylase 
C)  Deaminase 
D)  Decarboxylase

Question 15

This test determines if an organism is a delayed lactose-fermenter.

Accepted Answer

A)  b-Galactosidase 
B)  Dihydroxylase 
C)  Nitrate 
D)  Ortho-Nitrophenyl-b-D-galactopyranoside (ONPG) test 
A)  b-Galactosidase 
B)  Dihydroxylase 
C)  Nitrate 
D)  Ortho-Nitrophenyl-b-D-galactopyranoside (ONPG) test

Question 16

What two reagents can be used to visualize indole in the broth?

Accepted Answer

A)  Indole and xylene 
B)  40% sodium hydroxide and a-naphthol 
C)  10% ferric chloride 
D)  Ehrlich's and Kovac's 
A)  Indole and xylene 
B)  40% sodium hydroxide and a-naphthol 
C)  10% ferric chloride 
D)  Ehrlich's and Kovac's

Question 17

The Vitek AutoMicrobic System is manufactured by:

Accepted Answer

A)  Abbott 
B)  bioMériux 
C)  Dade Behring 
D)  Becton Dickinson 
A)  Abbott 
B)  bioMériux 
C)  Dade Behring 
D)  Becton Dickinson

Question 18

This identification system for Enterobacteriaceae has a series of 20 cupules attached to a plastic strip.Inside the cupules are lyophilized pH-based substrates.What is the name of this system?

Accepted Answer

A)  ID Tri-Panel 
B)  API 20E 
C)  Microbact 
D)  Enterotube II 
A)  ID Tri-Panel 
B)  API 20E 
C)  Microbact 
D)  Enterotube II

Question 19

What type of medium is used in the motility test?

Accepted Answer

A)  Semisolid 
B)  Cornmeal 
C)  Sabouraud dextrose 
D)  Peptone gel 
A)  Semisolid 
B)  Cornmeal 
C)  Sabouraud dextrose 
D)  Peptone gel

Question 20

Why does the Möeller decarboxylase base medium contain glucose if it is testing the decarboxylation of amino acids?

Accepted Answer

A)  The decarboxylation of the amino acids takes place during the glucose metabolic pathway. Once glucose is broken down into pyruvic acid, then the amino acid is modified. 
B)  To get the energy needed to take the carboxyl group off the amino acid, the bacteria must have glucose. 
C)  When glucose is fermented, one of the by-products is acetoin. This acetoin is part of the mechanism that cleaves the carboxyl group from the specific amino acid. 
D)  Decarboxylases are inducible enzymes produced in an acid pH. 
A)  The decarboxylation of the amino acids takes place during the glucose metabolic pathway. Once glucose is broken down into pyruvic acid, then the amino acid is modified. 
B)  To get the energy needed to take the carboxyl group off the amino acid, the bacteria must have glucose. 
C)  When glucose is fermented, one of the by-products is acetoin. This acetoin is part of the mechanism that cleaves the carboxyl group from the specific amino acid. 
D)  Decarboxylases are inducible enzymes produced in an acid pH.

Exam 9: Biochemical Identification of Gram-Negative Bacteria

This test is useful in the initial differentiation of Proteus,Morganella,and Providencia species from the rest of the Enterobacteriaceae.

A bacterial DNAase is:

Name the two reagents that are needed to visualize nitrite in the nitrate reduction test.

Biochemical tests are based on the _____ of microorganisms.

When performing the oxidative/fermentative (O/F)test,one tube is covered with mineral oil and one tube is left uncovered.Why is one tube covered with mineral oil?

Some bacteria are asaccharolytic.This means that these bacteria:

The medium used in the decarboxylase test is called:

This system provides rapid identification of gram-negative bacteria through the use of cards.

If a bacterium utilizes lactose or sucrose and produces H₂S,what will the triple sugar iron (TSI)reaction look like?

The biochemical pathway that the methyl red test confirms is:

The decarboxylase tests determine:

Extracellular DNAase can be produced by:

What advantage do the methods based on enzyme substrates have over conventional methods?

Amino acids can be metabolized by these substances that remove an amine group.What is this substance?

This test determines if an organism is a delayed lactose-fermenter.

What two reagents can be used to visualize indole in the broth?

The Vitek AutoMicrobic System is manufactured by:

This identification system for Enterobacteriaceae has a series of 20 cupules attached to a plastic strip.Inside the cupules are lyophilized pH-based substrates.What is the name of this system?

What type of medium is used in the motility test?

Why does the Möeller decarboxylase base medium contain glucose if it is testing the decarboxylation of amino acids?

Bacterial Cell Structure, physiology, Metabolism, and Genetics

Host-Parasite Interaction

Laboratory Role in Infection Control

Control of Microorganisms

Performance Improvement in the Microbiology Laboratory

Specimen Collection and Processing

Microscopic Examination of Infected Materials

Use of Colonial Morphology for the Presumptive Identification of Microorganisms

Immunodiagnosis of Infectious Diseases

Applications of Molecular Diagnostics

Antibiotic Mechanisms of Action and Resistance

Antimicrobial Susceptibility Testing

Staphylococci

Streptococcus, enterococcus, and Other Catalase-Negative Gram-Positive Cocci

Aerobic Gram-Positive Bacilli

Neisseria Species and Moraxella Catarrhalis

Haemophilus and Other Fastidious Gram-Negative Bacilli

Enterobacteriaceae

Vibrio,aeromonas,plesiomonas and Campylobacter Species

Nonfermenting and Miscellaneous Gram-Negative Bacilli

Anaerobes of Clinical Importance

Spirochetes

Chlamydia and Rickettsia

Mycoplasma and Ureaplasma

Mycobacterium Tuberculosis and Other Nontuberculosis Mycobacteria

Medically Significant Fungi

Diagnostic Parasitology

Clinical Virology

Agents of Bioterror

Biofilms: Architects of Disease

Upper and Lower Respiratory Tract Infections

Skin and Soft Tissue Infections

Gastrointestinal Infections and Food Poisoning

Infections of the Central Nervous System

Bacteremia and Sepsis

Urinary Tract Infections

Genital Infections and Sexually Transmitted Diseases

Infections in Special Populations

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