Question 1

The methyl red test detects metabolic by-products from what pathway?

Accepted Answer

A)  Mixed acid fermentation pathway 
B)  Butylene glycol pathway 
C)  Citrate pathway 
D)  Clark and Lubs pathway 
A)  Mixed acid fermentation pathway 
B)  Butylene glycol pathway 
C)  Citrate pathway 
D)  Clark and Lubs pathway

Question 2

Nucleic acid assays are based on the _____ of the organism and are believed to be more accurate.

Accepted Answer

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

Question 3

A positive test for motility:

Accepted Answer

A)  Turns the motility media blue 
B)  Shows hazy appearance throughout or movement away from a stab 
C)  Appears as a scum on the top of the media 
D)  Will turn blue after the addition of the indicator bromthymol blue 
A)  Turns the motility media blue 
B)  Shows hazy appearance throughout or movement away from a stab 
C)  Appears as a scum on the top of the media 
D)  Will turn blue after the addition of the indicator bromthymol blue

Question 4

What indicator is used in the methyl red test?

Accepted Answer

A)  Bromthymol blue 
B)  Phenolphthalein 
C)  Methyl red 
D)  Bromcresol green 
A)  Bromthymol blue 
B)  Phenolphthalein 
C)  Methyl red 
D)  Bromcresol green

Question 5

If an organism fermented glucose only and utilized peptones,what would the triple sugar iron (TSI)reaction be?

Accepted Answer

A)  Acid/acid 
B)  Alkaline/acid 
C)  Alkaline/alkaline 
D)  Acid/alkaline 
A)  Acid/acid 
B)  Alkaline/acid 
C)  Alkaline/alkaline 
D)  Acid/alkaline

Question 6

Decarboxylase tests exist for all the following amino acids EXCEPT:

Accepted Answer

A)  Lysine 
B)  Tyrosine 
C)  Ornithine 
D)  Arginine 
A)  Lysine 
B)  Tyrosine 
C)  Ornithine 
D)  Arginine

Question 7

Rapid identification of clinical isolates often involves commercially packaged identification kits and fully automated instruments.What do these kits use to assess the preformed bacterial enzymes?

Accepted Answer

A)  Extraction kits 
B)  Volatile benzenes 
C)  Chromogenic or fluorogenic substrates 
D)  Chemiluminescent substrates 
A)  Extraction kits 
B)  Volatile benzenes 
C)  Chromogenic or fluorogenic substrates 
D)  Chemiluminescent substrates

Question 8

Bacteria demonstrating weak decarboxylase activity:

Accepted Answer

A)  Will have a false-negative test 
B)  May take up to 4 days to be positive 
C)  Require extra reagents to show the positive reaction 
D)  Will have a false-positive test 
A)  Will have a false-negative test 
B)  May take up to 4 days to be positive 
C)  Require extra reagents to show the positive reaction 
D)  Will have a false-positive test

Question 9

This reagent is used to demonstrate a positive phenylalanine deaminase test.

Accepted Answer

A)  10% ferric chloride 
B)  Methyl red 
C)  a-Naphthol 
D)  40% sodium hydroxide 
A)  10% ferric chloride 
B)  Methyl red 
C)  a-Naphthol 
D)  40% sodium hydroxide

Question 10

What does the oxidase test determine?

Accepted Answer

A)  If the bacteria have the enzyme, oxidase, to reduce oxygen to carbon dioxide 
B)  If the bacteria have oxidase, which will allow for the oxidation of carbohydrates 
C)  If the bacteria can hydrolyze urea to ammonia and carbon dioxide 
D)  The presence of the cytochrome oxidase system that oxidizes reduced cytochrome with molecular oxygen 
A)  If the bacteria have the enzyme, oxidase, to reduce oxygen to carbon dioxide 
B)  If the bacteria have oxidase, which will allow for the oxidation of carbohydrates 
C)  If the bacteria can hydrolyze urea to ammonia and carbon dioxide 
D)  The presence of the cytochrome oxidase system that oxidizes reduced cytochrome with molecular oxygen

Question 11

This system is widely used in microbiology laboratories today.

Accepted Answer

A)  MicroScan 
B)  Mueller-Hinton 
C)  Enterotube 
D)  API 20E 
A)  MicroScan 
B)  Mueller-Hinton 
C)  Enterotube 
D)  API 20E

Question 12

Bacteria can utilize carbohydrates by:

Accepted Answer

A)  Oxidation 
B)  Synthesis 
C)  Reduction 
D)  Induction 
A)  Oxidation 
B)  Synthesis 
C)  Reduction 
D)  Induction

Question 13

A tech is reading the biochemical tests for identifying a particular gram-negative rod.The organism has produced acid,indicated by a color change,in the closed tube only.This indicates that the organism is:

Accepted Answer

A)  An oxidizer 
B)  A fermenter 
C)  Both an oxidizer and a fermenter 
D)  A reducer 
A)  An oxidizer 
B)  A fermenter 
C)  Both an oxidizer and a fermenter 
D)  A reducer

Question 14

Using Möeller's decarboxylase base medium,what color is a positive reaction and what causes this color to be produced?

Accepted Answer

A)  Purple, alkaline environment produced 
B)  Yellow, acid environment produced 
C)  Purple, acid environment produced 
D)  Yellow, alkaline environment produced 
A)  Purple, alkaline environment produced 
B)  Yellow, acid environment produced 
C)  Purple, acid environment produced 
D)  Yellow, alkaline environment produced

Question 15

Commercial identification systems fall into all of the following categories EXCEPT:

Accepted Answer

A)  pH-based reactions 
B)  Enzyme-based reactions 
C)  Visual detection of bacterial growth 
D)  Utilization of nitrogen and sulfur sources 
A)  pH-based reactions 
B)  Enzyme-based reactions 
C)  Visual detection of bacterial growth 
D)  Utilization of nitrogen and sulfur sources

Exam 9: Biochemical Identification of Gram-Negative Bacteria

The methyl red test detects metabolic by-products from what pathway?

Nucleic acid assays are based on the _____ of the organism and are believed to be more accurate.

A positive test for motility:

What indicator is used in the methyl red test?

If an organism fermented glucose only and utilized peptones,what would the triple sugar iron (TSI)reaction be?

Decarboxylase tests exist for all the following amino acids EXCEPT:

Rapid identification of clinical isolates often involves commercially packaged identification kits and fully automated instruments.What do these kits use to assess the preformed bacterial enzymes?

Bacteria demonstrating weak decarboxylase activity:

This reagent is used to demonstrate a positive phenylalanine deaminase test.

What does the oxidase test determine?

This system is widely used in microbiology laboratories today.

Bacteria can utilize carbohydrates by:

A tech is reading the biochemical tests for identifying a particular gram-negative rod.The organism has produced acid,indicated by a color change,in the closed tube only.This indicates that the organism is:

Using Möeller's decarboxylase base medium,what color is a positive reaction and what causes this color to be produced?

Commercial identification systems fall into all of the following categories EXCEPT:

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

Zoonotic Diseases

Ocular Infections

Filters