Question 1

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 2

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 3

Other sugars used to differentiate bacteria include all of the following except:

Accepted Answer

A) raffinose. 
B) arabinose. 
C) rhamnose. 
D) sucralose. 
A) raffinose. 
B) arabinose. 
C) rhamnose. 
D) sucralose.

Question 4

Some bacteria produce these enzymes that break down gelatin into amino acids.These enzymes are called:

Accepted Answer

A) DNase. 
B) gelatinase. 
C) proteolytic. 
D) malonate. 
A) DNase. 
B) gelatinase. 
C) proteolytic. 
D) malonate.

Question 5

The initial screening of gram-negative rods is done by testing for the use of the carbohydrate:

Accepted Answer

A) glucose. 
B) sucrose. 
C) lactose. 
D) mannitol. 
A) glucose. 
B) sucrose. 
C) lactose. 
D) mannitol.

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

What are the sugars present in triple sugar iron (TSI)?

Accepted Answer

A) Sucrose, glucose, lactose 
B) Mannitol, lactose, arabinose 
C) Sucrose, glucose, rhamnose 
D) Lactose, sucrose, raffinose 
A) Sucrose, glucose, lactose 
B) Mannitol, lactose, arabinose 
C) Sucrose, glucose, rhamnose 
D) Lactose, sucrose, raffinose

Question 8

A bacterial DNase is a(n):

Accepted Answer

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

Question 9

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

Accepted Answer

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

Question 10

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 11

How are organisms identified with commercial identification kits?

Accepted Answer

A) Numeric codes 
B) Color codes 
C) Alphabetic codes 
D) Alphanumeric codes 
A) Numeric codes 
B) Color codes 
C) Alphabetic codes 
D) Alphanumeric codes

Question 12

These bacteria are unable to ferment either lactose or glucose, but they can degrade the peptones present in the triple sugar iron (TSI) agar or Kligler's iron agar (KIA) aerobically or anaerobically, resulting in the production of alkaline by-products in the slant or deep, respectively, changing the indicator to a deep red color.What kind of bacteria cannot ferment lactose or glucose?

Accepted Answer

A) Nonenteric bacilli 
B) Anaerobic bacilli 
C) Gram-positive cocci 
D) Gram-positive rods 
A) Nonenteric bacilli 
B) Anaerobic bacilli 
C) Gram-positive cocci 
D) Gram-positive rods

Exam 9: Biochemical Identification of Gram-Negative Bacteria

Biochemical tests are based on the _____ of microorganisms.

Bacteria demonstrating weak decarboxylase activity:

Other sugars used to differentiate bacteria include all of the following except:

Some bacteria produce these enzymes that break down gelatin into amino acids.These enzymes are called:

The initial screening of gram-negative rods is done by testing for the use of the carbohydrate:

Some bacteria are asaccharolytic.This means that these bacteria:

What are the sugars present in triple sugar iron (TSI)?

A bacterial DNase is a(n):

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

Decarboxylase tests exist for all the following amino acids except:

How are organisms identified with commercial identification kits?

Bacterial Cell Structure, Physiology, Metabolism, and Genetics

Host-Parasite Interaction

The Laboratory Role in Infection Control

Control of Microorganisms

Performance Improvement in the Microbiology Laboratory

Specimen Collection and Processing

Microscopic Examination of Materials From Infected Sites

Use of Colony Morphology for the Presumptive Identification of Microorganisms

Immunodiagnosis of Infectious Diseases

Applications of Molecular Diagnostics

Antimicrobial Agent 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

The Spirochetes

Chlamydia, Rickettsia and Similar Organisms

Mycoplasma and Ureaplasma

Mycobacterium Tuberculosis and Nontuberculous Mycobacteria

Medically Significant Fungi

Diagnostic Parasitology

Clinical Virology

Agents of Bioterror and Forensic Microbiology

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

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