Micro ML Questions

A large number of which of these types of cells would indicate that a sputum specimen is suboptimal and should not be used for culture? Please select the single best answer -Yeast -Polymorphonuclear white blood cells (PMNs) -Squamous epithelial cells -Bacteria

-Squamous epithelial cells

What is the MINIMUM number of fields that should be examined before reporting a Gramstained direct smear? 2 5 8 10

10

Which of the following best describes yeast cells on a Gram stain as to size and staining characteristics? -About the same size as red blood cells/will stain blue -About the same size as red blood cells/will stain pink -About the same size as white blood cells/will stain blue -About the same size as bacteria/will stain pink

About the same size as red blood cells/will stain blue

Information from Gram stained direct smears may help the physician make a preliminary diagnosis when the Gram stain information is combined with clinical information. True/False

True

Can cause gram negative organisms to stain blue to purple, leading to an erroneous gram positive result

UNDER-decolorizing

Which of the following are part of the microorganism identification process? Please select the single best answer -Arrangement of bacterial cells -Size of the organism -Shape of the organism -Staining reaction -All of the above

-All of the above

When describing microorganisms seen on a Gram stained smear, what do terms such as diplococci, tetrads, chains, and clusters describe? Please select the single best answer -Gram stain reaction -Organism shape -Cellular arrangement

-Cellular arrangement

Which of the following is TRUE of the Gram stain procedure? Please select the single best answer -Used to distinguish between aerobic and anaerobic organisms -Organism morphology is MOST characteristic in smears prepared from 18 to 24hour broth subculture -Gram positive organisms demonstrate a bright orange fluorescence -Gram negative organisms stain blue to dark purple

-Organism morphology is MOST characteristic in smears prepared from 18 to 24hour broth subculture

Which of the following terms can be used to describe cocci? (Choose all that apply.) -Rodshaped -Round -Budding -Oval

-Round -Oval

Which of these would be a reason for performing a Gram stain on a clinical specimen before culturing the specimen? -Judge the quality of the specimen. -Provide the clinician with same-day information regarding possible pathogenic organisms, pending results of culture and sensitivity. -Provide internal quality control when direct smear results are compared to culture results. -All of the above reasons

All of the above reasons

Small, palisading grampositive rods demonstrating a picketfence arrangement

Corynebacterium species

The type of culture medium used to recover an organism does NOT have an effect on cellular arrangement. True/False

False

The presence of gram-negative intracellular diplococci in a genital specimen from a FEMALE is diagnostic of gonorrhea. True/False

False, only males

What is the purpose of the iodine that is used in the Gram stain procedure? -Is the primary stain that is used in the Gram stain procedure -Fixes the crystal violet to the cellular components of gram positive bacteria -Allows the counter stain to permeate the gram negative bacteria

Fixes the crystal violet to the cellular components of grampositive bacteria

Gramnegative diplococci with adjacent sides flattened

Neisseria species

Branching, long, thin filamentous grampositive rods; tend to stain with a beaded, gramvariable pattern

Nocardia species

Can cause gram positive organisms to stain pink to red, leading to an erroneous gram negative result

OVER-decolorizing

Host cells (e.g., white blood cells, epithelial cells) will appear what color on a properly stained Gram stain? -Blue -Pink -They do not pick up either stain and will appear colorless

Pink

Grampositive cocci in clusters and tetrads

Staphylococcus species

The Positive control (purple GPC) organism for gram stains is usually _______________, and the Negative control (pink GNR) organism is usually ________________.

Staphylococcus aureus; Escherichia coli

Bacilli can have tapered or rounded ends. True/False?

True

The preferred preparation for a Gram stain

Thin smear

A physician can use the information provided from a Gram stained culture smear to help make a preliminary diagnosis and begin treatment. True/False

True