19 Jan Morphological

• Question 1

The _________ test involves using rabbit plasma as a reagent and its results are determined by observation of thickening of the medium.

Answers: Catalase

Oxidase

Coagulase

Peroxidase

• Question 2

Gram-positive cocci in chains would be called staphylococci.

Answers: True

False

• Question 3

Which of the following bacterial species would be most likely to grow in bile esculin medium and hydrolyze the esculin?

Answers:

Enterococcus faecalis

Streptococcus pneumoniae

Staphylococcus aureus

Staphylococcus epidermidis

• Question 4

Identification of a bacterial species cannot be made on microscopic morphology alone because __________.

Answers: Bacterial shapes are usually variable and are not a reliable characteristic for identification

Many organisms have a similar microscopic morphology

Staining reactions are variable and not a reliable characteristic

Staining and microscopic observation is too time-consuming for routine use

• Question 5

The absence of hemolysis on a blood agar plate is referred to as _______ hemolysis

Answers: Alpha

Beta

Gamma

Delta

• Question 6

Which of the following is a characteristic of members of the resident microbiota?

Answers:

Resident microbiota can compete with and limit growth of harmful bacteria.

Resident microbiota are a major source of nutrients for our body.

Resident microbiota typically cause serious infections.

Resident microbiota often initiate allergic reactions.

• Question 7

When a large zone of no growth is found around an antibiotic disc being used for identification purposed, this generally means that the microbe is ______ to the antibiotic

Answers: Resistant

Pathogenic

Sensitive

Neutral

• Question 8

All of the following infections are frequently cause by Staphylococcus and Streptococcus species EXCEPT?

Answers: Endocarditis

Abscess

Diarrhea

Pneumonia

• Question 9

Which test uses a medium that is both selective and differential for members of the genus Staphylococcus?

Answers: MacConkey agar

Mannitol Salt agar

Coagulase test

Bile esculin hydrolysis

• Question 10

All of the following are methods that can be used to isolate bacteria from a mixed culture EXCEPT?

Answers: Streak plating

Loop dilution pour plating

Gram staining

Serial dilution followed by spread plating

• Question 11

How do you determine the species of an unknown bacterium?

Answers: You should make a careful investigation of the morphology of the bacterial cells using a microscope to make a firm identification.

You need to quantify the number of bacteria in the same to determine the species.

Identification can only be made based on the patient’s signs and symptoms.

You use standard tests and pre-existing knowledge to classify the bacterium.

• Question 12

All of the following body sites normally have large numbers of resident microbiota EXCEPT?

Answers: Nose

Large intestine

Skin

Blood

• Question 13

The field of study in which medicine and microbiology intersect is known as medical microbiology

Answers: True

False

• Question 14

A microorganisms that is most often harmless but may occasionally cause infection and disease if defenses are compromised is referred to as an opportunistic pathogen.

Answers: True

False

• Question 15

Which test utilizes hydrogen peroxide and the observation of gas bubble formation when attempting to identify an unknown bacterium?

Answers: Bile esculin hydrolysis

Coagulase test

Oxidase test

Catalase test

• Question 16

A bacterial isolate grown on a mannitol salt agar plate changes the pink agar to yellow and produces bright yellow colonies. This indicates that the isolate is _______ for mannitol fermentation.

Answers: Negative

Positive

• Question 17

Impetigo, a type of inflammatory skin infection, is caused by__________

Answers: Enterococcus faecalis

Streptococcus pneumoniae

Staphylococcus aureus

E. coli

• Question 18

The complete clearing or hemolysis that a bacterial isolate may produce on blood agar is called alpha hemolysis

Answers: True

False

• Question 19

The Gram stain is an example of a test that can be used to determine the ______ characteristics of a bacterium?

Answers: Physiological

Genetic

Morphological

Culturing

• Question 20

Before attempting to identify an unknown bacterial species, the organism must be isolated in a pure culture.

Answers: True

False