Exam 8: Use of Colonial Morphology for the Presumptive Identification of Microorganisms

A technician is reading plates from a cerebrospinal fluid (CSF)culture.She notices that there is growth on chocolate agar (CHOC),but no growth on sheep blood agar (SBA)or MacConkey (MAC)agar.The Gram stain showed a gram-negative bacillus.What organism should be suspected?

A technician is reading stool culture plates.She sees an organism that has a dry,pink colony with a surrounding "halo" of pink on MacConkey (MAC).What is a good presumptive identification of this organism?

The relative concentration of bacteria on culture plates is directly proportional to:

A technician is reading a vaginal culture.She sees the very white colonies that are g-hemolytic on a blood agar plate but appear to have feet.What organism could this possibly be?

When looking at a tube of thioglycollate broth,streamers or vines and puffballs are visible.What organism grows like this in thioglycollate?

The density of the bacterial colony can be described by all the following EXCEPT:

The elevation of bacterial colonies is described by all the following EXCEPT:

MacConkey agar is used to:

g-Hemolysis is:

All of the following terms are used to describe the consistency of a bacterial colony EXCEPT:

When microbiologists set up a biochemical identification using a commercial system on a suspected pathogen from a culture,they must:

A technician is reading stool culture plates.She sees an organism that has a large,mucoid pink colony on MacConkey (MAC).What is a good presumptive identification of this organism?

b-Hemolysis is:

Generally,microbiologists observe the colonial morphology of organisms on primary culture after how many hours of incubation?

The edge of the colonies is described as all the following EXCEPT:

When differentiating colony size on the culture plates,what organisms generally have the larger colonies by comparison?

Plate reading is:

Which of the following descriptions will directly facilitate identification of bacteria?

This organism is described as shiny,like a half-pearl,on blood-containing media.

A technician is reading the plates from a sputum culture.There is growth only on the chocolate plate.When the technician takes off the lid of the culture plate,he notices a distinct "mousy" smell.What organism can this be?