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

When microbiologists encounter a sputum specimen, they know that the upper respiratory tract contains many indigenous organisms and to identify every organism in the culture would be a time-consuming, cost-prohibitive, and insurmountable task.So microbiologists must:

Colonies of Bacillus anthracis are described as:

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

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

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

Colonies of Staphylococcus aureus are usually described as:

A microbiologist is reading stool culture plates.She is looking for enteric pathogens on the MacConkey (MAC) plate.What do they look like?

A microbiologist 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?

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

g-Hemolysis is:

Which organism is described as shiny, like a half-pearl, on media supplemented with horse blood?

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

All the following colors are commonly used to describe bacteria except:

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

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

All of the following characteristics are used to describe bacterial colony characteristics except: