You are working up a throat culture.
Standard procedure in plating throat cultures in your lab includes dropping an A disc near the initial inoculum in the first quandrant when streaking the specimen.
You examine the blood agar plate and see moderate normal flora and many beta hemolytic colonies that do not grow up to the A disc.
The beta hemolytic colonies are catalase negative gram positive cocci.
Which pathogen is in this throat culture?
b) Staphylococcus aureus
c) Streptococcus pyogenes
d) Staphylococcus epidermidis
You are working up a male genital culture.
You see no growth on the blood agar plate but small colonies growing on the chocolate agar plate. The gram stain shows gram negative cocci in pairs.
Which test will you do next?
You are working up a cerebrospinal fluid culture.
You find colonies growing on blood agar as well as chocolate agar.
The colonies are oxidase positive gram negative cocci.
The colonies ferment glucose and maltose but not sucrose or lactose.
You identify the pathogen as
a) Neisseria meningitidis
b) Haemophilus influenzae
c) Streptococcus pneumoniae
d) Neisseria gonorrhoeae
You are working up a urine culture.
You see >100 colonies that are gray and flat on the blood agar plate and >100 colonies that are bright pink on the MacConkey agar.
The IMViC results are Indole positive, Methyl Red positive, Vogues-Proskauer negative, Citrate negative.
You have identified the pathogen as
a) Citrobacter freundii
b) Escherichia coli
c) Enterobacter aerogenes
d) Proteus vulgaris
You are working up a stool culture.
On MacConkey agar you see many bright pink colonies and many clear colonies.
Which colonies are potential pathogens that require further testing?
a) Clear colonies, non lactose fermenters
b) Bright pink colonies, non lactose fermenters
c) Bright pink colonies, lactose fermenters
d) Clear colonies, lactose fermenters