TSI Agar: Differentiating Microorganisms

Following the TSI agar test, an organism is determined to be K/A H2S+. Which subsequent test would best differentiate between Proteus mirabilis and Salmonella spp.?

A TSI agar slant shows a K/A H2S- reaction. Which of the following sets of tests would best differentiate Providencia rettgeri from Citrobacter spp.?

After observing a K/K (no change) reaction on TSI agar, what is the MOST appropriate next step in identifying the non-lactose fermenting organism?

An organism produces an A/A H2S+ reaction on TSI agar. Which of the following additional tests would allow differentiation between Proteus vulgaris and Salmonella arizonae?

An isolate gives the following reactions: TSI: K/A H2S-, PAD: negative, Motility (37°C): positive, Citrate: negative . Based on the flow chart, which organism is MOST likely?

Which combination of tests would allow for the differentiation between Salmonella spp. and Edwardsiella tarda after both have been identified as K/A H2S+ on TSI agar and are PAD negative?

An organism is identified as K/A H2S- on TSI agar. If this organism is also PAD positive, which of the following organisms could it be?

An organism is identified as A/A H2S- on TSI agar. Which test is MOST important in differentiating Escherichia coli from Klebsiella spp., Enterobacter spp., and Serratia spp.?

Following an A/A H2S- result for an organism, IMViC testing yields ++-- results. Based on the flow chart, what is the MOST likely identity of the organism?

A TSI agar test results in a K/A H2S+ reaction, and the follow-up PAD test is positive. Which organism can be identified with these results?

An organism is determined to be A/A H2S+ on TSI agar and PAD negative. Which of the following organisms could it be?

An organism is K/A H2S- on TSI agar and PAD negative. What follow-up test would BEST differentiate Shigella spp. from Yersinia pestis?

Following a K/A H2S- TSI result, an organism is PAD negative, motile at 37°C and Citrate positive. What organism is MOST likely present?

When an organism displays a K/A H2S+ reaction on TSI agar, which of the following tests should be performed BEFORE lysine decarboxylation to narrow down the possible organisms?

Which of the following tests is MOST useful for differentiating Klebsiella spp. from Enterobacter spp. and Serratia spp. after all three have been shown to be A/A H2S- and IMViC --+?

Given a TSI result of K/K (no change), which of the following is the MOST appropriate next step in organism identification?

An organism produces the following results: TSI: A/A H2S-, IMViC: --+-, Motility: positive, Gas: negative. What organism is MOST likely present?

After obtaining a K/A H2S- result on TSI agar, what is the significance of a positive PAD reaction in narrowing down potential organisms?

An organism is A/A H2S+ on TSI, PAD negative, and lysine decarboxylase positive. What two organisms could this be?

After determining an organism produces an A/A H2S- reaction on TSI agar, why is it important to perform the IMViC series of tests?

Following a K/A H2S- TSI result, an organism is found to be PAD negative and motile at 37°C. A subsequent Citrate test is performed. What information does the Citrate test provide?

An organism is a K/A H2S+ on TSI, PAD positive and Indole negative. What organism is MOST likely present?

How is DNase production used in the identification of organisms that are A/A H2S-, IMViC --+-, motile, and gas negative?

What is the role of Lysine Decarboxylation test in identifying an organism that gives K/A H2S+ results on TSI agar and is PAD negative?

Why is it important to check for motility at 37°C when identifying an organism that is K/A H2S-, PAD negative, and Citrate negative?

How does Indole production aid in the identification of organisms that display a K/A H2S+ reaction on TSI agar and are PAD positive?

An organism demonstrates an A/A H2S- reaction on TSI agar and IMViC results of --+-. What additional test would BEST differentiate Enterobacter aerogenes from other possible organisms?

Following K/A H2S+ on TSI agar, and a negative PAD reaction, what test result combination identifies Salmonella spp.?

With a K/K result on TSI agar, what initial step determines the direction of further testing?

What is the clinical significance of differentiating Citrobacter freundii from Salmonella arizonae based on their reactions on TSI agar and subsequent tests?

How does the presence or absence of gas production (Gas +/-) differentiate among organisms showing A/A H2S- reaction on TSI agar and similar IMViC reactions?

Following a K/A H2S- TSI result, if an organism tests positive for PAD, what is the significance of testing for Citrate utilization and motility at 37°C?

What is the MOST crucial step in accurately interpreting TSI agar results to guide downstream biochemical testing for organism identification?

What initial step is MOST critical when an organism displays a K/K reaction (no change) on TSI agar?

How does the presence of H2S production affect the interpretation of TSI agar results when differentiating between Salmonella and Citrobacter freundii?