In identifying Enterobacteriaceae, which test is NOT typically used?

In identifying Enterobacteriaceae, which test is NOT typically used?

• A. Indole
• B. Oxidase
• C. H2S production
• D. Urease

Answer: (B)

The oxidase test is not typically used in the identification of Enterobacteriaceae because members of this family are generally oxidase-negative. Enterobacteriaceae is a large family of gram-negative bacteria that includes many pathogens as well as commensals, and they often share certain biochemical characteristics that are pivotal for identification. The indole test is frequently employed to differentiate between species within the family, as some members can produce indole while others cannot. Hydrogen sulfide (H2S) production is another important test, especially for identifying species like Salmonella that produce H2S in certain media. Urease production can also be indicative of specific genera within Enterobacteriaceae, such as Proteus. Oxidase testing is primarily used for differentiating other gram-negative bacteria, particularly to identify members of the family Pseudomonadaceae and Vibrionaceae, which are oxidase-positive. Therefore, the oxidase test is not relevant for Enterobacteriaceae and is not routinely performed in their identification, leading to it being the correct answer in this context.

The oxidase test is not typically used in the identification of Enterobacteriaceae because members of this family are generally oxidase-negative. Enterobacteriaceae is a large family of gram-negative bacteria that includes many pathogens as well as commensals, and they often share certain biochemical characteristics that are pivotal for identification.

The indole test is frequently employed to differentiate between species within the family, as some members can produce indole while others cannot. Hydrogen sulfide (H2S) production is another important test, especially for identifying species like Salmonella that produce H2S in certain media. Urease production can also be indicative of specific genera within Enterobacteriaceae, such as Proteus.

Oxidase testing is primarily used for differentiating other gram-negative bacteria, particularly to identify members of the family Pseudomonadaceae and Vibrionaceae, which are oxidase-positive. Therefore, the oxidase test is not relevant for Enterobacteriaceae and is not routinely performed in their identification, leading to it being the correct answer in this context.