It is generally most appropriate to perform a hippurate hydrolysis test to aid in the identification of

• A. Enterobacteriaceae
• B. Gram-negative cocci
• C. Gram-positive, spore-forming gram-positive bacilli
• D. Beta-hemolytic gram-positive cocci

Answer: (D)

Hippurate hydrolysis reveals whether an organism has hippuricase to cleave hippurate into glycine and benzoic acid. This enzymatic trait is characteristic of certain beta-hemolytic Gram-positive cocci, most notably Streptococcus agalactiae (Group B Streptococcus). In the lab, a positive result supports identifying Group B strep among beta-hemolytic cocci, helping distinguish it from other beta-hemolytic streptococci such as Streptococcus pyogenes, which is typically negative. The test is not routinely used to identify Enterobacteriaceae, Gram-negative cocci, or Gram-positive spore-forming bacilli, whose identification relies on different biochemical profiles. Therefore, hippurate hydrolysis is most appropriate for aid in identifying beta-hemolytic Gram-positive cocci, especially Group B Streptococcus.