Nutritionally variant streptococci (NVS) require specific nutrients. Which test fulfills this requirement?

Nutritionally variant streptococci (NVS), specifically those that are unable to synthesize certain vitamins or amino acids, can be cultivated on media supplemented with specific nutrients. The Staphylococcal cross-streak test is particularly relevant for demonstrating the growth requirements of NVS. In this test, a strain of Staphylococcus aureus is streaked on an agar plate, which produces an enzymatic factor that aids in the growth of NVS. This provides the necessary nutrients that NVS cannot produce on their own, facilitating their identification and growth in a laboratory setting.

The other test options are not primarily designed to assess the growth factors needed by nutritionally variant streptococci. The CAMP test is used to identify specific strains of Streptococcus agalactiae based on its ability to enhance the hemolysis of Staphylococcus aureus. The bacitracin susceptibility test is mainly used to differentiate Group A streptococci from other beta-hemolytic streptococci, and the bile solubility test is used to distinguish between certain species of Streptococcus, particularly in the context of Streptococcus pneumoniae versus other viridans group streptococci. None of these tests aid in providing