What organism is identified from a CSF sample growing gram-negative rods with positive ONPG and indole but negative motility?

The organism identified from the CSF sample is Chryseobacterium meningosepticum, which is consistent with the characteristics described: gram-negative rods that are ONPG positive, indole positive, and negative for motility.

Chryseobacterium meningosepticum is known for its association with central nervous system infections, especially in individuals who are immunocompromised or have underlying health conditions. The ONPG test reveals the ability of the organism to utilize lactose, leading to a positive result, while the indole test indicates that the organism can produce tryptophanase, which is characteristic of this species. The negative motility result is also typical for Chryseobacterium meningosepticum, as it is non-motile, distinguishing it from other enteric gram-negative rods that may show motility.

Other organisms listed, such as Pseudomonas aeruginosa, Acinetobacter baumannii, and E. coli, do not fit all of these characteristics. Pseudomonas and Acinetobacter can be motile and have other distinct biochemical properties, and E. coli, while indole positive, is motile and typically not associated with the specific context of a CSF sample in this situation