A comparison of chloramphenicol and ampicillin as bactericidal agents for Haemophilus influenzae type B.

In tests of bactericidal action against H. influenzae type b strains isolated from patients with meningitis, chloramphenicol was found to be far more reliable than ampicillin in dealing with large inocula, and more rapidly effective against both large and relatively small inocula. These findings provide a laboratory explanation for the somewhat better record of chloramphenicol as an agent for treatment of haemophilus meningitis.