Reply #7: Right on both scores, Nitpicky and technical designation. I am wrong. [View All]

[NNadir]

My error comes from the fact that I am a chemist, not a biologist. I am somewhat indifferent to the name of the species from which the drugs are derived. The structure is what matters to me and of course the penicillamine type core is found in both sets of molecules.

In any case, the technical designation is somewhat trivial in the sense that the drug mechanism, acylation of a transpeptidase is identical, and cross resistance is thus a factor for all beta lactams, and indeed any antibiotic that works by mimicing the D-Ala-D-Ala substrate.