Dear Colleagues,

For certain reasons I am seeking the OLD susceptible/intermediate/resistant breakpoint values for ampicillin and amoxicillin (alone, not combined with a β-lactamase inhibitor) for Ps. aeruginosa (and related non-fermentative Gram-negative bacilli, if available). I believe that this information is contained in

National Committee for Clinical Laboratory Standards. 1993. Document M7-A3. Methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically. 3rd ed. Approved standard, vol. 13, no. 25. National Committee for Clinical Laboratory Standards, Villanova, Pa.

However, when I wrote to the CLSI and asked for these historic breakpoint values, the replied that they would not send them to me and that the only way I could get them would be to buy an archival copy of the above guidebook for US120.-.

Does anyone have this old NCCLS guideline or otherwise have access to these historic breakpoints for Ps. aeruginosa et amici towards ampicillin and amoxicillin? If so, could you send me those breakpoint values?

Thanks in advance to all responders,

S. Shapiro
shapiro.stuart@basileapharma.com