MICs of 21 beta-lactams were determined by agar dilution against 283 penicillin-susceptible (pen-S), 122 intermediate (pen-I) and 23 fully penicillin-resistant (pen-R) pneumococci. MICs of all beta-lactams increased with increasing MICs of penicillin. Clometocillin was the most active penicillin against pen-I or pen-R pneumococci. All oral cephalosporins except cefuroxime and cefpodoxime were l...

The possible significance of impurities in the chemotherapeutic action of penicillin was first suggested by Cornman (1944) and by Lewis (1944), who observed that impure but not pure penicillin possessed a selective lethal action against rat and mouse sarcoma cells. Dunham and Rake in 1945 demonstrated that impure penicillin exerted a definite effect on the motility of Treponema pallidum, wherea...

introduction : streptococcus pneumoniae cause morbidity and mortality in infants and younger children. because of high prevalence of penicillin resistance, rapid and reliable diagnostic techniques for penicillin non-susceptible s. pneumoniae (pnssp) are important for prevention and treatment. we investigated the association of the restriction length polymorphism (rflp) patterns for pbp2b to dis...