1980 Volume 33 Issue 12 Pages 1521-1526
Two types of mutants highly sensitive to beta-lactam antibiotics were obtained from Pseudomonas aeruginosa PAO 2142 by treatment with N-methyl-N'-nitro-N-nitrosoguanidine. One type of mutant showed over 30 times higher sensitivity to mecillinam, carbenicillin and sulbenicillin than did the parent, but not to most other beta-lactam antibiotics tested. In contrast, the other type mutant was about 30 times more sensitive to ampicillin, cephaloridine, cefoxitin and cefmetazole, but resistant to mecillinam, carbenicillin and sulbenicillin at the same level as the parent. Beta-lactamase activity of these mutants was not different from that of the parent. Defect in either of penicillin-binding proteins 1A/1B or 5 was observed in some mutants of P. aeruginosa highly sensitive to beta-lactam antibiotics.
