Comparative susceptibility of Yersinia enterocolitica, Eikenella corrodens, and penicillin-resistant and penicillin-susceptible Streptococcus pneumoniae to beta-lactam and alternative antimicrobial agents.

The antimicrobial susceptibilities were determined for 14 strains of Yersinia enterocolitica, 28 strains of Eikenella corrodens, 10 strains of penicillin-resistant Streptococcus pneumoniae, and 10 strains of penicillin-susceptible S. pneumoniae. Y. enterocolitica was found to be susceptible to the aminoglycosides tested and to chloramphenicol, moxalactam, cefoperazone, and cefotaxime but resistant to ampicillin and variably susceptible to carbenicillin, cefoxitin, and cefazolin. On a weight basis, cefotaxime and moxalactam were the most active agents against E. corrodens. Most strains of E. corrodens were resistant to the aminoglycosides tested: gentamicin, tobramycin, kanamycin, and amikacin. Penicillin-resistant S. pneumoniae was most susceptible to cefotaxime and moxalactam. Cefotaxime was consistently active against all tested strains of Y. enterocolitica, E. corrodens, and penicillin-resistant S. pneumoniae, three unusual but clinically significant pathogens.