Importance of carbenicillin and gentamicin cross-resistant serotype 0:12 Pseudomonas aeruginosa in six Athens hospitals.

One hundred and six clinical isolates of Pseudomonas aeruginosa, collected from various hospitals were typed with O-antisera and studied for their susceptibility to antibiotics and phages. Forty-four of 49 multiresistant isolates belonged to the O12 serogroup, a serogroup rarely found among strains of other resistance phenotypes. Eleven of the 45, O12 isolates were resistant to all phages, and 31 were sensitive only to phage 68. The latter pattern was encountered in nine of the 61 strains comprising the other O-serogroups.