2 NOSOCOMIAL STRAINS OF STENOTROPHOMONAS-MALTOPHILIA TRANSFERRING ANTIBIOTIC-RESISTANCE TO PROTEUS-MIRABILIS P-38 RECIPIENT STRAIN

In this report we describe a specific transfer of carbenicillin and ce phaloridine resistance determinants from two different strains of Sten otrophomonas maltophilia: No. 215 and 221 isolated from two critically ill patients treated in different Intensive Care Units of a large Uni versity Hospital in Ostrava, Czech Republic. These strains were resist ant to flouroquinolones and the following beta-lactam drugs: carbenici llin, cephaloridine, cefotaxime, ceftazidime, cefepime, imipenem, mero penem and aztreonam. Both strains transferred carbenicillin and cephal oridine resistance determinants, with rather different frequency, to P roteus mirabilis P-38. All carbenicillin-selected transconjugants were found by an indirect selection method to be co-resistant to cephalori dine only. In a second cycle of transfers Proteus mirabilis R+ strains directly transferred carbenicillin and cephalothin determinants to Es cherichia coli K-12 No. 185 nal+ lac+ recipient strain.