Two Nosocomial Strains of Stenotrophomonas maltophilia Transferring Antibiotic Resistance to Proteus mirabilis P-38 Recipient Strain

Abstract

In this report we describe a specific transfer of carbenicillin and cephaloridine resistance determinants from two different strains of Stenotrophomonas maltophilia: No. 215 and 221 isolated from two critically ill patients treated in different Intensive Care Units of a large University Hospital in Ostrava, Czech Republic. These strains were resistant to flouroquinolones and the following β-lactam drugs: carbenicillin, cephaloridine, cefotaxime, ceftazidime, cefepime, imipenem, meropenem and aztreonam. Both strains transferred carbenicillin and cephaloridine resistance determinants, with rather different frequency, to Proteus mirabilis P-38. All carbenicillin-selected transconjugants were found by an indirect selection method to be co-resistant to cephaloridine only. In a second cycle of transfers Proteus mirabilis R+ strains directly transferred carbenicillin and cephalothin determinants to Escherichia coli K-12 No. 185 nal+ lac+ recipient strain.