Transduction of antibiotic resistance including imipenem resistance by wild type phages from nosocomial strains of Pseudomonas aeruginosa.

In this report we describe transduction of antibiotic resistance determinants by three wild type bacteriophages isolated from three Pseudomonas aeruginosa strains. The strains showed evident plaques of a lysis caused by a bacteriophage. The strains were identified as lysogenic among 31 imipenem (IMP)-resistant P. aeruginosa strains isolated at the National Institute of Oncology in Bratislava. The carbenicillin (CAR) resistance determinant was transduced by all the three phages to four P. aeruginosa recipients-PAO-1670, ML-M-88, ML-1292 and ML-1008. The gentamicin (GEN) resistance was transduced to ML-1008 only. The kanamycin (KAN) resistance was transduced in the following systems (combinations): "phage AP-37 to M-88", "phage AP-38 to PAO-1670, ML-1292 and M-88", and "phage AP-40 to M-88". The IMP resistance determinant was transduced by all the three phages to P. aeruginosa recipient strains. All transductant colonies were tested for the presence of directly not selected but co-transduced resistance determinants. Whereas transductants selected on media with IMP were resistant to five antibiotics (IMP, CAR, streptomycin (STR), KAN and GEN), transductants selected on CAR, KAN, STR, or GEN were resistant to a block of four of these antibiotics but not to IMP.