[Mobilization of genetic determinants of antibiotic resistance in strains of Pseudomonas aeruginosa].

The authors describe a phenomenon of mobilisation of antibiotic resistance from non-transferring strains of P. aeruginosa by cultivation with strains of P. aeruginosa capable to transfer determinants of antibiotic resistance to a susceptible recipient strain, by triparental cross. In this report three strains of P. aeruginosa (No. 282, 283 from Bata's Hospital in Zlín and 76 from Frankfurt University Clinics) are described capable to mobilise for transfer the resistance determinants in four strains of P. aeruginosa (No. 76, 229, 47 and 125 from Frankfurt University Clinics) with multiple antibiotic resistance which itself was not transferable to recipient strains. By an indirect selection method it was assessed, that all six antibiotics (cephalotin-cefazoline, carbenicillin, kanamycin, cefotaxime, ceftazidime and aztreonam), present in resistance spectrum of intermediary recipient strains, were mobilised for transfer. Imipenem and ofloxacin were not mobilised for transfer. In the second and third cycles of transfer the authors confirmed the stability and transferability of the block of six antibiotic resistance determinants, which were not previously transferable.