FURTHER-STUDIES OF TRANSFERABLE ANTIBIOTIC-RESISTANCE IN STRAINS OF PSEUDOMONAS-AERUGINOSA FROM 4 CLINICAL SETTINGS IN 3 COUNTRIES

This paper describes transferability of antibiotic resistance determin ants in clinical isolates of Pseudomonas aeruginosa resistant to imipe nem, cefotaxime and ceftazidime obtained from different clinical setti ngs in three different countries. Two strains of Enterobacteriaceae (E scherichia coli K-12 and Proteus mirabilis P-38) and two strains of P. aeruginosa (PAO and ML) were used as recipient strains. The conjugati ve transfer of resistance was very specific, i.e. donor strains of P. aeruginosa transferred individual resistance determinants either to re cipient strains E. coli K-12 and P, mirabilis P-38, or to P. aeruginos a PAO or ML. In a case when three different species (P. aeruginosa, Ac inetobacter calcoaceticus, Stenotrophomonas maltophilia) were isolated from a single patient, a block of resistance determinants was transfe rred both to Enterobacteriaceae and P, aeruginosa recipients. A single plasmid with rather specific properties was suspected of being exchan ged among strains of these different species. It was recommended to st udy the overall situation of transferability of individual resistance determinants in bacterial strains belonging to various species of noso comial bacteria, especially of P, aeruginosa, by using a rather specif ic methodology.