GENOMIC FINGERPRINTING ACINETOBACTER-BAUMANNII - AMPLIFICATION OF MULTIPLE INTER-REPETITIVE EXTRAGENIC PALINDROMIC SEQUENCES

Acinetobacter species are important nosocomial pathogens. A rapid and sensitive identification system, capable of providing strain identity at the genetic level, is required to identify outbreak strains and fac ilitate the early implementation of infection control procedures. Repe titive extragenic palindromic (REP) elements, have been identified in numerous bacteria and these genomic sequences provide useful targets f or DNA amplification. A method for amplifying inter-REP DNA sequences, REP-multiple arbitrary amplicon profiling (REP-MAAP), is described an d applied to 29 Acinetobacter baumannii from clinical samples. Amplifi ed polymorphic DNA patterns were demonstrated for all isolates and tho se displaying identical REP-MAAP patterns were considered identical at the genetic level. In the spring of 1993, 10 intensive care unit pati ents had endotracheal colonization with A. baumannii (five with REP-MA AP I and five with REP-MAAP II patterns). These findings suggested nos ocomial transmission of organisms which was terminated by standard inf ection control measures. No further A. baumannii were detected until t he winter of 1993 when isolates of different REP-MAAP groups emerged, suggesting that factors other than nosocomial transmission were implic ated.