MACRORESTRICTION ANALYSIS (PFGE) OF SEROLOGICALLY CROSS-REACTIVE SEROVARS OF ACINETOBACTER-BAUMANNII AND GENOSPECIES-3

Forty-two serovar reference strains of Acinetobacter baumannii and gen ospecies 3, which yielded major or minor, one-way or two-way (reciproc al) serological cross-reactions, were subjected to macrorestriction (S maI, ApaI) analysis with the aid of pulsed-field gel electrophoresis ( PFGE). The PFGE patterns of serovars 3 and 21 of genospecies 3 differe d by 3 (SmaI) and 2-4 (ApaI) DNA fragments and thus were closely/possi bly related in their genotype. Serovars 13 and 26 of genospecies 3 dif fered by only 2 DNA fragments (SmaI), suggesting close genetic related ness; however, these two particular serovars of genospecies 3 appeared to be genotypically indistinguishable following restriction with ApaI . Serovars 2, 4, and 12 of genospecies 3 appeared to be unrelated to s erovar 13 of genospecies 3 (SmaI); however, restriction with ApaI indi cated a possible relatedness. Genospecies 3 serovars 2 and 26 differed by 5 DNA fragments (SmnI and ApaI), implying a possible relatedness. All Other cross-reactive serovars examined proved to be genotypically unrelated, i. e., differed by greater than or equal to 7 DNA fragments (SmaI restriction).