Examination of polyclonal rabbit immune sera against serovars of Acinetobacter baumannii and genospecies 3 for cross-reactions with reference strainsof other named/unnamed genospecies of Acinetobacter

Polyclonal rabbit immune sera against 38 serovars of Acinetobacter baumanni i and genospecies 13 capable of growth at 44 degrees C and against 26 serov ars of genospecies 3 and genospecies 13 incapable of growth at 44 degrees C were examined for serological cross-reactivity with reference strains comp rising 17 genospecies (among them 6 named species) of Acinetobacter. Checke rboard agglutination tests yielded very few cross-reactions. Specifically, genospecies 17 cross-reacted weakly with A. baumannii serovar 27; strains g enospecies 13 (Bouvet), TU 14, and 'close to TU 13' were strongly agglu- ti nated by antiserum against A. baumannii serovar 18. Genospecies 14 (Bouvet) yielded a very weak cross-reaction with genospecies 3 serovar 20, and geno species TU 13 reacted weakly with anti-genospecies 3 serovar 15 serum. The 'between genospecies 1 and 3' reference strain proved to be A. baumannii se rovar 5 as determined with absorption tests.