Bacteriuria caused by Acinetobacter calcoaceticus biovars in a normal population and in general practice

A total of 14 strains of Acinetobacter calcoaceticus biovar anitratus and 93 strains of A. calcoaceticus biovar lwoffi from a total of 97 patients participating in studies of significant bacteriuria were cultured. These studies involved an interview survey of asymptomatic significant bacteriuria and a multiple-center investigation of urinary tract infection diagnosed in general practice. Antibiotic susceptibilities of the strains as determined by a disk diffusion technique were generally in agreement with the results in the available literature, although we found high activity exhibited by ampicillin, cephalosporin, chloramphenicol, erythromycin, and streptomycin. The following resistance patterns were seen. (i) The strains from the interview survey were more often resistant to ampicillin, oxacillin, and tetracycline than were strains from the general practice study. (ii) More biovar anitratus strains than biovar lwoffi strains were resistant to chloramphenicol, erythromycin, and mecillinam. (iii) More biovar anitratus strains than biovar lwoffi strains were resistant to carbenicillin in the interview survey. The literature relevant to the incidence and significance of A. calcoaceticus biovars in urinary cultures, as well as predisposing factors, was reviewed. The incidence of these organisms in significant bacteriuria seems to be increasing. We concluded that A. calcoaceticus biovars can cause urinary tract infection in abnormal hosts as well as in basically healthy individuals.