Acinetobacter calcoaceticus bacteremia: analysis of 48 cases

The medical records of 48 patients with Acinetobacter calcoaceticus bacteremia over a recent two-year period were reviewed retrospectively to determine the epidemiologic and clinical features. There were 34 males and 14 females with a median age of 51 years. Forty-six of the cases were hospital-acquired. The characteristics of these patients included residence in the intensive care unit, intubation and ventilatory support, preceding antibiotic therapy and intravascular catheterization. In vitro susceptibility testing for the isolated organisms revealed that 32% of these strains were resistant to gentamicin and 90% were aztreonam-resistant. Minocycline, amikacin, ceftazidime, ticarcillin, imipenem, and the new quinolones retained good activity. Although A. calcoaceticus causes septic pictures as do other aerobic Gram-negative bacilli and part of these isolates are multiple drug-resistant, the infection did not seem to be difficult to control. Twenty-six (54%) of these patients survived, including 9 patients without appropriate antimicrobial therapy initiated within 48 hours of blood sampling. The mortality was rarely due to bacteremia per se; most often, it resulted from the underlying diseases.