Fifteen multiresistant Acinetobacter baumannii isolates from patients in intensive care units and 14 nonoutbreak strains were tested to determine in vitro activities of nontraditional antimicrobials, including cefepime, meropenem, netilmicin, azithromycin, doxycycline, rifampin, sulbactam, and trovafloxacin. The latter five drugs were further tested against four of the strains for bactericidal or bacteriostatic activity by performing kill-curve studies at 0.5, 1, 2, and 4 times their MICs. In addition, novel combinations of drugs with sulbactam were examined for synergistic interactions by using a checkerboard configuration. MICs at which 90% of the isolates tested were inhibited for antimicrobials showing activity against the multiresistant A. baumannii strains were as follows (in parentheses): doxycycline (1 g/ml), azithromycin (4 g/ml), netilmicin (1 g/ml), rifampin (8 g/ml), polymyxin (0.8 U/ml), meropenem (4 g/ml), trovafloxacin (4 g/ml), and sulbactam (8 g/ml). In the kill-curve studies, azithromycin and rifampin were rapidly bactericidal while sulbactam was more slowly bactericidal. Trovafloxacin and doxycycline were bacteriostatic. None of the antimicrobials tested were bactericidal against all strains tested. The synergy studies demonstrated that the combinations of sulbactam with azithromycin, rifampin, doxycycline, or trovafloxacin were generally additive or indifferent.Acinetobacter baumannii is an aerobic, gram-negative, oxidase-negative, nonfermenting bacterium that has become an increasingly frequent cause of nosocomial infections, particularly in intensive care units (3,4,8,11). It has a propensity to develop antibiotic resistance extremely rapidly (2). Successive surveys have shown increasing resistance in clinical isolates, and high proportions of strains have become resistant to older, commonly used antibiotics (6, 10, 15). Only newer antibiotics, such as broad-spectrum cephalosporins, imipenem, tobramycin, amikacin, and fluoroquinolones, remain useful. The recent development of more universally resistant strains of A. baumannii has made the search for effective therapies more important and urgent (9, 13, 14; M. Wolff, M. L. Joly-Gillou, R. Farionotti, and C. Carbon, Abstr. 37th Intersci. Conf. Antimicrob. Agents Chemother., abstr. B-8, 1997).From 1996 through 1997, an outbreak of resistant A. baumannii infections involving 96 patients occurred in the intensive care units (ICUs) of Los Angeles County-University of Southern California (LAC-USC) Medical Center. The hospital clinical laboratory did routine susceptibility testing and reported that the isolates were resistant to imipenem, ceftazidime, cefotaxime, gentamicin, tobramycin, piperacillin-tazobactam, ticarcillin-clavulanate, ciprofloxacin, ofloxacin, and trimethoprim-sulfamethoxazole. The strains were moderately susceptible to ampicillin-sulbactam. Some strains were resistant to amikacin, and others were not. There was variability in susceptibility to amikacin among the strains, even among the same-patient strains, when testing was done ...

Background and Purpose-Although prior studies have demonstrated that 25% to 35% of stroke patients have had a recent infection, the role of infection as a risk factor remains unclear. Our aim was to characterize the effect of infectious/inflammatory syndromes on stroke risk. Methods-Case-control and crossover analyses of 233 cases and 363 controls aged 21 to 89 years were performed. Cases were patients hospitalized with a first ischemic stroke at a Los Angeles, California, medical center. Controls were outpatients in the hypertension, diabetes, and general medical clinics. All subjects were administered a neurological examination, an infection/inflammation (I/I) examination, and an interview to elicit recent I/I history at baseline (within several days of stroke onset) and again approximately 2 months later. Three physicians classified subjects by the presence or absence of I/I within 1 month of the index dates, based on findings of the I/I examination, the interview report, and laboratory results. Results-Infections, either total or specific, were not found more frequently in cases than controls. However, patients with a recent respiratory tract infection suffered more often from large-vessel atherothromboembolic or cardioembolic stroke than did patients without infection (48% vs 24%, Pϭ0.07). The age-and sex-adjusted relative risk estimate for these subtypes was 1.75 (95% CI, 0.86 to 3.55).