Clinical characteristics, antimicrobial susceptibilities, and outcomes of patients with Chryseobacterium indologenes bacteremia in an intensive care unit.

Ten patients with intensive care unit (ICU)-acquired Chryseobacterium indologenes bacteremia between January 2004 and December 2008 were studied. The primary site of infection was unknown for 80% of the cases. The known primary sites of infection were empyema (10%) and catheter-related bacteremia (10%). Eight patients (80%) had polymicrobial bacteremia, spent more than 21 days in the ICU, and received more than 14 days of broad-spectrum antibiotic therapy prior to the onset of C. indologenes bacteremia. All isolates were 100% susceptible to minocycline and trimethoprim/sulfamethoxazole. Vancomycin, imipenem, piperacillin/tazobactam, ciprofloxacin, and levofloxacin exhibited 0%, 10%, 20%, 30%, and 30%, respectively, susceptibility against this pathogen. All isolates were 100% resistant to ceftazidime, cefepime, meropenem, piperacillin, and amikacin. The 14-day mortality rate was 40%. Our findings suggest that this pathogen should be included among the causes of ICU-acquired bacteremia, especially in patients with a prolonged stay in an ICU or who had received long-term broad-spectrum antibiotic therapy. Extended-spectrum penicillins, third- and fourth-generation cephalosporins, and quinolones had very little or no effect against this pathogen. Therefore, choosing an appropriate antibiotic therapy for this pathogen is very difficult.