We report the seventh case of
Chryseobacterium indologenes in the United States of America (USA), occurring in a Caucasian woman aged 32 years with metastatic breast cancer.
C. indologenes is a rare human pathogen reported to have caused hospital-acquired infections in Taiwan and rarely elsewhere: six cases have been reported in Europe, two in Australia, and four in the USA [
1‐
4]. In addition, ophthalmic
C. indologenes infections have been reported including one case report in the USA, one in Taiwan and one in Spain [
5‐
7].
C. indologenes was first isolated from a clinical specimen in 1993 from the tracheal aspirate of a patient with ventilator-associated pneumonia. The Gram-negative bacillus is ubiquitous in soil and water, but it has not been found in human microflora and is rarely isolated from clinical specimens.
C. indologenes can survive chlorination, is found in municipal water supplies, and can colonize sink basins and taps [
8,
9].
C. indologenes has also been found in medical devices that use water, for example humidifiers and ventilators [
9]. The
Chryseobacterium species form circular, convex, bright-yellow colonies on blood, Tryptic soy, or nutrient agar; however, it grows poorly on MacConkey medium [
10].
Chryseobacterium bacteria are known to be resistant to extended spectrum penicillin, first and second generation cephalosporins and aztreonam; susceptibility to quinolones, aminoglycosides and cephalosporins varies. Combination antimicrobial therapy with trimethoprim-sulfamethoxazole and rifampin has been successful in treating
C. indologenes infection [
11,
12]
. Studies in Taiwan have indicated hospitalization, cancer and prolonged antibiotic treatment (>14 days) as risk factors for infection [
9,
13].