Two cases of bacteremia caused by Leptotrichia trevisanii in patients with febrile neutropenia.

We present two cases of bacteremia caused by Leptotrichia trevisanii: a 12-year-old girl with recurrent myeloid leukemia of the mandible and a 66-year-old man with esophageal carcinoma. As this filamentous bacillus showed indefinite Gram staining and the identification based on biochemical enzymatic reactions was not definitive, identification required 16s rRNA analysis. For this organism, drug sensitivity testing showed susceptiblity to each ß-lactam antibiotics and clindamycin, but resistance to fluoroquinolone and erythromycin. This filamentous bacillus needs careful identification and appropriate antibiotic treatment.