Achromobacter species are Gram-negative waterborne bacteria that occasionally cause bacteremia primarily in immunocompromised hosts. Cancer patients have increased risk due to their use of intravascular catheters and immunosuppression from neoplasm, chemotherapy, and prolonged steroids. In this study, we investigated the clinical characteristics of cancer patients with Achromobacter bacteremia and identified risk factors, outcomes, and susceptibility patterns in this selective population.
We retrospectively reviewed all cases of Achromobacter bacteremia occurring from March 2010 to March 2015 at Moffitt Cancer Center. Data collected included age, sex, comorbidities, underlying malignancy, neutropenia status, prior bacteremia, treatment course, and patterns of susceptibilities of the isolates. We also reviewed outcomes such as discharge disposition and death.
Eleven patients were identified with positive blood cultures for Achromobacter species. Central venous catheters were infected in 9 patients (82%), and 2 patients had recurrent bacteremia, which resolved after removal of the catheter. Eight (73%) patients had a history of prior bacteremia. Patients were treated with meropenem (n = 4), piperacillin/tazobactam (n = 3), cefepime, ceftazidime, and trimethoprim-sulfamethoxazole (TMP-SMX). The isolates were susceptible to meropenem (8 of 8 isolates), piperacillin/tazobactam (10 of 10), ceftazidime (7 of 7), and TMP-SMX (8 of 8). Most of isolates were resistant to aminoglycosides and fluoroquinolones.
The major predisposing factors for Achromobacter bacteremia were infected intravascular catheters and prior history of bacteremia. Infections can be treated with piperacillin/tazobactam, a carbapenem, or TMP-SMX. Compared with other studies, we observed similar risk factors and morbidity but with a higher rate of intravascular catheter infections.