Epidemiology and clinical features of Shewanella infection over an eight-year period

Abstract

Shewanella is a rare human pathogen that can lead to fatal infections. However, clinical information about this bacterium remains scarce. In this study, we retrospectively reviewed all patients with laboratory isolates of Shewanella over an 8-y period to assess risk factors, clinical manifestations and outcome. Twenty-nine patients were identified. Shewanella was most commonly isolated from intra-abdominal specimens (48.2%), followed by skin and soft tissue specimens (27.6%), blood (13.8%) and sputum (10.3%). Malignancy, hepatobiliary disease and diabetes mellitus were common underlying diseases. The overall 30-day mortality rate was 20.6%. Shewanella was considered a definite causative pathogen in 7 patients, and a recurrent infection occurred in 2 patients. Colonization of the biliary tract was common. Among co-isolated pathogens, the enteric flora was most represented. All isolates were susceptible to ceftazidime and aminoglycosides, but 1 isolate was resistant to imipenem. In conclusion, Shewanella may become a colonizing bacterium, subsequently causing invasive diseases in patients with an underlying disease.