Cutaneous Serratia marcescens infections in Korea: A retrospective analysis of 13 patients

Serratia marcescens is a Gram-negative bacillus belonging to the Enterobacteriaceae family. Because of increasing reports of antimicrobial resistance, this bacterium has received considerable attention and has emerged as an important pathogen. In order to reveal clinical and microbiological characteristics of S. marcescens cutaneous infection and to suggest appropriate antibiotic treatment, we retrospectively analyzed 17 strains isolated from wound swabs of Korean patients between November 2005 and March 2014. A total of 13 patients (five men and eight women) were included in our study, with a mean age of 46.3 years (range, 21-82). Based on medical history, seven patients were classified as immunocompromised. Prior predisposing factors for infections were noted in 12 patients, including pre-existing leg ulcers or dermatitis (5/13), preceding cancer surgeries (2/13), plastic surgeries and filler injection (2/13), traumas (2/13) and medical procedures following cutaneous abscess (1/13). Cutaneous infections showed various clinical presentations, including spontaneous dermal abscess, fingernail change, painful nodules and papular erosions. We found that third- and fourth-generation cephalosporins, gentamicin, levofloxacin and meropenem appeared active against all 17 strains in vitro. Clinically, all patients treated with empirical first-generation cephalosporin showed treatment resistance, and oral quinolone monotherapy was the most preferred antibiotic regimen without treatment failure, with an average treatment duration of 25 days (range, 14-42). This study demonstrates the various clinical presentations and treatment responses for cutaneous S. marcescens infection. Moreover, we suggest that initial antibiotic coverage should be broad enough to account for multidrug resistance in this rare pathogen.