Background: Infections caused by non-typhoid Salmonella (NTS) have increased, and the increasing incidence of multidrug-resistant NTS bacteremia in adult patients has also been noted. This study aimed to investigate the clinical and microbiological characteristics of NTS bacteremia.
Methods: A total of 71 episodes of NTS bacteremia among 65 patients were identified between 2004 and 2006. Clinical characteristics were collected from medical records. The agar dilution method described by the Clinical and Laboratory Standards Institute was used to determine the in vitro activities of each antibiotic. Multiple logistic regression analysis was used to evaluate the relationship between patient characteristics and all other covariates studied for prognosis.
Results: Salmonella enteritidis was isolated in 30 cases (42.3%), Salmonella typhimurium in 22 (31.0%), and Salmonella choleraesuis in 19 (26.7%). Thirty-two (45.1%) isolates of 71 NTS bacteremias were susceptible to chloramphenicol, 37 (52.1%) to ampicillin, 47 (66.2%) to trimethoprim/sulfamethoxazole (TMP/SMX), 56 (78.9%) to moxifloxacin, 57 (80.3%) to ciprofloxacin and levofloxacin, and 71 (100%) to ceftriaxone. The crude 30-day mortality rate was 19.7%. In multiple logistic regression analysis, the following variables were independent and significant predictors of mortality: coma (odds ratio, 12.03) and inadequate antibiotic treatment (odds ratio, 6.63).
Conclusion: S. enteritidis was the most frequently isolated serotype. High resistance rates of NTS to some readily available antimicrobials (ampicillin, chloramphenicol, TMP/SMX, fluoroquinolones) were found. Patients with the factor of coma or inadequate antibiotic treatment had poor prognosis.