title: Serratia marcescens bacteremia at a medical center in southern Taiwan: high prevalence of cefotaxime resistance.
abstract: Antimicrobial resistance of isolates and risk factors for mortality were retrospectively investigated in 71 adult patients with Serratia marcescens bacteremia. During the 4-year study period, 78 clinically significant episodes of S. marcescens bacteremia occurred in 71 patients. The mean age of the patients was 65 years (range, 25-86 years) with a male predominance (45 patients, 63%). Most of the bacteremic episodes were nosocomial (78%), and 34% were polymicrobial. The overall mortality rate within 2 weeks after the onset of bacteremia was 41%. The presence of malignancy and critical illness at initial presentation were independent risk factors for mortality. By disk susceptibility test, 72 isolates were resistant to cefotaxime (92%) but susceptible to ceftazidime (99%). All isolates were susceptible to meropenem. Among the 47 patients with monomicrobial S. marcescens bacteremia, the mortality rate within 5 days of onset in patients receiving appropriate empirical antimicrobial therapy was lower than that in patients receiving inappropriate therapy although this difference was not significant (14% vs 28%, p = 0.27). Among the patients with cefotaxime-resistant but ceftazidime-susceptible S. marcescens bacteremia treated with ceftazidime, 6 of 7 patients (86%) survived for more than 2 weeks, suggesting the potential effectiveness of ceftazidime in the treatment of cefotaxime-resistant Serratia infections. Further clinical studies are required to delineate the clinical role of ceftazidime therapy for infections caused by S. marcescens with this resistant phenotype.
authors.affiliation: Department of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan.
authors.forename: Hsin-I
authors.initials: HI
authors.lastname: Shih
authors.forename: Hsin-Chun
authors.initials: HC
authors.lastname: Lee
authors.forename: Nan-Yao
authors.initials: NY
authors.lastname: Lee
authors.forename: Chia-Ming
authors.initials: CM
authors.lastname: Chang
authors.forename: Chi-Jung
authors.initials: CJ
authors.lastname: Wu
authors.forename: Li-Rong
authors.initials: LR
authors.lastname: Wang
authors.forename: Nai-Ying
authors.initials: NY
authors.lastname: Ko
authors.forename: Wen-Chien
authors.initials: WC
authors.lastname: Ko
mesh_terms: D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D016470:Bacteremia / Q000188:drug therapy / Q000382:microbiology* / Q000401:mortality; D002439:Cefotaxime / Q000494:pharmacology*; D002442:Ceftazidime / Q000494:pharmacology; D016638:Critical Illness; D003428:Cross Infection / Q000188:drug therapy / Q000382:microbiology*; D024881:Drug Resistance, Bacterial; D005260:Female; D006801:Humans; D008297:Male; D000077731:Meropenem; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications; D012189:Retrospective Studies; D012307:Risk Factors; D016868:Serratia Infections / Q000188:drug therapy / Q000382:microbiology* / Q000401:mortality; D012706:Serratia marcescens / Q000187:drug effects* / Q000302:isolation & purification; D013624:Taiwan; D013845:Thienamycins / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D013845:Thienamycins; D002442:Ceftazidime; D000077731:Meropenem; D002439:Cefotaxime