title: Carbapenems and piperacillin/tazobactam for the treatment of bacteremia caused by extended-spectrum β-lactamase-producing Proteus mirabilis.
abstract: This study was intended to delineate the role of carbapenems and piperacillin/tazobactam in treating bacteremia caused by extended-spectrum β-lactamase (ESBL)-producing Proteus mirabilis. We performed a multicenter and retrospective study of the patients with ESBL-producing P. mirabilis bacteremia. The outcomes of the patients treated by piperacillin/tazobactam or a carbapenem for at least 48 hours and the MICs of the prescribed drugs for these isolates were analyzed. Forty-seven patients with available clinical data were included. The overall 30-day mortality rate was 29.8%. All available isolates (n = 44) were susceptible to ertapenem, meropenem, and doripenem, and 95.6% were susceptible to piperacillin/tazobactam; however, only 11.4% of the isolates were susceptible to imipenem. Among the 3 patients infected with isolates exhibiting non-susceptibility to imipenem (MIC ≥2 mg/L) who were treated with imipenem, none died within 28 days. The 30-day (14.3% versus 23.1%, P = 0.65) or in-hospital (19.1% versus 30.8%, P = 0.68) mortality rate of 21 patients treated by a carbapenem was lower than that of 13 treated by piperacillin/tazobactam. However, among those treated by piperacillin/tazobactam, the mortality rate of those infected by the isolates with lower piperacillin/tazobactam MICs (≤0.5/4 mg/L) was lower than that of the isolates with MICs of ≥1/4 mg/L (0%, 0/7 versus 60%, 3/5; P = 0.045). ESBL-producing P. mirabilis bacteremia is associated with significant mortality, and carbapenem therapy could be regarded as the drugs of choice. The role of piperacillin/tazobactam, especially for the infections due to the isolates with an MIC ≤0.5/4 mg/L, warrants more clinical studies.
authors.affiliation: Section of Infectious Diseases, Department of Internal Medicine, Far Eastern Memorial Hospital, New Taipei City, Taiwan.
authors.forename: Hsih-Yeh
authors.initials: HY
authors.lastname: Tsai
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, Kaohsiung Medical University Hospital, Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung City, Taiwan.
authors.forename: Yen-Hsu
authors.initials: YH
authors.lastname: Chen
authors.affiliation: Departments of Medicine and Medical Research, Chi Mei Medical Center, Tainan City, Taiwan.
authors.forename: Hung-Jen
authors.initials: HJ
authors.lastname: Tang
authors.affiliation: Department of Internal Medicine, National Cheng Kung University Hospital and Department of Medicine, National Cheng Kung University Medical College, No. 138, Sheng Li Road, Tainan, 704, Taiwan.
authors.forename: Chi-Chang
authors.initials: CC
authors.lastname: Huang
authors.affiliation: Section of Infectious Diseases, Department of Internal Medicine, Far Eastern Memorial Hospital, New Taipei City, Taiwan.
authors.forename: Chun-Hsing
authors.initials: CH
authors.lastname: Liao
authors.affiliation: Department of Clinical Pathology, Far Eastern Memorial Hospital, New Taipei City, Taiwan.
authors.forename: Fang-Yeh
authors.initials: FY
authors.lastname: Chu
authors.affiliation: Departments of Medicine and Medical Research, Chi Mei Medical Center, Tainan City, Taiwan.
authors.forename: Yin-Ching
authors.initials: YC
authors.lastname: Chuang
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Wang-Huei
authors.initials: WH
authors.lastname: Sheng
authors.affiliation: Department of Internal Medicine, National Cheng Kung University Hospital and Department of Medicine, National Cheng Kung University Medical College, No. 138, Sheng Li Road, Tainan, 704, Taiwan. Electronic address: winston3415@gmail.com.
authors.forename: Wen-Chien
authors.initials: WC
authors.lastname: Ko
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan; Department of Laboratory Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, No. 7, Chung-Shan S. Rd, Taipei 100, Taiwan. Electronic address: hsporen@ntu.edu.tw.
authors.forename: Po-Ren
authors.initials: PR
authors.lastname: Hsueh
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D016470:Bacteremia / Q000188:drug therapy* / Q000382:microbiology; D015780:Carbapenems / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D010397:Penicillanic Acid / Q000031:analogs & derivatives* / Q000627:therapeutic use; D010878:Piperacillin / Q000627:therapeutic use; D000077725:Piperacillin, Tazobactam Drug Combination; D011512:Proteus Infections / Q000188:drug therapy* / Q000382:microbiology; D011513:Proteus mirabilis / Q000187:drug effects / Q000201:enzymology* / Q000302:isolation & purification; D012189:Retrospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D015780:Carbapenems; D000077725:Piperacillin, Tazobactam Drug Combination; D010397:Penicillanic Acid; D001618:beta-Lactamases; D010878:Piperacillin
keywords: Bacteremia; Carbapenems; Extended-spectrum β-lactamase; Piperacillin/tazobactam; Proteus mirabilis; Treatment outcomes