Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.
Infect Control Hosp Epidemiol. 2013 Jan;34(1):49-55. doi: 10.1086/668778. Epub 2012 Nov 20.
An analysis of a cluster of New Delhi metallo-β-lactamase-1-producing Klebsiella pneumoniae (NDM1-Kp) and a retrospective case-cohort analysis of risk factors for acquisition in contacts of NDM1-Kp-positive patients.
A 1,100-bed Canadian academic tertiary care center.
Two index patients positive for NDM1-Kp as well as 45 contacts (roommates, ward mates, or environmental contacts) were investigated.
Retrospective chart reviews of all patients colonized or infected with NDM1-Kp as well as contacts of these patients were performed in order to describe the epidemiology and impact of infection prevention and control measures. A case-cohort analysis was conducted investigating 45 contacts of NDM1-Kp-positive patients to determine risk factors for acquisition of NDM1-Kp. Rectal swabs were screened for NDM1-Kp using chromogenic agar. Presence of bla(NDM-1) was confirmed by multiplex polymerase chain reaction. Clonality was assessed with pulsed-field gel electrophoresis (PFGE) using restriction enzyme XbaI.
Two index cases carrying NDM1-Kp with different PFGE patterns were identified. Nosocomial transmission to 7 patients (4 roommates, 2 ward mates, and 1 environmental contact) was subsequently identified. Risk factors for acquisition of NDM1-Kp were a history of prior receipt of certain antibiotics (fluoroquinolones [odds ratio (OR), 16.8 (95% confidence interval [CI], 1.30-58.8); [Formula: see text]], trimethoprim-sulfamethoxazole [OR, 11.3 (95% CI, 1.84-70.0); [Formula: see text]], and carbapenems [OR, 16.8 (95% CI, 1.79-157.3); [Formula: see text]]) and duration of exposure to NDM1-Kp-positive roommates (26.5 vs 6.7 days; [Formula: see text]).
Two distinct clones of NDM1-Kp were transmitted to 7 inpatient contacts over several months. Implementation of contact precautions, screening of contacts for NDM1-Kp carriage, and attention to environmental disinfection contributed to the interruption of subsequent spread of the organism. The appropriate duration and frequency of screening contacts of NDM1-Kp-positive patients require further study.
新德里金属β-内酰胺酶 1 生产肺炎克雷伯菌（NDM1-Kp）的聚类分析以及对 NDM1-Kp 阳性患者接触者获得该酶的危险因素的回顾性病例对照分析。
加拿大一家拥有 1100 张床位的学术型三级护理中心。
对 2 名携带 NDM1-Kp 的指数患者以及 45 名接触者（室友、病房同伴或环境接触者）进行了调查。
对所有携带或感染 NDM1-Kp 的患者以及这些患者的接触者进行了回顾性图表审查，以描述感染预防和控制措施的流行病学和影响。对 45 名携带 NDM1-Kp 的患者的接触者进行病例对照分析，以确定获得 NDM1-Kp 的危险因素。使用显色琼脂筛查直肠拭子中的 NDM1-Kp。通过多重聚合酶链反应确认 bla（NDM-1）的存在。使用 XbaI 限制酶进行脉冲场凝胶电泳（PFGE）评估克隆性。
发现了携带不同 PFGE 模式的 2 个 NDM1-Kp 携带指数病例。随后确定了向 7 名患者（4 名室友、2 名病房同伴和 1 名环境接触者）的医院传播。获得 NDM1-Kp 的危险因素是先前接受某些抗生素（氟喹诺酮类[比值比（OR），16.8（95%置信区间[CI]，1.30-58.8）[公式：见正文]）、复方磺胺甲恶唑[OR，11.3（95% CI，1.84-70.0）[公式：见正文]）和碳青霉烯类[OR，16.8（95% CI，1.79-157.3）[公式：见正文]）以及与 NDM1-Kp 阳性室友的接触时间（26.5 天 vs. 6.7 天；[公式：见正文]）。
2 个不同的 NDM1-Kp 克隆在几个月内传播给 7 名住院接触者。实施接触预防措施、对 NDM1-Kp 携带的接触者进行筛查以及关注环境消毒有助于中断该病原体的后续传播。对 NDM1-Kp 阳性患者的接触者进行适当的筛查时间和频率需要进一步研究。
