Service des Laboratoires, Centre national de greffe de moelle osseuse, 1006 Tunis, Tunisia; Université de Tunis El Manar, Faculté de médecine de Tunis, UR 12ES02, 1007 Tunis, Tunisia.
Service des Laboratoires, Centre national de greffe de moelle osseuse, 1006 Tunis, Tunisia; Université de Tunis El Manar, Faculté de médecine de Tunis, UR 12ES02, 1007 Tunis, Tunisia.
Int J Antimicrob Agents. 2018 Dec;52(6):861-865. doi: 10.1016/j.ijantimicag.2018.08.022. Epub 2018 Aug 31.
The aim of this retrospective study was to investigate the resistance determinants and genetic relatedness of colistin-resistant Klebsiella pneumoniae (Col-Kp) isolates in the National Bone Marrow Transplant Center of Tunis (NBMTC) between 2002 and 2013. Minimum inhibitory concentrations (MICs) for colistin of Col-Kp isolates were assessed using a UMIC broth microdilution kit. All isolates were screened by PCR for the resistance genes mcr-1, bla, bla, bla, bla, bla, bla, bla, bla, bla, bla, bla and bla as well as class 1, 2 and 3 integrons. The clonality of Col-Kp isolates was investigated by pulsed-field gel electrophoresis (PFGE). A total of 24 non-duplicate Col-Kp isolates were collected with MICs ranging from 16 mg/L to >64 mg/L, representing 3.4% (24/709) of the total K. pneumoniae isolates. The colistin resistance gene mcr-1 was not found. The bla gene was present in all of the isolates, bla in 18 isolates, bla and bla in 15 isolates each and bla in two isolates. The bla was found in five carbapenem-resistant isolates and was associated with bla, bla, bla and bla. All isolates were negative for the remaining carbapenemases. Class 1 integron was found in 19 isolates. PFGE showed non-clonal spread of Col-Kp isolates in this center. The increasing rate of colistin resistance in K. pneumoniae isolates in NBMTC was neither associated to clonal diffusion nor to the plasmid-mediated colistin resistance gene mcr-1. Its association with the use of colistin in total digestive decolonization in transplant patients at NBMTC must be investigated.
这项回顾性研究的目的是调查 2002 年至 2013 年期间突尼斯国家骨髓移植中心（NBMTC）耐粘菌素肺炎克雷伯菌（Col-Kp）分离株的耐药决定因素和遗传相关性。使用 UMIC 肉汤微量稀释试剂盒评估 Col-Kp 分离株的粘菌素最小抑菌浓度（MIC）。所有分离株均通过 PCR 筛选 mcr-1、bla、bla、bla、bla、bla、bla、bla、bla、bla、bla、bla 和 bla 耐药基因以及 1、2 和 3 类整合子。通过脉冲场凝胶电泳（PFGE）研究 Col-Kp 分离株的克隆性。共收集了 24 个非重复的 Col-Kp 分离株，MIC 范围为 16mg/L 至>64mg/L，占肺炎克雷伯菌总分离株的 3.4%（24/709）。未发现粘菌素耐药基因 mcr-1。所有分离株均携带 bla 基因，18 株携带 bla 基因，15 株携带 bla 和 bla 基因，2 株携带 bla 基因。在 5 株耐碳青霉烯类的分离株中发现了 bla 基因，该基因与 bla、bla、bla 和 bla 相关。所有分离株均未检测到其余碳青霉烯酶。19 株分离株中发现了 1 类整合子。PFGE 显示该中心 Col-Kp 分离株呈非克隆传播。NBMTC 中肺炎克雷伯菌分离株对粘菌素的耐药率增加既与克隆扩散无关，也与质粒介导的粘菌素耐药基因 mcr-1 无关。必须在 NBMTC 的移植患者中使用粘菌素进行全面消化道去定植的情况下对其进行调查。
