Chidoribashi General Hospital, Fukuoka 812-0044, Japan.
Department of Infection Control and Prevention, Kurume University School of Medicine, Kurume 830-0011, Japan.
Int J Mol Sci. 2019 Nov 26;20(23):5954. doi: 10.3390/ijms20235954.
Bloodstream infection (BSI) due to carbapenem-resistant Enterobacteriaceae (CRE) has a high mortality rate and is a serious threat worldwide. Ten CRE strains (eight , one and one ) were isolated from the blood of nine patients, a percentage of whom had been treated with indwelling devices. The steps taken to establish cause included minimum inhibitory concentration (MIC) tests, a pulsed-field gel electrophoresis (PFGE), biofilm study, a multiplex PCR for resistant genes of carbapenemases and extended-spectrum beta-lactamases (ESBLs), and plasmid incompatibility typing. All strains showed a tendency toward resistance to multiple antibiotics, including carbapenems. Frequently isolated genes of ESBLs and carbapenemases include (four strains), (four strains) and (six strains). A molecular analysis by PFGE was used to divide the I-digested genomic DNAs of 10 CRE strains into eight patterns, and the analysis showed that three strains detected from two patients were either identical or closely related. The biofilm production of all CRE strains was examined using a microtiter biofilm assay, and biofilm growth in continuous flow chambers was observed via the use of a confocal laser scanning microscope. Our study indicates that biofilm formation on indwelling devices may pose a risk of BSI due to CRE.
血流感染（BSI）由耐碳青霉烯肠杆菌科（CRE）引起，死亡率高，是全球面临的严重威胁。从 9 名患者的血液中分离出 10 株 CRE 菌株（8 株 、1 株 、1 株 ），其中一些患者曾使用过留置装置。建立病因的步骤包括最小抑菌浓度（MIC）试验、脉冲场凝胶电泳（PFGE）、生物膜研究、耐碳青霉烯酶和超广谱β-内酰胺酶（ESBLs）的耐药基因的多重 PCR 检测，以及质粒不相容性分型。所有菌株均表现出对多种抗生素（包括碳青霉烯类）的耐药倾向。经常分离到的 ESBLs 和碳青霉烯酶基因包括 （4 株）、 （4 株）和 （6 株）。通过 PFGE 的分子分析将 10 株 CRE 菌株的 I 型消化基因组 DNA 分为 8 种模式，分析表明，从两名患者中检测到的 3 株 菌株是相同或密切相关的。通过微量滴定板生物膜测定法检查所有 CRE 菌株的生物膜生成情况，并通过使用共聚焦激光扫描显微镜观察连续流动室中的生物膜生长情况。我们的研究表明，留置装置上生物膜的形成可能会导致 CRE 引起的 BSI 风险增加。
