Xie D R, Qian C J, Li Z X, Shi W, Zhong Z D, Xia L H, Wu Q L, Hong M
Department of Hematology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
Department of Hematology, The First Affiliated Hospital of Henan University of Science and Technology, Key Laboratory of Transplantation Immunology for Haematological Diseases, Luoyang 471000, China.
Zhonghua Xue Ye Xue Za Zhi. 2024 Nov 14;45(11):1043-1050. doi: 10.3760/cma.j.cn121090-20240607-00213.
This study aimed to analyze the homology between carbapenem-resistant organisms (CRO) intestinal colonization strains and bloodstream infection (BSI) strains in patients undergoing hematopoietic stem cell transplantation (HSCT), confirming the clinical use of the real-time rectal swab Xpert Carba-R assay, and investigate its feasibility in early warning of BSI. Drug-resistant strains obtained from rectal swabs and blood culture samples of patients undergoing the same HSCT from January 2021 to December 2021 were collected and analyzed. The homology of the CRO intestinal colonization and BSI strains was confirmed using strain identification, antimicrobial resistance phenotyping, whole genome sequencing (WGS), multilocus sequence typing (MLST), and carbapenemase type identification. Rectal swab cultures and the real-time rectal swab Xpert Carba-R assay were conducted concurrently on patients with HSCT from August 2021 to August 2022. The accuracy of the real-time rectal swab Xpert Carba-R assay was confirmed with the sequencing results of polymerase chain reaction amplification products of the carbapenemase gene from purified colonies as a reference standard. This study included 24 CRO strains from 10 patients undergoing HSCT, including 14 intestinal colonizers and 10 CRO-BSI strains. The results revealed that the CRO intestinal colonization strains and CRO-BSI strains from the same patient and their carbapenemase genes were almost identical. Additionally, WGS revealed that CRO intestinal colonization and CRO-BSI strains from the same patient were more closely related than strains from different patients. Additionally, this study included 488 rectal swab specimens from 184 patients undergoing HSCT, with CRO detection rates of 16.4% for rectal swab culture and 18.4% for the real-time rectal swab Xpert Carba-R assay. The overall sensitivity, specificity, and positive and negative predictive values of the real-time rectal swab Xpert Carba-R assay were 96.6%, 72.8%, 90.6%, and 88.9%, respectively. A high degree of homology was found between the CRO intestinal colonization strains and the CRO-BSI strains in patients undergoing HSCT. The real-time rectal swab Xpert Carba-R assay is a reliable and convenient method for detecting common carbapenemase genes, serving as an alternative to rectal swab culture for early warning of CRO-BSI.
本研究旨在分析接受造血干细胞移植（HSCT）患者的耐碳青霉烯类微生物（CRO）肠道定植菌株与血流感染（BSI）菌株之间的同源性，确认实时直肠拭子Xpert Carba-R检测法的临床应用，并探讨其在BSI早期预警中的可行性。收集并分析了2021年1月至2021年12月期间接受相同HSCT患者的直肠拭子和血培养样本中分离出的耐药菌株。通过菌株鉴定、抗菌药物耐药表型分析、全基因组测序（WGS）、多位点序列分型（MLST）和碳青霉烯酶类型鉴定，确认CRO肠道定植菌株与BSI菌株的同源性。对2021年8月至2022年8月期间接受HSCT的患者同时进行直肠拭子培养和实时直肠拭子Xpert Carba-R检测法。以纯化菌落的碳青霉烯酶基因聚合酶链反应扩增产物的测序结果作为参考标准，确认实时直肠拭子Xpert Carba-R检测法的准确性。本研究纳入了10例接受HSCT患者的24株CRO菌株，其中包括14株肠道定植菌和10株CRO-BSI菌株。结果显示，同一患者的CRO肠道定植菌株与CRO-BSI菌株及其碳青霉烯酶基因几乎相同。此外，WGS显示，同一患者的CRO肠道定植菌株与CRO-BSI菌株之间的亲缘关系比不同患者的菌株更为密切。此外，本研究纳入了184例接受HSCT患者的4
