Transplantation-Oncology Infectious Diseases Program, Division of Infectious Diseases, Department of Medicine, Weill Cornell Medicine, New York, New York, USA.
Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, New York, USA.
Clin Infect Dis. 2021 Oct 5;73(7):1257-1265. doi: 10.1093/cid/ciab404.
Levofloxacin prophylaxis is recommended to prevent gram-negative bloodstream infections (BSIs) in patients with prolonged chemotherapy-induced neutropenia. However, increasing fluoroquinolone resistance may decrease the effectiveness of this approach.
We assessed the prevalence of colonization with fluoroquinolone-resistant Enterobacterales (FQRE) among patients admitted for hematopoietic cell transplantation (HCT) from November 2016 to August 2019 and compared the risk of gram-negative BSI between FQRE-colonized and noncolonized patients. All patients received levofloxacin prophylaxis during neutropenia. Stool samples were collected upon admission for HCT and weekly thereafter until recovery from neutropenia, and underwent selective culture for FQRE. All isolates were identified and underwent antimicrobial susceptibility testing by broth microdilution. FQRE isolates also underwent whole-genome sequencing.
Fifty-four of 234 (23%) patients were colonized with FQRE prior to HCT, including 30 of 119 (25%) allogeneic and 24 of 115 (21%) autologous HCT recipients. Recent antibacterial use was associated with FQRE colonization (P = .048). Ninety-one percent of colonizing FQRE isolates were Escherichia coli and 29% produced extended-spectrum β-lactamases. Seventeen (31%) FQRE-colonized patients developed gram-negative BSI despite levofloxacin prophylaxis, compared to only 2 of 180 (1.1%) patients who were not colonized with FQRE on admission (P < .001). Of the 17 gram-negative BSIs in FQRE-colonized patients, 15 (88%) were caused by FQRE isolates that were genetically identical to the colonizing strain.
Nearly one-third of HCT recipients with pretransplant FQRE colonization developed gram-negative BSI while receiving levofloxacin prophylaxis, and infections were typically caused by their colonizing strains. In contrast, levofloxacin prophylaxis was highly effective in patients not initially colonized with FQRE.
左氧氟沙星预防方案被推荐用于预防因化疗导致的中性粒细胞减少症而延长的患者的革兰氏阴性血流感染（BSI）。然而，氟喹诺酮类药物耐药性的增加可能会降低这种方法的效果。
我们评估了 2016 年 11 月至 2019 年 8 月期间因造血细胞移植（HCT）入院的患者中氟喹诺酮耐药肠杆菌科（FQRE）定植的流行率，并比较了 FQRE 定植和非定植患者的革兰氏阴性 BSI 风险。所有患者在中性粒细胞减少症期间接受左氧氟沙星预防。在 HCT 入院时采集粪便样本，并在那之后每周采集一次，直到从中性粒细胞减少症中恢复，然后进行 FQRE 的选择性培养。所有分离株均经过鉴定，并通过肉汤微量稀释法进行了抗菌药物敏感性测试。FQRE 分离株还进行了全基因组测序。
234 名患者中有 54 名（23%）在 HCT 前定植了 FQRE，其中 119 名（25%）异基因和 115 名（21%）自体 HCT 受者。近期使用抗菌药物与 FQRE 定植相关（P=0.048）。定植 FQRE 分离株的 91%为大肠杆菌，29%产生了超广谱β-内酰胺酶。尽管接受了左氧氟沙星预防，但在 17 名 FQRE 定植患者中仍发生了 17 例革兰氏阴性 BSI，而在 180 名入院时未定植 FQRE 的患者中仅有 2 例（P<0.001）。在 FQRE 定植患者的 17 例革兰氏阴性 BSI 中，15 例（88%）由与定植株遗传上相同的 FQRE 分离株引起。
近三分之一的接受 HCT 前有 FQRE 定植的患者在接受左氧氟沙星预防的同时发生了革兰氏阴性 BSI，并且感染通常是由其定植株引起的。相比之下，在最初未定植 FQRE 的患者中，左氧氟沙星预防方案非常有效。
