Background The causes and clinical characteristics of recurrent gram-negative bacterial bloodstream infections (GNB-BSI) are poorly understood. Methods We used a prospectively ascertained cohort of patients with GNB-BSI to identify clinical characteristics, microbiology, and risk factors associated with recurrent GNB-BSI. Bacterial genotyping (both pulsed field gel electrophoresis [PFGE] and whole genome sequencing [WGS]) was used to define whether these episodes were due to relapse or reinfection. Multivariable logistic regression was used to identify risk factors associated with recurrence. Results Of the 1423 patients with GNB-BSI that met criteria for inclusion in this study, 60 (4%) had recurrent GNB-BSI. Non-white race (OR: 2.35; CI95% 1.38-4.01; p = 0.002), admission to a surgical service (OR: 2.18; CI95% 1.26-3.75; p = 0.005) and presence of an indwelling cardiac device (OR: 2.73; CI95% 1.21-5.58, p = 0.009) were associated with increased risk for recurrent GNB-BSI. Among the 48 patients with recurrent GNB-BSI whose paired bloodstream isolates underwent genotyping, 63% were due to relapse (30/48) and 38% were due to reinfection (18/48) based on WGS. Compared with WGS, PFGE correctly differentiated relapse and reinfection in 98% (47/48) of cases. Median time to relapse and reinfection was similar (113 days [IQR: 35-222 days] vs. 174 days [IQR: 69-599 days], p = 0.13). Presence of a cardiac device was associated with relapse (Relapse: 7/27 [26%]; Non-relapse: 65/988 [7%]; p = 0.002). Conclusions In this study, recurrent GNB-BSI was most commonly due to relapse. PFGE accurately differentiated relapse from reinfection when compared with WGS. Presence of a cardiac device was a risk factor for relapse.

中文翻译：

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复发性革兰氏阴性血流感染的临床和分子分析

背景 人们对复发性革兰氏阴性细菌血流感染（GNB-BSI）的原因和临床特征知之甚少。方法 我们使用前瞻性确定的 GNB-BSI 患者队列来确定与复发性 GNB-BSI 相关的临床特征、微生物学和危险因素。细菌基因分型（脉冲场凝胶电泳 [PFGE] 和全基因组测序 [WGS]）用于确定这些发作是否是由于复发或再感染所致。使用多变量逻辑回归来识别与复发相关的危险因素。结果 在符合本研究纳入标准的 1423 名 GNB-BSI 患者中，60 名 (4%) 患有复发性 GNB-BSI。非白人种族（OR：2.35；CI95% 1.38-4.01；p = 0.002）、接受外科手术（OR：2.18；CI95% 1.26-3.75；p = 0.005）以及存在留置心脏装置（OR： 2.73；CI95% 1.21-5.58，p = 0.009）与复发 GNB-BSI 风险增加相关。根据 WGS，在 48 名复发性 GNB-BSI 患者中，其配对血流分离株接受了基因分型，其中 63% 是由于复发 (30/48)，38% 是由于再感染 (18/48)。与 WGS 相比，PFGE 在 98% (47/48) 的病例中正确区分复发和再感染。复发和再感染的中位时间相似（113 天 [IQR：35-222 天] vs. 174 天 [IQR：69-599 天]，p = 0.13）。心脏装置的存在与复发相关（复发：7/27 [26%]；非复发：65/988 [7%]；p = 0.002）。结论 在本研究中，复发性 GNB-BSI 最常见的原因是复发。与 WGS 相比，PFGE 可以准确区分复发和再感染。心脏装置的存在是复发的危险因素。