CIBER de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III (ISCIII), Madrid, Spain; Spanish Network for Research in Infectious Diseases (REIPI), Instituto de Salud Carlos III (ISCIII), Madrid, Spain; Infectious Diseases (GC-03), Clinical and Molecular Microbiology (GC-24), and Lifestyles, Innovation and Health (GA-16) Groups, Maimonides Biomedical Research Institute of Cordoba (IMIBIC/Reina Sofía University Hospital/University of Córdoba), Cordoba, Spain; Department of Agricultural Chemistry, Edaphology and Microbiology and Department of Medicine, University of Cordoba, Cordoba, Spain.
Spanish Network for Research in Infectious Diseases (REIPI), Instituto de Salud Carlos III (ISCIII), Madrid, Spain; Infectious Diseases (GC-03), Clinical and Molecular Microbiology (GC-24), and Lifestyles, Innovation and Health (GA-16) Groups, Maimonides Biomedical Research Institute of Cordoba (IMIBIC/Reina Sofía University Hospital/University of Córdoba), Cordoba, Spain.
J Glob Antimicrob Resist. 2022 Sep;30:16-22. doi: 10.1016/j.jgar.2022.04.010. Epub 2022 Apr 17.
To monitor quantitatively the extent of intestinal colonisation by KPC-producing Klebsiella pneumoniae (KPC-Kp) in colonised patients who receive selective digestive decontamination (SDD) with oral gentamicin.
We developed a real-time quantitative PCR (qPCR) method for determination of the relative load of bla (RL) within the gut microbiota. Clinical validation was performed using a culture method as the gold standard and receiver operating curve (ROC) analysis. Fifteen patients were observationally and prospectively followed for one year. Clinical, microbiological variables and rectal swab samples were collected at 0 (baseline), 14 and 30 days and monthly thereafter.
Clinical validation performed on 111 rectal swab samples demonstrated that the PCR method detected 17% more positives than the culture method. ROC curve analysis documented excellent agreement between both methods (area under the curve, 0.96; 95% confidence interval 0.93-0.99). The RL decreased in 6/15 (40%) and 7/12 (58.3%) patients on days 14 and 30, respectively. Persistent eradication was observed in 2/12 (16.7%), 3/9 (33.3%), 4/8 (50%) and 7/8 (87.5%) patients at 1, 3, 6 and 12 months, respectively, with a median time of 150 days (range 30-270) to persistent eradication. Gentamicin-resistant KPC-Kp isolates were identified in 4/15 (26.7%) patients. The rates of infections (57.1% vs. 12.5%, P = 0.119) and deaths (71.4% vs. 0%, P = 0.007) were higher among patients with high baseline RL.
Following SDD, a rapid reduction on intestinal load is observed when the colonising KPC-Kp isolate is susceptible to gentamicin; however, persistent eradication at the end of SDD is low. Intestinal carriage of KPC-Kp persists after three months in about one third of patients.
通过监测接受选择性消化道去污染（SDD）联合口服庆大霉素治疗的定植患者肠道中产 KPC 肺炎克雷伯菌（KPC-Kp）的定植程度，实现对其的定量监测。
我们开发了一种实时定量 PCR（qPCR）方法，用于确定肠道微生物群中 bla（RL）的相对负荷。采用培养方法作为金标准和受试者工作特征曲线（ROC）分析对临床验证进行了评估。15 例患者进行了为期一年的前瞻性观察。在 0（基线）、14 天和 30 天以及此后每月收集临床、微生物学变量和直肠拭子样本。
对 111 份直肠拭子样本进行的临床验证表明，PCR 方法比培养方法多检测出 17%的阳性样本。ROC 曲线分析记录了两种方法之间的极好一致性（曲线下面积，0.96；95%置信区间 0.93-0.99）。在第 14 天和第 30 天，分别有 6/15（40%）和 7/12（58.3%）名患者的 RL 降低。在 1、3、6 和 12 个月时，分别有 2/12（16.7%）、3/9（33.3%）、4/8（50%）和 7/8（87.5%）名患者持续清除，持续清除的中位时间为 150 天（范围 30-270 天）。在 15 名患者中发现 4 名（26.7%）患者存在耐庆大霉素的产 KPC-Kp 分离株。基线 RL 较高的患者感染率（57.1% vs. 12.5%，P=0.119）和死亡率（71.4% vs. 0%，P=0.007）更高。
在 SDD 后，如果定植的 KPC-Kp 分离株对庆大霉素敏感，肠道负荷会迅速降低；然而，SDD 结束时的持续清除率较低。在大约三分之一的患者中，KPC-Kp 在三个月后仍会持续携带。
