Edwards B D, Greysson-Wong J, Somayaji R, Waddell B, Whelan F J, Storey D G, Rabin H R, Surette M G, Parkins M D
Department of Medicine, University of Calgary, Calgary, Alberta, Canada.
Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada.
J Clin Microbiol. 2017 Jul;55(7):2074-2085. doi: 10.1128/JCM.02556-16. Epub 2017 Apr 26.
species are increasingly being detected in cystic fibrosis (CF) patients, with an unclear epidemiology and impact. We studied a cohort of patients attending a Canadian adult CF clinic who had positive sputum cultures for species in the period from 1984 to 2013. Infection was categorized as transient or persistent (≥50% positive cultures for 1 year). Those with persistent infection were matched 2:1 with age-, sex-, and time-matched controls without a history of infection, and mixed-effects models were used to assess pulmonary exacerbation (PEx) frequency and lung function decline. Isolates from a biobank were retrospectively assessed, identified to the species level by sequencing, and genotyped using pulsed-field gel electrophoresis (PFGE). Thirty-four patients (11% of those in our clinic), with a median age of 24 years (interquartile range [IQR], 20.3 to 29.8 years), developed infection. Ten patients (29%) developed persistent infection. Persistence did not denote permanence, as most patients ultimately cleared infection, often after years. Patients were more likely to experience PEx at incident isolation than at prior or subsequent visits (odds ratio [OR], 2.7 [95% confidence interval {CI}, 1.2 to 6.7]; = 0.03). Following persistent infection, there was no difference in annual lung function decline (-1.08% [95% CI, -2.73 to 0.57%] versus -2.74% [95% CI, -4.02 to 1.46%]; = 0.12) or the odds of PEx (OR, 1.21 [95% CI, 0.45 to 3.28]; = 0.70). Differential virulence among species was not observed, and no cases of transmission occurred. We demonstrated that incident infection was associated with a greater risk of PEx; however, neither transient nor chronic infection was associated with a worsened long-term prognosis. Large, multicenter studies are needed to clarify the clinical impact, natural history, and transmissibility of .
在囊性纤维化（CF）患者中越来越多地检测到某种物种，其流行病学和影响尚不清楚。我们研究了一组前往加拿大一家成人CF诊所就诊的患者，这些患者在1984年至2013年期间痰培养中该物种呈阳性。感染被分类为短暂性或持续性（连续1年培养阳性率≥50%）。将持续性感染患者与年龄、性别和时间匹配的无该物种感染史的对照按2:1进行匹配，并使用混合效应模型评估肺部加重（PEx）频率和肺功能下降情况。对生物样本库中的分离株进行回顾性评估，通过测序鉴定到物种水平，并使用脉冲场凝胶电泳（PFGE）进行基因分型。34名患者（占我们诊所患者的11%）发生了该物种感染，中位年龄为24岁（四分位间距[IQR]，20.3至29.8岁）。10名患者（29%）发生了持续性感染。持续性并不意味着永久性，因为大多数患者最终清除了感染，通常是在数年之后。患者在初次分离时比在之前或之后的就诊时更有可能经历PEx（优势比[OR]，2.7[95%置信区间{CI}，1.2至6.7]；P = 0.03）。在持续性感染后，年度肺功能下降（-1.08%[95%CI，-2.73至0.57%]与-2.74%[95%CI，-4.02至1.46%]；P = 0.12）或PEx的几率（OR，1.21[95%CI，0.45至3.28]；P = 0.70）没有差异。未观察到该物种不同菌株间的毒力差异，也未发生传播病例。我们证明初次该物种感染与PEx风险增加有关；然而，短暂性或慢性感染均与长期预后恶化无关。需要进行大型多中心研究以阐明该物种的临床影响、自然史和传播性。
