PDF(Pubmed)
Abstract：
Urinary tract infections (UTIs) are among the most common late-onset infections in preterm infants, characterized by nonspecific symptoms and a pathogenic spectrum that diverges from that of term infants and older children, which present unique diagnostic and therapeutic challenges. Existing data on the role of gut microbiota in UTI pathogenesis in this demographic are limited. This study aims to investigate alterations in gut microbiota and fecal calprotectin levels and their association with the development of UTIs in hospitalized preterm infants. A longitudinal case-control study was conducted involving preterm infants admitted between January 2018 and October 2020. Fecal samples were collected weekly and analyzed for microbial profiles and calprotectin levels. Propensity score matching, accounting for key perinatal factors including age and antibiotic use, was utilized to match samples from UTI-diagnosed infants to those from non-UTI counterparts. Among the 151 preterm infants studied, 53 were diagnosed with a UTI, predominantly caused by Enterobacteriaceae (79.3%) and Enterococcaceae (19.0%). Infants with UTIs showed a significantly higher abundance of these families compared to non-UTI infants, for both Gram-negative and positive pathogens, respectively. Notably, there was a significant pre-UTI increase in the abundance of pathogen-specific taxa in infants later diagnosed with UTIs, offering high predictive value for early detection. Shotgun metagenomic sequencing further confirmed the dominance of specific pathogenic species pre-UTI and revealed altered virulence factor profiles associated with Klebsiella aerogenes and Escherichia coli infections. Additionally, a decline in fecal calprotectin levels was observed preceding UTI onset, particularly in cases involving Enterobacteriaceae. The observed pathogen-specific alterations in the gut microbiota preceding UTI onset offer novel insight into the UTI pathogenesis and promising early biomarkers for UTIs in preterm infants, potentially enhancing the timely management of this common infection. However, further validation in larger cohorts is essential to confirm these findings.
摘要：
尿路感染（UTI）是早产儿最常见的迟发性感染之一。具有非特异性症状和与足月婴儿和较大儿童不同的致病谱，这带来了独特的诊断和治疗挑战。关于肠道微生物群在UTI发病机制中的作用的现有数据在该人口统计学中是有限的。这项研究旨在调查住院早产儿肠道菌群和粪便钙卫蛋白水平的变化及其与UTI发展的关系。进行了一项纵向病例对照研究，涉及2018年1月至2020年10月期间收治的早产儿。每周收集粪便样品并分析微生物谱和钙网蛋白水平。倾向得分匹配，考虑到关键的围产期因素，包括年龄和抗生素使用，用于将UTI诊断婴儿的样本与非UTI同行的样本进行匹配。在研究的151名早产儿中，53人被诊断患有UTI,主要由肠杆菌科（79.3％）和肠球菌科（19.0％）引起。患有UTI的婴儿与非UTI婴儿相比，这些家庭的丰度明显更高，对于革兰氏阴性和阳性病原体，分别。值得注意的是,在后来诊断为UTI的婴儿中，UTI前病原体特异性分类群的丰度显着增加，为早期检测提供高预测价值。Shot弹枪宏基因组测序进一步证实了UTI前特定致病物种的优势，并揭示了与产气克雷伯菌和大肠杆菌感染相关的毒力因子谱的改变。此外,在UTI发作之前观察到粪便钙卫蛋白水平下降，特别是在涉及肠杆菌科的病例中。在UTI发病之前观察到的肠道微生物群中的病原体特异性改变提供了对UTI发病机理的新见解，并为早产儿UTI的早期生物标志物提供了新的见解。有可能加强对这种常见感染的及时管理。然而,在更大的队列中进一步验证对于确认这些发现至关重要.
