Department of Public Health, School of Medicine, University of Naples Federico II, Naples, Italy.
Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples, Italy.
Front Endocrinol (Lausanne). 2023 Aug 4;14:1204729. doi: 10.3389/fendo.2023.1204729. eCollection 2023.
It is well recognized that the human uterus and adjoining tissues of the female reproductive tract exist in a non-sterile state where dysbiosis can impact reproductive outcomes. The endometrial microbiota is a part of this greater milieu. To date, it has largely been studied using 16S rRNA or metagenomics-based methodologies. Despite the known advantages of sequencing analysis, several difficulties have been noted including sample contamination and standardization of DNA extraction or sequencing. The aim of this study was to use a culturomics-based method to analyze the endometrial microbiota and correlate the results with ongoing pregnancy rates.
A prospective cohort study was performed at the University of Naples from June 2022 to December 2022. Ninety-three patients undergoing an IVF cycle with single embryo transfer (ET) (fresh or frozen) were enrolled in the study. Following ET, the catheter tip was inserted into brain heart infusion (BHI) medium under sterile conditions for culture. After 24h and 48h of incubation the microorganisms in the colonies were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS).
Overall, 68 (73,92%) patients resulted positive for one or more microbes and 25 patients (26,08%) had no microbial growth. Across all participants, the four most important phyla were (87,76%), (27,94%), (10,29%) and (8,82%). species, in particular, was significantly correlated with ongoing pregnancy rate (p=0,05). On the other hand, Staphylococcus subspecies (spp.) (p<0,05) and Enterobacteriaceae (p<0,001) were found to have a negative impact on the implantation rate.
Detection of bacteria by culturomics from catheter tips used for embryo transfer has been shown to be a reliable method to detect pathogen growth. Endometrial microbiota testing in clinical practice could certainly offer a means to further improve diagnosis and treatment strategies in IVF patients.
众所周知，人类子宫及其女性生殖道的毗邻组织处于非无菌状态，菌群失调可能会影响生殖结局。子宫内膜微生物群就是这个更大环境的一部分。迄今为止，它主要是通过 16S rRNA 或宏基因组学方法进行研究的。尽管测序分析具有已知的优势，但也注意到了一些困难，包括样本污染以及 DNA 提取或测序的标准化。本研究旨在使用基于培养组学的方法来分析子宫内膜微生物群，并将结果与持续妊娠率相关联。
本前瞻性队列研究于 2022 年 6 月至 2022 年 12 月在那不勒斯大学进行。93 名接受单胚胎移植（新鲜或冷冻）的体外受精（IVF）周期的患者入组本研究。在 ET 后，将导管尖端在无菌条件下插入脑心浸液（BHI）培养基中进行培养。孵育 24h 和 48h 后，通过基质辅助激光解吸/电离飞行时间质谱（MALDI-TOF MS）鉴定菌落中的微生物。
总体而言，68 名（73.92%）患者的一个或多个微生物呈阳性，25 名（26.08%）患者无微生物生长。在所有参与者中，最重要的四个门是 （87.76%）、 （27.94%）、 （10.29%）和 （8.82%）。特别是 物种与持续妊娠率显著相关（p=0.05）。另一方面，发现葡萄球菌亚种（spp.）（p<0.05）和肠杆菌科（p<0.001）对种植率有负面影响。
从用于胚胎移植的导管尖端通过培养组学检测细菌已被证明是一种可靠的方法，可以检测病原体的生长。子宫内膜微生物组检测在临床实践中肯定可以提供一种手段，以进一步改善 IVF 患者的诊断和治疗策略。
