ena-STUDY-TEL AVIV UNIVERSITY-18-12-2018-04:43:21:812-177
Assessing the involvement of the placental microbiome and virome in preeclampsia using a novel method for pathogen detection
Preeclampsia is one of the most dangerous complications of pregnancy and the leading cause of ?maternal and perinatal morbidity and mortality. The cause of preeclampsia is unknown, though the ?placenta is believed to have a central role in its pathogenesis. An association between maternal ?infection and preeclampsia has been demonstrated, yet involvement of the placental microbiome in ?the etiology of preeclampsia has not been determined. In this study we examined whether ?preeclampsia is associated with an imbalanced microorganism composition in the placenta. To this end, ?we developed a novel method for pathogen detection based on sequencing of small non-coding RNA, ?which increases the pathogen-to-host ratio?, this being a major challenge in pathogen detection ?methods. We validated the method on various infected tissues and demonstrated its efficiency in ?detecting microorganisms in samples with extremely low bacterial/viral biomass. We then applied the ?method to placenta specimens from preeclamptic and healthy pregnancies. Since the placenta is a ?remarkably large and heterogeneous organ, we explored the bacterial and viral RNA at each of 15 ?distinct locations. Bacterial RNA was detected at all locations, without significant differences between ?the preeclampsia and control groups. However, the bacterial RNA composition differed significantly ?between various areas of the placenta. Our results suggest that the bacterial and viral abundance in ?the placenta may have only limited involvement in the pathogenesis of preeclampsia. The evidence of ?a heterogenic bacterial RNA composition in the various placental locations warrants further ?investigation of regions of the placenta in order to ?capture the true nature of the placental ?microbiome?. ?
Preeclampsia is one of the most dangerous complications of pregnancy and the leading cause of ?maternal and perinatal morbidity and mortality. The cause of preeclampsia is unknown, though the ?placenta is believed to have a central role in its pathogenesis. An association between maternal ?infection and preeclampsia has been demonstrated, yet involvement of the placental microbiome in ?the etiology of preeclampsia has not been determined. In this study we examined whether ?preeclampsia is associated with an imbalanced microorganism composition in the placenta. To this end, ?we developed a novel method for pathogen detection based on sequencing of small non-coding RNA, ?which increases the pathogen-to-host ratio?, this being a major challenge in pathogen detection ?methods. We validated the method on various infected tissues and demonstrated its efficiency in ?detecting microorganisms in samples with extremely low bacterial/viral biomass. We then applied the ?method to placenta specimens from preeclamptic and healthy pregnancies. Since the placenta is a ?remarkably large and heterogeneous organ, we explored the bacterial and viral RNA at each of 15 ?distinct locations. Bacterial RNA was detected at all locations, without significant differences between ?the preeclampsia and control groups. However, the bacterial RNA composition differed significantly ?between various areas of the placenta. Our results suggest that the bacterial and viral abundance in ?the placenta may have only limited involvement in the pathogenesis of preeclampsia. The evidence of ?a heterogenic bacterial RNA composition in the various placental locations warrants further ?investigation of regions of the placenta in order to ?capture the true nature of the placental ?microbiome?. ?