No microorganism was detected in amniotic fluid of healthy pregnancies from the second trimester to the delivery
Abstract Background The early colonization and establishment of the microbiome in newborns is a crucial step in the development of the immune system and host metabolism. However, the exact timing of initial microbial colonization remains a subject of ongoing debate. While numerous studies have attem...
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BMC
2025-01-01
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| Series: | Microbiome |
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| Online Access: | https://doi.org/10.1186/s40168-024-02024-3 |
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| author | Yu Liu Jingmei Ma Xiang Li Haijuan Zhao Qubo Ai Lanying Zhang Yulong Tong Lingzhen Meng Huixia Yang |
| author_facet | Yu Liu Jingmei Ma Xiang Li Haijuan Zhao Qubo Ai Lanying Zhang Yulong Tong Lingzhen Meng Huixia Yang |
| author_sort | Yu Liu |
| collection | DOAJ |
| description | Abstract Background The early colonization and establishment of the microbiome in newborns is a crucial step in the development of the immune system and host metabolism. However, the exact timing of initial microbial colonization remains a subject of ongoing debate. While numerous studies have attempted to determine the presence or absence of intrauterine bacteria, the majority of them have drawn conclusions based on sequencing data from maternal or infant samples taken at a single time point. In this study, we aimed to investigate the microbial population in amniotic fluid (AF) from the second trimester until the time of delivery using multiple microbiological methods. Methods AF samples were collected during the second trimester (19–21 gestational weeks) and at the time of delivery. Cohort 1 included 51 women who underwent the term and elective cesarean section, with both their second trimester and delivery AF samples (n = 55, respectively) analyzed. Cohort 2 contained 22 women who experienced infection-related adverse pregnancy outcomes (including preterm birth, histological chorioamnionitis, and stillbirth), with only their second trimester AF samples (n = 24) examined. Additionally, multiple procedural negative controls and technical positive controls were applied to this study to remove potential contamination. Microbial profiles were assessed through cultivation, quantitative real-time polymerase chain reaction, 16S ribosomal RNA gene sequencing, and cytokine analysis. Results In cohort 1, the bacterial load and community structure in the second trimester AF samples were indistinguishable from negative controls. Although marginally higher bacterial loads and different bacterial communities were observed in the delivery AF samples compared to negative controls, these bacterial DNA were not considered biologically functional due to the absence of maternal inflammatory responses. In cohort 2, the bacterial load and community structure of the second trimester AF samples differed significantly from those of negative controls, with Ureaplasma and Lactobacillus identified as the most prevalent genera against negative controls. Conclusions Our study demonstrates that no microorganisms were detected in the AF of healthy pregnancies from the second trimester to the delivery. The presence of Ureaplasma and Lactobacillus in the second trimester AF may be associated with infection-related adverse pregnancy outcomes. Video Abstract |
| format | Article |
| id | doaj-art-0509dc45c34a4540b4b7e40d03bff0af |
| institution | Kabale University |
| issn | 2049-2618 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | BMC |
| record_format | Article |
| series | Microbiome |
| spelling | doaj-art-0509dc45c34a4540b4b7e40d03bff0af2025-01-26T12:43:12ZengBMCMicrobiome2049-26182025-01-0113111410.1186/s40168-024-02024-3No microorganism was detected in amniotic fluid of healthy pregnancies from the second trimester to the deliveryYu Liu0Jingmei Ma1Xiang Li2Haijuan Zhao3Qubo Ai4Lanying Zhang5Yulong Tong6Lingzhen Meng7Huixia Yang8Department of Obstetrics and Gynecology, Peking University First HospitalDepartment of Obstetrics and Gynecology, Peking University First HospitalCOYOTE Medical LaboratoryCOYOTE Medical LaboratoryCOYOTE Medical LaboratoryCOYOTE Medical LaboratoryDepartment of Obstetrics and Gynecology, Peking University First HospitalDepartment of Laboratory, Peking University First HospitalDepartment of Obstetrics and Gynecology, Peking University First HospitalAbstract Background The early colonization and establishment of the microbiome in newborns is a crucial step in the development of the immune system and host metabolism. However, the exact timing of initial microbial colonization remains a subject of ongoing debate. While numerous studies have attempted to determine the presence or absence of intrauterine bacteria, the majority of them have drawn conclusions based on sequencing data from maternal or infant samples taken at a single time point. In this study, we aimed to investigate the microbial population in amniotic fluid (AF) from the second trimester until the time of delivery using multiple microbiological methods. Methods AF samples were collected during the second trimester (19–21 gestational weeks) and at the time of delivery. Cohort 1 included 51 women who underwent the term and elective cesarean section, with both their second trimester and delivery AF samples (n = 55, respectively) analyzed. Cohort 2 contained 22 women who experienced infection-related adverse pregnancy outcomes (including preterm birth, histological chorioamnionitis, and stillbirth), with only their second trimester AF samples (n = 24) examined. Additionally, multiple procedural negative controls and technical positive controls were applied to this study to remove potential contamination. Microbial profiles were assessed through cultivation, quantitative real-time polymerase chain reaction, 16S ribosomal RNA gene sequencing, and cytokine analysis. Results In cohort 1, the bacterial load and community structure in the second trimester AF samples were indistinguishable from negative controls. Although marginally higher bacterial loads and different bacterial communities were observed in the delivery AF samples compared to negative controls, these bacterial DNA were not considered biologically functional due to the absence of maternal inflammatory responses. In cohort 2, the bacterial load and community structure of the second trimester AF samples differed significantly from those of negative controls, with Ureaplasma and Lactobacillus identified as the most prevalent genera against negative controls. Conclusions Our study demonstrates that no microorganisms were detected in the AF of healthy pregnancies from the second trimester to the delivery. The presence of Ureaplasma and Lactobacillus in the second trimester AF may be associated with infection-related adverse pregnancy outcomes. Video Abstracthttps://doi.org/10.1186/s40168-024-02024-3Amniotic fluidBacteriaPregnancyPreterm birthInfection |
| spellingShingle | Yu Liu Jingmei Ma Xiang Li Haijuan Zhao Qubo Ai Lanying Zhang Yulong Tong Lingzhen Meng Huixia Yang No microorganism was detected in amniotic fluid of healthy pregnancies from the second trimester to the delivery Microbiome Amniotic fluid Bacteria Pregnancy Preterm birth Infection |
| title | No microorganism was detected in amniotic fluid of healthy pregnancies from the second trimester to the delivery |
| title_full | No microorganism was detected in amniotic fluid of healthy pregnancies from the second trimester to the delivery |
| title_fullStr | No microorganism was detected in amniotic fluid of healthy pregnancies from the second trimester to the delivery |
| title_full_unstemmed | No microorganism was detected in amniotic fluid of healthy pregnancies from the second trimester to the delivery |
| title_short | No microorganism was detected in amniotic fluid of healthy pregnancies from the second trimester to the delivery |
| title_sort | no microorganism was detected in amniotic fluid of healthy pregnancies from the second trimester to the delivery |
| topic | Amniotic fluid Bacteria Pregnancy Preterm birth Infection |
| url | https://doi.org/10.1186/s40168-024-02024-3 |
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