Onderdonk Andrew B, Delaney Mary L, DuBois Andrea M, Allred Elizabeth N, Leviton Alan
Harvard Medical School and the Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA.
Am J Obstet Gynecol. 2008 Jan;198(1):110.e1-7. doi: 10.1016/j.ajog.2007.05.044.
The objective of the study was to quantify and identify aerobic and anaerobic bacteria as well as Mycoplasma and Ureaplasma in the chorionic parenchyma.
A sample of the chorionic parenchyma from neonates delivered between 23-27 completed weeks was cultured and tested by polymerase chain reaction (PCR) methods using universal bacterial primers for the presence of bacteria and mycoplasmas.
The culture positive rate was higher for vaginal deliveries (333/489; 68%) than for cesarean sections (363/876; 41%). Thirty percent of all culture-positive samples had only aerobic bacteria, 21% of the samples had only anaerobic bacteria, and 9% of the samples had only Mycoplasma/Ureaplasma. The mean concentration of Mycoplasma/Ureaplasma (4.00 +/- 1.11 log10 CFU/g) was significantly higher (P < .001) than the total count of either aerobes (3.24 +/- 1.12 log10 CFU/g) or anaerobes (2.89 +/- 0.99 log10 CFU/g). Staphylococcus sp. and Corynebacterium sp. as well as organisms associated with bacterial vaginosis were the most frequently recovered. A PCR product was not detected from either randomly selected or known culture-positive samples.
Approximately half of second-trimester placentas harbor organisms within the chorionic plate. The chorion parenchyma appears to harbor constituents that prevent the identification of bacterial deoxyribonucleic acid by PCR methods.
本研究的目的是对绒毛膜实质中的需氧菌、厌氧菌以及支原体和脲原体进行定量和鉴定。
收集23至27足周出生的新生儿的绒毛膜实质样本,使用通用细菌引物通过聚合酶链反应(PCR)方法进行培养和检测,以确定是否存在细菌和支原体。
经阴道分娩的培养阳性率(333/489;68%)高于剖宫产(363/876;41%)。所有培养阳性样本中,30%仅含有需氧菌,21%仅含有厌氧菌,9%仅含有支原体/脲原体。支原体/脲原体的平均浓度(4.00±1.11 log10 CFU/g)显著高于需氧菌(3.24±1.12 log10 CFU/g)或厌氧菌(2.89±0.99 log10 CFU/g)的总数(P<.001)。葡萄球菌属和棒状杆菌属以及与细菌性阴道病相关的微生物是最常分离出的菌种。在随机选择的或已知培养阳性的样本中均未检测到PCR产物。
大约一半的孕中期胎盘在绒毛膜板内含有微生物。绒毛膜实质似乎含有能够阻止通过PCR方法鉴定细菌脱氧核糖核酸的成分。