Perinatal infection and maternofetal inflammation is strongly associated with preterm birth. Inflammation probably represents an important mechanism for cerebral damage, and both overt lesions and maldevelopment can result. Epidemiological data and multiple animal models to link infection, inflammation and brain damage exist, but proof of causation is elusive.
A large number of bacterial species have been identified in fetal membranes after preterm labour (PTL) associated with intrauterine infection by microbiological culture. In this study, we have investigated a molecular and bioinformatic approach to organism identification which surmounts the need for specific and diverse microbiological culture conditions required by conventional methods. Samples of fetal membranes were taken from 37 preterm infants, and 6 normal term controls delivered by caesarean section, in which bacteria had been detected by in situ hybridization of 16S ribosomal RNA using a generic probe. Degenerate primers were designed to amplify bacterial 16S ribosomal DNA by PCR and used to amplify bacterial DNA from human fetal membranes. Amplicons were cloned, sequenced and bacteria were identified bioinformatically by comparison of sequences with known bacterial DNA genomes. In situ hybridization using an organism specific probe was then used to confirm the presence of the commonest identified organism in tissue samples. Bacterial DNA amplified from 15/43 samples, all from preterm deliveries, and the bioinformatic approach identified organisms in all cases. Multiple bacteria were identified including Mycoplasma hominis, Pasturella multocida, Pseudomonas PH1, Escherichia coli and Prevotella bivia. The commonest organism Fusobacterium nucleatum was found in 9/15 (60%) of samples. Ten of the 12 samples obtained after prolonged membrane rupture were positive for bacterial DNA, and 7 of these (70%) contained DNA from F. nucleatum. Bacteria from fetal membranes may be identified by molecular and bioinformatic methods. Further work is warranted to investigate the apparent linkage between F. nucleatum, fetal membrane rupture and preterm delivery.
Labour at all gestational ages has clear biochemical parallels with an inflammatory response, typified by the increased output of prostaglandins (PGs) and cytokines within the pregnant uterus. The main sources are the fetal membranes, including the amnion, chorion and decidua, and it is well established that stimuli [bacteria, bacterial endotoxins, interleukin (IL)-1beta, corticotrophin releasing hormone and platelet activating factor], as well as negative regulators (progesterone and IL-10), control the net output of PGs and cytokines in vitro. In this study, we have investigated the effect of oxygen tension on fetal membrane biology, as a reconsideration of the literature suggests that fetal membranes are normally exposed to approximately 3% O(2) (approximately 20 mmHg) in vivo, rather than the 20% O(2) (150 mmHg) used for in vitro culture. The output of prostaglandin E(2) from non-activated fetal membranes in response to IL-1beta was decreased by approximately 80% at 16 and 24 h of culture, whereas the inhibition of IL-6 production was time-dependent, reaching 90% after 16 h and 50% after 24 h. Tissues obtained after labour (or after the activation of inflammatory processes leading to labour) were not inhibited by the low levels of oxygen, indicating that only before the onset of labour does oxygen regulate fetal membrane biology. The data identify oxygen as a regulator of fetal membrane inflammatory functions during human pregnancy, and its mechanism of action requires further study.
Background: Adequate nutrient intake is essential to prevent postnatal growth retardation in preterm infants. In January 2002 a neonatal nutrition support team (NNST) was introduced in our Neonatal Intensive Care in order to increase the awareness of the importance of optimum nutrition as part of the overall patient treatment. The NNST focused on optimization of energy and protein intake and postnatal growth. We hypothesize that the establishment of a NNST improves nutrient intake and postnatal weight gain in preterm infants.Aim: To evaluate: 1. the computerized energy and protein prescription; 2. the effect on postnatal growth in preterm infants, before (Ͻ2002) and after (Ͼ2002) the establishment of a NNST.Study Design: Nutrient prescription and body weight were recorded using a computerized prescription system (PDMS) for all newborn infants admitted between July 1999 and December 2004. PDMS provides a quick and complete overview of the amount of fluid, nutrients and medication prescribed, and records these data in a database. Data from preterm infants Ͻ32 weeks gestational age, admitted within 72 hours after birth and staying Ͼ3 days, were included in the analysis (nϭ871).Results: Gestational age and birth weight were comparable: Ͻ2002: 29.3 Ϯ 1.7 weeks and 1206 Ϯ 326 g; Ͼ2002: 29.4 Ϯ 1.7 weeks and 1226 Ϯ 352 g. Energy and protein prescriptions increased significantly over the years, as did percent weight gain from birth weight in the first 4 postnatal weeks (PϽ0.001). Weight gain expressed as days to regain birth weight was better in the group Ͼ2002: 11.3 Ϯ 4.5 vs. 12.9 Ϯ 4.9 days in the group Ͻ2002 (pϽ0.001).Conclusions: The establishment of a NNST in our Neonatal Intensive Care resulted in increased energy and protein prescription, and improved postnatal weight gain in preterm infants. MOLECULAR AND BIOINFORMATIC DETECTION OF BACTERIAL IN-FECTION IN PRETERM DELIVERYA large number of bacterial species have been identified in fetal membranes after preterm labour associated with intrauterine infection by microbiological culture. In this study we have investigated a molecular and bioinformatic approach to organism identification which surmounts the need for specific and diverse microbiological culture conditions required by conventional methods.Methods: Samples of fetal membranes were taken from 37 preterm infants, and 6 normal term controls delivered by Caesarean section, in which bacteria had been detected by in situ hybridisation of 16S ribosomal RNA using a generic probe. Degenerate primers were designed to amplify bacterial 16S ribosomal DNA by polymerase chain reaction and used to amplify bacterial DNA from human fetal membranes. Amplicons were cloned, sequenced and bacteria identified bioinformatically by comparison of sequences with known bacterial DNA genomes. In situ hybridisation using an organism specific probe was then used to confirm the presence of the commonest identified organism in tissue samples.Results: Bacterial DNA amplified from 15/43 samples, all from preterm deliveries, and the bioinfor...
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