Nasogastric enteral feeding tubes modulate preterm colonization in early life.

BACKGROUND: Preterm infants are generally fed through nasogastric enteral feeding tubes (NEFTs). The aim of this work was to evaluate the role of NEFTs in the initial colonization of the preterm gut and its evolution within the first 2 weeks after birth. METHODS: For this purpose, fecal and NEFT-derived samples from 30 preterm infants hospitalized in a neonatal intensive care unit (NICU) were collected from birth to the second week of life. Samples were cultivated in ten culture media, including three for the isolation of antibiotic-resistant microorganisms. RESULTS: Isolates (561) were identified by 16S ribosomal RNA gene sequencing. Although the first NEFTs inserted into the neonates after birth were rarely colonized, analysis of NEFTs and fecal samples over time revealed a significant increase in bacterial abundance, diversity, and detection frequency. Results showed a parallel colonization between time-matched NEFTs and fecal samples, suggesting an ongoing bidirectional transfer of bacteria from the neonatal gut to the NEFTs and vice versa. CONCLUSIONS: In short-term hospitalization, length is by far the determinant factor for the early colonization of preterm infants. As NEFT populations reflect the bacterial populations that are colonizing the preterm in a precise moment, their knowledge could be useful to prevent the dissemination of antibiotic-resistant strains. IMPACT: The hospital environment modulates preterm colonization immediately after birth. The colonization of preterm feces and NEFTs occurs in parallel. There is an ongoing bidirectional transfer of microorganisms from the neonatal gut to the NEFTs and vice versa. Bacterial communities inside NEFTs could act as reservoirs of antibiotic resistance genes. NEFT populations reflect the bacteria that are colonizing the preterm at a precise moment.

Experimental study showed that adding fortifier and extra-hydrolysed proteins to preterm infant mothers' milk increased osmolality.

AIM: Measuring milk osmolality after adjustable fortification is clinically relevant, as values exceeding recommended safety thresholds might result in gastrointestinal consequences. The aim of this study was to evaluate the effect of four fortification levels and storage time on the osmolality of human milk. METHODS: This was an experimental study using 71 spare samples of fresh breastmilk collected from 31 mothers of preterm infants. Osmolality was measured before and after adding commercial human milk fortifier containing dextrinomaltose and hydrolysed proteins at four different concentrations. Measurements were performed at various points during the 23 hours after fortification. RESULTS: The mean basal osmolality of the 71 human milk samples was 296 ± 14 milliosmoles (mOsm)/kg, and these remained stable over a period of 23 hours. Just after fortification, the four fortified formulas showed higher osmolalities than the nonfortified human milk, ranging between 384 ± 14 and 486 ± 15 mOsm/kg, respectively (p < 0.01). This osmolality increased significantly from 20 minutes to 23 hours after fortification (p < 0.05). CONCLUSION: Adding fortifier and extra-hydrolysed proteins to human preterm milk increased osmolality, and these osmolality levels also increased with time. We recommend evaluating the risk of hyperosmolality when a higher fortification level is needed, to avoid gastrointestinal problems.

Linking preterm infant gut microbiota to nasograstric enteral feeding tubes: exploring potential interactions and microbial strain transmission.

Introduction: Preterm birth is a growing problem worldwide. Staying at a neonatal intensive care unit (NICU) after birth is critical for the survival of preterm infants whose feeding often requires the use of nasogastric enteral feeding tubes (NEFT). These can be colonized by hospital-associated pathobionts that can access the gut of the preterm infants through this route. Since the gut microbiota is the most impactful factor on maturation of the immune system, any disturbance in this may condition their health. Therefore, the aim of this study is to assess the impact of NEFT-associated microbial communities on the establishment of the gut microbiota in preterm infants. Material and methods: A metataxonomic analysis of fecal and NEFT-related samples obtained during the first 2 weeks of life of preterm infants was performed. The potential sharing of strains isolated from the same set of samples of bacterial species involved in NICU's outbreaks, was assessed by Random Amplification of Polymorphic DNA (RAPD) genotyping. Results: In the samples taken 48 h after birth (NEFT-1 and Me/F1), Staphylococcus spp. was the most abundant genera (62% and 14%, respectively) and it was latter displaced to 5.5% and 0.45%, respectively by Enterobacteriaceae. Significant differences in beta diversity were detected in NEFT and fecal samples taken at day 17 after birth (NEFT-3 and F3) (p = 0.003 and p = 0.024, respectively). Significant positive correlations were found between the most relevant genera detected in NEFT-3 and F3. 28% of the patients shared at least one RAPD-PCR profile in fecal and NEFT samples and 11% of the total profiles were found at least once simultaneously in NEFT and fecal samples from the same patient. Conclusion: The results indicate a parallel bacterial colonization of the gut of preterm neonates and the NEFTs used for feeding, potentially involving strain sharing between these niches. Moreover, the same bacterial RAPD profiles were found in neonates hospitalized in different boxes, suggesting a microbial transference within the NICU environment. This study may assist clinical staff in implementing best practices to mitigate the spread of pathogens that could threaten the health of preterm infants.

[A guide to the clinical diagnosis and urgent treatment of neonatal hyperammonaemia]. / Guía clínica de diagnóstico y tratamiento urgente de hiperamonemia neonatal.

Symptomatic hyperammonaemia in newborn is a medical emergency that should be recognised in its early stages, specifically diagnosed and aggressively treated to improve the immediate and long-term prognosis of these children. The paediatrician and the neonatal doctor should have a diagnosis-therapy scheme for its urgent management.

[Survey on scientific research activity in Spanish neonatal divisions between 2000 and 2004]. / Encuesta sobre la actividad investigadora en los servicios de neonatología en España en el período 2000-2004.

Research is an essential activity in neonatology. Following the recommendation of the Spanish Neonatal Society (SEN), a questionnaire on the state of research activity was sent to all Spanish neonatal divisions belonging to all public and private institutions with structured neonatal activity. The following items were included: (i) clinical level of the units; (ii) academic degrees and professional qualifications of the staff members; (iii) characteristics of the scientific activity performed, and (iv) financial and technical aid supporting research. Of a total of 115 eligible hospitals, 86 hospitals (74.8 %), including most of the referral centers, participated in the survey. Notable among the positive results were the findings that a significant number of neonatologists have doctoral degrees (17.4 %), are active members of the SEN (74.9 %), and wish to participate in scientific research (100 %). In addition, the presence of epidemiologists (100 %), research support units (85 %) and ethical committees (93 %) in the hospitals is widespread. Negative aspects include the lack of a specific budget to initiate research (74 %), lack of protected time even with research grants (86 %), and lack of interrelation with other groups of basic or clinical researchers (43 %). Analysis of scientific production revealed that most of the abstracts presented are restricted to Spanish national meetings, and only a small number of consolidated groups publish regularly in peer-reviewed international journals with impact factor. Measures that could help to improve the current situation are the formation of multi-hospital groups, participation in comprehensive databases (SEN 1500), and joint meetings for basic and clinical scientists, among others. The results of this survey were presented at the Congress of Perinatal Medicine held in Las Palmas (November, 2005).

[Ability of neonatal head circumference to predict long-term neurodevelopmental outcome]. / Utilidad del perímetro cefálico en el recién nacido para anticipar problemas en el neurodesarrollo.

AIM: We review the ability of head circumference (HC) at birth and head growth during the neonatal period to predict neurodevelopmental outcome, putting emphasis on new knowledge in this area. DEVELOPMENT: During infancy HC correlates closely with intracranial volume and constitutes an accurate predictor of cerebral volume. Both an abnormal head size at birth and an abnormal head growth during the neonatal period, can express brain damage or the presence of entities that involve varied degrees of neurological dysfunction in childhood. In general, the influence of head size or growth abnormalities on neurodevelopment is more related to the underlying etiology and/or the presence of structural diseases of the brain than with the HC alteration itself. HC evaluation is of particular interest in sick neonates, specially very low birth weight infants, regardless of whether they are normal or small for gestational age, and both during admission an during the first months of life. In these patients, HC catch-up within the first months of life represents a favorable neurodevelopmental prognostic factor. CONCLUSION: HC measuring and head growth evaluation constitute the most simple, inexpensive and quick available tools to assess the development of the central nervous system and identify neonates at risk of neurodevelopmental disorders.

[Studying intestinal maturation in newborn infants by means of stable isotopes]. / Estudio de la maduración intestinal en neonatos con isótopos estables.

Survival and subsequent quality of life in low birth weight infants are related to an adequate early nutrition. Premature children require parenteral nutrition support in the first days of life due to their intolerance enteral nutrition. In experimental studies, parenteral nutrition promotes intestinal abnormalities. Minimal enteral feeding has been proposed to minimise these adverse effects. Stable isotopes technology is an adequate tool to investigate metabolism in the perinatal period. The amino acid Leucine has been used by different authors for the study of protein turnover. The double tracer technology allows to follow the seizure of an amino acid administered enterally in splanchnic tissue. By continuous infusion and breath tests we can estimate protein synthesis in these children.

[Nutrition and Metabolism Group of the Spanish Neonatology Society: recommendations and evidence for dietary supplementation with probiotics in very low birth weight infants]. / Grupo de Nutrición y Metabolismo Neonatal, Sociedad Española de Neonatología: recomendaciones y evidencias para la suplementación dietética con probióticos en recién nacidos de muy bajo peso al nacer.

Clinical practice guidelines are an important tool for improving healthcare. In recent years there has been accumulating evidence on the impact of nutritional supplementation with probiotics in the very low birth weight infants. With no uniformity in microorganisms and strains used. The Spanish Neonatology Society (SENeo), through its Nutrition and Metabolism Group has undertaken to develop recommendations that will be useful as a guide for the neonatologist in this field.

Risk factors for the development of necrotizing enterocolitis: a case-control study.

AIM: To determine risk or protective factors for the development of necrotizing enterocolitis in very low birth weight infants. METHODS: This retrospective case-control study was conducted at La Paz University Hospital including infants with a birth weight of <1500 g for three years. Cases with confirmed diagnosis of necrotizing enterocolitis were evaluated; each one was paired with a control infant of the same gestational age. Statistical analysis included unadjusted and multivariable analyses. RESULTS: A total of 576 very low birth weight infants were admitted; of them 30 infants (5.2%) developed necrotizing enterocolitis. The main clinical and demographic characteristics did not differ between the two groups. The frequency of infants transfused with packed red blood cells was similar in cases (63%) and control patients (77%). However, a greater number of transfusions increased the odds of necrotizing enterocolitis [OR 1.5, 95%CI (1.01 to 2.24)]. CONCLUSIONS: A greater number of transfusions of packed red blood cells are associated with an increased risk of necrotizing enterocolitis in very low birth weight infants. The other analyzed variables in this study do not identify the infants at risk. Caution is advocated in using transfusions in newborns.