Bloodstream infections during the onset of necrotizing enterocolitis and their relation with the pro-inflammatory response, gut wall integrity and severity of disease in NEC.

INTRODUCTION: Bacterial involvement is believed to play a pivotal role in the development and disease outcome of NEC. However, whether a bloodstream infection (BSI) predisposes to NEC (e.g. by activating the pro-inflammatory response) or result from the loss of gut wall integrity during NEC development is a longstanding question. OBJECTIVE: We hypothesize that the occurrence of a BSI plays a complementary role in the pathogenesis of NEC. The first aim of the study was to correlate the occurrence of a BSI during the early phase of NEC with intestinal fatty acid-binding protein (I-FABP) levels, as a marker for loss of gut wall integrity owing to mucosal damage, and Interleukin (IL)-8 levels, as a biomarker for the pro-inflammatory cascade in NEC. The second aim of the study was to investigate the relation between the occurrence of a BSI and disease outcome. MATERIAL AND METHODS: We combined data from prospective trials from two large academic pediatric surgical centers. Thirty-eight neonates with NEC, 5 neonates with bacterial sepsis, and 14 controls were included. RESULTS: BSIs occurred in 10/38 (26%) neonates at NEC onset. No association between the occurrence of BSIs and I-FABP levels in plasma (cohort 1: median 11ng/mL (range 0.8-298), cohort 2: median 6.8ng/mL (range 1.3-15)) was found in NEC patients (cohort 1: p=0.41; cohort 2: p=0.90). In addition, the occurrence of BSIs did not correlate with IL-8 (median 1562pg/mL (range 150-7,500); p=0.99). While the occurrence of a BSI was not correlated with Bell's stage (p=0.85), mortality was higher in patients with a BSI (p=0.005). CONCLUSION: The low incidence of BSIs and the absent association of both the markers for loss of gut wall integrity and the pro-inflammatory response during the early phase of NEC, support the hypothesis that the presence of a BSI does not precede NEC.

Intestinal fatty acid-binding protein levels in Necrotizing Enterocolitis correlate with extent of necrotic bowel: results from a multicenter study.

BACKGROUND: Intestinal fatty acid-binding protein (I-FABP) is considered as a specific marker for enterocyte damage in necrotizing enterocolitis (NEC). OBJECTIVE: The purpose of this study was to evaluate the association of plasma and urinary I-FABP levels with the extent of macroscopic intestinal necrosis in surgical NEC. METHODS: We combined data from prospective trials from two large academic pediatric surgical centers. Nine and 10 infants with surgical NEC were included, respectively. Plasma and urinary of I-FABP at disease onset were correlated with the length of intestinal resection during laparotomy. RESULTS: Median length of bowel resection was 10cm (range 2.5-50) and 17cm (range 0-51), respectively. Median I-FABP levels were 53ng/mL (range 6.3-370) and 4.2ng/mL (range 1.1-15.4) in plasma in cohort 1 respectively cohort 2 and 611ng/mL (range 3-23,336) in urine. The length of bowel resection significantly correlated with I-FABP levels in plasma (Rho 0.68; p=0.04 and Rho 0.66;p=0.04) and in urine (Rho 0.92; p=0.001). CONCLUSION: This 'proof of concept' study demonstrates that plasma and urine I-FABP levels at disease onset was strongly associated with the length of intestinal resection in surgical NEC. This offers further evidence that I-FABP levels are a promising biomarker for assessing intestinal necrosis in infants with advanced NEC.

Amniocentesis for the detection of congenital toxoplasmosis: results from the nationwide Austrian prenatal screening program.

Prenatal diagnosis of congenital toxoplasmosis (CT) influences therapeutical management in pregnant women and their offspring. In Austria, a nationwide serological healthcare program to identify potential maternal toxoplasma infections during pregnancy exists. We assessed the clinical use of amniocentesis for toxoplasma-specific polymerase chain reaction (PCR) on amniotic fluid to detect CT. Data on serology, amniocentesis, PCR, complications, treatment, and paediatric clinical outcome were collected retrospectively among the birth cohort 1992-2008. There were 1386 women with amniocentesis, but only in 707 cases (51%) was acute maternal infection confirmed serologically. A high proportion (49%) of amniocenteses with negative PCR results in women with chronic infection or seronegativity were performed without clinical justification for the women or their foetuses. The positive and negative predictive values of PCR were 94.4% and 99.3%, respectively. Thirty-nine foetuses with CT, including four deaths, were reported. The five PCR-negative but infected infants were identified by the serological and clinical follow-up program. Thirty percent of amniocenteses were performed in the third trimester, and gestational age or treatment did not influence PCR sensitivity. Amniocentesis is indicated in women with acute maternal infection, and facilitated targeted therapies in pregnant women and their offspring. In women with late toxoplasma infection, negative amniotic fluid PCR made treatment of infants unnecessary. Serological and clinical follow-up of infants is important to confirm the infection status of the infant. Recommendations, based on our 17-year experience, to improve the current diagnostic strategies and to reduce unnecessary amniocentesis, are given.

A quantitative real-time PCR assay for the highly sensitive and specific detection of human faecal influence in spring water from a large alpine catchment area.

AIMS: The aim of the study was the development of a sensitive human-specific quantitative real-time PCR assay for microbial faecal source tracking (MST) in alpine spring water. The assay detects human-specific faecal DNA markers (BacH) from 16S rRNA gene sequences from the phylum Bacteroidetes using TaqMan minor groove binder probes. METHODS AND RESULTS: The qualitative and quantitative detection limits of the PCR assay were 6 and 30 marker copies, respectively. Specificity was proved by testing 41 human faeces and waste water samples and excluding cross-amplification from 302 animal faecal samples from Eastern Austria. Marker concentrations in human faecal material were in the range from 6.6 x 10(9) to 9.1 x 10(10) marker equivalents per gram. The method was sensitive enough to detect a few 100 pg of faeces in faecal suspensions. The assay was applied on water samples from an alpine karstic spring catchment area and the results reflected the expected levels of human faecal influence. CONCLUSIONS: The method exhibited sufficient sensitivity to allow quantitative source tracking of human faecal impact in the investigated karstic spring water. SIGNIFICANCE AND IMPACT OF THE STUDY: The developed method constitutes the first quantitative human-specific MST tool sensitive enough for investigations in ground and spring water.