Gut bacteria and necrotizing enterocolitis: cause or effect?

Development of necrotising enterocolitis (NEC) is considered to be dependent on the bacterial colonisation of the gut. With little concordance between published data and a recent study failing to detect a common strain in infants with NEC, more questions than answers are arising about our understanding of this complex disease.

Proportionate reduction in uncertainty of late onset infection in pre-term infants by neutrophil CD64 measurement.

OBJECTIVE: Establish how neutrophil CD64 performs as a marker of definite infection in pre-term infants in comparison to C reactive protein (CRP) and procalcitonin (PCT). METHODS: A total of 38 pre-term infants with suspected late onset infection had CD64 measured by flow cytometry. Proportionate reduction in uncertainty (PRU) curves were generated for CD64 counts at various threshold values. RESULTS: PRU curves reduced the residual uncertainty of the presence of infection by up to 64%. CONCLUSIONS: The CD64 appears to be a useful point of care test (POCT) for further defining the likelihood of infection and performs better than CRP or PCT at helping to rule in infection.

Bacterial and fungal viability in the preterm gut: NEC and sepsis.

BACKGROUND AND AIMS: Evidence suggests that microbial communities in the preterm gut may influence the development of necrotising enterocolitis (NEC) and sepsis. Existing data often neglect fungi and whether bacteria were metabolically active or not. We sought to characterise the bacterial and fungal stool flora of preterm neonates and organism viability and evaluate any associations with NEC and sepsis. PATIENTS: 136 stools from 32 patients (<32 weeks gestation) were collected between birth and day 95. Seven infants developed NEC and 13 sepsis. METHODS: Stools were analysed by PCR-DGGE for assessment of the total bacterial and fungal communities by analysis of 16S rRNA and 28S rRNA, respectively. In 65 samples (25 infants), the viable (RNA) bacterial and fungal communities were analysed. Analyses were performed to examine the possible effects of demographic or treatment related factors and the development of NEC or sepsis. RESULTS: 80 (66 viable) bacterial species were identified overall and 12 fungal (none viable). Total bacterial communities significantly differed between healthy infants and those with NEC or sepsis, with Sphingomonas spp. significantly associated with NEC. Significant drivers of community structure differed based on either total or viable analysis. Antifungal prophylaxis was associated with altered bacterial community and a reduction in bacterial richness was observed in week 4, correlating with high antibiotic exposure. CONCLUSIONS: Total and viable communities differ in preterm infants, and non-viable fungal species are present in infants on fungal prophylaxis. Exploration of viability and non-bacterial contributors to the total community may increase understanding of NEC and sepsis.