Bacterial and fungal viability in the preterm gut: NEC and sepsis
- Christopher James Stewart1,
- Andrew Nelson1,
- David Scribbins1,
- Emma Clare L Marrs2,
- Clare Lanyon1,
- John David Perry2,
- Nicholas D Embleton3,
- Stephen Peter Cummings1,
- Janet Elizabeth Berrington3
- 1Faculty of Health and Life Sciences, University of Northumbria, Newcastle upon Tyne, UK
- 2Department of Microbiology, Freeman Hospital, Newcastle upon Tyne, UK
- 3Newcastle Neonatal Service, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
- Correspondence to Dr Janet Elizabeth Berrington, Newcastle Neonatal Service, Newcastle upon Tyne Hospitals NHS Foundation Trust, Queen Victoria Road, Newcastle upon Tyne NE1 4LP, UK;
- Received 31 March 2012
- Revised 20 November 2012
- Accepted 22 January 2013
- Published Online First 20 February 2013
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.