J. D. Bowling1, J. Lim1, J. Golden1, A. Dossa1, B. Bell1, L. Chase1, J. Wang1, A. Grishin1, H. R. Ford1 1Children’s Hospital Los Angeles,Pediatric Surgery,Los Angeles, CA, USA
Introduction: Early post-natal microbiota is presumed to play a critical role in the pathogenesis of necrotizing enterocolitis (NEC), a severe gastrointestinal disease found often in premature infants. Whereas some colonizing bacteria may act as opportunistic pathogens, other bacteria might be innocuous and even protective. In our previous studies, the presence of E. coli CE10 in 4 day old rats negatively correlated with NEC. Here we tested the hypothesis that CE10 is capable of colonizing neonatal rats and protecting them from NEC.
Methods: E. coli CE10 was transformed with a plasmid (pJK_proK14_eGFR) conferring ampicillin resistance and expression of green fluorescent protein (GFP). Transformed bacteria were introduced to neonatal rats with the first feeding. Afterwards, the animals were subjected to 4 days of the NEC-inducing formula-feeding/hypoxia (FF/H) regimen. NEC was scored histologically. Stool and ileum samples were plated for total bacterial load and the numbers of E. coli C10. The level of apoptosis was analyzed using TUNEL staining and fluorescence microscopy.
Results: E. coli CE10 established itself as a first colonizer in animals that received it. FF/H alone caused NEC in 60% of neonatal rats. Introduction of E. coli CE10 reduced the incidence of NEC to 39% (p = 0.027). FF/H yielded a higher rate of apoptosis than E. coli CE10 via TUNEL staining. EC was scored histologically. Stool and ileum samples were plated for total bacterial load and the numbers of E. coli C10. The level of apoptosis was analyzed using TUNEL staining and fluorescence microscopy
Conclusion: E. coli 07:K1 CE10 is an efficient first colonizer in neonatal rats. CE10 significantly reduced the incidence of NEC. Bacteria similar to this strain can be used for the prophylaxis of NEC.
