%0 Journal Article %T Parenteral Antibiotics Reduce Bifidobacteria Colonization and Diversity in Neonates %A S¨Ļamus Hussey %A Rebecca Wall %A Emma Gruffman %A Lisa O'Sullivan %A C. Anthony Ryan %A Brendan Murphy %A Gerald Fitzgerald %A Catherine Stanton %A R. Paul Ross %J International Journal of Microbiology %D 2011 %I Hindawi Publishing Corporation %R 10.1155/2011/130574 %X We investigated the impact of parenteral antibiotic treatment in the early neonatal period on the evolution of bifidobacteria in the newborn. Nine babies treated with intravenous ampicillin/gentamicin in the first week of life and nine controls (no antibiotic treatment) were studied. Denaturing gradient gel electrophoresis was used to investigate the composition of Bifidobacterium in stool samples taken at four and eight weeks. Bifidobacteria were detected in all control infants at both four and eight weeks, while only six of nine antibiotic-treated infants had detectable bifidobacteria at four weeks and eight of nine at eight weeks. Moreover, stool samples of controls showed greater diversity of Bifidobacterium spp. compared with antibiotic-treated infants. In conclusion, short-term parenteral antibiotic treatment of neonates causes a disturbance in the expected colonization pattern of bifidobacteria in the first months of life. Further studies are required to probiotic determine if supplementation is necessary in this patient group. 1. Introduction Up to 10% of newborn infants require admission to the neonatal intensive care unit (NICU) for ongoing medical care [1¨C3]. Many of these infants require treatment with parenteral antibiotics for variable periods of time. Antibiotic administration is known to perturb the composition of the intestinal microbiota, resulting in suppression of anaerobic bacteria (with the exception of clostridia, which remain at detectable levels) and increased numbers of potentially pathogenic bacteria such as Klebsiella, Enterobacter, Citrobacter, and Pseudomonas [4, 5]. Since the pioneering microbiota of infancy probably create perpetual habitats for themselves, defining the life-long composition of the gut microbiota and consequently contributing to host health and well-being [6, 7], the initial colonization of the infant gastrointestinal tract is of significant importance. Bifidobacterium spp. have several reported health-promoting effects, including inhibition of growth of harmful bacteria, stimulation of the immune system, alleviation of constipation, and prevention of intestinal infections [8¨C13]. Species commonly associated with humans include Bifidobacterium infantis, B. longum, B. bifidum, B. breve, B. catenulatum, B. pseudocatenulatum, B. angulatum, B. gallicum, and B. adolescensis [8], of which the first four are prevalent in infants [14]. Suppression of the bifidobacteria population as occurred following antibiotic exposure in children [5, 15, 16] may have negative effects on host well-being and can be associated %U http://www.hindawi.com/journals/ijmicro/2011/130574/