Stool microflora in extremely low birthweight infants

Abstract

Aim-To serially characterise aerobic and anaerobic stool microflora in extremely low birthweight infants and to correlate colonisation patterns with clinical risk factors. Methods-Stool specimens from 29 infants of birthweight <1000 g were collected on days 10, 20, and 30 after birth. Quantitative aerobic and anaerobic cultures were performed. Results-By day 30, predominant species were Enterococcus faecalis, Escherichia coli, Staphylococcus epidermidis, Enterbacter cloacae, Klebsiella pneumoniae, and Staphylococcus haemolyticus. Lactobacillus and Bifidobacteria spp were identified in only one infant. In breast milk fed (but not in formula fed) infants, the total number of bacterial species/stool specimen increased significantly with time (2.50 (SE 0.34) on day 10; 3.13 (0.38) on day 20; 4.27 (0.45) on day 30) as did quantitative bacterial counts; Gram negative species accounted for most of the increase. On day 30, significant inverse correlations were found between days of previous antibiotic treatment and number of bacterial species (r=0.491) and total organisms/g of stool (r=0.482). Gestational age, birthweight, maternal antibiotic or steroid treatment, prolonged rupture of the membranes, and mode of delivery did not seem to aVect colonisation patterns. Conclusions-The gut of extremely low birthweight infants is colonised by a paucity of bacterial species. Breast milking and reduction of antibiotic exposure are critical to increasing fecal microbial diversity.

Investigation of the early intestinal microflora in premature infants with/without necrotizing enterocolitis using two different methods

“…Most studies on the composition of the gut microflora in neonates who go on to develop NEC have been carried out using traditional techniques of culture (11)(12)(13)(14). Some studies have found an association between various bacterial species and NEC (15)(16)(17)(18)(19)(20), whereas others did not observe any association between NEC and any specific bacterial species (8,21).…”

Impact of empiric antibiotic regimen on bowel colonization in neonates with suspected early onset sepsis

“…Differences in proportions were compared using Chi-square test. To compensate for the influence of other [6,7,9,11,12,[20][21][22][23][24][25][26][27][28][29][30] was performed. The study was approved by the Ethics Committee of the University of Tartu.…”

“…As for Gram negative microorganisms and Candida spp, the number of colonized patients in both treatment arms was similar but greater CDs of K. pneumonia, AR Serratia spp and Candida spp were seen in the ampicillin arm and that of AR Acinetobacter spp in the penicillin arm. Studies have shown that gut colonization of a neonate is a complex process influenced by several intrinsic and extrinsic factors [6,7,11,12,[27][28][29][30]. Thus, when evaluating the interference of early antibacterial therapy with this process the methodological considerations are of utmost importance.…”

“…Finally, also maternal, neonatal and environmental factors known to interfere with gut colonization like GA, use of broad spectrum antibiotics, severity of disease, etc. were taken into account [6,7,11,12,[27][28][29][30]. We believe that such an approach enabled us to characterize adequately the true differences of these two antibiotic regimens on bowel colonization.…”

“…Studies have shown that broad spectrum antibiotics including ampicillin have led to increased rates of colonization by potentially pathogenic members of Enterobacteriaceae and Candida spp. [5][6][7]. On the other hand narrow spectrum penicillins like penicillin G have the least potential of interfering with normal gut colonization [8].…”