Neonatal Candida spp. infections: an update

Gut colonization by aerobic microorganisms is associated with route and type of nutrition in premature neonates

We hypothesized that the beneficial effects of early enteral compared with parenteral feeding are related to the increased variety of aerobic microorganisms that colonize the gut. Our aim was to describe the relationship, first, between the type of feeding and mucosal colonization and, second, between the type of feeding and the development of late-onset sepsis (LOS) and necrotizing enterocolitis (NEC) in preterm neonates. In total, 159 neonates aged 72 hours or less with risk factors for early-onset sepsis were recruited to a prospective 2-center study. Rectal swabs were collected on admission and twice per week thereafter. The feeding regimen was recorded for the first 7 days and categorized into total parenteral nutrition (TPN) and 2 regimens of enteral nutrition, that is, breast milk containing regimen (BMCR), for which breast milk constituted at least 11% of the enteral diet, or formula. Herein, 70 neonates received formula, 48 received BMCR, and 41 received TPN; 69 cases of LOS and 15 cases of NEC were observed in 50 neonates. A multiple logistic regression analysis indicated that formula and BMCR were associated with 4- to 5-fold increases in colonization by Gram-negative bacteria (odds ratio [OR], 4.52; 1.87-10.95, and OR, 4.95; 1.90-12.87, respectively) and 5 to 9 times higher odds of colonization by Gram-positive microorganisms (OR, 5.75; 1.89-16.72, and OR, 8.61; 2.52-29.36, respectively) compared with TPN. The only difference between BMCR and the other feeding groups was the higher colonization with Staphylococcus haemolyticus in the latter (formula-OR, 6.24; 1.73-22.50; TPN-OR, 2.75; 1.08-6.97). Compared with BMCR, TPN was associated with an increased odds of LOS (OR, 3.04; 1.02-9.07) and an increased odds of death (19.75; 3.64-107.12) compared with formula. Although early enteral feeding is associated with a higher odds of colonization with opportunistic microorganisms, it should be preferred over TPN whenever feasible, due to the favorable effect on the prevention of LOS.

Risk factors associated with gut and nasopharyngeal colonization by common Gram-negative species and yeasts in neonatal intensive care units patients

AIM

To characterize dynamics of mucosal colonization of neonates by common aerobic Gram negative species and Candida spp. and to identify independent perinatal, neonatal, and environmental factors influencing the colonization process.

STUDY DESIGN

The nasopharyngeal (n=1145) and rectal (n=1242) swabs were collected on admission and thereafter twice a week in neonates with risk factors of early onset sepsis (n=276) admitted within the first 72 h of life. The association between colonization by different microbes and a total of 22 predefined risk factors was assessed using univariate and multiple logistic regression analyses.

RESULTS

Throughout the study about half of the patients had rectal (55.8%) or nasopharyngeal colonization (42.8%) with common Gram-negative microorganisms. Colonization dynamics and risk factors were in general similar for a given bacterial species in both mucosal sites; nonfermentative microbes more often found in nasopharyngeal swabs and Enterobacteriaceae in rectal swabs. All organisms except Escherichia coli were influenced by the duration of intensive care unit stay but other risk factors were species specific, perhaps reflecting their mode of acquisition. While colonization by E. coli and Candida albicans was associated with perinatal factors like term birth, vaginal delivery, and breast milk feeding; colonization by Klebsiella pneumoniae, Enteribacter cloacae, Acinetobacter spp. and non-albicans Candida spp. were mostly determined by hospital environment (treatment unit and period, artificial interventions and their duration) and gestation age ≤ 28 weeks.

CONCLUSIONS

The knowledge of risk factor profiles may permit the development of strategies to prevent heavy colonization and subsequent invasive disease in high risk infants.