Distortions in Development of Intestinal Microbiota Associated with Late Onset Sepsis in Preterm Infants

Abstract

Late onset sepsis (LOS) is a major contributor to neonatal morbidity and mortality, especially in premature infants. Distortions in the establishment of normal gut microbiota, commensal microbes that colonize the digestive tract, might increase the risk of LOS via disruption of the mucosal barrier with resultant translocation of luminal contents. Correlation of distortions of the intestinal microbiota with LOS is a necessary first step to design novel microbiota-based screening approaches that might lead to early interventions to prevent LOS in high risk infants. Using a case/control design nested in a cohort study of preterm infants, we analyzed stool samples that had been prospectively collected from ten preterm infants with LOS and from 18 matched controls. A 16S rRNA based approach was utilized to compare microbiota diversity and identify specific bacterial signatures that differed in their prevalence between cases and controls. Overall α-diversity (Chao1) was lower in cases two weeks before (p<0.05) but not one week before or at the time of diagnosis of LOS. Overall microbiota structure (Unifrac) appeared distinct in cases 2 weeks and 1 week before but not at diagnosis (p<0.05). Although we detected few operational taxonomic units (OTUs) unique or enriched in cases, we found many OTUs common in controls that were lacking in cases (p<0.01). Bifidobacteria counts were lower in cases at all time points. Our results support the hypothesis that a distortion in normal microbiota composition, and not an enrichment of potential pathogens, is associated with LOS in preterm infants.

Application of Fecal Volatile Organic Compound Analysis in Clinical Practice: Current State and Future Perspectives

“…The origin of LOS has traditionally been linked to colonization of intravascular catheters, however, recent studies demonstrated genetic incongruity between organisms isolated from blood culture and bacteria cultured from intravascular catheter tip, suggesting another origin [63][64][65]. Studies shown genetic similarity between cultured LOS pathogens and isolates from the gastrointestinal tract, indicating LOS pathogens might originate from the gut [66][67][68][69][70][71][72]. Therefore, Berkhout et al studied fecal VOC profiles in 36 preterm infants with confirmed LOS and compared these to 40 non-LOS controls.…”

Colonization and infection in the newborn infant: Does chlorhexidine play a role in infection prevention?

“…This suggests that the absence of certain non pathogenic microorganisms -rather than the presence of pathogenic microorganisms in itself-may be one of the risk factors for the development of neonatal sepsis. 18 A study carried out in low birth weight newborn infants at a NICU showed that the risk factor for multi-drug resistant Enterobacteriaceae was prior maternal colonization. 19 …”

Colonización e infección en el neonato. ¿Hay un rol para el uso de la clorhexidina en la prevención de infecciones?

“…Esto sugiere que la ausencia de ciertos microorganismos no patógenos, más que la presencia de patógenos per se, sería uno de los factores de riesgo para el desarrollo de sepsis neonatal. 18 Un estudio en neonatos de bajo peso al nacer en una UCIN mostró que el factor de riesgo de adquisición de enterobacterias multirresistentes era la colonización previa de la madre.…”

“…Los enterococos, enterobacterias, Acinetobacter sp., Pseudomonas aeruginosa pueden aislarse en la piel y convertirse en patógenos Tabla 2. Colonización del tracto intestinal en neonatos con y sin sepsis [9][10][11][12][13][15][16][17][18][19] oportunistas y ser responsables de infecciones asociadas al cuidado de la salud. 10,22 Los microorganismos más frecuentemente implicados en la etiología de la sepsis de origen intrahospitalario son los que colonizan la piel, el tracto gastrointestinal, las mucosas y los diferentes sistemas de monitorización y soporte.…”