Primary research between intestinal flora and late-onset sepsis in premature infants / 中国医师杂志

ABSTRACT

Objective:To compare the characteristics and differences of intestinal flora in premature infants with late-onset sepsis (LOS) and pneumonia by high-throughput sequencing technology, and to investigate the relationship between intestinal flora and LOS.Methods:Through the case-control method, premature infants with late-onset sepsis who were hospitalized in the neonatal department of Hunan Children′s Hospital from August 2018 to October 2019 were selected as the case group ( n=8). At the same time, premature infants diagnosed with pneumonia were selected as the control group ( n=8). The fecal samples of 16 premature infants were collected for the first time, and the DNA was extracted. The DNA of the target region was amplified by polymerase chain reaction(PCR). High-throughput sequencing was performed using NovaSeq 6000 platform to analyze the composition and diversity of intestinal flora between the two groups. Results:(1) Alpha diversity analysis showed that there was no significant difference in the richness and diversity of intestinal flora between the two groups(all P>0.05). (2) The intestinal flora in premature infants of LOS group and control group were dominated by Firmicutes and Proteobacteria, and facultative anaerobes such as Enterococcus and Escherichia-Shigella were the dominant flora at the genus level. Metastas statistical analysis showed that there was no statistically significant difference in flora composition between the two groups at the phylum level ( P>0.05). (3) Metastas statistical analysis was carried out at the level of class, order, family, genus, and species. The relative abundance of actinomycetes, digestive streptococcaceae and Clostridium in LOS group was higher than that in pneumonia group, and the difference was statistically significant (all P<0.05). (4) The relative abundance of Staphylococcus in the LOS group was significantly greater than that in the control group, but Metastas statistical analysis showed that there was no statistically significant difference in the relative abundance of staphylococcus between the two groups ( P>0.05). (5) Among the 8 cases of LOS, 3 premature infants had positive blood cultures, namely Streptococcus agalactiae, Streptococcus mitis, and Enterococcus faecalis. Enterococcus faecalis belongs to the genus Enterococcus, and Enterococcus belongs to the dominant genus in the LOS group. Conclusions:Different site infections have effects on intestinal microecology of premature infants. There were differences in intestinal flora composition between premature infants with LOS and premature infants with pneumonia.