Microfloral analysis of pediatric respiratory syncytial virus infection, with and without the use of antibiotics

摘要

Objectives To describe, in detail, the influence of antibiotics on the microflora of children with respiratory syncytial virus (RSV) infection.Methods Eight hospitalized infants with RSV infection were included in the study. To examine the change in the microflora before and after the use of antibiotics, we simultaneously collected nasopharyngeal and stool swabs from each patient at 3 points; before antibiotics use, during antibiotics use, after use. The use of antibiotics was determined by clinicians. In 6 patients, antibiotics were used, and in 2, they were not. We analyzed the nasopharyngeal and fecal microflora through the clone library method, using amplified fragments of the16S ribosomalRNA gene with universal primers.Results With regards to nasopharyngeal microflora, of the 6 patients who were prescribed antibiotics, 4 had pathogenic bacteria including Haemophilus influenzae and Moraxella catarrhalis, on admission, and only1patient had M. catarrhal is 3-5 days after admission. However, in 3 patients, M. catarrhalis was the dominant bacterium,1-2 weeks after hospital discharge. Among the patients who were not prescribed antibiotics, the representative pathogens of childhood pneumonia were not observed in any of the patients1-2 weeks after hospital discharge, despite them having those pathogens on admission or 3-5 days after. With regards to fecal microflora, the number of bacterial species decreased after antibiotics use, except in1patient. One to 2 weeks after hospital discharge, the number of bacterial species was lower than that observed on admission, in all the cases in which antibiotics were used. Conclusions The number of bacterial species both in the nasopharyngeal and fecal samples decreased after antibiotic use. The change in the dominant bacteria of the nasopharynx may be different between the cases in which antibiotics were administered and those in which they were not. These results suggest that clinicians should administer antibiotics, taking into consideration their influence on patients' microflora.