Identification of Secondary Bacterial Infection for RSV-infected children through 16srRNA Sequencing

Background: Pediatric respiratory tract infections are most commonly caused by the respiratory syncytial virus (RSV). Due to incomplete knowledge of RSV etiology, there are still no vaccinations or specific antiviral treatments for RSV. To better identify at-risk patients and create therapeutically protective microbial assemblages that might promote immunoprotection, our goal was to discover the respiratory tract secondary bacterial profile linked with severe RSV patients.

Methods: This study included children under the age of five who were suspected of having ARI and SARI. For alpha and beta diversity analyses, 24 samples for the IPD group and 21 samples for the OPD group were collected. DNA extraction and qRT-PCR were performed for detection of RSV. 16S rRNA gene sequencing was employed to evaluate the composition of the respiratory microbiota. Raw sequencing data was collected for bioinformatic analysis.

Results:Beta diversity, which distinguishes patients with moderate and severe RSV from controls, was significantly different in all three groups. The analysis of species-level abundance revealed the presence of Streptococcus pneumoniae (N=16), Enterococcus faecium (N=1), and Gardenella vaginalis (N=10) among RSV-A-infected individuals. Among 16 S. pneumoniae identified cases, 8 belonged to the moderate RSV-A group. Similarly, the remaining 8 were reported among hospitalized cases (severe RSV-A). Furthermore, this species was reported to be high among RSV-A-infected children aged 2 years (N=6), followed by those aged 1 year (N=5). Gender-wise analysis revealed S. pneumoniae was more frequent among RSV-A-infected females compared to males.

Conclusions: Taken together, these data show that severe RSV disease with admission to the inpatient settings of the hospital is related to a specific respiratory tract microbial composition. To ascertain whether the variations in respiratory tract microbiota are the cause or effects of severe RSV disease, more mechanistic studies are required.