Application of Next-Generation Sequencing in Identification of Enterobacter Species in Patients with Hepatitis B virus infection

Background: Effective management and surveillance of infectious diseases rely on the accurate detection and identification of microbial pathogens. Characterizing of microbial communities provides valuable insights into disease mechanisms and supports targeted therapeutic strategies. Aim: This study aimed to apply Next-Generation Sequencing (NGS) technology for the identification of Enterobacter species in patients with Hepatitis B virus (HBV) infection. Methodology: A total of 160 clinical samples were collected from individuals admitted to Kirkuk Hospital, Iraq, between March and May 2024. Three stools DNA samples (two from HBV-infected patients and one from a healthy control) were analyzed at Macrogen Inc. (Seoul, South Korea) using metagenomic NGS. DNA amplification was confirmed by a 1500 bp band on electrophoresis before sequencing. Bioinformatics tools were used for taxonomic and compositional analysis of the microbial community. Results: NGS analysis revealed clear microbial dysbiosis in patients with HBV infection compared to the healthy control. The microbial composition showed a disruption in the balance between Bacillota and Bacteroidota phyla, characterized by an increase in Bacilli and a decline in Bacteroidales. Notably, reductions in Faecalibacterium duncaniae and Bifidobacterium adolescentis were accompanied by an elevated abundance of Succinivibrio dextrinosolvens. These findings suggest a shift from short-chain fatty acid (SCFA)-producing bacteria toward species associated with inflammation and metabolic dysfunction. Conclusion: Patients with Hepatitis B virus infection exhibit gut microbial dysbiosis marked by loss of beneficial bacteria (Faecalibacterium, Bifidobacteriaceae) and enrichment of Succinivibrio, indicating an altered gut ecosystem potentially contributing to disease progression.