Diversity of bacterial communities in the Sundarbans mangrove, Bangladesh, with special focus on pathogens affecting aquatic organisms

• Published in: Comparative immunology reports 2024-06, Vol.6, p.200131, Article 200131
• Main Authors: Hossain, Md. Mer Mosharraf, Mojumdar, Shoumik, Farjana, Nawshin, Sharmeen Moon, Rubab, Islam, Md Saiful, Rahman, Nimur, Rojoni, Suraiya Alam, Rubayea, Ummay, Sen, Bipul Kumar, Mondal, Subrata, Rahman, Md. Anisur
• Format: Article
• Language: English
• Subjects: 16S rRNA gene; Finfish and shellfishes; Non-pathogenic bacteria; Pathogenic bacteria; The Sundarbans mangrove
• ISSN: 2950-3116; 2950-3116
• DOI: 10.1016/j.cirep.2023.200131

•The analysis of 16S rRNA sequences reveals a more diverse microbial habitat in the Sundarbans mangrove forest of Bangladesh.•The research found 872 bacterial species, 94 genera, 38 families, and 6 phyla. Out of these, 49.3% are typically harmless and non-pathogenic.•There is still a 24.9% uncertainty, with 13.4% showing pathogenic and non-pathogenic, and 8.4% being strictly pathogenic to other organisms.•There are varying levels of pathogenicity, with 2.6% potentially non-highly pathogenic, 1.3% occasionally pathogenic, and 0.1% pathogenic.•By establishing a genomic baseline for harmful bacterial communities in mangrove habitats, diseases in fish and shellfish may be reduced. The Sundarbans, located in Bangladesh, is the world's largest mangrove forest with a rich and diverse microbial community. The main objective of this study was to use 16S rRNA sequencing to identify the bacterial community in the Sundarban mangrove forest, particularly pathogenic bacteria to aquatic organisms. This study conducted in Bangladesh collected 225 samples of soil, water, fish, and shellfish from five locations with a typical mangrove environment. All samples underwent genomic DNA extraction, quantification, gel documentation, and subsequent sequencing. Sanger sequencing was then carried out, followed by sequencing 11 concentrated samples using the universal bacterial primer 16S rRNA. The study found 872 bacterial species, 94 genera, 38 families, and 6 phyla. Pseudomonades or proteobacteria accounted for 92% of the phylum composition, with firmicutes, bactericides, cyanobacteria, Verrucomicrobia, and actinobacteria also present at smaller percentages. Chromatiaceae had the highest species count (20.3%), followed by Ectothiorhodospiraceae (15.5%), Methylococcaceae (12.3%), Moraxellaceae (10.7%), Thiotrichaceae (8.7%), Idiomarinaceae (5.4%), and smaller groups. All the species that were identified were gram-negative bacteria and were found in different environments, mainly halophilic ones. Based on 16 s rRNA sequencing, additional experimental and clinical data, as well as NCBI (BLAST), approximately 49.3% of the 872 bacterial species are typically harmless and not classified as pathogenic. The pathogenic characteristics of 24.9% of the species are still unidentified. 13.4% showed either pathogenic or non-pathogenic characteristics (a bacterium as having the potential to exhibit pathogenic or non-pathogenic characteristics in certain circumstances), while 8.4% were exclusivel