We report the draft genome sequences of four bacterial strains (all of which are putatively novel species) belonging to four different genera. The Gram-positive
Bacillus
sp. strain GG161 and
Rhodococcus
sp. strain GG48 and the Gram-negative
Achromobacter
sp. strain GG226 and
Shigella
sp. strain GCP5 were all isolated from the gut of the optionally intestine-breathing freshwater fish
Lepidocephalichthys guntea
.
Oxygen depletion, or hypoxia, a common consequence of eutrophication, has adverse effect on aquatic flora and fauna. Bacteria living within or around aquatic macroorganisms struggle to thrive in low dissolved oxygen (DO2) conditions. The goal of our study was to see how the bacterial population in the intestine of a bottom-feeding fish, Cirrhinus mrigala, changed when the DO2 level in the water decreased from 7 ± 0.5 ppm to 0.35 ± 0.05 ppm. The V3 regions of 16S rRNA genes derived out of metagenome extracted from the intestines of control and experimental fishes were sequenced and analysed. The findings revealed that during DO2 stress (0.35 ± 0.05ppm), the aerobic bacterial population in the gut (existing when fish lived in 7 ± 0.5ppm DO2) changed significantly, transforming the microbial community into a facultative and/or obligate anaerobic community with dominance of microaerophilic bacterial populations; density of Cetobacterium increased in intestinal samples, which is linked to the prevention of paradoxical anaerobism in fish tissues. The current research advances our understanding of the microbial ecology of intestinal bacterial flora under DO2 stress, as well as their interactions with changing environmental parameters within the host body.
The bacterial strain GCP5 was isolated from the gut of a bottom-dwelling fish Lepidocephalichthys guntea, that lives in the Magurmari River near North Bengal University in Siliguri, India. GCP5 was phylogenetically assigned to the Shigella genus using whole genome-based trees, k-mer analysis, the multilocus species tree (MLST), and single nucleotide polymorphism (SNP)-based trees, and the genetic makeup of the isolate was determined following assembly of the genome sequences and genome annotation with several bioinformatics tools. The presence of a complete package of general-secretory-pathway (gsp) genes, grouped in an operon identical to a well-characterized type II secretion system (T2SS), was confirmed by genome mining of Shigella sp. GCP5. The operon’s gsp genes shared the most homology with Escherichia coli gsp genes. A few more high-pathogenicity islands (HPIs) in the GCP5 genome were validated using the pan-genomes analysis pipeline (PGAP) and island viewer. Several antibiotic-resistance genes were found in this genome, as well as the existence of key antibiotic efflux pump families, allowing for the creation of a gene network of several antibiotic efflux transporters. In addition, the genome contained genes specific for nickel transport, the nikABCD system, and the RND family transporter cusCFBA, which confers resistance to copper and silver by effluxing out Cu+ and Ag+ ions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.