Antagonistic activity of Exiguobacterium indicum LIS01 isolated from sediment

The bacterial resistance over antibiotics has gained significant concern worldwide for the last few decades. This study aimed to isolate and characterize antibiotic producing bacteria from different water sediment sources in Bangladesh. A total of 9 samples were collected from three different sediment sources from Gopalganj, Bangladesh. Bacterial isolates grown in nutrient agar with cycloheximide were tested for antagonistic activity following disc-diffusion assay. Based on preliminary careening, three isolates namely LIS01, LIS02 and LIS03 showed antibacterial activity against six clinical isolates: E. coli, Salmonella sp., Shigella sp., Klebsiella pneumoniae, Streptococcus sp., and Staphylococcus sp. The isolate LIS01 with the highest (P<0.05) zone of inhibition was characterized using 16S rRNA gene sequencing. According to phylogenetic analysis, the isolate was identified as Exiguobacterium indicum with more than 99.7% sequence similarity to previously characterized strains. The results of our study are very promising considering the antibiotic resistant bacteria and could be helpful in treating diseases associated with drug failure caused.