First comprehensive whole genome sequencing report of a multidrug-resistant Serratia nematodiphila strain from Bangladesh

Serratia spp. have emerged as one of the most prevalent causative agents of nosocomial infections. This study aims to study the whole genome sequence of of a multidrug-resistant Serratia nematodiphila strain as well as characterize the prevalence of multidrug-resistant (MDR) Serratia spp., in hospital environments in Bangladesh. A total of 78 samples comprising hospital sewage and soil were collected from seven renowned hospitals across Dhaka city. Next, the samples tested positive for Serratia spp. were subjected to further analysis. Antibiotic susceptibility test and biofilm formation assay were carried out for these isolates, and the most antimicrobial resistant Serratia isolate, along with moderate biofilm-forming ability, was subjected to whole genome sequencing (WGS). Subsequently, the WGS as well as pan-genomic and pan-resistome analysis were performed. A total of 23 Serratia spp. isolates along with 47.8% of MDR properties were identified. WGS analysis identified the highly MDR isolate, KS1, as Serratia nematodiphila . Further analysis revealed the presence of numerous antimicrobial resistance and efflux pump genes, a variety of mobile genetic elements, virulence factor genes, and prodigiosin producing biosynthetic gene cluster. These features are predicted to be responsible for its multidrug-resistant properties and high virulence. Furthermore, the lower core/pan ratio of this pangenome indicated the likelihood to acquire more antimicrobial resistance and virulence genes. To date, this is the first detailed genomic study of Serratia nematodiphila in Bangladesh. Further extensive researches are required to find out the prevalence and clinical significance of this particular organism.