Insights from the draft genome into the pathogenicity of a clinical isolate of Elizabethkingia meningoseptica Em3

Abstract

Elizabethkingia meningoseptica is an emerging, healthcare-associated pathogen causing a high mortality rate in immunocompromised patients. We report the draft genome sequence of E. meningoseptica Em3, isolated from sputum from a patient with multiple underlying diseases. The genome has a length of 4,037,922 bp, a GC-content 36.4%, and 3673 predicted protein-coding sequences. Average nucleotide identity analysis (>95%) assigned the bacterium to the species E. meningoseptica. Genome analysis showed presence of the curli formation and assembly operon and a gene encoding hemagglutinins, indicating ability to form biofilm. In vitro biofilm assays demonstrated that E. meningoseptica Em3 formed more biofilm than E. anophelis Ag1 and E. miricola Emi3, both lacking the curli operon. A gene encoding thiol-activated cholesterol-dependent cytolysin in E. meningoseptica Em3 (potentially involved in lysing host immune cells) was also absent in E. anophelis Ag1 and E. miricola Emi3. Strain Em3 showed α-hemolysin activity on blood agar medium, congruent with presence of hemolysin and cytolysin genes. Furthermore, presence of heme uptake and utilization genes demonstrated adaptations for bloodstream infections. Strain Em3 contained 12 genes conferring resistance to β-lactams, including β-lactamases class A, class B, and metallo-β-lactamases. Results of comparative genomic analysis here provide insights into the evolution of E. meningoseptica Em3 as a pathogen.