Enterobacter asburiae Strain L1: Complete Genome and Whole Genome Optical Mapping Analysis of a Quorum Sensing Bacterium

Abstract

Enterobacter asburiae L1 is a quorum sensing bacterium isolated from lettuce leaves. In this study, for the first time, the complete genome of E. asburiae L1 was sequenced using the single molecule real time sequencer (PacBio RSII) and the whole genome sequence was verified by using optical genome mapping (OpGen) technology. In our previous study, E. asburiae L1 has been reported to produce AHLs, suggesting the possibility of virulence factor regulation which is quorum sensing dependent. This evoked our interest to study the genome of this bacterium and here we present the complete genome of E. asburiae L1, which carries the virulence factor gene virK, the N-acyl homoserine lactone-based QS transcriptional regulator gene luxR and the N-acyl homoserine lactone synthase gene which we firstly named easI. The availability of the whole genome sequence of E. asburiae L1 will pave the way for the study of the QS-mediated gene expression in this bacterium. Hence, the importance and functions of these signaling molecules can be further studied in the hope of elucidating the mechanisms of QS-regulation in E. asburiae. To the best of our knowledge, this is the first documentation of both a complete genome sequence and the establishment of the molecular basis of QS properties of E. asburiae.

Cloning and characterization of short‐chain N‐acyl homoserine lactone‐producing Enterobacter asburiae strain L1 from lettuce leaves

“…In previous work by Lau et al. (), the whole‐genome sequencing of E . asburiae strain L1 was performed using PacBio sequencing platform (Pacific Biosciences, Menlo Park, CA, USA).…”

“…Recently, a novel AHL‐producing Enterobacter asburiae strain L1 has been isolated from lettuce leaves and its genome was completely sequenced by PacBio sequencing platform. This isolate was found to secrete N ‐butanoyl homoserine lactone (C4‐HSL) and N –hexanoyl homoserine lactone (C6‐HSL) (Lau, Sulaiman, Chen, Yin, & Chan, ; Lau, Yin, & Chan, ). Previous studies have shown that E .…”

“…Recently, a novel AHL-producing Enterobacter asburiae strain L1 has been isolated from lettuce leaves and its genome was completely sequenced by PacBio sequencing platform. This isolate was found to secrete N-butanoyl homoserine lactone (C4-HSL) and N-hexanoyl homoserine lactone (C6-HSL) (Lau, Sulaiman, Chen, Yin, & Chan, 2013;Lau, Yin, & Chan, 2014). Previous studies have shown that E. asburiae strains have been isolated from water, soil, food, and human sources, that is, blood culture, wounds, and exudates as well as from respiratory sources (Brenner, McWhorter, Kai, Steigerwalt, & Farmer, 1986; Castellanos-Arévalo, Castellanos-Arévalo, Camarena-Pozos, Colli-Mull, & Maldonado-Vega, 2015; Khalifa, Alsyeeh, Almalki, & Saleh, 2015;Shin et al, 2007).…”

Whole-genome sequencing in the prediction of antimicrobial resistance

“…Advancements in NGS instrumentation has enabled NGS to be performed using single molecules that generate long read lengths to yield complete genomes instead of draft genomes [19,20]. A complete genome will ease the downstream bioinformatics analysis for the accurate prediction of antimicrobial resistance genes, but, at present, the cost of obtaining a complete genome is still exorbitant [21][22][23].…”

Chania multitudinisentens gen. nov., sp. nov., an N-acyl-homoserine-lactone-producing bacterium in the family Enterobacteriaceae isolated from landfill site soil

“…Colonies of strain RB-25 T were slightly raised with very pale white pigmentation on LB medium after 24 h of incubation. Gram staining of cells was performed using a Gram staining kit (Difco), and cell morphology was determined using a Hitachi TM3000 analytical tabletop microscope (Lau et al, 2014) in which the cells were observed to be Gram-stain-negative, motile and rodshaped (3-4Â7.5-9 µm) (Fig. S1, available in the online Supplementary Material).…”