Draft Genome Sequence of Listeria monocytogenes LM201, Isolated from Foodstuff.

Listeria monocytogenes is a facultative intracellular foodborne pathogen that can cause listeriosis in humans and animals. L. monocytogenes LM201 was isolated from foodstuff. The draft genome sequence of strain LM201 provides the genetic basis for the application of this strain in biotechnological vaccine production.

GENOME ANNOUNCEMENT

Listeria monocytogenes is a Gram-positive, nonsporulating, aerobic and facultative anaerobic, rod-shaped, and facultative intracellular bacterium (1, 2). It is a foodborne pathogen (3) that can cause listeriosis (gastroenteritis, meningitis, encephalitis, septicemia, and abortion) in animals and humans, especially immunocompromised individuals (the old, neonates, and pregnant women), with a mean mortality rate of 20–30% or higher (4). L. monocytogenes LM201, a serovar 4b strain, was isolated from foodstuff in Hubei province (China). The LD50 of strain LM201 was 6.3 × 106 CFU for Kunming mice after i.p. infection. Strain LM201 was also assayed for other phenotypic characteristics and was determined to be a good candidate for developing a vaccine. Here we report the genome sequence of L. monocytogenes LM201, which provides the genetic basis for rationally designing and generating defined virulence-attenuated strains for biotechnological vaccine production.

Genomic DNA of the strain LM201 was sequenced with a whole-genome shotgun strategy using an Illumina HiSeq 2000 platform. Two different sequencing libraries (300-bp paired end and 5,000-bp mate pair) were prepared. In total, 43,930,390 paired-end reads of 100 bp and 20,921,890 mate-pair reads of 90 bp were obtained from the sequencing (1,910-fold genome coverage). De novo assembly was done using ABySS version 1.3.4 software (5), yielding 86 contigs with an N50 size of 226,587 bp and a maximum contig size of 342,356 bp. A total of 66 scaffolds were produced, with a total size of 3,200,729 bp and a G+C content of 37.44%.

Genome annotation was accomplished using the RAST server (6). Gene prediction revealed 3,165 protein-coding genes (CDSs), 6 rRNA operons, and 35 tRNA genes. Among the protein-coding genes, there were 2,736 genes with function prediction; 2,504 were identified in the COG database; and 2,674 were identified in the Pfam database.

Nucleotide sequence accession number.

The L. monocytogenes LM201 draft genome sequence has been deposited in the GenBank database under the accession number AYPT00000000. The version described in this paper is the first version.